US20010037771A1 - Apparatus And Method For Aligning A Wafer - Google Patents
Apparatus And Method For Aligning A Wafer Download PDFInfo
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- US20010037771A1 US20010037771A1 US09/481,055 US48105500A US2001037771A1 US 20010037771 A1 US20010037771 A1 US 20010037771A1 US 48105500 A US48105500 A US 48105500A US 2001037771 A1 US2001037771 A1 US 2001037771A1
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- support member
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- 235000012431 wafers Nutrition 0.000 description 190
- 238000012545 processing Methods 0.000 description 22
- 239000002245 particle Substances 0.000 description 15
- 238000000151 deposition Methods 0.000 description 6
- 230000008021 deposition Effects 0.000 description 6
- 238000005229 chemical vapour deposition Methods 0.000 description 5
- 239000000356 contaminant Substances 0.000 description 3
- 238000005240 physical vapour deposition Methods 0.000 description 3
- 238000012360 testing method Methods 0.000 description 3
- 230000015572 biosynthetic process Effects 0.000 description 2
- 230000007717 exclusion Effects 0.000 description 2
- 230000007246 mechanism Effects 0.000 description 2
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- 238000010926 purge Methods 0.000 description 2
- 239000004065 semiconductor Substances 0.000 description 2
- 238000011109 contamination Methods 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005530 etching Methods 0.000 description 1
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- 238000005259 measurement Methods 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 238000005086 pumping Methods 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
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Classifications
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- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C16/00—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes
- C23C16/44—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes characterised by the method of coating
- C23C16/458—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes characterised by the method of coating characterised by the method used for supporting substrates in the reaction chamber
- C23C16/4582—Rigid and flat substrates, e.g. plates or discs
- C23C16/4583—Rigid and flat substrates, e.g. plates or discs the substrate being supported substantially horizontally
- C23C16/4585—Devices at or outside the perimeter of the substrate support, e.g. clamping rings, shrouds
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- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C16/00—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes
- C23C16/44—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes characterised by the method of coating
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
- H01L21/67—Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere
- H01L21/68—Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere for positioning, orientation or alignment
Definitions
- the present invention relates to the field of semiconductor wafer processing equipment. More particularly, the present invention relates to a method and apparatus for aligning a wafer on a wafer support member.
- PVD physical vapor deposition
- CVD chemical vapor deposition
- etch processes are often carried out in a vacuum environment to, among other things, reduce the particulate level to which the wafers are exposed.
- Wafers are introduced into a vacuum processing system through a loadlock where robots within the vacuum processing system move the wafers from the loadlock into a transfer chamber and then sequentially through the system positioning the wafers in a series of processing chambers.
- the processing steps carried out within the vacuum chambers typically require the deposition, or etching of multiple metal, dielectric and semiconductor film layers on the surface of a wafer. During these processing steps, one must properly align and secure the wafer in the processing chamber in which the desired deposition or etch process is performed.
- the wafer is supported in the chamber on a support member, commonly called a susceptor or pedestal.
- the wafer is placed on or secured to, the upper surface of the support member prior to the deposition or etch process.
- the wafer must be properly aligned relative to the support member.
- the position of the support member in the chamber is selected to provide a desired spacing and relative geometry between the generally planar surface of the wafer and other portions of the process chamber such as a gas plate in a CVD process or a target in a PVD process.
- a shadow or clamp ring is used to shield the edge of a wafer and/or, in the case of a clamp ring, secure the wafer to the support member.
- shadow rings In addition to acting as a shield, shadow rings also function in wafer capturing or alignment on the support member. Wing members extend downwardly and outwardly from the shadow ring to form a funnel. As the support member moves the wafer upward into the processing position, the support member moves the wafer into the funnel which directs the wafer into alignment with the shadow ring and the support member.
- the funnel applies vertical and lateral forces to the wafer when the slanted wing members achieve lateral alignment of a misaligned wafer with the shadow ring and support member as the support member moves the wafer to the top end of the funnel and the shadow ring settles on the support member.
- a primary goal of wafer processing is to obtain as many useful die as possible from each wafer. Many factors influence the processing of wafers in the chamber and effect the ultimate yield of die from each wafer processed therein including the existence of contaminants within the chamber that can attach to the wafer and contaminate one or more die therein.
- the processing chambers have many sources of particle contaminants which, if received on the wafer, reduce the die yield.
- One source of particulate contamination occurs when a misaligned wafer is introduced into the chamber. As the wing members of the shadow ring align with the wafer, the wafer slides on the flat surface of the support member and, due to the frictional forces between the wafer and the support member, may create particulate contaminants.
- the frictional forces between the wafer and the support member cause the misaligned wafer to actually move the shadow ring, thereby preventing proper alignment of the wafer and reducing repeatability of the zone of exclusion shielded by the shadow ring and the process.
- the present invention provides methods and apparatuses for aligning a wafer on a support member in a vacuum chamber.
- the method comprises the steps of introducing the wafer into the vacuum chamber, increasing the pressure within the vacuum chamber and moving the wafer into alignment with a support member and/or shadow ring.
- the method comprises providing a shadow ring having a lower portion that is outwardly tapered for receipt of a wafer and an upper aperture having a diameter that is slightly less than the outer diameter of the wafer, introducing the wafer into the vacuum chamber and onto the support member, increasing the pressure within the chamber, and subsequently moving the support member towards the shadow ring so that the shadow ring aligns the wafer on the support member.
- the apparatus for aligning a wafer on a support member in a vacuum chamber is an apparatus comprising a support member positioned within the vacuum enclosure and having a wafer receiving surface thereon, a shadow ring located within the vacuum chamber, a gas supply in fluid communication with the vacuum chamber, and a gas flow controller that controls the flow of gas to the vacuum chamber and, thereby, regulates the pressure within the vacuum chamber such that, after the wafer is positioned on the support member and before the wafer is raised into the shadow ring, the control member raises the pressure within the chamber to about 1 Torr.
- the shadow ring used in this apparatus comprises an upper shield portion defining a circular aperture therethrough, the circular aperture having a diameter that is slightly less than the outer diameter of the wafer, a lower portion extending from the upper shield portion having an annular cross section defining a frustoconical inner cavity, the diameter of the inner cavity decreases from a lower mouth aperture to an upper end, and the diameter of the upper end of the inner cavity is slightly greater than the outer diameter of the wafer.
- the pressure is preferably raised to a pressure greater than about 1 Torr and more preferably to a pressure between about 1 Torr and 100 Torr and most preferably between about 1 Torr and 10 Torr. Further, the pressure is raised is to approximately equal to or less than the process pressure. Also, the pressure between the wafer and the support member is preferably equal to or greater than the pressure in the chamber before the wafer is aligned.
- FIG. 1 is a partial cross sectional view of the vacuum chamber.
- FIG. 2 is a schematic drawing of the vacuum chamber and the pressure control system.
- FIG. 3 is a cross sectional view of a typical support member having a wafer thereon that is partially covered by a shadow ring.
- FIG. 4 is a partial, cross sectional view of a shadow ring, a wafer, and a support member showing the wafer misaligned on the support member as they enter the inner cavity of the shadow
- the present invention relates to a method and apparatus for aligning a wafer 20 on a support member 60 in a vacuum chamber 30 .
- the alignment apparatus is depicted generally as 10 .
- the preferred embodiment described below refers to an alignment apparatus 10 that uses a shadow ring 40 to align the wafer 20 on the support member 60 .
- the invention is not limited to this precise form of apparatus for it may apply to any number of alignment mechanisms.
- the term “shadow ring,” as used herein, refers generally to both shadow rings and clamp rings.
- FIG. 1 shows a typical vacuum chamber 30 defined by an outer body 32 .
- the vacuum chamber 30 houses a support member 60 that may take the form of a pedestal or susceptor mounted on a generally vertically oriented shaft 62 .
- the support member 60 serves to support a wafer 20 on its flat upper supporting surface 64 .
- the support member 60 also includes a step formation 68 formed on its outer perimeter to receive and support a shadow ring 40 and includes four finger apertures 66 .
- a gas supply 170 is provided in fluid communication with the vacuum chamber 30 .
- a gas flow controller 180 positioned intermediate the gas supply 170 and the vacuum chamber 30 controls the flow from the gas supply 170 to the vacuum chamber 30 .
- the gas flow controller 180 selectively provides a flow of gas to the vacuum chamber 30 .
- the gas flow controller 180 controls the pressure within the vacuum chamber 30 . It is possible to provide the gas to the chamber 30 through the support member 60 to the back side of the wafer 20 .
- the gas When provided to the back side of the wafer 20 , the gas creates a pressure between the wafer 20 and the support member 60 that is initially greater than the pressure in the chamber 30 .
- This back side gas may be provided, for example, by a bypass line 200 that provides communication from the gas flow controller 180 to the upper surface 64 of the support member 60 between the support member 60 and the wafer 20 .
- FIG. 1 also illustrates a wafer lifting finger 90 received in a finger aperture 66 passing through the body of the support member 60 .
- the processing chamber would include four such lifting fingers 90 .
- These lifting fingers 90 operate to lift the wafer 20 clear of the upper supporting surface 64 of the support member 60 after processing. This removal of the wafer 20 is achieved by means of a conventional processing apparatus robot arm (not shown) which enters the vacuum chamber 30 through the slit valve opening 36 . The same robot arm is also used to insert the wafers 20 into the vacuum chamber 30 .
- the lifting fingers 90 are movable vertically under action of a lifting mechanism 92 of which only the upper portion is shown.
- a shadow ring 40 housed within the vacuum chamber 30 operates to provide an exclusionary zone where no deposition occurs at the edge of the wafer 20 .
- the shadow ring 40 also operates to force a misaligned wafer 20 into alignment as the support member 30 moves from a lowered, or idle, position to a raised, or processing, position.
- the shadow ring 40 is supported around its perimeter by an outer support ring 38 that is, in turn, supported by a conventional pumping plate 39 attached to the vacuum chamber 30 .
- the two rings, 40 and 38 divide the vacuum chamber 30 into upper and lower sections, 30 a and 30 b respectively.
- the shadow ring 40 has a lower portion 42 that rests on the upper surface 64 of the support member 60 and supports the upper shield portion 50 of the shadow ring 40 above the upper surface of the wafer 20 .
- the shield portion 50 is held about 5 to 10 mils above the wafer 20 .
- the upper shield portion 50 of the shadow ring 40 defines a circular upper aperture 46 therethrough.
- the diameter of the upper aperture 46 may be slightly less than the outer diameter of the wafer 20 to form the exclusionary zone on the wafer 20 .
- new processes may require no overhang of the shadow ring 40 over the wafer 20 .
- the step formation 68 shown in FIG.
- the overhanging portion defines an exclusionary zone of about 3 to 5 mm about the edge of the wafer 20 .
- this exclusionary zone is no greater than 1.5 mm from the edge of the wafer 20 .
- the exclusionary zone at any one edge is preferably about 1.5 mm or less. This relatively small exclusionary zone is necessary to allow deposition on the wafer 20 at a position 1.5 mm from the wafer edge.
- a purge gas is directed through the support member 60 about the periphery of the wafer 20 .
- the purge gas flows between the shadow ring 40 and the wafer 20 to help shield the exclusionary zone of the wafer 20 .
- a lower portion 42 of the shadow ring 40 extends downwardly from the upper shield portion 50 .
- the lower portion 42 has an annular cross section throughout its length and defines a frustoconical inner cavity 44 therein that is concentric with the upper aperture 52 .
- the support member 60 is circular as is the inner cavity cross section.
- the diameter of the inner cavity 44 decreases from the lower mouth portion 46 to the upper end 48 of the inner cavity 44 to form a funnel-like structure for aligning the wafer 20 on the support member 60 . Accordingly, the surface of the inner cavity 44 is relatively smooth to facilitate the sliding receipt and abutment of the wafer 20 in the inner cavity 44 .
- the diameter of the upper end 46 of the inner cavity 44 is slightly greater than and, preferably, approximately equal to the outer diameter of the wafer 20 .
- the wafer 20 must be aligned so that the shadow ring overhangs the wafer 20 by no more than 1.5 mm about its full periphery so that the film will be allowed to deposit on the wafer 20 at 1.5 mm from the edge of the wafer 20 .
- the diameter of the upper end 46 of the inner cavity 44 is preferably at most only slightly more than 3 mm greater than the upper aperture 52 and only slightly greater than the outer diameter of the wafer 20 to ensure that the edge of the wafer 20 is within 1.5 mm of the periphery of the upper aperture 52 .
- the shadow ring 40 only overhangs the wafer 20 at most by about 1.5 mm about the full periphery of the wafer 20 .
- the outer diameter of the support member 60 must be sufficiently small that it can also be positioned proximal the upper end 52 of the inner cavity 44 .
- the support member 60 must cover substantially the full area of the wafer 20 . Therefore, the wafer must occupy most of the upper surface area of the support member 60 .
- FIG. 1 As shown in FIG. 1, once positioned in the vacuum chamber 30 , a wafer 20 rests on the upper supporting surface 64 of the support member 30 . This placement is made with the support member 60 in its lowered position. Before processing may begin, the wafer 20 must first be raised by the support member 60 to the raised position. It is during the movement from the lowered position to the raised position that any misalignment of the wafer 20 is corrected and the wafer 20 is aligned. As the support member 60 moves upward from the lowered position, a misaligned wafer 20 contacts the inner cavity 44 of the shadow ring 40 at a position intermediate the upper end 48 and the lower mouth portion 46 .
- FIG. 4 illustrates a misaligned wafer 20 on the support member 60 .
- the point of contact is dependent upon the magnitude of the misalignment. Preferably, there is no misalignment.
- the angled side of the frustoconically-shaped inner cavity 44 exerts a lateral force on the edge of the wafer 20 forcing the wafer 20 into alignment. Consequently, when the support member 60 reaches its raised position so that the wafer 20 is at the upper end 48 of the inner cavity 44 of the shadow ring 40 , the wafer 20 is aligned due to the relative diameters of the wafer 20 and the shadow ring components.
- the outer portion of the wafer 20 When in this raised position, depending upon the type of process involved, the outer portion of the wafer 20 may either bear against the shadow ring 40 and slightly lift the shadow ring 40 under action of the support member 60 or may rest on the shoulder 68 of the support member 60 and, thereby, leave a small gap between the shadow ring 40 and the wafer 20 .
- the application refers primarily to those processes wherein the wafer 20 does not contact the shadow ring 40 although the present invention is applicable to all processes.
- the sliding movement of the wafer 20 on the support member 60 during alignment creates particles within the vacuum chamber 30 . These particles are generated as a result of the friction between the wafer 20 and the support member 60 which is generally characterized by the coefficient of friction of the interface multiplied by the weight of the wafer 20 .
- Other forces acting upon the wafer 20 also affect the magnitude of the frictional forces.
- vacuum chucking may affect the friction between the wafer 20 and the support member 60 .
- the downward component of the force exerted by the frustoconical inner cavity 44 increases the frictional forces between the abutting surfaces.
- the friction force between the surfaces equals the coefficient of friction between the surfaces multiplied by the downward, normal forces exerted on the wafer 20 whatever their source.
- the weights of the wafers 20 are relatively constant. Greater frictional forces on the wafer 20 and the support surface 60 cause greater particle generation and decrease the energy efficiency of the system.
- high frictional forces may cause misalignment and may cause the wafer 20 to move the shadow ring 40 out of alignment, rather than the shadow ring 40 moving the wafer 20 into alignment, if the lateral force applied on the wafer 20 by the shadow ring is insufficient to overcome the frictional forces.
- the relevant normal and frictional forces are generally characterized by the following formulas respectively wherein N represents the normal force applied to the wafer 20 , F is the frictional force applied to the wafer 20 , G is the weight of the wafer 20 , A is the surface area of the wafer 20 , P 1 is the pressure in the chamber 30 , P 0 is the pressure between the wafer 20 and the support member 60 , and ⁇ is the coefficient of friction.
- N G ⁇ ( P 1 ⁇ P 0 ) A
- the normal force is equal to the weight of the wafer 20 less the force created by the pressure differential on the top and bottom surfaces of the wafer 20 .
- the force created by this pressure differential equals the difference between the pressure between the wafer 20 and the support member 60 and the pressure in the chamber 30 multiplied by the surface area of the wafer 20 .
- the frictional forces equal the normal forces multiplied by the coefficient of friction.
- the increased pressure somehow lowers the coefficient of friction (e.g., by possibly creating a cushion of gas between the wafer 20 and the support member 60 ).
- Another possibility is that the increased pressure somehow lowers the normal force on the wafer 20 .
- the result is that the frictional forces are reduced and, thus, the wafer 20 may be moved on the support member 60 with less resistance and less particle generation.
- the resulting decrease in frictional force allows freer movement of the wafer 20 on the support member 60 and, thereby, reduces the resulting scratches and generated particles.
- Gas from the gas supply 170 is introduced into the vacuum chamber 30 to increase the pressure therein.
- the gas may be introduced generally into the chamber 30 or through gas inlets positioned in the upper surface 64 of the support member 60 . It is in this latter case that the pressure below the wafer 20 is greater than the pressure above the wafer 20 .
- the method of the present invention involves increasing the pressure within the vacuum chamber 30 to at least about one Torr before moving the wafer 20 on the support member 60 for alignment.
- the pressure within the vacuum chamber 30 when the wafer 20 is introduced therein is about one milliTorr or less.
- the wafer is, thus, introduced into the vacuum chamber 30 onto the support member 60 which is in a lowered position.
- the support member 60 is then raised to the lower mouth aperture 46 of the shadow ring 40 .
- the pressure within the vacuum chamber 30 is increased to at least about one Torr.
- this step of increasing the pressure may take place at any time before the support member 60 is raised into the inner cavity 44 of the shadow ring 40 .
- the pressure is raised to between about 1 Torr and 100 Torr or, more preferably, between about 1 Torr and 10 Torr and approximately equal to or less than the operating pressure of the process.
- the operating pressure of the process is the pressure at which the process, such as a chemical vapor deposition process, is carried out in the vacuum chamber 30 .
- the pressure between the wafer 20 and the support member 60 is provided so that the pressure between the wafer 20 and the support member 60 is approximately equal to or greater than the pressure in the vacuum chamber 30 .
- the support member 60 is raised to the raised, or processing, position.
- any misaligned wafer 20 will contact the angled sides of the inner cavity 44 which will force the wafer 20 into alignment.
- the pressure within the vacuum chamber 30 may be altered as needed.
- the pressure within the vacuum chamber 30 is manipulated by a gas supply 170 and a gas flow controller 180 .
- the gas flow controller 180 uses predetermined set of instructions to adjust the pressure within the vacuum chamber 30 as needed.
- a vacuum pump 190 or series of vacuum pumps 190 , are used to evacuate the vacuum chamber 30 .
- This system has been tested to determine its effectiveness as follows.
- a misaligned wafer 20 was positioned upon a support member 60 in a vacuum chamber 30 and was raised from a lowered position to a raised position.
- the test was conducted under vacuum conditions (i.e., moving the wafer 20 without first increasing the pressure in the chamber) and under pressurized conditions (i.e., moving the wafer 20 only after increasing the pressure in the chamber).
- pressurized conditions i.e., moving the wafer 20 only after increasing the pressure in the chamber.
- the tests were conducted with both the pressure beneath the wafer 20 equal to and greater than the pressure in the chamber 30 . In both of these pressurized condition tests, the results were essentially the same.
- the wafers 20 were then inspected using a SURISCAN 6200 manufactured by Tencor Instruments to determine the number of particles generated as a result of the wafer 20 moving on the support member 60 .
- the shadow ring 40 often moved with the wafer 20 as the support member 60 lifted the shadow ring 40 due to the frictional forces holding the wafer 20 to the support member 60 . This resulted in a misaligned wafer 20 and reduced repeatability of the process.
- the movement of the wafer 20 on the support member 60 generated only approximately Twenty (20) particles when the wafer 20 contacted the shadow ring 40 and less than 2000 backside particles. Further, the misaligned wafer 20 moved on the support member 60 more readily and was, therefore, properly centered which increased repeatability of the edge exclusion and the process.
Abstract
A method for aligning a wafer on a support member within a vacuum chamber includes increasing the pressure within the vacuum chamber to at least about 1 Torr before aligning the wafer. The wafer is introduced into the vacuum chamber on the support member, the pressure is increased to at least about one Torr, and the support member is lifted into a shadow ring that has a frustoconical inner cavity constructed to funnel the wafer to a centered, aligned position.
Description
- 1. Field of the Invention
- The present invention relates to the field of semiconductor wafer processing equipment. More particularly, the present invention relates to a method and apparatus for aligning a wafer on a wafer support member.
- 2. Background of the Related Art
- In the fabrication of integrated circuits, the various processes, such as physical vapor deposition (PVD), chemical vapor deposition (CVD), and etch processes, are often carried out in a vacuum environment to, among other things, reduce the particulate level to which the wafers are exposed. Wafers are introduced into a vacuum processing system through a loadlock where robots within the vacuum processing system move the wafers from the loadlock into a transfer chamber and then sequentially through the system positioning the wafers in a series of processing chambers.
- The processing steps carried out within the vacuum chambers typically require the deposition, or etching of multiple metal, dielectric and semiconductor film layers on the surface of a wafer. During these processing steps, one must properly align and secure the wafer in the processing chamber in which the desired deposition or etch process is performed.
- Typically, the wafer is supported in the chamber on a support member, commonly called a susceptor or pedestal. The wafer is placed on or secured to, the upper surface of the support member prior to the deposition or etch process. To ensure proper processing of the wafer, the wafer must be properly aligned relative to the support member. The position of the support member in the chamber is selected to provide a desired spacing and relative geometry between the generally planar surface of the wafer and other portions of the process chamber such as a gas plate in a CVD process or a target in a PVD process.
- Generally, a shadow or clamp ring is used to shield the edge of a wafer and/or, in the case of a clamp ring, secure the wafer to the support member. Although the present invention is equally applicable to both shadow rings and clamp rings, the following description will refer primarily to shadow rings such as those typically used in CVD processes. In addition to acting as a shield, shadow rings also function in wafer capturing or alignment on the support member. Wing members extend downwardly and outwardly from the shadow ring to form a funnel. As the support member moves the wafer upward into the processing position, the support member moves the wafer into the funnel which directs the wafer into alignment with the shadow ring and the support member. Consequently, the funnel applies vertical and lateral forces to the wafer when the slanted wing members achieve lateral alignment of a misaligned wafer with the shadow ring and support member as the support member moves the wafer to the top end of the funnel and the shadow ring settles on the support member.
- A primary goal of wafer processing is to obtain as many useful die as possible from each wafer. Many factors influence the processing of wafers in the chamber and effect the ultimate yield of die from each wafer processed therein including the existence of contaminants within the chamber that can attach to the wafer and contaminate one or more die therein. The processing chambers have many sources of particle contaminants which, if received on the wafer, reduce the die yield. One source of particulate contamination occurs when a misaligned wafer is introduced into the chamber. As the wing members of the shadow ring align with the wafer, the wafer slides on the flat surface of the support member and, due to the frictional forces between the wafer and the support member, may create particulate contaminants. In some cases, the frictional forces between the wafer and the support member cause the misaligned wafer to actually move the shadow ring, thereby preventing proper alignment of the wafer and reducing repeatability of the zone of exclusion shielded by the shadow ring and the process.
- Prior efforts aimed at reducing the creation of particles have reduced the alignment movement of the wafer on the support member and simply increased the amount of overhang by the shadow ring. In this way, the shadow ring is able to cover the wafer without substantial movement of the wafer. One way that this is accomplished is by increasing the diameter of the shadow ring funnel upper end so that this diameter is larger relative to the diameter of the wafer and the support member. Thus, rather than substantially moving the wafers to align them, these systems simply accept a greater misalignment and accept greater coverage of the wafer upper surface area.
- However, a second factor influencing the processing of wafers in the chamber and affecting the ultimate yield of die from each wafer processed therein is the repeatability of the positioning of the wafer and the area covered by the shadow ring. The wafer must be properly aligned relative to the support member and the shadow ring to ensure that the film is properly deposited on the wafer. Therefore, these prior efforts that avoid alignment of the wafer and cover more surface area are not acceptable.
- It would, therefore, be desirable to provide a relatively simple system and method for reducing the coefficient of friction between the support member and the wafer that would allow alignment of the wafer without substantial particle generation.
- In view of the foregoing, it is an object of the invention to provide a relatively simple apparatus and method for reducing the frictional forces between the support member and the wafer. It is another object of the invention to enhance repeatability and to provide a shadow ring that covers a minimal area of the upper surface of the wafer. Yet another object of the invention is to provide a system and method for aligning a wafer that is relatively inexpensive, efficient, simple to implement, and reliable. Other objects of the invention will become apparent from time to time throughout the specification and claims as hereinafter related.
- The present invention provides methods and apparatuses for aligning a wafer on a support member in a vacuum chamber. In one aspect of the invention, the method comprises the steps of introducing the wafer into the vacuum chamber, increasing the pressure within the vacuum chamber and moving the wafer into alignment with a support member and/or shadow ring.
- In another aspect, the method comprises providing a shadow ring having a lower portion that is outwardly tapered for receipt of a wafer and an upper aperture having a diameter that is slightly less than the outer diameter of the wafer, introducing the wafer into the vacuum chamber and onto the support member, increasing the pressure within the chamber, and subsequently moving the support member towards the shadow ring so that the shadow ring aligns the wafer on the support member.
- In accordance with the methods, the apparatus for aligning a wafer on a support member in a vacuum chamber is an apparatus comprising a support member positioned within the vacuum enclosure and having a wafer receiving surface thereon, a shadow ring located within the vacuum chamber, a gas supply in fluid communication with the vacuum chamber, and a gas flow controller that controls the flow of gas to the vacuum chamber and, thereby, regulates the pressure within the vacuum chamber such that, after the wafer is positioned on the support member and before the wafer is raised into the shadow ring, the control member raises the pressure within the chamber to about 1 Torr. The shadow ring used in this apparatus comprises an upper shield portion defining a circular aperture therethrough, the circular aperture having a diameter that is slightly less than the outer diameter of the wafer, a lower portion extending from the upper shield portion having an annular cross section defining a frustoconical inner cavity, the diameter of the inner cavity decreases from a lower mouth aperture to an upper end, and the diameter of the upper end of the inner cavity is slightly greater than the outer diameter of the wafer.
- In each of these methods and apparatuses, the pressure is preferably raised to a pressure greater than about 1 Torr and more preferably to a pressure between about 1 Torr and 100 Torr and most preferably between about 1 Torr and 10 Torr. Further, the pressure is raised is to approximately equal to or less than the process pressure. Also, the pressure between the wafer and the support member is preferably equal to or greater than the pressure in the chamber before the wafer is aligned.
- So that the manner in which the above recited features, advantages and objects of the present invention are attained and can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to the embodiments thereof which are illustrated in the appended drawings.
- It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.
- FIG. 1 is a partial cross sectional view of the vacuum chamber.
- FIG. 2 is a schematic drawing of the vacuum chamber and the pressure control system.
- FIG. 3 is a cross sectional view of a typical support member having a wafer thereon that is partially covered by a shadow ring.
- FIG. 4 is a partial, cross sectional view of a shadow ring, a wafer, and a support member showing the wafer misaligned on the support member as they enter the inner cavity of the shadow
- As shown in FIG. 1, the present invention relates to a method and apparatus for aligning a
wafer 20 on asupport member 60 in avacuum chamber 30. The alignment apparatus is depicted generally as 10. - The preferred embodiment described below refers to an
alignment apparatus 10 that uses ashadow ring 40 to align thewafer 20 on thesupport member 60. However, the invention is not limited to this precise form of apparatus for it may apply to any number of alignment mechanisms. As previously mentioned, the term “shadow ring,” as used herein, refers generally to both shadow rings and clamp rings. - FIG. 1 shows a
typical vacuum chamber 30 defined by an outer body 32. Thevacuum chamber 30 houses asupport member 60 that may take the form of a pedestal or susceptor mounted on a generally vertically orientedshaft 62. Thesupport member 60 serves to support awafer 20 on its flat upper supportingsurface 64. Thesupport member 60 also includes astep formation 68 formed on its outer perimeter to receive and support ashadow ring 40 and includes fourfinger apertures 66. - In a
typical vacuum chamber 30, the pressure within thevacuum chamber 30 is controlled by a pressure control system such as the one shown schematically in FIG. 2. In this system, agas supply 170 is provided in fluid communication with thevacuum chamber 30. Agas flow controller 180 positioned intermediate thegas supply 170 and thevacuum chamber 30 controls the flow from thegas supply 170 to thevacuum chamber 30. Using a predetermined set of instructions, thegas flow controller 180 selectively provides a flow of gas to thevacuum chamber 30. As the gas flows into thevacuum chamber 30, the pressure within thevacuum chamber 30 increases. In this way, thegas flow controller 180 controls the pressure within thevacuum chamber 30. It is possible to provide the gas to thechamber 30 through thesupport member 60 to the back side of thewafer 20. When provided to the back side of thewafer 20, the gas creates a pressure between thewafer 20 and thesupport member 60 that is initially greater than the pressure in thechamber 30. This back side gas may be provided, for example, by a bypass line 200 that provides communication from thegas flow controller 180 to theupper surface 64 of thesupport member 60 between thesupport member 60 and thewafer 20. - FIG. 1 also illustrates a
wafer lifting finger 90 received in afinger aperture 66 passing through the body of thesupport member 60. Typically, the processing chamber would include foursuch lifting fingers 90. These liftingfingers 90 operate to lift thewafer 20 clear of the upper supportingsurface 64 of thesupport member 60 after processing. This removal of thewafer 20 is achieved by means of a conventional processing apparatus robot arm (not shown) which enters thevacuum chamber 30 through theslit valve opening 36. The same robot arm is also used to insert thewafers 20 into thevacuum chamber 30. The liftingfingers 90 are movable vertically under action of alifting mechanism 92 of which only the upper portion is shown. - A
shadow ring 40 housed within thevacuum chamber 30 operates to provide an exclusionary zone where no deposition occurs at the edge of thewafer 20. Theshadow ring 40 also operates to force amisaligned wafer 20 into alignment as thesupport member 30 moves from a lowered, or idle, position to a raised, or processing, position. When thesupport member 30 is in the lowered position, theshadow ring 40 is supported around its perimeter by anouter support ring 38 that is, in turn, supported by aconventional pumping plate 39 attached to thevacuum chamber 30. Together, the two rings, 40 and 38, divide thevacuum chamber 30 into upper and lower sections, 30 a and 30 b respectively. - During processing, the
support member 60 moves upward into a raised position lifting theshadow ring 40. Theshadow ring 40 has alower portion 42 that rests on theupper surface 64 of thesupport member 60 and supports theupper shield portion 50 of theshadow ring 40 above the upper surface of thewafer 20. Preferably, theshield portion 50 is held about 5 to 10 mils above thewafer 20. Theupper shield portion 50 of theshadow ring 40 defines a circularupper aperture 46 therethrough. The diameter of theupper aperture 46 may be slightly less than the outer diameter of thewafer 20 to form the exclusionary zone on thewafer 20. However, new processes may require no overhang of theshadow ring 40 over thewafer 20. In one typical processing operation, thestep formation 68, shown in FIG. 1, is in the range of 3.8 to 3.9 mm high, theshadow ring 40 is in the range of 5 to 5.1 mm thick, and the overhanging portion is in the range of 0.8 to 0.9 mm thick. The overhanging portion defines an exclusionary zone of about 3 to 5 mm about the edge of thewafer 20. However, in the preferred embodiment, this exclusionary zone is no greater than 1.5 mm from the edge of thewafer 20. To accommodate the current industry standards, the exclusionary zone at any one edge is preferably about 1.5 mm or less. This relatively small exclusionary zone is necessary to allow deposition on thewafer 20 at a position 1.5 mm from the wafer edge. Industry standards demand a film thickness at 1.5 mm from the wafer edge that is at least 90 percent of the film thickness at the wafer center. No deposition is allowed on the beveled edge of thewafer 20. Therefore, for atypical wafer 20 having a 0.5 mm chamfer about its edge, this allows a deviation of only about 1 mm from center. As used herein, all dimensions account for thermal expansion and are representative of measurements at process temperatures. - Preferably, a purge gas is directed through the
support member 60 about the periphery of thewafer 20. The purge gas flows between theshadow ring 40 and thewafer 20 to help shield the exclusionary zone of thewafer 20. - A
lower portion 42 of theshadow ring 40, as shown in FIG. 4, extends downwardly from theupper shield portion 50. Thelower portion 42 has an annular cross section throughout its length and defines a frustoconicalinner cavity 44 therein that is concentric with theupper aperture 52. Becausewafers 20 are circular in shape, thesupport member 60 is circular as is the inner cavity cross section. The diameter of theinner cavity 44 decreases from thelower mouth portion 46 to theupper end 48 of theinner cavity 44 to form a funnel-like structure for aligning thewafer 20 on thesupport member 60. Accordingly, the surface of theinner cavity 44 is relatively smooth to facilitate the sliding receipt and abutment of thewafer 20 in theinner cavity 44. To allow receipt of the wafer withininner cavity 44 and to properly align thewafer 20 with theshadow ring 40, the diameter of theupper end 46 of theinner cavity 44 is slightly greater than and, preferably, approximately equal to the outer diameter of thewafer 20. As previously mentioned, current industry practice demands that the thickness of the deposited film at a position 1.5 mm from the edge of thewafer 20 to 90 percent of the thickness at the center of thewafer 20. Accordingly, thewafer 20 must be aligned so that the shadow ring overhangs thewafer 20 by no more than 1.5 mm about its full periphery so that the film will be allowed to deposit on thewafer 20 at 1.5 mm from the edge of thewafer 20. Therefore, the diameter of theupper end 46 of theinner cavity 44 is preferably at most only slightly more than 3 mm greater than theupper aperture 52 and only slightly greater than the outer diameter of thewafer 20 to ensure that the edge of thewafer 20 is within 1.5 mm of the periphery of theupper aperture 52. In this way, theshadow ring 40 only overhangs thewafer 20 at most by about 1.5 mm about the full periphery of thewafer 20. Because thewafer 20 rests on theupper surface 64 of thesupport member 60 and thewafer 20 is relatively thin, the outer diameter of thesupport member 60 must be sufficiently small that it can also be positioned proximal theupper end 52 of theinner cavity 44. However, to provide proper support for thewafer 20, thesupport member 60 must cover substantially the full area of thewafer 20. Therefore, the wafer must occupy most of the upper surface area of thesupport member 60. - As shown in FIG. 1, once positioned in the
vacuum chamber 30, awafer 20 rests on the upper supportingsurface 64 of thesupport member 30. This placement is made with thesupport member 60 in its lowered position. Before processing may begin, thewafer 20 must first be raised by thesupport member 60 to the raised position. It is during the movement from the lowered position to the raised position that any misalignment of thewafer 20 is corrected and thewafer 20 is aligned. As thesupport member 60 moves upward from the lowered position, amisaligned wafer 20 contacts theinner cavity 44 of theshadow ring 40 at a position intermediate theupper end 48 and thelower mouth portion 46. FIG. 4 illustrates amisaligned wafer 20 on thesupport member 60. The point of contact is dependent upon the magnitude of the misalignment. Preferably, there is no misalignment. As thesupport member 60 continues to move upward, the angled side of the frustoconically-shapedinner cavity 44 exerts a lateral force on the edge of thewafer 20 forcing thewafer 20 into alignment. Consequently, when thesupport member 60 reaches its raised position so that thewafer 20 is at theupper end 48 of theinner cavity 44 of theshadow ring 40, thewafer 20 is aligned due to the relative diameters of thewafer 20 and the shadow ring components. When in this raised position, depending upon the type of process involved, the outer portion of thewafer 20 may either bear against theshadow ring 40 and slightly lift theshadow ring 40 under action of thesupport member 60 or may rest on theshoulder 68 of thesupport member 60 and, thereby, leave a small gap between theshadow ring 40 and thewafer 20. For convenience, the application refers primarily to those processes wherein thewafer 20 does not contact theshadow ring 40 although the present invention is applicable to all processes. With thesupport member 60 in the raised position, the outer portion of thewafer 20 is covered by theupper shield portion 50 of theshadow ring 40. - However, as mentioned previously, the sliding movement of the
wafer 20 on thesupport member 60 during alignment creates particles within thevacuum chamber 30. These particles are generated as a result of the friction between thewafer 20 and thesupport member 60 which is generally characterized by the coefficient of friction of the interface multiplied by the weight of thewafer 20. Other forces acting upon thewafer 20 also affect the magnitude of the frictional forces. For example, vacuum chucking may affect the friction between thewafer 20 and thesupport member 60. Likewise, the downward component of the force exerted by the frustoconicalinner cavity 44 increases the frictional forces between the abutting surfaces. Nevertheless, the friction force between the surfaces equals the coefficient of friction between the surfaces multiplied by the downward, normal forces exerted on thewafer 20 whatever their source. Generally, the weights of thewafers 20 are relatively constant. Greater frictional forces on thewafer 20 and thesupport surface 60 cause greater particle generation and decrease the energy efficiency of the system. In addition, high frictional forces may cause misalignment and may cause thewafer 20 to move theshadow ring 40 out of alignment, rather than theshadow ring 40 moving thewafer 20 into alignment, if the lateral force applied on thewafer 20 by the shadow ring is insufficient to overcome the frictional forces. For the purposes of the present application, the relevant normal and frictional forces are generally characterized by the following formulas respectively wherein N represents the normal force applied to thewafer 20, F is the frictional force applied to thewafer 20, G is the weight of thewafer 20, A is the surface area of thewafer 20, P1 is the pressure in thechamber 30, P0 is the pressure between thewafer 20 and thesupport member 60, and μ is the coefficient of friction. - N=G−(P 1 −P 0)A
- F=μN=μ(G−(P 1 −P 0)A)
- Thus, the normal force is equal to the weight of the
wafer 20 less the force created by the pressure differential on the top and bottom surfaces of thewafer 20. The force created by this pressure differential equals the difference between the pressure between thewafer 20 and thesupport member 60 and the pressure in thechamber 30 multiplied by the surface area of thewafer 20. The frictional forces equal the normal forces multiplied by the coefficient of friction. - Reducing the frictional forces between the
wafer 20 and thesupport member 60 reduces the number of particles generated when thewafer 20 is moved on thesupport member 60. Accordingly, in order to reduce the number of particles generated, the coefficient of friction or the normal force between thewafer 20 and thesupport member 60 must be reduced. The present invention accomplishes this by increasing the pressure within thevacuum chamber 30 to at least about one Torr. Empirical studies, which are more fully discussed below, have shown that increasing the pressure within thevacuum chamber 30, so that the pressure between thewafer 20 and thesupport member 60 is equal to or greater than the pressure in thevacuum chamber 30, reduces the frictional forces between thewafer 20 and thesupport member 60. In order for this decrease in frictional force to occur, one of two things must happen. One possibility is that the increased pressure somehow lowers the coefficient of friction (e.g., by possibly creating a cushion of gas between thewafer 20 and the support member 60). Another possibility is that the increased pressure somehow lowers the normal force on thewafer 20. Regardless of the manner in which increasing the pressure affects the frictional forces, the result is that the frictional forces are reduced and, thus, thewafer 20 may be moved on thesupport member 60 with less resistance and less particle generation. The resulting decrease in frictional force allows freer movement of thewafer 20 on thesupport member 60 and, thereby, reduces the resulting scratches and generated particles. Gas from thegas supply 170 is introduced into thevacuum chamber 30 to increase the pressure therein. The gas may be introduced generally into thechamber 30 or through gas inlets positioned in theupper surface 64 of thesupport member 60. It is in this latter case that the pressure below thewafer 20 is greater than the pressure above thewafer 20. - Therefore, the method of the present invention involves increasing the pressure within the
vacuum chamber 30 to at least about one Torr before moving thewafer 20 on thesupport member 60 for alignment. Typically, the pressure within thevacuum chamber 30 when thewafer 20 is introduced therein is about one milliTorr or less. The wafer is, thus, introduced into thevacuum chamber 30 onto thesupport member 60 which is in a lowered position. Thesupport member 60 is then raised to thelower mouth aperture 46 of theshadow ring 40. However, before raising thesupport member 60 to the processing position the pressure within thevacuum chamber 30 is increased to at least about one Torr. Of course, this step of increasing the pressure may take place at any time before thesupport member 60 is raised into theinner cavity 44 of theshadow ring 40. Preferably, the pressure is raised to between about 1 Torr and 100 Torr or, more preferably, between about 1 Torr and 10 Torr and approximately equal to or less than the operating pressure of the process. The operating pressure of the process is the pressure at which the process, such as a chemical vapor deposition process, is carried out in thevacuum chamber 30. Also, before raising thesupport member 60 to the raised position, the pressure between thewafer 20 and thesupport member 60 is provided so that the pressure between thewafer 20 and thesupport member 60 is approximately equal to or greater than the pressure in thevacuum chamber 30. Once the pressure in thevacuum chamber 30 is sufficiently raised and the pressure beneath thewafer 20 is equalized, thesupport member 60 is raised to the raised, or processing, position. As previously discussed, when thesupport member 60 moves into theshadow ring 40, anymisaligned wafer 20 will contact the angled sides of theinner cavity 44 which will force thewafer 20 into alignment. After thesupport member 60 is in the raised position and thewafer 20 is aligned, the pressure within thevacuum chamber 30 may be altered as needed. - As previously described, the pressure within the
vacuum chamber 30 is manipulated by agas supply 170 and agas flow controller 180. In operation, thegas flow controller 180 uses predetermined set of instructions to adjust the pressure within thevacuum chamber 30 as needed. Avacuum pump 190, or series ofvacuum pumps 190, are used to evacuate thevacuum chamber 30. - Example
- This system has been tested to determine its effectiveness as follows. A
misaligned wafer 20 was positioned upon asupport member 60 in avacuum chamber 30 and was raised from a lowered position to a raised position. The test was conducted under vacuum conditions (i.e., moving thewafer 20 without first increasing the pressure in the chamber) and under pressurized conditions (i.e., moving thewafer 20 only after increasing the pressure in the chamber). When tested under pressurized conditions, the tests were conducted with both the pressure beneath thewafer 20 equal to and greater than the pressure in thechamber 30. In both of these pressurized condition tests, the results were essentially the same. Thewafers 20 were then inspected using a SURISCAN 6200 manufactured by Tencor Instruments to determine the number of particles generated as a result of thewafer 20 moving on thesupport member 60. The results revealed that, without first increasing the pressure in the chamber, alignment of the wafer generated approximately 50 to 200 particles when thewafer 20 contacted the shadow ring and approximately 5000 backside particles. In addition, without first increasing the pressure in the chamber, theshadow ring 40 often moved with thewafer 20 as thesupport member 60 lifted theshadow ring 40 due to the frictional forces holding thewafer 20 to thesupport member 60. This resulted in amisaligned wafer 20 and reduced repeatability of the process. However, using the present invention, wherein the pressure is raised to at least about one Torr before moving thewafer 20, the movement of thewafer 20 on thesupport member 60 generated only approximately Twenty (20) particles when thewafer 20 contacted theshadow ring 40 and less than 2000 backside particles. Further, themisaligned wafer 20 moved on thesupport member 60 more readily and was, therefore, properly centered which increased repeatability of the edge exclusion and the process. - While the foregoing is directed to the preferred embodiment of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims which follow.
Claims (23)
1. A method for aligning a wafer within a vacuum chamber, comprising the steps of:
introducing the wafer into the vacuum chamber;
increasing the pressure within the vacuum chamber, and
subsequently moving the wafer into alignment.
2. The method of wherein the pressure in the vacuum chamber when the wafer is introduced therein is 1 milliTorr or less.
claim 1
3. The method of further comprising the step of increasing the pressure in the vacuum chamber to at least about 1 Torr.
claim 1
4. The method of further comprising the step of increasing the pressure in the vacuum chamber to a pressure that is at least about 1 Torr and less than an operating pressure of the chamber.
claim 1
5. The method of further comprising the step of increasing the pressure in the vacuum chamber to a pressure between about 1 Torr and 100 Torr.
claim 1
6. The method of further comprising the step of increasing the pressure in the vacuum chamber to a pressure between about 1 Torr and 10 Torr.
claim 1
7. The method of further comprising the step of waiting until the pressure between the wafer and the support member is equal to or greater than the pressure in the vacuum chamber before aligning the wafer.
claim 1
8. A method for aligning a wafer on a support member within a vacuum chamber, comprising the steps of:
providing a shadow ring having a lower portion that is outwardly tapered for receipt of the wafer and an upper aperture having a diameter that is slightly less than the outer diameter of the wafer;
introducing the wafer into the vacuum chamber and onto the support member;
increasing the pressure within the chamber; and
subsequently moving the support member toward the shadow ring so that the shadow ring aligns the wafer on the support member.
9. The method of wherein the pressure in the vacuum chamber when the wafer is introduced therein is 1 milliTorr or less.
claim 8
10. The method of further comprising the step of increasing the pressure in the vacuum chamber to a pressure at least about 1 Torr.
claim 8
11. The method of further comprising the step of increasing the pressure in the vacuum chamber to a pressure that is at least about 1 Torr and less than an operating pressure of the chamber.
claim 8
12. The method of further comprising the step of increasing the pressure in the vacuum chamber to a pressure between about 1 Torr and 100 Torr.
claim 8
13. The method of further comprising the step of increasing the pressure in the vacuum chamber to a pressure between about 1 Torr and 10 Torr.
claim 8
14. The method of further comprising the step of waiting until the pressure beneath the wafer is equal to or greater than the pressure in the vacuum chamber before aligning the wafer.
claim 8
15. The method of further comprising the step of raising the wafer to a position below the shadow ring before increasing the pressure within the chamber.
claim 8
16. An apparatus for aligning a wafer on a support member in a vacuum chamber, comprising:
a support member is positioned within the vacuum enclosure having a wafer receiving surface thereon;
a shadow ring located within the vacuum chamber, the shadow ring comprising:
an upper shield portion defining a circular upper aperture therethrough, the upper aperture having a diameter that is slightly less than the outer diameter of the wafer;
a lower portion extending from the upper shield portion having an annular cross section defining a frustoconical inner cavity;
the diameter of the inner cavity decreases from a lower mouth aperture to an upper end; and
the diameter of the upper end of the inner cavity is slightly greater than the outer diameter of the wafer;
a gas supply in fluid communication with the vacuum chamber;
a gas flow controller that controls the flow of gas from the gas supply to the vacuum chamber and regulates the pressure within the vacuum chamber such that, after the wafer is positioned on the support member and before the wafer is raised into the shadow ring, the control member raises the pressure within the chamber.
17. The apparatus of wherein the control member raises the pressure within the vacuum chamber to about 1 Torr.
claim 16
18. The apparatus of wherein the control member raises the pressure within the vacuum chamber to a pressure between 1 Torr and 100 Torr.
claim 16
19. The apparatus of wherein the control member raises the pressure within the vacuum chamber to a pressure between 1 Torr and 10 Torr.
claim 16
20. The apparatus of wherein the control member raises the pressure within the vacuum chamber to a pressure that is at least about 1 Torr and below an operating pressure.
claim 16
21. The apparatus of wherein the difference between the diameter of the upper aperture in the upper shield portion and the outer diameter of the wafer is no greater than 5 millimeters.
claim 16
22. The apparatus of wherein the difference between the diameter of the upper aperture in the upper shield portion and the outer diameter of the wafer is no greater than 3 millimeters.
claim 16
23. The apparatus of wherein the diameter of the upper end of the inner cavity is substantially equal to the outer diameter of the wafer.
claim 12
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US09/481,055 US6436192B2 (en) | 1997-07-11 | 2000-01-11 | Apparatus for aligning a wafer |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US08/893,461 US6063440A (en) | 1997-07-11 | 1997-07-11 | Method for aligning a wafer |
US09/481,055 US6436192B2 (en) | 1997-07-11 | 2000-01-11 | Apparatus for aligning a wafer |
Related Parent Applications (1)
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US08/893,461 Division US6063440A (en) | 1997-07-11 | 1997-07-11 | Method for aligning a wafer |
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US20010037771A1 true US20010037771A1 (en) | 2001-11-08 |
US6436192B2 US6436192B2 (en) | 2002-08-20 |
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US08/893,461 Expired - Fee Related US6063440A (en) | 1997-07-11 | 1997-07-11 | Method for aligning a wafer |
US09/481,055 Expired - Fee Related US6436192B2 (en) | 1997-07-11 | 2000-01-11 | Apparatus for aligning a wafer |
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US08/893,461 Expired - Fee Related US6063440A (en) | 1997-07-11 | 1997-07-11 | Method for aligning a wafer |
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US20140116340A1 (en) * | 2012-10-26 | 2014-05-01 | Epicrew Corporation | Epitaxial growth device |
CN103882390A (en) * | 2012-12-20 | 2014-06-25 | 北京北方微电子基地设备工艺研究中心有限责任公司 | Reaction chamber and magnetron sputtering apparatus |
CN113764328A (en) * | 2020-06-02 | 2021-12-07 | 拓荆科技股份有限公司 | Apparatus and method for processing wafer |
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Family Cites Families (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5131460A (en) * | 1991-10-24 | 1992-07-21 | Applied Materials, Inc. | Reducing particulates during semiconductor fabrication |
US5292554A (en) * | 1992-11-12 | 1994-03-08 | Applied Materials, Inc. | Deposition apparatus using a perforated pumping plate |
US5326725A (en) * | 1993-03-11 | 1994-07-05 | Applied Materials, Inc. | Clamping ring and susceptor therefor |
US5800686A (en) * | 1993-04-05 | 1998-09-01 | Applied Materials, Inc. | Chemical vapor deposition chamber with substrate edge protection |
US5476548A (en) * | 1994-06-20 | 1995-12-19 | Applied Materials, Inc. | Reducing backside deposition in a substrate processing apparatus through the use of a shadow ring |
JP2748881B2 (en) * | 1995-02-03 | 1998-05-13 | 日本電気株式会社 | Semiconductor manufacturing apparatus and manufacturing method |
US5994678A (en) * | 1997-02-12 | 1999-11-30 | Applied Materials, Inc. | Apparatus for ceramic pedestal and metal shaft assembly |
-
1997
- 1997-07-11 US US08/893,461 patent/US6063440A/en not_active Expired - Fee Related
-
1998
- 1998-07-10 JP JP10195902A patent/JPH1180950A/en not_active Withdrawn
-
2000
- 2000-01-11 US US09/481,055 patent/US6436192B2/en not_active Expired - Fee Related
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US20140116340A1 (en) * | 2012-10-26 | 2014-05-01 | Epicrew Corporation | Epitaxial growth device |
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CN113764328A (en) * | 2020-06-02 | 2021-12-07 | 拓荆科技股份有限公司 | Apparatus and method for processing wafer |
Also Published As
Publication number | Publication date |
---|---|
US6436192B2 (en) | 2002-08-20 |
US6063440A (en) | 2000-05-16 |
JPH1180950A (en) | 1999-03-26 |
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