CN103390553A

CN103390553A - Rapid thermal annealing method

Info

Publication number: CN103390553A
Application number: CN2012101472176A
Authority: CN
Inventors: 苏小鹏; 谭秀文
Original assignee: CSMC Technologies Corp
Current assignee: CSMC Technologies Corp
Priority date: 2012-05-11
Filing date: 2012-05-11
Publication date: 2013-11-13
Anticipated expiration: 2032-05-11
Also published as: CN103390553B

Abstract

The invention discloses a rapid thermal annealing method. The method comprises the steps of obtaining first uniformity distribution data of a wafer which is obtained through quality control parameter thermal annealing; obtaining second uniformity distribution data of a wafer which is obtained through product actual thermal annealing; comparing the first uniformity distribution data with the second uniformity distribution data to obtain wafer areas where differences occur; performing power adjustment on lamp tubes corresponding to the wafer areas where the differences occur. According to the rapid thermal annealing method, different power is used for performing set point adjustment on the lamp tubes of different areas, so that the uniformity of products can be improved.

Description

Quick thermal annealing method

Technical field

The present invention relates to the semiconductor manufacturing, particularly relate to a kind of quick thermal annealing method.

Background technology

Ion implantation technique is a kind of doping method in semiconductor fabrication process, and it will make silicon chip possess P type or N type semiconductor characteristic in the Impurity injection silicon chip.High-temperature annealing process is a kind of inhomogeneity method of control product, and the impurity activation that it will be injected in silicon chip, make the resistance of silicon chip surface regional more consistent.Conventional high temperature long term annealing method can make implanted dopant spread again, causes effective raceway groove to shorten, and has limited the advantage performance of injection technology.Therefore, usually all adopt rapid thermal anneal process.

Along with the development of manufacture of semiconductor, the uniformity requirement of product is more and more higher, particularly for the narrower product of live width, and the too poor component failure that probably makes of uniformity of (wafer in wafer, WIW) in monolithic.

In manufacture of semiconductor, usually all can service quality control (quality control, QC) and guarantee that one of product makes peace stable.The menu parameter of resulting rapid thermal annealing when the QC of thermal anneal process namely makes wafer uniformity reach the best by power of lamp tube corresponding to adjustment wafer regional.

Traditional regulative mode is, the menu parameter of gained when all high temperature menus of product all use QC, yet the uniform distribution figure as the uniform distribution figure of fruit product and QC is inconsistent, is difficult to adjust by the uniformity of independent adjustment QC menu the uniformity of product.

Summary of the invention

, based on this, be necessary to provide a kind of raising product inhomogeneity quick thermal annealing method.

A kind of quick thermal annealing method, comprise the steps: to obtain the first uniform distribution data that adopt the resulting wafer of quality-controlling parameters thermal annealing; Obtain the second uniform distribution data of the resulting wafer of the actual thermal annealing of product; More described the first uniform distribution data and the second uniform distribution data, obtain producing the wafer area of difference; The fluorescent tube that the wafer area of described generation difference is corresponding carries out the power adjustment.

Therein in embodiment, the described fluorescent tube corresponding to wafer area that will produce difference carries out in step that power adjusts, corresponding fluorescent tube parameter in the quality control menu in board being adjusted as fluorescent tube parameter corresponding in the product menu.

In embodiment, described the first uniform distribution data and the second uniform distribution data are the contour map of the sheet resistance of wafer therein.

Above-mentioned quick thermal annealing method, fix a point to adjust to the different power of fluorescent tube employing of zones of different, can improve the uniformity of product.

Description of drawings

Fig. 1 (a) is rapid thermal annealing components of system as directed structure vertical view;

Fig. 1 (b) is rapid thermal annealing components of system as directed structure side view;

Fig. 2 is the time-temperature curve in the rapid thermal annealing system;

Fig. 3 is the quick thermal annealing method flow chart of an embodiment;

Fig. 4 is the first uniform distribution figure of the wafer that obtains under certain QC menu;

Fig. 5 is the second uniform distribution figure of the wafer that obtains of the product actual production of the QC menu of corresponding diagram 4.

Embodiment

Rapid thermal annealing be activate after wafer carries out Implantation the wafer intermediate ion than effective method.As shown in Figure 1 (a) and Fig 1 (b) shows, the thermal source of this rapid thermal anneler 10 adopts the up and down two orthogonal staggered fluorescent tubes of row, and every row all comprise the fluorescent tube 110 of some equidistant distributions, and wafer 120 is between staggered fluorescent tube 110.Staggered fluorescent tube 110 is all corresponding different heating region, when carrying out thermal annealing, the temperature contrast that wafer 120 is heated between rear regional is less when wafer 120, and the resistance uniformity of wafer 120 is higher, and the quality of product is better.

Rapid thermal annealing comprises three Main Stage: temperature rise period, temperature keep stage and quick cooling stage.As shown in Figure 2, be a kind of time-temperature curve figure of more general rapid thermal annealing.

Temperature rise period is to adopt fluorescent tube that certain zone of wafer is risen to predetermined temperature from normal temperature, can control as required the temperature variation in the unit interval, and in the rapid thermal annealing system, the temperature variation in the unit interval can reach 250 ℃/s.

Temperature keeps the stage after the temperature rise period finishes, and temperature arrives certain default value (for example 1000 ℃) and keeps the regular hour (for example 10 ~ 15 seconds) ion is fully activated and reach poised state.

Just enter afterwards quick cooling stage.

In the technique of rapid thermal annealing, the temperature rise period is also named the pre-stab stage, and temperature keeps stage and quick cooling stage also to be main operation stage.Wherein the pre-stab stage generally continues 5 ~ 20 seconds, and this step is larger for the uniformity impact of product, can not change easily.In the manufacture craft of different product, need to use different main technique, thereby the temperature and time of main technique is different.So just produced the uniformity difference under QC menu and product menu.

For the uniformity that makes product is consistent, the power of fluorescent tube corresponding to wafer regional is carried out independent adjustment.The quick thermal annealing method of one embodiment is provided.As shown in Figure 3, the quick thermal annealing method of an embodiment comprises the following steps.

Step S101: obtain the first uniform distribution data that adopt the resulting wafer of quality control (QC) parameter thermal annealing.In semiconductor technology, usually all adopt quality control that the quality of product is guaranteed.Quality-controlling parameters is through monitoring, test and the parameter of comparatively optimizing that obtains after adjusting.In the rapid thermal annealing processing procedure of the present embodiment, quality-controlling parameters may comprise the power contorl parameters of each fluorescent tube, controls respectively programming rate, temperature hold-time and cooling rate etc. that each fluorescent tube can reach.As shown in Figure 4, be the first uniform distribution data of the wafer that obtains under certain QC menu.These the first uniform distribution data are resistance sizes distribution maps of the sheet resistance of wafer, adopt contour to represent that the resistance size is identical.In Fig. 4, the contour of wafer outer rim is all comparatively intensive, and middle body is comparatively sparse, show that the marginal portion change in resistance is large thereby consistency is poor, and the middle body change in resistance is less thereby consistency is better.

Step S102: the second uniform distribution data of obtaining the resulting wafer of the actual thermal annealing of product.As previously mentioned, the wafer that obtains with QC in the product actual production process has difference, therefore is necessary to obtain the second uniform distribution data of the resulting wafer of the actual thermal annealing of product.The second uniform distribution data of the wafer that obtains for the product actual production of the aforesaid QC menu of correspondence as shown in Figure 5.These the second uniform distribution data are the resistance sizes distribution map of the sheet resistance of wafer equally, and adopt contour to represent that the resistance size is identical.In Fig. 5, the contour of wafer outer rim is all comparatively intensive, and middle body is comparatively sparse, show that the marginal portion change in resistance is large thereby consistency is poor, and the middle body change in resistance is less thereby consistency is better.

Step S103: more described the first uniform distribution data and the second uniform distribution data obtain producing the wafer area of difference.The sheet resistance of the wafer in Fig. 4 and Fig. 5 presents identical distribution characteristics, but has some difference in part.The zone 1 that for example identifies in Fig. 5, zone 2 and zone 3.In this distribution of resistance figure, occur that "+" expression resistance is bigger than normal, occur that "-" represents that resistance is less than normal.Wafer resistance for zone 1, Fig. 4 is bigger than normal, and the wafer resistance of Fig. 5 is less than normal.Wafer resistance for zone 2, Fig. 4 is bigger than normal, and the wafer resistance of Fig. 5 is less than normal.Wafer resistance for zone 3, Fig. 4 is bigger than normal, and the wafer resistance of Fig. 5 is less than normal.

Step S104: the fluorescent tube that the wafer area of described generation difference is corresponding carries out the power adjustment., for the difference zone, need to adjust the watt level of corresponding fluorescent tube.This adjustment is adjusted corresponding fluorescent tube parameter in the quality control menu in board as fluorescent tube parameter corresponding in the product menu.In process of production, be all to utilize the menu of board to control the product processing procedure, so the watt level of adjusting fluorescent tube in the present embodiment is namely adjusted the menu of board.And the adjustment of the present embodiment is take the quality control menu as basis, therefore can be adjusting in the independent substitution production of the fluorescent tube parameter menu in corresponding generation difference zone in the quality control menu.

Concrete is adjusted into: the power of lamp tube of zone 1, zone 2 and regional 3 correspondences is all raised to reduce this regional resistance.

Following table is after adjusting according to said method, the uniformity performance of the wafer of producing.

Can find out, through adjusting, the consistent variance rate that reaches the resistance in wafer between wafer is less, and namely the uniformity of product is better.

The above embodiment has only expressed several execution mode of the present invention, and it describes comparatively concrete and detailed, but can not therefore be interpreted as the restriction to the scope of the claims of the present invention.Should be pointed out that for the person of ordinary skill of the art, without departing from the inventive concept of the premise, can also make some distortion and improvement, these all belong to protection scope of the present invention.Therefore, the protection range of patent of the present invention should be as the criterion with claims.

Claims

1. a quick thermal annealing method, is characterized in that, comprises the steps:

Obtain the first uniform distribution data that adopt the resulting wafer of quality-controlling parameters thermal annealing;

Obtain the second uniform distribution data of the resulting wafer of the actual thermal annealing of product;

More described the first uniform distribution data and the second uniform distribution data, obtain producing the wafer area of difference;

The fluorescent tube that the wafer area of described generation difference is corresponding carries out the power adjustment.

2. quick thermal annealing method according to claim 1, it is characterized in that, the described fluorescent tube corresponding to wafer area that will produce difference carries out in the step of power adjustment, and corresponding fluorescent tube parameter in the quality control menu in board is adjusted as fluorescent tube parameter corresponding in the product menu.

3. quick thermal annealing method according to claim 1, is characterized in that, described the first uniform distribution data and the second uniform distribution data are the contour map of the sheet resistance of wafer.