CN103390553B

CN103390553B - Quick thermal annealing method

Info

Publication number: CN103390553B
Application number: CN201210147217.6A
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: 2016-08-03
Anticipated expiration: 2032-05-11
Also published as: CN103390553A

Abstract

The open a kind of quick thermal annealing method of the present invention, comprises the steps: to obtain the first uniform distribution data using the wafer obtained by quality-controlling parameters thermal annealing；Second uniform distribution data of the wafer obtained by the acquisition actual thermal annealing of product；Relatively described first uniform distribution data and the second uniform distribution data, obtain producing the wafer area of difference；Fluorescent tube corresponding for the wafer area of described generation difference is carried out power adjustment.Above-mentioned quick thermal annealing method, uses different power to carry out fixed point adjustment the fluorescent tube of zones of different, it is possible to increase the uniformity of product.

Description

Quick thermal annealing method

Technical field

The present invention relates to 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 impurity is injected and makes silicon chip possess p-type or N-type semiconductor characteristic in silicon chip by it.High-temperature annealing process is then a kind of method controlling product uniformity, and it will be implanted into the impurity activation in silicon chip, and the resistance making silicon chip surface regional is more consistent.Conventional high temperature long term annealing method can make implanted dopant spread again, causes effective raceway groove to shorten, and the advantage limiting injection technology plays.Therefore, rapid thermal anneal process is the most all used.

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

In manufacture of semiconductor, quality control (qualitycontrol, QC) the most all can be used to ensure, and the one of product is made peace stably.The menu parameter of the rapid thermal annealing that the QC of thermal anneal process is obtained when i.e. making wafer uniformity reach optimal by the power of lamp tube that adjustment wafer regional is corresponding.

Traditional regulative mode is, the menu parameter of gained when all high temperature menus of product all use QC, but as inconsistent in the uniform distribution figure of fruit product and the uniform distribution figure of QC, then it is difficult to be adjusted the uniformity of product by the uniformity individually adjusting QC menu.

Summary of the invention

Based on this, it is necessary to provide a kind of quick thermal annealing method improving product uniformity.

A kind of quick thermal annealing method, comprises the steps: to obtain the first uniform distribution data using the wafer obtained by quality-controlling parameters thermal annealing；Second uniform distribution data of the wafer obtained by the acquisition actual thermal annealing of product；Relatively described first uniform distribution data and the second uniform distribution data, obtain producing the wafer area of difference；Fluorescent tube corresponding for the wafer area of described generation difference is carried out power adjustment.

Wherein in an embodiment, in the described step that fluorescent tube corresponding for the wafer area producing difference is carried out power adjustment, fluorescent tube parameter corresponding in the quality control menu in board is adjusted as corresponding fluorescent tube parameter in product menu.

Wherein in an embodiment, described first uniform distribution data and the second uniform distribution data are the contour map of the sheet resistance of wafer.

Above-mentioned quick thermal annealing method, uses different power to carry out fixed point adjustment the fluorescent tube of zones of different, it is possible to increase the uniformity of product.

Accompanying drawing explanation

Fig. 1 (a) is rapid thermal anneal systems part-structure top view；

Fig. 1 (b) is rapid thermal anneal systems part-structure side view；

Fig. 2 is the time-temperature curve in rapid thermal anneal systems；

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

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

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

Detailed description of the invention

Rapid thermal annealing is the more effective method activating wafer intermediate ion after wafer carries out ion implanting.As shown in Figure 1 (a) and Fig 1 (b) shows, the thermal source of this rapid thermal anneler 10 uses upper and lower two to arrange orthogonal staggered fluorescent tube, and each column all includes 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 wafer 120 is when carrying out thermal annealing, after wafer 120 is heated, the temperature contrast between regional is the least, then the resistance homogeneity of wafer 120 is the highest, and the quality of product is the best.

Rapid thermal annealing includes three Main Stage: temperature rise period, temperature keep stage and quick cooling stage.As in figure 2 it is shown, be the time-temperature curve figure of a kind of more universal rapid thermal annealing.

Temperature rise period is to use fluorescent tube that from room temperature, certain region of wafer is risen to predetermined temperature, can control the temperature variation in the unit interval as required, and in rapid thermal anneal systems, the temperature variation in the unit interval can reach 250 DEG C/s.

Temperature keeps the stage after the temperature rise period terminates, and temperature arrives certain value (such as 1000 DEG C) preset and keeps the regular hour (such as 10 ~ 15 seconds) to make ion fully activate and reach poised state.

It is put into quick cooling stage afterwards.

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 to be also main operation stage.Wherein the pre-stab stage typically continues 5 ~ 20 seconds, and this step affects bigger for the uniformity of product, it is impossible to change easily.In the processing technology of different product, need to use different main technique, thus the temperature and time of main technique is different.This creates the terminal the uniformity difference under QC menu and product menu.

In order to make the uniformity of product keep consistent, the power of the fluorescent tube corresponding to wafer regional carries out independent adjustment.The quick thermal annealing method of one embodiment is provided.As it is shown on figure 3, the quick thermal annealing method of an embodiment comprises the following steps.

Step S101: acquisition uses the first uniform distribution data of the wafer obtained by quality control (QC) parameter thermal annealing.In semiconductor processing, quality control is the most all used to make the quality of product be guaranteed.Quality-controlling parameters is the parameter more optimized obtained after monitoring, testing and adjust.In the rapid thermal annealing processing procedure of the present embodiment, quality-controlling parameters potentially includes the power contorl parameters of each fluorescent tube, controls programming rate, temperature hold-time and cooling rate etc. that each fluorescent tube can reach respectively.As shown in Figure 4, the first uniform distribution data of the wafer for obtaining under certain QC menu.These the first uniform distribution data are the resistance sizes scattergrams of the sheet resistance of wafer, use equal pitch contour to represent that resistance size is identical.In Fig. 4, the equal pitch contour of wafer outer rim is the most intensive, and middle body is the most sparse, show marginal portion change in resistance compared with big thus concordance is poor, and middle body change in resistance is less thus concordance is preferable.

Step S102: the second uniform distribution data of the wafer obtained by the acquisition actual thermal annealing of product.As it was previously stated, the wafer obtained with QC in product actual production process has difference, it is therefore necessary to obtain the second uniform distribution data of wafer obtained by the actual thermal annealing of product.As it is shown in figure 5, the second uniform distribution data of the wafer obtained for the product actual production of corresponding aforesaid QC menu.These the second uniform distribution data are the resistance sizes scattergram of the sheet resistance of wafer equally, and resistance size is identical to use equal pitch contour to represent.In Fig. 5, the equal pitch contour of wafer outer rim is the most intensive, and middle body is the most sparse, show marginal portion change in resistance compared with big thus concordance is poor, and middle body change in resistance is less thus concordance is preferable.

Step S103: relatively described first uniform distribution data and the second uniform distribution data, obtains 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 local.Such as in Fig. 5 region 1, region 2 and the region 3 of mark.In this distribution of resistance figure, occur "+" represent that resistance is bigger than normal, occur that "-" then represents that resistance is less than normal.For region 1, the wafer resistance of Fig. 4 is bigger than normal, and the wafer resistance of Fig. 5 is less than normal.For region 2, the wafer resistance of Fig. 4 is bigger than normal, and the wafer resistance of Fig. 5 is less than normal.For region 3, the wafer resistance of Fig. 4 is bigger than normal, and the wafer resistance of Fig. 5 is less than normal.

Step S104: fluorescent tube corresponding for the wafer area of described generation difference is carried out power adjustment.For diff area, need to adjust the watt level of corresponding fluorescent tube.Fluorescent tube parameter corresponding in quality control menu in board is adjusted by this adjustment as corresponding fluorescent tube parameter in product menu.In process of production, being all that product processing procedure is controlled by the menu utilizing board, the watt level therefore adjusting fluorescent tube in the present embodiment i.e. adjusts the menu of board.And the adjustment of the present embodiment is based on quality control menu, therefore the fluorescent tube parameter producing diff area corresponding in quality control menu individually can be substituted in production menu and be adjusted.

Concrete is adjusted to: the power of lamp tube of region 1, region 2 and region 3 correspondence all raises to reduce the resistance in this region.

Following table be adjust according to said method after, the performance of the uniformity of the wafer produced.

It can be seen that be adjusted, the consistent variance rate of the resistance between wafer and in wafer is less, i.e. the uniformity of product is preferable.

Embodiment described above only have expressed the several embodiments of the present invention, and it describes more concrete and detailed, but therefore can not be interpreted as the restriction to the scope of the claims of the present invention.It should be pointed out that, for the person of ordinary skill of the art, without departing from the inventive concept of the premise, it is also possible to make some deformation and improvement, these broadly fall into protection scope of the present invention.Therefore, the protection domain of patent of the present invention should be as the criterion with claims.

Claims

1. a quick thermal annealing method, it is characterised in that comprise the steps:

Acquisition uses the first uniform distribution data of the wafer obtained by quality-controlling parameters thermal annealing；

Second uniform distribution data of the wafer obtained by the acquisition actual thermal annealing of product；

Relatively described first uniform distribution data and the second uniform distribution data, obtain producing the wafer area of difference；Described first uniform distribution data and the second uniform distribution data are the contour map of the sheet resistance of wafer；

Fluorescent tube corresponding for the wafer area of described generation difference is carried out power adjustment.

Quick thermal annealing method the most according to claim 1, it is characterized in that, in the described step that fluorescent tube corresponding for the wafer area producing difference is carried out power adjustment, fluorescent tube parameter corresponding in the quality control menu in board is adjusted as corresponding fluorescent tube parameter in product menu.