Thermal budget automatic control method and automatic control system thereof

Abstract

The invention discloses a thermal budget automatic control method. The method comprises the steps of setting a side wall thickness target value, a qualified interval and a thermal budget tolerance interval; calculating the side wall thickness average value and the deviation between the inner side wall thickness values of different side wall annular areas and the side wall thickness target value; judging whether a first deviation between the side wall thickness average value and the side wall thickness target value is within a side wall thickness qualified interval, and if not, discarding the silicon wafer; judging whether a second deviation between the inner side wall thickness value of the annular area of the side wall and the side wall thickness target value is within a thermal budget tolerance interval; if the second deviation is within the thermal budget tolerance interval, keeping the thermal budget temperature; if the second deviation is negative, reducing the thermal budget temperature; if the second deviation is positive, increasing the thermal budget temperature; and executing rapid thermal annealing according to the adjusted thermal budget temperature of the annular areaof each side wall. The invention further discloses a thermal budget automatic control system. According to the method, the uniformity of the performance of the silicon wafer device can be realized, and the product yield can be improved on a large scale.

Description

technical field [0001] The invention relates to the field of integrated circuit manufacturing, in particular to a thermal budget control method for rapid thermal annealing SMT RTA process of integrated circuit stress memory technology. Background technique [0002] The SMT RTA temperature adjustment method of existing 40nm / 28nm products is as follows: figure 1 As shown, including: first measure the entire leakage current of the product chip, and the large leakage current corresponds to the high temperature of the SMT RTA here. Then compare the on-chip distribution of the leakage current of this chip with the on-chip distribution of the resistance of the control chip that monitors the temperature change of the SMT RTA. The low resistance of the control chip means that the temperature of the SMTRTA is high here. Judging whether the place where the leakage current of the product sheet is relatively large corresponds to the low resistance on the control sheet, or whether the pl...

AI Technical Summary

Problems solved by technology

This method of manually adjusting the SMT RTA temperature based on the leakage current results of the product is an after-the-fact remedy. It is similar to a remedy after a dead sheep. It is only suitable for improving the device performance of subsequent batches of products. There is no remedial measure for current products, and it is not timely.

In addition, the existing SMTRTA adjustment method can only be used for the whole batch of products, and cannot be dynamically adjusted for different silicon wafers in the same batch, so the uniformity of device performance between wafers cannot be improved.

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