Method and device for setting grinding time upper limit and grinding time lower limit

Abstract

The invention provides a method and a device for setting grinding time upper limit and a grinding time lower limit. The method comprises the following steps of obtaining ideal grinding time corresponding to a first preset number of wafers of the same model; fitting the ideal grinding time to obtain a fitting function; and according to an ideal grinding time area corresponding to the ideal grindingtime, adding up the fitting function and a first threshold value together as the grinding time upper limit, and subtracting a second threshold value from the fitting function as the grinding time lower limit, so as to enable a preset ratio of the ideal grinding time area to be distributed between the grinding time upper limit and the grinding time lower limit. Both the grinding time upper limit and the grinding time lower limit are set as dynamic values rather than fixed values. Compared with the prior art, through the adoption of the scheme, the actual grinding time of the wafers to be produced is more likely to be distributed between the grinding time upper limit and the lower grinding time lower limit, and the difference between the grinding time upper limit and the grinding time lowerlimit is relatively small, thereby improving the stability of the grinding process.

Description

technical field [0001] The invention relates to the field of integrated circuit manufacturing, in particular to a method and a device for setting the upper limit and the lower limit of the grinding time. Background technique [0002] Chemical Mechanical Polish (CMP) was gradually applied in the integrated circuit manufacturing process in the 1980s, and its application has become more extensive with the further refinement of the manufacturing process. The thickness of the wafer after grinding is the most critical parameter of chemical mechanical polishing, and it is also an important parameter of integrated circuit design. The process thickness and design thickness need to be highly matched. The mismatch between the two may cause yield or performance loss. Therefore, the wafer Thickness stability after circular grinding is one of the most important goals pursued by the CMP process. There are many measures to improve the stability of wafer thickness after grinding, mainly inc...

AI Technical Summary

Problems solved by technology

[0005] The present invention provides a method and device for setting the upper limit of the grinding time and the lower limit of the grinding time, so as to solve the technical problem that the fixed upper limit of the grinding time and the lower limit of the grinding time in the prior art cause the wafer to be thicker or thinner after grinding

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