Method of identifying bottlenecks and improving throughput in wafer processing equipment
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsTony Kao, Stark Chen
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Abstract
Throughput in a semiconductor wafer processing system, such as in-line photolithography equipment, is improved by identifying and correcting bottlenecks in the flow of wafers through multiple, associative segments of the equipment. Segmental rather than total processing times are monitored in order to identify the segments having the longest processing times. The theory of constraints is applied to identify the process segment representing a bottleneck in the process, and effect improvements in the bottleneck segment that provide greater overall throughput.
Claims17
A method for improving the throughput performance of a photolithography cluster tool having a plurality of process segments each associated with a different processing operation within said cluster tool for processing semiconductor wafers within the cluster tool, comprising the steps of:
- (A) determining the segmental process time for each of said segments based on a wafer lot of predetermined size, wherein each of the plurality of process segments has associated plurality of tool units that carry out identical process functions within the plurality of process segments;
- (B) identifying a segment causing a bottleneck in the flow of wafers through said segments based on the times determined in step (A);
- and,
- (C) making process changes in the segment identified in step (B).
A method for determining a bottleneck in the flow of product through a cluster tool having a plurality of differing process segments, and multiple tool units in each of said segments, comprising the steps of:
- (A) determining the number of said tool units in each of said segments, wherein each of multiple tool units in each of said segments carry out identical process functions within the plurality of differing process segments;
- (B) determining the segmental process time for each of said segments based on a product lot sample of preselected size;
- (C) calculating the throughput of said product through each of said segments;
- and,
- (D) identifying the bottleneck based on the process segment having the longest segmental process time.
Dependencies are inferred from the claim text.