Test wafer usage forecast modeling method
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsYi-Chun Tsai, Jung-Sheng Jao, Tai-Kun Lin
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Abstract
A method for modeling usage of semiconductor test wafers comprises the steps of: calculating an individual demand for test wafers by each of a plurality of tools, assigning respective ones of the plurality of tools to a plurality of levels based on ability of each tool to use wafers that have been processed by another one of the plurality of tools, assigning wafers made available by one of the plurality of tools to at least two other ones of the plurality of tools in proportion to the individual demands of each of the at least two other tools, and determining a total demand for test wafers, based on the number of wafers assigned to each of the plurality of tools in the lowest one of the plurality of levels.
Claims23
A method for modeling usage of semiconductor test wafers, comprising the steps of:
- (a) calculating an individual demand for test wafers by each of a plurality of tools;
- (b) calculating a respective flow demand for each downgrade flow among the plurality of tools, based on the individual demands;
- (c) determining a total demand for each type of test wafer, based on the flow demands, taking into account at least one constraint limiting the ability for one of the tools to use test wafers from at least one of a plurality of upstream tool sources.
A method for modeling usage of semiconductor test wafers, comprising the steps of:
- (a) calculating an individual demand for test wafers by each of a plurality of tools;
- (b) assigning the plurality of tools to a plurality of levels based on ability of each tool to use wafers that have been processed by another one of the plurality of tools;
- (c) assigning wafers made available by one of the plurality of tools to at least two other ones of the plurality of tools in proportion to the individual demands of each of the at least two other tools;
- (d) determining a total demand for test wafers, based on the number of wafers assigned to each of the plurality of tools in the lowest one of the plurality of levels.
A method for modeling usage of semiconductor test wafers, comprising the steps of:
- (a) calculating an individual demand for test wafers by each of a plurality of tools;
- (b) assigning the plurality of tools to a plurality of levels based on ability of each tool to use wafers that have been processed by another one of the plurality of tools;
- (c) assigning wafers made available by respective ones of the plurality of tools to downstream tools in the plurality of tools, including assigning wafers made available by one of the plurality of tools to at least two other ones of the plurality of tools in proportion to the individual demands of each of the at least two other tools;
- (d) determining a total demand for test wafers, based on the number of new or reclaimed wafers assigned to a subset of the plurality of tools, wherein the new or reclaimed wafers are not provided from upstream tools within the plurality of tools.
Dependencies are inferred from the claim text.