Identifying causes of semiconductor production yield loss
First Claim
1. A method of identifying causes which reduce yield of a manufacturing process, said process producing wafers containing semiconductor circuitry and involving multiple processing steps including a first specific process step which potentially introduces particulate deposits on wafers, comprising the steps of:
- detecting a number and location of particulate deposits on a wafer prior to and subsequent to said first specific process step, and determining therefrom a number and locations of particulate deposits introduced during said first specific process step;
electrically testing semiconductor circuitry in a plurality of locations of said wafer subsequent to said first specific process step, and identifying locations of said wafer which contain faulty circuitry;
correlating the locations of particulate deposits introduced during said first specific process step to the locations of said wafer containing faulty circuitry subsequent to said first specific process step; and
determining, from said correlating, a first measure of reductions in yield of said manufacturing process caused by particulate deposits introduced during said first specific process step relative to other causes of reductions in yield.
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Accused Products
Abstract
A method for identifying those process steps which produce "high risk" particulate contamination that is most likely to produce defects. The die positions of particulate deposits on a wafer are measured prior to and subsequent to a specific process step, to determine the die positions of particulate deposits introduced during that specific process step. Then, subsequent electrical tests of the wafer are used to determine which locations on the wafer contain faulty circuitry. The locations of particulate deposits introduced during the specific process step are then correlated to the locations of faulty circuitry. The result is a measure of the extent to which particulate deposits introduced during the specific process step contribute to reductions in yield of the manufacturing process.
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Citations
14 Claims
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1. A method of identifying causes which reduce yield of a manufacturing process, said process producing wafers containing semiconductor circuitry and involving multiple processing steps including a first specific process step which potentially introduces particulate deposits on wafers, comprising the steps of:
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detecting a number and location of particulate deposits on a wafer prior to and subsequent to said first specific process step, and determining therefrom a number and locations of particulate deposits introduced during said first specific process step; electrically testing semiconductor circuitry in a plurality of locations of said wafer subsequent to said first specific process step, and identifying locations of said wafer which contain faulty circuitry; correlating the locations of particulate deposits introduced during said first specific process step to the locations of said wafer containing faulty circuitry subsequent to said first specific process step; and determining, from said correlating, a first measure of reductions in yield of said manufacturing process caused by particulate deposits introduced during said first specific process step relative to other causes of reductions in yield. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. Apparatus for of identifying causes which reduce yield of a manufacturing process, said process producing wafers containing semiconductor circuitry and involving multiple processing steps including a first specific process step which potentially introduces particulate deposits on wafers, comprising:
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circuitry determining, from a number and location of particulate deposits on a wafer prior to and subsequent to said first specific process step, a number and locations of particulate deposits introduced during said first specific process step; circuitry correlating the locations of particulate deposits introduced during said first specific process step to the locations of said wafer determined to contain faulty circuitry subsequent to said first specific process step; and circuitry determining, from said correlating, a first measure of reductions in yield caused by particulate deposits introduced during said first specific process step relative to other causes of reductions in yield. - View Dependent Claims (10, 11, 12, 13, 14)
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Specification