System and method for finding defective tools in a semiconductor fabrication facility
US6701204B1 · kind B1 · utility
Assignees
Inventor
Key dates
| Filing date | May 22, 2000 |
| Grant date | Mar 2, 2004 |
| Priority date | — |
| Expiry date | May 22, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L22/20
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A system and method for finding a defective tool in a semiconductor fabrication facility is disclosed. When the tools process the wafers, data representing the time period during which each wafer passes through each tool is sent to a database. The wafers are tested for defects, and lots having wafers with common failure signatures are determined. A lot list for each tool is generated, a positive weight value is assigned to each bad lot, and a negative weight value is assigned to each good lot. A cumulative value is calculated for each tool by sequentially adding the weight values of each lot in the lot list and keeping the cumulative value above or equal to zero. The tool with the largest maximum cumulative value is the tool that is most likely to be defective.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.