Wafer rotation randomization for process defect detection in semiconductor fabrication
US6625556B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 8, 2000 |
| Grant date | Sep 23, 2003 |
| Priority date | — |
| Expiry date | Mar 8, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L22/20
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
The detection of a processing deviation in a multiple stage wafer processing system is achieved by assigning individual wafers a set of positional coordinates each time the wafer moves within the wafer processing system. In an example embodiment, a wafer is placed into a first processing stage and it is rotated to a certain angle of rotation. As the wafer moves from one processing stage to another the wafer is given a different angle of rotation; both the rotation angle and the wafer location are then recorded as a set of positional coordinates. The processed wafer is examined for surface deviations arising from variations in the processing parameters. The positional coordinates are used to develop a wafer movement map that aids in identifying the processing stage location where the deviation in the processing parameters occurred. An important advantage is the increased processing deviation traceability that the method brings to wafer processing.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.