Wafer rotation randomization in cluster tool processing
US6662070B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 8, 2000 |
| Grant date | Dec 9, 2003 |
| Priority date | — |
| Expiry date | Mar 8, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/67259
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
The detection of a processing deviation in a cluster tool of a wafer processing system is achieved by assigning individual wafers a set of positional coordinates each time the wafer moves within the cluster tool. In an example embodiment, a wafer is placed into a first chamber of the cluster tool and it is rotated to a certain angle of rotation. Each time the wafer moves within the cluster tool 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 wafer exits the cluster tool and is examined for structural or surface defects that indicate that there was a variation in the processing parameters. A wafer movement map is developed from the positional coordinates and the map is then used as an analysis tool to identify the processing location that caused defect to occur. An important advantage is the increased control and traceability that the tracking method brings to single wafer handling and processing.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.