Method to calibrate the wafer transfer for oxide etcher (with clamp)
US6531326B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 20, 2001 |
| Grant date | Mar 11, 2003 |
| Priority date | — |
| Expiry date | Sep 20, 2021 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L22/34
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A method for calibrating the wafer transfer system by using an inspection control wafer after plasma etching is described. An inspection control wafer is provided comprising a polysilicon layer overlying an oxide layer on the surface of a semiconductor substrate wherein the polysilicon layer does not cover the oxide layer for a first distance from the edge of the wafer. The inspection control wafer is entered into the wafer transfer system wherein the wafer is transferred to a spin-on-glass etchback chamber wherein the wafer is held by clamps which extend a second distance from the edge of the wafer and wherein there is designed an overlap difference between the first and second distances. The wafer is subjected to a spin-on-glass etchback step and then inspected for damage to the oxide layer. Oxide layer damage occurs if the second distance is less than the first distance by more than the overlap difference. Oxide layer damage indicates the need to recalibrate the wafer transfer system.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.