Method of wafer marking for multi-layer metal processes
US6743694B2 · kind B2 · utility
6Cited by
5References
25Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Apr 30, 2002 |
| Grant date | Jun 1, 2004 |
| Priority date | — |
| Expiry date | Jul 21, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L2924/0002
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A new method of forming a laser mark without damage to the wafer surface is described. A pad oxide layer is formed on a silicon wafer. A nitride layer is deposited overlying the pad oxide layer. A first trench is laser cut through the nitride layer and the pad oxide layer into the silicon wafer. The trench is etched to a second depth wherein the nitride layer is used as a hard mask and wherein the trench forms an identification mark.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.