Mark protection with transparent film
US6207966A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 4, 1998 |
| Grant date | Mar 27, 2001 |
| Priority date | — |
| Expiry date | Dec 4, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L2924/0002
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
An alignment mark protection structure (95) is disclosed which is used to ensure an integrity of an alignment scheme for a substrate (50) which is to be subjected to lithographic processing. The alignment mark protection structure (95) comprises the substrate (50) and an alignment mark (52) associated with the substrate (50). The alignment mark (52) reflects an alignment light (208) which is then used to determine an optimum alignment between the substrate (50) and a lithographic mask (214). A cap (100) overlies the alignment mark (52) and is substantially transparent with respect to the alignment light (208). The cap (100) protects the underlying alignment mark (52) from lithographic process-induced damage during processing and thus reduces alignment light noise, thereby improving the alignment between a mask (214) and the substrate (50) and minimizing the registration error associated with overlying layers formed on the substrate (50).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.