Simplified process for the fabrication of deep clear laser marks using a photoresist mask
US6063695A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 16, 1998 |
| Grant date | May 16, 2000 |
| Priority date | — |
| Expiry date | Nov 16, 2018 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S438/94
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A process for the formation of deep clear laser marks on silicon wafers is described. Tall ridges of material which is erupted from the wafer surface during the deep laser penetration form adjacent to the marks. These ridges are of the order of 3 to 15 microns in height and must be removed prior to subsequent wafer processing to avoid fragmentation causing scratches and particulate contamination. The process of the invention deposits a non-conformal layer of photoresist or other flowable material on the wafer. The peaks of the ridges protrude above the surface of the conformal layer be a significant amount and are then etched away using an aqueous silicon etch. The non-conformal layer protects the wafer surface from the silicon etch so that only the ridges are removed. After the ridges are etched, the non-conformal layer is removed leaving residual ridges of a height less than or equal to the thickness of the conformal layer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.