System and method for selectively modifying a wet etch rate in a large area
US7172973B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 2, 2004 |
| Grant date | Feb 6, 2007 |
| Priority date | — |
| Expiry date | Mar 20, 2025 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/3083
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A system and method is disclosed for selectively increasing a wet etch rate of a large raised area portion of a semiconductor wafer with respect to a wet etch rate of a small raised area portion of the semiconductor wafer. A resist mask on the semiconductor wafer is etched to create a large via over the large raised area portion and a small via over the small raised area portion. An ion implantation beam is applied with an impact direction that enables ions to pass through the large via but does not enable ions to pass through the small via. The ions that pass through the large via increase the wet etch rate of the underlying portion of the semiconductor wafer. In one embodiment the impact direction has a tilt angle of forty five degrees and a rotation angle of forty five degrees.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.