Method for etching a quartz layer in a photoresistless semiconductor mask
US6969568B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 28, 2004 |
| Grant date | Nov 29, 2005 |
| Priority date | — |
| Expiry date | Mar 14, 2024 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/31116
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A chromeless phase lithography mask (30) that does not require photoresist to manufacture has a quartz substrate (32) is etched by using a plasma (38) containing one of a nitrogen augmented hydro-fluorocarbon oxygen mixture and a nitrogen augmented fluorocarbon oxygen mixture. Various hydro-fluorocarbons or fluorocarbons may be used. The nitrogen addition results in etched openings in the quartz substrate that have substantially vertical sidewalls in a uniform manner across the substrate. Surface roughness is minimized and edges of the openings are well-defined with minimal rounding. The etch rate is rendered controllable by reducing bias power without degrading a desired vertical sidewall profile.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.