Process for dry lithographic etching
US5948570A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 26, 1995 |
| Grant date | Sep 7, 1999 |
| Priority date | — |
| Expiry date | May 26, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/32139
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
Patterning of a layer of material that can be etched with gaseous mixture of oxygen, chlorine, and nitrogen as etchant species, such as a chromium or a chromium-containing compound layer, is accomplished by using a patterned organometallic resist, such as a polymer which contains silicon or germanium. Although gaseous mixtures of chlorine and oxygen etch chromium anisotropically. Some undercut of the chromium is still observed. This undercut is controlled or eliminated by adding nitrogen to the gas mixture. Layers of material that have been patterned in this way can then be used for photolithographic masks or reticles, for X-ray masks, for e-beam masks. or for direct patterning of other, underlying layers in semiconductor integrated circuits or other devices.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.