Magnetically enhanced plasma oxide etch using hexafluorobutadiene
US6613689B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 13, 2002 |
| Grant date | Sep 2, 2003 |
| Priority date | — |
| Expiry date | May 13, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/76802
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
An oxide etch process practiced in a plasma etch reactor, such as a magnetically enhanced reactive ion etch (MERIE) reactor. The etching gas includes approximately equal amounts of a hydrogen-free fluorocarbon, most preferably C4F6, and oxygen and a much larger amount of argon diluent gas. The magnetic field is preferably maintained above about 50 gauss and the pressure at 40 milliTorr or above with chamber residence times of less than 70 milliseconds. A two-step process may be used for etching holes with very high aspect ratios. In the second step, the magnetic filed and the oxygen flow are reduced. Other fluorocarbons may be substituted which have F/C ratios of less than 2 and more preferably no more than 1.6 or 1.5.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.