Advanced processing technique and system for preserving tungsten in a device structure
US8093157B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 3, 2007 |
| Grant date | Jan 10, 2012 |
| Priority date | — |
| Expiry date | Apr 12, 2029 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J2237/3342
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
Removing photoresist from a workpiece is described when a region of tungsten is exposed. A plasma is generated from a gas input consisting essentially of hydrogen gas and oxygen gas in a predetermined ratio. The plasma causes the photoresist to be removed from the workpiece while the region of tungsten is left substantially unmodified. The ratio of the hydrogen to oxygen can be adjusted to a particular value which causes the photoresist to be removed at about a maximum removal rate that corresponds to a minimum tungsten loss rate of about zero. Polysilicon oxidation in the presence of tungsten is described with little or no tungsten loss.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.