Etching method of silicon wafer surface and etching apparatus of the same
US5916824A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 30, 1996 |
| Grant date | Jun 29, 1999 |
| Priority date | — |
| Expiry date | May 30, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/30604
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A silicon wafer is held in an airtight chamber by a silicon wafer holder. The silicon wafer holder is cooled by a cooler. High purity nitric acid is stored in a storage container disposed in the airtight container. The storage container is heated by a heater, thereby producing nitric acid gas. The nitric acid gas is condensed on the surface of the silicon wafer so that a thin film is formed. Thus, the surface of the silicon wafer is rendered hydrophilic. Thereafter, high purity hydrofluoric acid is dropped on high purity nitric acid in the storage container by an acid dropper, thereby producing hydrofluoric acid gas. By introducing the hydrofluoric acid gas into the thin film formed on the surface of the silicon wafer, an etching is performed while maintaining the surface of the silicon wafer in a good condition.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.