Generation of ionized air for semiconductor chips
US5432670A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 13, 1993 |
| Grant date | Jul 11, 1995 |
| Priority date | — |
| Expiry date | Dec 13, 2013 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S438/909
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
Ionization of air without the use of corona discharge tips, thereby to avoid the generation of particulates from corrosion of the corona tips, is accomplished by use of a laser beam focussed to a small focal volume of intense electric field adjacent a semiconductor chip. The electric field is sufficiently intense to ionize air. In the manufacture of a semiconductor circuit chip, during those steps which are conducted in an air environment, opportunity exists to remove from a surface of a chip, or wafer, charge acquired during the manufacturing process. The ionized air is passed along the chip surface. Ions in the air discharge local regions of the chip surface which have become charged by steps of a manufacturing process. By way of further embodiment of the invention, the ionization may be produced by injection of molecules of water into the air, which molecules are subsequently ionized by a laser beam and directed toward the chip via a light shield with the aid of a magnetic field.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.