Cleaning system and method
US5770000A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 28, 1996 |
| Grant date | Jun 23, 1998 |
| Priority date | — |
| Expiry date | May 28, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/67028
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
An improved cleaning system is provided for removing impurities from a material to be cleaned. The system includes two electrodes, a positive electrode ("anode") on one side, near to or in contact with the material to be cleaned, and a negative collector electrode ("cathode") located at a distance from the second side of the material. The material and the two electrodes are placed into a chamber. The system also includes a medium of conductivity which, when under voltage between anode and cathode, produces the flow of negative charge either as electrons or as negative ions. The chamber may be a vacuum chamber or a chamber filled with an inert gas or other electro-negative gases. The flow of negative charges provides layer of negative charge near the second surface of the material so as to induce the positive impurity ions to move towards the surface. Since a grid electrode is absent, the impure ions are removed unhindered from the material to be cleaned.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.