Post-lapping cleaning process for silicon wafers
US5837662A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 12, 1997 |
| Grant date | Nov 17, 1998 |
| Priority date | — |
| Expiry date | Dec 12, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/67057
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A process for cleaning contaminants from the surface of a semiconductor wafer after the wafer has been lapped. The process comprises contacting the wafer with an oxidizing agent to oxidize organic contaminants which may be present on the surface of the wafer. The wafer is then immersed in an aqueous bath comprising citric acid into which sonic energy is being directed to remove metallic contaminants which may be present on the surface of the wafer. After being immersed in the citric acid bath, the wafer is contacted with hydrofluoric acid to remove a layer of silicon dioxide which may be present on the surface of the wafer. The wafer is then immersed in an aqueous bath comprising an alkaline component and a surfactant, and into which sonic energy is being directed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.