Wafer flattening system
US6360687B1 · kind B1 · utility
Assignees
Inventors
Key dates
| Filing date | Oct 4, 1999 |
| Grant date | Mar 26, 2002 |
| Priority date | — |
| Expiry date | Oct 4, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/30625
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A wafer flattening system is provided to consecutively and automatically remove the natural oxide film from a wafer and flatten and smooth the wafer so as to improve the surface roughness of the wafer and improve the work efficiency. A step of immersing the wafer in an aqueous solution of hydrofluoric acid of a natural oxide film removing device is performed so as to remove the natural oxide film, then followed by a step of locally etching the surface of the wafer at a local etching apparatus by an activated species gas produced from SF6 gas to flatten the surface. Then, a step of giving a mirror finish to the wafer surface by a CMP apparatus is performed to smooth it. It is also possible to perform the step of removal of the natural oxide film by spraying the entire surface of the wafer by an activated species gas produced from a mixed gas of CF4 gas and H2 gas and possible to perform the step of smoothing by spraying the entire surface of the wafer by an activated species gas produced from a mixed gas of CF4 gas and O2 gas.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.