Method and apparatus for radiation assisted electrochemical etching and etched product
US6790340B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 11, 2001 |
| Grant date | Sep 14, 2004 |
| Priority date | — |
| Expiry date | Dec 11, 2021 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC25F3/12
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
An electrochemical etching system has an etching bath for holding an n-type silicon substrate with a first surface of the substrate in contact with hydrofluoric acid, an electrode positioned in the hydrofluoric acid, a power source having a positive pole connected to the silicon substrate and a negative pole connected to the electrode, and an illumination unit having a light source for illumination of a second surface of the silicon substrate. The illumination unit illuminates the second surface of the silicon substrate with an illumination intensity of 10 m W/cm2 or more. A ratio of a maximum illumination to a minimum illumination of the second surface of the silicon substrate is 1.69:1 or less. With the etching system, pores and/or trenches of a certain size and shape can be formed in an entire area of the silicon substrate having a diameter of more than three inches.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.