Method for electrochemical etching of semiconductor material using positive potential dissolution (PPD) in solutions free from hydrogen fluoride (HF)
US7494936B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 16, 2005 |
| Grant date | Feb 24, 2009 |
| Priority date | — |
| Expiry date | Oct 29, 2025 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/3063
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
A method for electrochemical etching of a semiconductor material using positive potential dissolution (PPD) in solutions that do not contain hydrofluoric acid (HF-free solutions). The method includes immersing an as-cut semiconductor material in an etching solution, and positive biasing at atypically highly positive (anodic) potentials, thereby significantly increasing the value of the anodic current density (measured as A/cm2) of the semiconductor material. The application of positive biasing at atypically highly positive (anodic) potentials, is combined with specifically controlling and directing illumination on the semiconductor material surface contacted and wetted by the etching solution. This is done for a necessary and sufficient period of time to enable a positive synergistic effect on the rate and extent of etching of the semiconductor material therefrom.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.