System and method for controlling an etch process for a single crystal having a buried layer
US8007675B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 11, 2005 |
| Grant date | Aug 30, 2011 |
| Priority date | — |
| Expiry date | Jul 20, 2026 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L22/12
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A system and method is disclosed that terminates an etch process of a semiconductor crystal material at a precisely located depth. The semiconductor crystal is made of a first material and has a buried layer of a second material that is stoichiometrically different than the first material. The buried layer is located at a depth in the first material at which it is desired to terminate the etch process. During the etch process an optical emission spectrum of the first material is monitored. The intensity of the spectrum decreases when the etch process reaches the second material of the buried layer. The etch process is terminated when the decrease in spectrum intensity is detected.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.