Processes for monitoring the levels of oxygen and/or nitrogen species in a substantially oxygen and nitrogen-free plasma ashing process
US7381651B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 22, 2006 |
| Grant date | Jun 3, 2008 |
| Priority date | — |
| Expiry date | Mar 22, 2026 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/31138
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Processes for monitoring the levels of oxygen and/or nitrogen in a substantially oxygen and nitrogen-free plasma ashing process generally includes monitoring the plasma using optical emission. An effect produced by the low levels of oxygen and/or nitrogen species present on other species generally abundant in the plasma is monitored and correlated to amounts of oxygen and nitrogen present in the plasma. This so-called “effect detection” process monitors perturbations in the spectra specifically associated with species other than nitrogen and/or oxygen due to the presence of trace amounts of oxygen and/or nitrogen species and is used to quantitatively determine the amount of oxygen and/or nitrogen at a sensitivity on the order of 1 part per million and potentially 1 part per billion.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.