Method and apparatus for process control in time division multiplexed (TDM) etch process
US7115520B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 31, 2004 |
| Grant date | Oct 3, 2006 |
| Priority date | — |
| Expiry date | Oct 16, 2024 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T137/2544
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The present invention provides a method for controlling pressure in a vacuum chamber during a time division multiplexed process. A throttle valve is pre-positioned and held for a predetermined period of time. A process gas is introduced into the vacuum chamber during the associated plasma step (deposition or etching) of the silicon wafer. At the end of the predetermined period of time, the process gas continues to flow with the throttle valve being released from the set position. At this point, the throttle valve is regulated through a proportional derivative and integral control for a period that lasts the remaining time of the associated plasma step.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.