Apparatus and methods for actively controlling RF peak-to-peak voltage in an inductively coupled plasma etching system
US6422173B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Sep 29, 2000 |
| Grant date | Jul 23, 2002 |
| Priority date | — |
| Expiry date | Nov 10, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J37/321
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An inductively coupled plasma etching apparatus includes a chamber and a window for sealing a top opening of the chamber. The window has an inner surface that is exposed to an internal region of the chamber. A metal plate, which acts as a Faraday shield, is disposed above and spaced apart from the window. A coil is disposed above and spaced apart from the metal plate. The coil is conductively connected to the metal plate at a connection location that is configured to generate a peak-to-peak voltage on the metal plate that optimally reduces sputtering of the inner surface of the window while substantially simultaneously preventing deposition of etch byproducts on the inner surface of the window. In another embodiment, the apparatus includes a controller for externally applying a peak-to-peak voltage to the metal plate. The controller includes an oscillation circuit, a matching circuit, an RF generator, and a feedback control for monitoring the applied peak-to-peak voltage. Methods for optimizing operation of an inductively coupled plasma etching apparatus also are described.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.