摘要 |
An inductively coupled plasma etching apparatus includes a chamber (100) and a window (10) for sealing a top opening of the chamber. The window (10) has an inner surface that is exposed to an internal region of the chamber (100). A metal plate (217), which acts as a Faraday shield, is disposed above and spaced apart from the window (10). A coil (117) is disposed above and spaced apart from the metal plate (217). The coil (117) is conductively connected to the metal plate (217) at a connection location (see connector 207) 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 (10) 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 (217). 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. |