Inventors:
Padmapani Nallan - San Jose CA
John Holland - San Jose CA
Valentin Todorov - Fremont CA
Thorsten Lill - Sunnyvale CA
Assignee:
Applied Materials, Inc. - Santa Clara CA
International Classification:
H01L 21302
US Classification:
438706, 438710, 438720, 156345
Abstract:
In accordance with the present invention, process parameters are controlled to provide a stable etch plasma. We have discovered that it is possible to operate a stable plasma with a portion of the power deposited to the plasma being a capacitive contribution and a portion of the power deposited being an inductive contribution. In particular, a stable plasma may be obtained within two process regions. In the first region, the gradient of the capacitive power to the power applied to the inductively coupled source for plasma generation [âP /âP ] is greater than 0. In the second region, plasma stability is controlled so that [âP /âP ] is less than 0 and so that P P. Typically, the magnitude of P is less than about 10% of the magnitude of P. In addition, in a plasma processing apparatus having a dual power control, at a given application of power to the plasma generation source, the stability of the plasma is extended by increasing the pressure in the etch process chamber. This enables operation of the etch process using lower power application for plasma generation.