Patent ID: 8303834
Filing Date: 2012-11-06
Classification: H01J

Abstract:
1. A plasma etching method for performing an etching process on a Si-containing insulating film by using a plasma processing apparatus including a vacuum evacuable processing chamber; a lower electrode for mounting a substrate thereon in the processing chamber; an inner upper electrode provided in the processing chamber to face the lower electrode; an outer upper electrode provided in a ring shape at a radially outside of the inner upper electrode in the processing chamber and electrically isolated from the inner upper electrode; a processing gas supply unit for supplying a processing gas into a processing space between the inner and the outer upper electrode and the lower electrode; a radio frequency (RF) power supply unit for applying an RF power to the lower electrode or the inner and the outer upper electrode to generate a plasma of the processing gas by RF discharge; a first DC power supply unit for applying a first variable DC voltage to the inner upper electrode; and a second DC power supply unit for applying a second variable DC voltage to the outer upper electrode, the plasma etching method comprising: controlling an etching rate distribution characteristic across a surface of the substrate by varying the second variable DC voltage on the outer upper electrode, while fixing the first variable DC voltage on the inner upper electrode to a specific value, wherein both of the first and the second variable DC voltage are not greater than 0V, and the magnitude of the second variable DC voltage is equal to or greater than the magnitude of the first variable DC voltage.