MKS Instruments, Inc.
Apparatus and Method for Controlling Ion Energy Distribution in Process Plasmas

Abstract:

Multiple harmonic frequency components are used for plasma excitation in a plasma process. Relative amplitude and/or phase shift between the different frequency components is controlled so as to provide desired ion energy plasma properties. The relative amplitude and/or phase shift may be controlled without direct and/or manual ion energy measurements. Rather, the ion energy within the plasma may be dynamically controlled by monitoring one or more electrical characteristics within the plasma apparatus, such as for example, impedance levels, electrical signals in the radio frequency (RF) generator, electrical signals in a the matching networks, and electrical signals in other circuits of the plasma processing apparatus. The monitoring and control of the ion energy may be accomplished dynamically during the plasma process so as to maintain a desired ion energy distribution.