DEPOSITION APPARATUS AND METHOD

摘要

An asymmetric alternating voltage (preferably 40 KHz) is provided between a pair of targets having a coaxial (preferably frusto-conical) relationship to (1) deposit the material in a uniform thickness on the substrate surface (2) eliminate dielectric material from the surfaces of the targets and other components (3) provide a single ignition of the targets and eliminate target ignitions thereafter and (4) reduce the substrate temperature by using low energy ("cold") electrons from a plasma discharge to produce a low energy current. The asymmetry may result from amplitude differences between the voltage in alternate half cycles and the voltage in the other half cycles. A second alternating voltage (preferably radio frequency) modulates the asymmetric alternating voltage to provide the smooth plasma ignition. The different voltage amplitudes applied to each of the targets are also instrumental in providing for a substantially constant deposition thickness at the different positions on the surface of the substrate.