Method of chemical vapor deposition in a vacuum plasma processor responsive to a pulsed microwave source

摘要

A dielectric layer is deposited on a workpiece by a chemical vapor deposition method in an electron cyclotron resonance vacuum plasma processor having a plasma chamber responsive to a repetitively pulsed microwave field and gases from a plasma source. A reaction chamber responds to at least one reacting gas containing at least one element that chemically reacts in the presence of the plasma with at least one element in at least one of the gases from the plasma source to form the deposited layer on the workpiece. The turn off periods are long enough to cause electrons in the plasma on the deposited dielectric layer to be cooled sufficiently (from about 3.5 eV to a lower value having a minimum value of about 0.1 eV) to reduce the tendencies for opposite polarity charges to be established across the deposited dielectric layer and for damaging discharge current to flow across the deposited dielectric layer. The layer is deposited in a gap having an initial aspect ratio of at least about 1:1; the turn on and turn off times are such as to cause the gap to be bridged by a different deposited film each time the microwave energy is turned on. The films build up to form a layer. The turn off time is greatest during initial deposition of the layer and becomes zero as the gap is filled. The peak power per pulse and the time between pulses are controlled.