Apparatus for the coating of material on a substrate using a microwave or UHF plasma

In a plasma generating apparatus for coating a substrate with a material from a plasma including a plasma source employing a radiofrequency, including UHF or microwave, wave coupler means which is metallic and in the shape of a hollow cavity and which is excited in a TM mode of resonance and optionally including a static magnetic field around the plasma which aids in coupling radiofrequency energy at electron cyclotron resonance and aids in confining ions in the plasma in an electrically insulated chamber means in the coupler means, and wherein the chamber means has a central longitudinal axis in common with the coupler means and is mounted in closely spaced and sealed relationship to an area of the coupler means with an opening from the chamber means at one end;

• gas supply means for providing a gas which is ionized to form the plasma in the chamber means, wherein the radiofrequency wave applied to the coupler means creates and maintains the plasma around the central longitudinal axis in the chamber means;
• movable metal plate means in the cavity mounted in the coupler means perpendicular to the central longitudinal axis and movable along the central longitudinal axis towards and away from the chamber means;
• and a movable probe means connected to and extending inside the coupler means for coupling the radiofrequency waves to the coupler means, the improvements which comprises:
• (a) the probe means which is elongate and is mounted in the coupler means along the central longitudinal axis of the chamber means and coupler means, with an end of the probe in spaced relationship to the chamber means;
• (b) the plate means having an opening along the central longitudinal axis of the chamber means, wherein the plate means supports the probe means so that the probe means can be moved in the opening in the plate means along the central longitudinal axis;
• (c) stage means which forms part of the cavity and provides for mounting a substrate to be coated with the material, the stage means having a support surface which is in a plane substantially perpendicular to and around the longitudinal axis and which is movable towards and away from the plasma in the chamber means so that the substrate can be coated with the material from the plasma;
• (d) support means for the probe means mounted on the coupler means and including an adjustable means which allows movement of the probe means along the central longitudinal axis of the chamber means so as to vary the spacing between the chamber means and the end of the probe means;
• and
• (e) holder means adjustably mounted on the support means and connected to the plate means supporting the probe means so as to allow the plate means to be moved towards and away from the chamber means, wherein movement of the plate means and the probe means in the coupler means achieves a selected TM mode of resonance by iterative movement that adjusts the reflected power to a low level of the radiofrequency wave in the chamber means.