Stationary aperture plate for reactive sputter deposition

A reactive sputter deposition apparatus for reactively depositing a uniform film and reducing the formation of a reactive film layer on the surface of the sputter target including an evacuatable chamber, the apparatus further comprising:

• a mount for holding a sputter target within the evacuatable chamber;
• an electrical system for electrically biasing the sputter target;
• a gas introduction system for introducing an ionizable gas into the chamber proximate to the sputter target;
• an ionizing system for ionizing the gas into a plasma containing ionized particles having an electrical charge opposite in polarity to the biased sputter target so that the ionized particles are attracted away from the plasma to bombard the target and sputter particles from the target at a first rate;
• a substrate mount for holding a substrate generally opposite the sputter target so that sputtered particles deposit upon a surface of the substrate to form a film;
• a reactive gas introduction system for introducing a reactive gas proximate to the substrate surface to chemically react with the sputter particles which deposit upon the substrate surface and thereby form a reaction product film on the substrate surface;
• an aperture plate situated between the target and the substrate, the plate having a plurality of apertures with low aspect ratios in the range of 0.05 to 0.5 formed therein so as to be substantially non-collimating, the apertures having associated cross-sectional areas and depth dimensions and configured to intercept a percentage of the sputter particles and to allow other particles to pass through the plate and deposit on the substrate at a second rate which is lower than the first rate by an amount sufficient to allow the reactive deposition reaction to occur at the substrate but not lower by more than approximately 75%, the plate being spaced from said substrate to virtually eliminate any sharp delineation of the aperture pattern onto the substrate surface, the first and second rates being maintained by the plate such that the target is sputtered away at a rate sufficiently high to reduce the formation of a reactive layer on the target, but the deposited particles are deposited upon the substrate at a rate sufficiently low to achieve a desired reaction between the sputter particles and the reactive gas at the substrate surface;
• and
• the plate having various regions, and the apertures in one region having aspect ratios different than aspect ratios of apertures in another region to vary the deposition rates between the regions relative to a non-uniform sputtering rate and produce a more uniformly deposited film on the substrate;
• whereby a desired uniform film is formed on the substrate while the formation of an undesired reactant film on the target is reduced.