Sputter coating collimator with integral reactive gas distribution

A sputtering apparatus comprising:

• a vacuum sputter coating chamber;
• means for holding a substrate in the chamber;
• means for supporting a sputtering target in the vacuum chamber with a sputtering surface thereof facing a substrate held on the holding means;
• means for producing a plasma in the space between the target and the substrate and for energizing ions in the plasma to bombard the target to dislodge coating material therefrom for propagation onto the substrate;
• a collimator interposed between the plasma and the substrate in the chamber, the collimator including a web structure physically occupying space between the target and the substrate, the web structure having openings therethrough and being dimensioned to restrict propagation paths of material sputtered from the target through the openings and onto the substrate;
• gas distribution passages carried by the collimator in the space physically occupied by the web structure or otherwise out of the propagation paths of the sputtered material, the passages including outlets distributed across the collimator for discharging gas from the passages toward the substrate;
• and
• means for supplying processing gas to the passages.

A method of reactive sputter coating a film onto three dimensional features of a semiconductor wafer having a central area and an outer rim, the method comprising the steps of:

• supporting a stepped semiconductor wafer in a vacuum sputter coating chamber;
• supporting a sputtering target in the vacuum chamber with a sputtering surface thereof facing the wafer;
• filling the chamber with a sputtering gas at a vacuum pressure level;
• producing a plasma of the sputtering gas in the space between the target and the wafer and bombarding the target with ions from the plasma to sputter coating material therefrom for propagation onto the wafer;
• disposing a collimator in the chamber between the plasma and the wafer, the collimator including a grid of vanes having a width extending in a direction from the target to the wafer to restrict propagation paths of the sputtered material onto the wafer;
• and
• supplying reactive gas through passages in the vanes and discharging the reactive gas from the passages in a region inward of the outer rim of the wafer.