The influence of the target material on sputter etching processes

The presence of reactive gases as contaminants of the gas atmosphere in a sputter etching machine can cause a strong increase in the etch rate of commonly used photoresist masks. When an appropriate part of the target material has a high getter efficiency, the partial pressure of reactive gases can be markedly reduced. The influence of a copper and of a titanium target on the partial pressure of oxygen in a sputter etching equipment has been investigated. The use of a titanium target results in a drastic decrease in the etch rate of photoresist masks at oxygen pressures in the range 10-6-10-4 Torr.