| Abstract: | A fabrication process employing the use of ScAlN as an etch mask is
disclosed. The ScAlN etch mask is chemically nonvolatile in
fluorine-based etch chemistries and has a low sputter yield, resulting in
greater etch mask selectivity and reduced surface roughness for silicon
and other semiconductor materials. The ScAlN etch mask has an etch mask
selectivity of greater than 200,000:1 relative to silicon compared to an
etch mask selectivity of less than 40,000:1 for a prior art AlN etch mask
relative to silicon. Further, due to reduced sputtering of the ScAlN etch
mask, and thus reduced micromasking, the ScAlN etch mask yielded a
surface roughness of 0.6 .mu.m compared to a surface roughness of 2.8
.mu.m for an AlN etch mask. |