Redeposition: a factor in ion-beam etching topography

Abstract

The design of high performance SAW resonators and reflection pulse compression filters using grooves as the reflective arrays requires that the profiles of the grooves be rectangular and reproducible. The use of neutralized ion-beam technology has largely been adopted for etching these grooves in quartz and lithium niobate because of the precision and control which can be exercised in its use. The experimental work presented here asserts the major contribution that redeposition makes in the evolution of ion-beam etched topography of amorphous, polycrystalline and crystalline materials in a way which is directly useful to the determination of groove profiles. Data are also presented on the relationship between the incidence angle of the ion beam and the etch rate of some important SAW materials indicating the connection between this function and the etching characteristics of the materials.