Surface science issues in plasma etching

Pattern transfer by plasma-based etching is one of several key processes re quired for fabricating silicon-based integrated circuits. We present a brie f review of elementary plasma-etching processes on surfaces and within inte grated-circuit microstructures-and an overview of recent work in our labora tory on plasma-etching aspects of the formation of self-aligned contacts to a polysilicon layer through a SiO2 layer and a SI3N4 etch-stop layer. The work illustrates the richness of associated surface science issues that mus t be understood and controlled in order to most effectively achieve plasma- based pattern transfer.