REACTIVE ION ETCHING FOR SUBMICRON STRUCTURES OF REFRACTORY METAL SILICIDES AND POLYCIDES.

Reactive ion etching experiments have been conducted on sputter-deposited films of MoSi//2, CVD n** plus polysilicon, and thermal SiO//2 using admixtures of SF//6 with O//2. The influence of partial pressure and total pressure on profile control and etch selectivity has been determined. Highly anisotropic etching of n** plus polysilicon and MoSi//2 was obtained using a gas mixture of SF//6 plus 50% oxygen. Examples of 0. 2 mu anisotropically etched structures of silicides and n** plus polysilicon/silicide stacked films have ben realized using electron beam lithography and one step dry etching. Mechanisms of profile control involved in the SF//6/O//2 system are discussed. In addition, exploratory reactive ion etching studies using SiF//4/Cl//2 gas mixtures for these materials and TaSi//2 have been carried out.