REACTIVE ION ETCHING IN SF6 GAS-MIXTURES

Reactive ion etching of crystalline silicon, polysilicon, SiO//2, and Si//3N//4 has been studied in a parallel plate electrode configuration, with and without magnetic confinement, in SF//6 gas diluted with varying proportions of O//2, N//2, H//2, and Ar. Experimental results indicate the following: (i) significant contamination occurs on the etched surface with the aluminum covered cathode, but no detectable contamination occurs with the quartz plate covered cathode, (ii) there are etch rate maxima both for silicon and polysilicon with O//2 dilution in the range 10-20 volume percent for aluminum covered cathode; these maxima are more pronounced at higher power levels.