Post thermal annealing crystallization and reactive ion etching of SiC films produced by PECVD

Abstract

Crystallization of a-SiC:H films obtained by PECVD technique at low temperatures and results on corrosion by reactive ion etching (RIE) of these films are presented. The crystallization process was characterized by FTIR and XRD analysis; these results show evidences of crystallization with the formation of cubic SiC polycrystals (3C–SiC). The optimized RIE parameters for as-deposited a-SiC:H films indicates a maximum etch rate for 60% O2 in the gas mixture. With this condition the etch rate increases linearly with the rf power. Increasing process pressures leads to a monotonic etch rate increase, remaining nearly constant at a maximum value of 125nm/min for pressures in the 200–300mTorr range. For the annealed films a strong influence of the degree of crystallinity on the etch rate is observed approaching values similar to those reported for 3C–SiC plasma etching.