REACTIVE ION ETCHING OF SILICON-CARBIDE (SIXC1-X)

The reactive ion etching of low pressure chemical vapour deposited SixC1-x layers (x = 0.5 and 0.8) on oxide covered Si(100) wafers has been investigated using in-situ ellipsometry, mass spectrometry and optical emission spectroscopy. Etch rates using SF6/O-2 and F-2/Ar/O-2 plasmas have been monitored and the conditions identified under which the etch rate of SiC relative to Si can be varied between approximate to 0.2 and approximate to 5 and SiC relative to SiO2 from approximate to 1 to approximate to 4. Etch products have been identified and an etch mechanism proposed that accounts for the observed variation in etch rates with percentage O-2 for SF6/O-2 plasmas.