PLASMA-ASSISTED FORMATION OF LOW DEFECT DENSITY SIC-SIO2 INTERFACES

The initial stages of SiC-SiO2 interface formation by low temperature (300 degrees C) remote plasma assisted oxidation (RPAO) on flat and vi cinal 6H SiC(0001) wafers with Si faces have been studied by on-line A uger electron spectroscopy (AES). Changes in AES spectral features ass ociated with Si-C and Si-O bonds are readily evident as oxidation prog resses; however, there are no detectable AES features that can be attr ibuted to C-O bonds. Initial oxidation rates as determined from AES da ta are greater for vicinal wafers than for flat wafers paralleling res ults for RPAO oxidation of Si. Devices fabricated on vicinal SiC wafer s require an 1150 degrees C anneal in an H-2 containing ambient to red uce defect densities from the 10(13) to 10(11) cm(-2) range, consisten t with termination of C atom step edge dangling bonds by H atoms, Devi ces prepared by thermal oxidation also require a 1150 degrees C anneal in H-2 even though silicon oxycarbide regions with C-O bonds are form ed in a transition region at the SiC-SiO2 interfaces. (C) 1997 America n Vacuum Society.