Process-property relationships of SiC chemical vapor deposition in the Si/H/C/O system

A comprehensive thermodynamic analysis has been performed for the Si/H/C/O system from which a priori process-property relationships of the chemical v apor deposition (CVD) of silicon carbide (SiC) are obtained. The parameter space for pure silicon carbide growth is reported for five orders of magnit ude of the system water vapor level (1 ppb-100 ppm), four orders of magnitu de of system pressure (0.1-760 Torr), and two orders of magnitude of C/Si F eed ratio (0.25-20) and H-2/Si feed ratio (50-10,000). Lower growth tempera tures for pure SIC are predicted in clean systems with low system water vap or levels, at stoichiometric to near carbon excess conditions (C/Si congrue nt to 1 to C/Si > 1). at high carrier gas flow rates (large H-2/Si feed rat ios), and at low operating pressures. Because relative C/Si and H-2/Si feed ratios have been considered, the predictions in this study are applicable to both multiple and single precursor systems. Further, these results are v alid for the CVD of alpha-SiC as well as beta-SiC. Experimental data report ed on the growth of alpha-SiC and beta-SiC are found to be in satisfactory agreement with our theoretical predictions, for numerous systems that inclu de multiple and single source, silicon and carbon, species. (C) 1999 The El ectrochemical Society. S0013-4651(98)11-042-X. All rights reserved.