INFLUENCE OF BORON DOPING AND HYDROGEN DILUTION ON P-TYPE MICROCRYSTALLINE SILICON-CARBIDE THIN-FILMS PREPARED BY PHOTOCHEMICAL VAPOR-DEPOSITION

Boron doped mu c-SiC:H films have been prepared by low power (10 mW/cm(2)) photochemical vapor decomposition of SiH4, C2H2, and B2H6 gases diluted with hydrogen. The effect of boron doping and hydrogen dilution on structural and opto-electronic properties have been studied. The microstructure,consists of Si crystallites while carbon remains at the grain boundaries and amorphous parts. Diborane doping beyond an optimum value has been observed to deteriorate the formation of microcrystallites. By optimizing the process parameters, p-type mu c-SiC:H having sigma d similar to 3.0X10(-3) S cm(-1) with an E(04) of 2.34 eV has been obtained. This film exhibits high optical transmittivity compared to its amorphous counterpart. (C) 1995 American Institute of Physics.