PHOSPHORUS AND NITROGEN DOPING INTO POLYCRYSTALLINE SIC FILMS PREPARED BY PLASMA-ENHANCED CHEMICAL VAPOR-DEPOSITION AT 700 DEGREES-C

Doped polycrystalline SiC films were deposited from a SiH4-CH4-H-2-(PH3 or N2) mixture by plasma-enhanced chemical vapor deposition at 700-degrees-C. The best crystallinity was obtained at x approximately 0.53 in Si1-xCx for both undoped and doped films. The crystallinity was enhanced by both P and N doping, but deteriorated again under high doping conditions. Also, better crystallinity was obtained by doping with P rather than N. Intrinsic tensile and compressive stresses were observed for P- and N-doped films, respectively. The resistivity and dangling-bond density decreased in correspondence to the enhancement in crystallinity. Origins of the dangling bonds and of a change in the crystallinity were discussed.