Phosphorus and nitrogen doping into polycrystalline SiC films prepared by plasma-enhanced chemical vapor deposition at 700 °C

Doped polycrystalline SiC films were deposited from a SiH₄-CH₄-H₂-(PH₃ or N₂) mixture by plasma-enhanced chemical vapor deposition at 700 °C. The best crystallinity was obtained at x∼0.53 in Si_1-xC_x 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.