Fabrication of P-channel MOS TFT's on rapid thermal CVD polycrystalline silicon-germanium films

Abstract

P-channel metal-oxide-semiconductor (PMOS) thin-film transistors (TFT's) have been fabricated on rapid thermal chemical vapor deposition (RTCVD) polycrystalline silicon-germanium (poly-Si0.82Ge0.18) films for the first time. The transistors with a channel length of 1.5 mu m exhibit good electrical characteristics. The device performance is degraded in proportion to oxygen content, based on measurements using secondary ion mass spectrometry (SIMS). After electron cyclotron resonance (ECR) plasma hydrogenation under optimal conditions, the density of trap states is markedly decreased in short-channel devices, resulting in relatively low leakage current (similar to 12.1pA/mu m) and high field-effect hole mobility (similar to 13.4cm(2)/V . s).