Low-Temperature Formation of Gate-Si02 Films for Poly-Si TFTs by 02-Ar Sputtering.

High-quality gate-oxide films for poly-Si TFTs are obtained successfully by oxygen-argon sputter deposition at low temperature (200°C). Si02 films deposited in an oxygen-argon mixture on poly-Si have higher resistivities and breakdown fields than those deposited only in argon and thermal oxides grown on poly-Si, resulting in the same film characteristics as thermal oxides grown on single-Si. Moreover, poly-Si TFF mobilities are improved considerably by mixing oxygen, resulting in very high mobility of 383 cm²/V s. This high mobility is caused by reduction in Si02/Si interface states and in barrier heights at the poly-Si grain boundaries in addition to the improvement of poly-Si films. These characteristic improvements result from migration enhancement of sputtering particles on film surface and the reduction of plasma damage by oxygen mixture. These results confirm the usefulness of gateoxide films sputter-deposited in an oxygen-argon mixture for low-temperature fabrication of high-quality poly-Si TFTs. [ABSTRACT FROM AUTHOR]