DEPOSITION OF HIGH QUALITY AMORPHOUS SILICON FILMS WITH STRONG HYDROGEN DILUTED SILANE AS REACTANT GAS SOURCE

By using strongly hydrogen diluted silane as a reactant gas source C(=SiH₄/(SiH₄+H₂))<5% in a conventional diode PECVD system, we have deposited high quality a-Si:H films which exhibit almost no Steable-Wronski (S-W) effect, The H radical in rf plasma erodes the growing surface and eliminates the weak Si-Si bonds, thus re-ducing the density of metastable defects of a-Si:H films and causing the amorphous network to be more perfect. Our results show that as C value decreases from 5.4 % to 0.8 %, the peak location of TO mode in Raman spectra changes from 480 to 500 cm^-1, the average distortion of bond angles \Delta\theta, which is calculated from the width of half full height of TO peaks, reduces from 9.0° to 3.8°. The hydrogen content C_H of the samples which show almost no S-W effect is less than 10at%.