Title :
Silane and germane plasma diagnostics for depositing photosensitive a-SiGe:H films
Author :
Shing, Y.H. ; Perry, J.W. ; Allevato, C.E.
Author_Institution :
Jet Propulstion Lab., California Inst. of Technol., Pasadena, CA, USA
Abstract :
Highly photosensitive a-SiGe:H films with a light-to-dark conductivity ratio of 8*103 and an optical bandgap of 1.40 eV have been produced by RF glow discharge using hydrogen dilution of SiH4 and GeH4 mixed gas plasma. The critical role of hydrogen dilution in GeH4 containing plasmas is to suppress the gas-phase polymerization and promote the incorporation of Ge into the film. It is observed that inelastic laser light scattering of the RF plasma is a sensitive method for monitoring the onset of the gas-phase polymerization. In situ coherent anti-Stokes Raman spectroscopy measurements have shown that the dissociation rate of GeH4 is a factor of three larger than that of SiH4.
Keywords :
Ge-Si alloys; amorphous semiconductors; glow discharges; high-frequency discharges; hydrogen; plasma CVD coatings; plasma diagnostics; polymerisation; semiconductor materials; solar cells; 1.4 eV; RF glow discharge; amorphous SiGe:H solar cells; coherent anti-Stokes Raman spectroscopy measurements; gas-phase polymerization; inelastic laser light scattering; light-to-dark conductivity ratio; optical bandgap; Conductive films; Conductivity; Hydrogen; Optical films; Optical scattering; Optical sensors; Plasma diagnostics; Plasma measurements; Polymer films; Radio frequency;
Conference_Titel :
Photovoltaic Specialists Conference, 1988., Conference Record of the Twentieth IEEE
Conference_Location :
Las Vegas, NV, USA
DOI :
10.1109/PVSC.1988.105692
