INVESTIGATION OF INTERFACE STATE DENSITY BETWEEN A-SI-H AND INSULATING LAYERS BY ESR AND PHOTOTHERMAL DEFLECTION SPECTROSCOPY

The nature of surface defects in insulating films and interface defect s between a-Si:H and insulating layers was investigated by electron sp in resonance measurements. Surface state densities in a-Si:H, a-SiN1.7 :H and a-SiO2.0 were estimated by the thickness dependence of ESR sign al intensity. The interface state densities in a-SiN1.7:H/a-Si:H and a -SiO2.0/a-Si:H were estimated by using stacked structures of the thin layers. These results were compared with results of photothermal defle ction spectroscopy. The main peak of electron spin resonance absorptio n in these structures was near g = 2.0055. This value means that the d efects in these structures lie at the a-Si:H side of the interface. Th e results obtained by the electron spin resonance measurements are con sistent with our previous report that the interface defects in the top insulator structures are formed by plasma surface reaction.