IN-SITU INFRARED ELLIPSOMETRY STUDY OF THE HYDROGEN INCORPORATION IN P-DOPED AMORPHOUS-SILICON AND P-I INTERFACES

An in situ investigation of the influence of p-doping on the vibration al properties of a-Si:H, by infrared ellipsometry, is presented. The p resence of B2H6 in the gas phase induces a catalytic effect revealed b y an increase of hydrogen bonded as SiH2 at the a-Si:H surface. This e ffect is interpreted in terms of surface reaction mechanisms and energ etic considerations. The in situ study of p(+) -i interfaces reveals a complicated behaviour. They are found to be affected by the depositio n sequence and the doping gas (B2H6 or B(CH3)(3)).