INSITU INFRARED ELLIPSOMETRY STUDY OF THE VIBRATIONAL PROPERTIES, AND THE GROWTH OF AMORPHOUS-SEMICONDUCTOR ULTRATHIN FILMS

An in situ study of the growth mechanisms and the vibrational properties of plasma-deposited amorphous semiconductor thin films (df < 800 A ̊) by ir spectroscopic phase-modulated ellipsometry is presented. The high sensitivity of this new experimental technique is underlined. Real time measurements evidence a clear departure from the uniform behaviour during the early stage of a-Si:H growth on glass substrate (df < 100 A ̊). SiO bonds are identified after air exposure of a-Si:H, by spectroscopic measurements, at a few monolayer level. The vibrational properties of thin a-SiC:H samples (df = 200 A ̊) are also presented. © 1990.