DEEP STATES IN SILICON-ON-SAPPHIRE BY TRANSIENT-CURRENT SPECTROSCOPY

It is demonstrated that deep states in silicon on sapphire (SOS) films can be evaluated by transient-current spectroscopy (TCS). In the TCS spectra, a broad peak extending over 100-200 K was observed for the 60 00-Angstrom-thick n-type SOS film. Assuming the value of capture cross section to be 10(-15) cm(2) and independent of temperature, the densi ty distribution of deep states was estimated. The density distribution shows a peak of 1.2 x 10(12) cm(-2) eV(-1) at E-C-0.25 eV. Raman back scattering spectroscopy was also performed to evaluate the stress in t he silicon film, It was concluded that the defects detected by TCS sho uld be caused by the compressive stress of 6.2 x 10(8) Pa in the silic on film. (C) 1997 American Institute of Physics.