INVESTIGATION OF DEEP LEVELS IN SEMIINSULATING GAAS BY PHOTOINDUCED-ADMITTANCE TRANSIENT SPECTROSCOPY

The photoinduced admittance of a ''metal-semi-insulating semiconductor -metal'' structure is analyzed theoretically, and a new nondestructive method for investigating deep levels in bulk semi-insulating and high -resistance semiconductors is proposed on the basis of this analysis. It is shown that, in contrast to the method of photoinduced-current tr ansient spectroscopy, the proposed method makes it possible to investi gate trapping and emission processes under identical conditions. This enables a more accurate determination of the lifetime of charge carrie rs and of the concentration of deep levels. The method was tested on C zochralski-grown semi-insulating gallium arsenide. (C) 1995 American I nstitute of Physics.