Relaxation effects at semiconductor-insulator interfaces

Relaxation mechanisms such as volume and surface generation, charging of surface states, and charge transfers in the insulator may be identified from time dependence of the MOS capacitance after applying a voltage step. The measuring method described allows the separation of the various mechanisms and the determination of bulk lifetime, surface recombination velocity, and the time constant of carrier emission from surface states. Experimental results obtained with thermally oxidized n-type silicon are given.