Effect of chalcogenide elements on the electrical characteristics of GaAs MIS structures

The influence of S, Se and Te on the capacitance-voltage (C-U) and conducta nce-voltage (G-U) characteristics of metal-insulator-GaAs structures has be en investigated. It has been found that the result of passivation of the Ga As surface by chalcogenide elements (S, Se and Te) depends on the type of s emiconductor. The presence of S and Se on the insulator-p-GaAs interface gi ves rise to a reduction of the total density of surface states, to a shift of the C-U and G-U characteristics at zero voltage and to a decrease in the frequency dispersion of the electrical characteristics and the conductance . Passivation of the n-GaAs surface causes a reverse effect. (C) 1999 Elsev ier Science Ltd. All rights reserved.