ELECTRICAL-PROPERTIES OF SILNXPYOZ-INSB METAL-INSULATOR-SEMICONDUCTOR STRUCTURES

The electrical properties of n-type InSb metal-insulator-semiconductor (MIS) structures have been investigated. As gate insulators, SiIn(x)P(y)O(z) layers are formed on InSb by a new method. In the method, an In-SiO(x') double layer is formed on the InSb (111)B surface by evaporation of SiO and In. Further, a P(y')O(z') layer is deposited on the double layer. The reaction between a P(y')O(z') layer and In-SiO(x') double layer yields a SiIn(x)P(y)O(z) layer. The SiIn(x)P(y)O(z) layers exhibit high resistivities rho, i.e., rho almost-equal-to 6.5 x 10(15)-OMEGA-cm at 100 K and 1.0 x 10(14)-OMEGA-cm at room temperature. The hysteresis in the capacitance-voltage (C-V) and conductance-voltage (G-V) curves of InSb MIS structures at 100 K is found to be less than 0.6 V and an injection type. The surface-state density in the MIS interface is evaluated by including the effects of the nonparabolicity of the conduction band and Fermi-Dirac statistics for electrons in InSb. A typical value of the minimum surface state density is observed as 8.3 x 10(11) cm-2 eV-1 at about 0.05 eV below the conduction-band edge. Further, the C-V characteristics of InSb MIS structures at room temperature are discussed by including the features of the narrow band-gap semiconductor.