Interface Properties of InSb MIS Structure

Metal-insulator-lnSb structures with excellent interface properties, as measured at 77 K, have been developed. A simple MIS structure has been fabricated and used to characterize the surface physics of the InSb MIS interface, The C-V characteristics of these structures follow the simple ideal MIS capacitive model. A completely inverted low-frequency type CoV response occurs at about 10 Hz, indicating that the minority carrier thermal relaxation rate is small in these devices. Conductance measurements were made to investigate the interface properties of the MIS structure. These give a detailed description of the interface. Surface state densities in the 10¹²cm^-2eV^-1range were found. The experimental results also show that the interface of these structures can be characterized as a Shockley-Read-Hall type. The minority carrier thermal generation in the structure has been further analyzed, via conductance measurements, in the strong inversion region. The current density of the spacecharge generation was determined to be about 3.2 X 10^-6A/ cm². The effect of a photon flux on the generation current for the MIS device is briefly discussed.