Low Frequency C-V Characteristics of MIS-Schottky Barrier Diodes

Abstract

Low frequency 1/C² vs V characteristics of MIS-Schotky barrier diodes have been studied taking voltage dependence of semiconductor surface potential into consideration. An expression for the bias voltage for which strong inversion sets in a semiconductor has been derived in terms of metal work function, doping and non-ideal parameters like interfacial layer thickness, interface trap density and interface interface charge density. It has been shown that under conditions of inversion, 1/C²- vs V plot of MIS Schottky structure is nonlinear and exhibits a peak. For a high value of metal work function, this peak occurs at a positive bias voltage (for n-type semiconductor). Presence of such a peak in the 1/C² vs V characteristic thereby provides a way to detect inversion mode of operation of MIS-diode.

Indexing terms:

• MIS-Schottky barrier diode
• Surface potential
• Inversion voltage
• Capacitance