A COMPARATIVE STUDY OF MOS CAPACITORS FABRICATED ON SINGLE-CRYSTAL AND POLYCRYSTALLINE SILICON

Abstract

The properties of bulk and interface traps in device grade single-crystal silicon and solar cell grade polycrystalline silicon are studied and compared, using MOS capacitors with 1 mm diameter aluminium gates and approximately 1000 Å thick gate oxide as test device. The device capacitance and conductance are measured as functions of gate bias in the range O to +-4V, of excitation signal in the frequency range 2 Hz to 5 MHz, and of ambient temperature varying from 25°C to 200°C. Analysis of these data is based on the response of carriers generated at traps to the gate signal. Significant differences exist between the single-crystal and polycrystalline materials.