Noise spectroscopy of local surface levels in semiconductors

Abstract
A method is proposed for extracting parameters of local surface levels in semiconductors from noise spectroscopic data. Analytical expressions have been derived to calculate the energy position of the surface level in the forbidden gap, E ts , capture cross section n , and surface concentration N ts . The results are applied to noise data for a 4H-SiC field-effect transistor with buried p+ -n gate. The parameters of the surface level responsible for the low frequency noise at elevated temperatures are found: E c - E ts 1.3 eV, n ~ 10-14 cm2 , N ts 1.5 × 1012 cm-2 .