Noise spectroscopy of local surface levels in semiconductors

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 sigma(n), and surface concentration N-ts. The results are applied to noise data for a 4H-SiC held-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 approximate to 1.3 eV, sigma(n) similar to 10(-14) cm(2), N-ts approximate to 1.5 x 10(12) cm(-2).