NOISE SPECTROSCOPY OF LOCAL-LEVELS IN SEMICONDUCTORS

A method for extracting the parameters of local levels from noise spectroscopic data for the case when the capture cross section of electrons a, depends on temperature exponentially, sigma(n) = sigma0 exp(-E1/kT), has been suggested. For the limiting cases when the Fermi level E(F) lies significantly below (E(F) - E0 >> kT) or above (E0 - E(F) >> kT) the level E0, analytic expressions have been obtained to calculate sigma0, E0, E1 and the level concentration N(t). The results have been applied to noise-measurement data for GaAs samples with electron concentrations n0 approximately 10(15), 10(16) and 10(17) cm-3. It has been shown that the technique proposed can be applied to a wide variety of experimental situations.