LOW-FREQUENCY NOISE MEASUREMENTS AS A TOOL TO ANALYZE DEEP-LEVEL IMPURITIES IN SEMICONDUCTOR-DEVICES

An analysis method to extract the pertinent trap parameters of impurities, i. e. , energy level, trap density, spin degeneracy and capture cross section, from low-frequency noise measurements is discussed. This method, which is based on the model of traps interacting independently with the conduction band, is applied to generation recombination noise spectra measured on planar n** plus -n-n ** plus Si resistors as a function of temperature, and trap parameters are obtained. Since the analysis makes use of some assumptions, its validity is verified by using obtained trap parameters as input for an exact multilevel computer simulation program. This program generates zero-frequency plateau levels and characteristic times in agreement with the measured data, indicating that the assumptions were warranted. An alternative explanation of the noise data in terms of a double-donor model is studied.