Low frequency noise spectroscopy method for extracting the parameters of deep level centers in semiconductor materials

摘要

Low Noise Frequency Spectroscopy (LFNS) is a powerful tool for study of deep level impurities in semiconductors materials. The technique is based on analysis of generation and recombination noise. The number of free electrons in the conduction band may fluctuate, because of generation and recombination processes induced by traps. Measurement data are present as spectral noise density versus temperature at selected frequencies. The trapping and re-trapping processes in the sample manifest themselves by several noise peaks in measured noise spectrum. In LFNS method spectral noise density versus temperature for selected frequencies is measured. The analysis of spectral noise density versus temperature at selected frequencies is very promising - in sample A eight traps were identified, in sample B six traps were identified. Low Noise Frequency Spectroscopy (LFNS) can be applied to characterization of both high and low resistivity materials.