DEFECT-LEVEL ANALYSIS OF SEMICONDUCTORS BY A NEW DIFFERENTIAL EVALUATION OF N(1-T)-CHARACTERISTICS

A new method for the defect-level analysis of extrinsic semiconductors is described. Provided that the defect-level concentration is not too large and the temperature is not too low, the Fermi level E F is shifted with increasing temperature from a position near the conduction (or valence) band towards the middle of the forbidden gap monotonously. Thus majority carriers are emitted into the conduction (or valence) band from the defect levels successively. If for a small increment of the temperature the Fermi level E F is shifted by ΔE F and the concentration of free majority carriers is increased by Δn, then the ratio Δn/ΔE F is a measure of the defect-level concentration within ΔE F . Furthermore we discuss how this analysis is influenced by additional defect levels outside the range over which the Fermi energy can be shifted by variation of the temperature. © 1979 Springer-Verlag.