Self consistent fitting method for defect analysis by low-frequency noise measurements in reverse biased p-n junctions
A method for analysis of defects close to a metallurgical junction in the space charge region of a reverse biased degraded p-n junction by low-frequency current noise and current-voltage measurements at room temperature is given. The current g-r noise spectrum (separated from the total low-frequency noise spectrum) and the current-voltage characteristics are used to calculate defect parameters like defect density, energy level, capture coefficients and defect region boundary by fitting the theoretical and experimental results in a self-consistent way. This procedure is used to analyse the defects in a silicon field plated PIN photodiode with a soft current-voltage characteristic. II is found that the defects which are responsible for the soft current-voltage characteristics and low-frequency excess g-r noise are distributed up to a distance of 3 mu m from the metallurgical junction. (C) 1997 Elsevier Science Ltd.