Accurate measurement of excess carrier lifetime using carrier decay method

摘要

A method is described for accurate measuring of the excess carrier lifetime on a semiconductor sample from the carrier decay after termination of the excitation pulse imposed on the steady-state carrier excitation. The method includes determining a quality of decay parameter using progressing segments in each carrier decay; establishing an accurate lifetime measurement multiparameter domain for experimental variables whereby the quality of decay parameter falls within prescribed limits from the ideal exponential decay value of QD=1; and determining an excess carrier lifetime for the semiconductor sample based on experimental measurement conditions within the domain and the quality of decay value within the predetermined range indicative of an accurate excess carrier lifetime measurement.

主权项

1. A method of accurate determination of excess carrier lifetime of a semiconductor sample based on measurement of excess carrier decay; method comprising:
exciting of excess carriers in a semiconductor sample with a steady bias light illumination that generates steady-state excess carrier concentration; exciting additional excess carriers with a light pulse imposed on a background steady-state illumination; after termination of light pulse excitation, measuring a decay signal represents the excess carriers decay to a steady-state background value; determining a quality of decay parameter from a ratio of successive time increment values corresponding to a drop of decay signal by a predetermined factor C in a progressing excess carrier decay; and determining an excess carrier lifetime for the semiconductor sample based on a measured decay where the quality of decay value is within a predetermined range indicative of an accurate excess carrier lifetime measurement.