Verfahren zur Bestimmung der tatsächlichen Ladungsträger-Lebensdauer eines Halbleitersubstrates aus einer dynamischen und differentiellen Messung der Relaxationszeit freier Ladungsträger

The invention relates to a method for determining the actual charge carrier lifetime of a semiconductor substrate from a dynamic and differential measurement of the relaxation time of free charge carriers, comprising method steps A and B: A generating a first excess charge carrier density [Delta]n1 and at least one second excess charge carrier density [Delta]n2 in the semiconductor substrate, wherein the first excess charge carrier density [Delta]n1 is different from the second excess charge carrier density [Delta]n2 , and dynamically and differentially measuring a first charge carrier relaxation time TM,1 and a first generation rate G1 in the semiconductor substrate starting from the first excess charge carrier density [Delta]n1 and at least one second charge carrier relaxation time TM,2 and a second generation rate G2 in the semiconductor substrate starting from the second excess charge carrier density [Delta]n2 , B calculating the actual charge carrier lifetime T0,I(i=1,2) for the excess charge carrier density [Delta]nI (i=1,2) on the basis of the measurement variables TM,1, G1, TM,2 and G2 determined in method step A; the essential factor is that the charge carrier relaxation time TM,I is measured in method step A as a characteristic relaxation time of the excess charge carrier density after the generation rate has been changed GI [xi] GI (i= 1,2), where 0, and that the actual charge carrier lifetime T0,I(i=1,2) is determined in method step B using an analytical relationship between T0,I and the measurement variables TM,I and GI (i=1,2)