The minority carrier lifetime (τb) and surface recombination velocity (
S) have been separately measured in wafer from silicon by contactless method using the injection carrier profile control. The injected carrier profile control is obtained by the injection light pulse width (P. W). In this method, τb and
S are estimated from the comparison of the numerically calculated curves with the experimental values of saturated modulation lifetime (τ1/2 sat.) and the pulse width at saturation point of the modulation lifetime (P. W
99% sat. τ
1/2 sat.).
S of mechanically lapped, chemically etched and oxidized (
A) silicon wafers are about 1100cm/sec, 700cm/sec and20cm/sec, respectively. The values of
S by this method in n-type silicon are compared to those obtained by the ordinary decay curve method.
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