Absolute standard of diffusion length and lifetime of minority charge carriers in single-crystal silicon

摘要

A substantial difference in electron recombination cross sections on Fe-B complexes (sigma(1)) and on activated iron ions (sigma(2)) in boron-doped single-crystal silicon is used to independently determine the lifetime of electrons in the standard T (st) using the surface photo-emf method. Pairs of values of the lifetime T (1) and T (2) before and after the decomposition of the Fe-B complexes were measured for each of 600 ingots at arbitrary diffusion length L (cal) for the calibrating specimen and were placed on the plane (T (1), T (2)). At the boundary of the region filled with the points, ingots are presented that are only contaminated with iron ions, so that T (2)/T (1) = sigma(1)/sigma(2). The true values of L (st) and T (st) of the calibrating specimen and the ratio sigma(1)/sigma(2) = 12.5 +/- 0.5 are determined by selecting a new value of the diffusion length for the calibrating specimen, which straightens the boundary of the region filled with the points after the recalculation of the values of T (1) and T (2).