PHOTOCONDUCTANCE MINORITY-CARRIER LIFETIME VS SURFACE PHOTOVOLTAGE DIFFUSION LENGTH IN SILICON

Recombination lifetime and diffusion length measured with the photocon ductance decay and surface photovoltage techniques are compared theore tically and experimentally, and reasons for possible discrepancies are discussed. Specific examples are given which show that, if full advan tage of these noncontact and nondestructive procedures is to be taken, it is necessary that surface recombination be considered in the analy sis of any experimental data. This is particularly true for samples wh ere the diffusion length is greater than one-fourth of the wafer thick ness, a condition for which it is essential that theoretical algorithm s for separating the bulk and surface components of recombination be d eveloped.