Reconstruction of diffusion length distributions in semiconductors by photocurrent measurements with the depletion region modulation

The photocurrent measurements in combination with a modulation of the deple tion region is a method which has the potentiality to determine the diffusi on length profile in semiconductors directly. In this article the method is applied to strongly compensated (Au-doped) silicon. The expressions for si gnal description are derived and the situations in which the reconstruction of the diffusion length profile can be obtained are presented. An example of diffusion length profile reconstruction is given for a structure highly compensated by Au and the profile obtained has been compared with that calc ulated in the frame of the kick-out mechanism with the help of secondary io n mass spectrometry experiments. (C) 1999 American Institute of Physics. [S 0021-8979(99)02121-0].