Reconstruction of Semiconductor Doping Profile from Laser-Beam-Induced Current Image

Abstract

In this paper, the authors study the reconstruction of a semiconductor doping profile or, equivalently, the equilibrium potential, from its LBIC (laser-beam-induced current) image. For the one-dimensional case, the authors first characterize the attainable class of current measurements, and from this they show the nonuniqueness of the inverse problem. Then the reconstruction of the equilibrium potential is reduced to finding two constants subject to some constraints. A reconstruction algorithm is established based on a least squares formulation of the problem. The case of noise-collapsed data is also discussed. For a special case of two-dimensional domain, the authors apply the one-dimensional algorithm supplemented with a correction from the other spatial direction to establish an alternate direction iteration algorithm for reconstruction of the two-dimensional equilibrium potential. The authors also present some numerical examples to illustrate the reconstruction results by these algorithms.