A new technique for the determination of twodimensional impurity profiles using methods developed for emission computed tomography is presented. Several one-dimensional impurity profiles obtained at different directions through the sample are used to reconstruct the twodimensional profile. A simulation study of the experiment is described, and the effects of various experimental and reconstruction parameters are discussed. Reconstructions of an area of 4 μm x 4 μm from thirteen one-dimensional measurements, with a resolution of 1000Å, are numerically possible. © 1989 IEEE