Nondestructive high resolution resistivity topography of semi-insulating GaAs and InP wafers

The capacitive charge transient measurement technique generates laterally resolved two-dimensional resistivity topograms of wafers with diameters up to 150 mm. The method is applicable to semi-insulating substrates with resistivities between 10high6 and 10high9 Omegacm. The range and characteristic lateral patterns of homogeneity variations in substrates of different vendors will be addressed, including LEC GaAs, VB GaAs and LEC InP. The effect of annealing treatments and interrelations between electrical and optical topograms will also be discussed.