Combination of μW-PCD and SPV techniques for bulk and surface defects densities measurements

Abstract

In semiconductor applications, surface and interface defects play a key-role on the electronic properties of the device. Several non destructive tools can be combined to characterize these defects. From microwave-Photo-Conductivity Decay (μW-PCD) measurements, one can access to an effective measurement of lifetime of minority carriers that characterizes both the surface and the bulk semiconductor material. On the other hand, Surface Photo-Voltage (SPV) is a powerful technique that gives credible bulk lifetime values from minority carriers’ diffusion length measurements. In this paper, we use a nondestructive method by which we determine the surface and bulk defects densities in crystalline silicon wafers by combining μW-PCD and SPV tools using an adequate theoretical approach. We apply this method to three surface morphologies; a mirror-polished sample, a CP4 etched sample and a pyramidal textured sample.