Charge collection scanning electron microscopy

TLDR

This review discusses the application of scanning electron microscopy with electron beam induced conductivity for studying semiconductor materials and devices, covering both theory and practical aspects. The technique uses the electron beam to generate charge carriers that are collected by an internal electric field and measured as a current, producing images that map electrical property variations. It enables measurement of carrier lifetime, diffusion length, defect energy levels, surface recombination velocities, and visualization of p‑n junctions, recombination sites, and doping inhomogeneities.

Abstract

This review encompasses the application of the scanning electron microscope to the study and characterization of semiconductor materials and devices by the Electron Beam Induced Conductivity (EBIC) method. In this technique, the charge carriers generated by the electron beam of the microscope are collected by an electric field within the material and sensed as a current in an external circuit. When employed as the video signal of the SEM, this collected current image reveals inhomogeneities in the electrical properties of the material. The technique has been used to determine carrier lifetime, diffusion length, defect energy levels, and surface recombination velocities. Charge collection images reveal the location of p-n junctions, recombination sites such as dislocations and precipitates, and the presence of doping level inhomogeneities. Both the theoretical foundation and the practical aspects of these effects are discussed in a tutorial fashion in this review.