Scanning electron microscope studies of electroluminescent diodes of GaAs and GaP

Abstract

GaAs laser diodes and GaP lamp diodes were examined by scanning electron microscopy using the emissive, conductive, and cathodoluminescence modes of operation. Observations of non‐uniform doping and gross malformation of p‐n junctions were made in both types of device. The dependence of the contrast due to segregation and impurity growth striations on the impurity concentration and the type of photomultiplier used isoutlined. The cathodoluminescence micrographs of GaAs lasers exhibited the same contrast as the charge collection, barrier electron voltaic effect micrographs in regions in the n‐type material well away from the junction. This is evidence that both types of signal in these regions arise from the infrared radiation generated by electron beam bombardment. Copyright © 1973 WILEY‐VCH Verlag GmbH & Co. KGaA