EBIC Measurements of Minority Carrier Diffusion Length in a Gan-based Light Emitting Diode

Abstract

This study involved the application of the Scanning Electron Microscope (SEM) for the characterization of a GaN-based Light Emitting Diode (LED) by the Electron Beam Induced Current (EBIC) method. The diffusion length of the minority carriers in both the p and n-type regions of a GaN-based LED structure was determined with the EBIC technique in the line scan configuration. The diffusion length is a critical physical parameter that directly affects the electrical and optical properties of these devices. This value is generally understood to be a material property of the layers within a device. However, the measured values of the diffusion length are sensitive to the sample design, experimental conditions, measurement technique, and data analysis model and method utilized.The EBIC measurements were performed at room temperature in a Hitachi S-3200N SEM using a GW Electronics Type 31 Specimen Current Amplifier.