Defect Analysis of High Electron Mobility Transistors Using a Scanning Electron and Laser Beams Induced Current (SELBIC) System

A defect analysis of high electron mobility transistors (HEMTs) was performed using the scanning electron and laser beams induced current (SELBIC) system. An electron gun and two infra red (IR) laser sources with wavelengths of 1064 and 1400 [nm] were located coaxially. Electron and laser beams were irradiated to a GaAs substrate from the reverse side through a quartz window. Two-dimensional current images between gate and source electrodes were observed during the scanning by the 1064 [nm] IR-laser beam under non-biased conditions. The area in which the current changed was observed on the gate electrode, and current leakage was measured from I-V characteristics. The image obtained by simultaneously using two laser beams with wavelengths of 1064 and 1400 [nm] showed different contrasts for each current change.