An investigation and comparison of 45-degree spread the modeland other techniques to extract junction temperature of HBT and PHEMT for reliability life test

Abstract

Several techniques were applied on HBT and pHEMT evaluation vehicles fabricated at WIN Semiconductors' 6-inch GaAs foundry to extract device's junction temperature and compare the results and their impacts on the accelerated life test. From the reliability results of Arrhenius plots, the 45' spread model WIN Semiconductors used to obtain Tj matched well with liquid crystal thermography (LC) and Cooke model, but the infrared microscopy (IR) shows its space resolution limitation on the small area devices.