ADVANCES IN CHARACTERIZATION OF HI-NITRIDES BY SECONDARY ION MASS SPECTROMETRY

摘要

Recent developments in the Ⅲ-Nitrides have prompted the expansion of our capabilities for the characterization of these materials by Secondary Ion Mass Spectrometry (SIMS). The list of elements of interest, be it as dopant or impurity, has increased steadily. Also, opto-electronic (LED and Laser Diode) and transistor (HEMT and MESFET) devices have shrunk in size and consist of more complex layer structures. The improvements are threefold. Firstly, increased accuracy of concentration measurements for dopants and impurities based on a new suite of Relative Sensitivity Factors (RSFs) for GaN and AlGaN. Secondly, optimization of a Cameca IMS-6f SMS instrument to be able to profile areas as small as 30 x 30 microns. This allows for the characterization of both individual die and structures on processed wafers. Thirdly, the development of advanced sample preparation methods for failure analysis and reverse engineering.