RADIATION RESPONSE AND RELIABILITY OF AlGaN

...........................................................................................................................................1 CHAPTER I: INTRODUCTION ............................................................................................................2 OVERVIEW OF GAN HEMTS ...................................................................................................................... 2 GROWTH TECHNIQUES OF GAN HEMTS .................................................................................................... 4 BRIEF INTRODUCTION OF RADIATION-INDUCED DEGRADATION ................................................................. 7 OVERVIEW OF THESIS ................................................................................................................................. 8 CHAPTER II:BACKGROUND ............................................................................................................10 RADIATION DAMAGE OF GAN-BASED DEVICES ........................................................................................ 10 LOW FREQUENCY 1/F NOISE ..................................................................................................................... 16 CHAPTER III:DEVICE INFORMATION AND EXPERIMENT SETTINGS OF GAN HEMTS ......19 INTRODUCTION ......................................................................................................................................... 19 DEVICE INFORMATION .............................................................................................................................. 19 DC CHARACTERISTICS ............................................................................................................................. 20 v TEMPERATURE DEPENDENCE ................................................................................................................... 22 EXPERIMENT SETUP AND MEASUREMENT TECHNIQUES ........................................................................... 24 CHAPTER IV:RADIATION EFFECTS OF ALGAN/GAN HEMTS ..................................................27 INTRODUCTION ......................................................................................................................................... 27 DC MEASUREMENT AFTER X-RAY IRRADIATION ...................................................................................... 27 DC MEASUREMENT AFTER PROTON IRRADIATION .................................................................................... 30 CONCLUSIONS .......................................................................................................................................... 33 CHAPTER V: LOW FREQUENCY 1/F NOISE MEASUREMENT ...................................................34 INTRODUCTION ......................................................................................................................................... 34 GATE BIAS DEPENDENCE OF SVD ............................................................................................................. 34 NOISE SPECTRUM OF ALGAN/GAN HEMTS ............................................................................................ 38 CONCLUSIONS .......................................................................................................................................... 43 CHAPTER VI: HOT CARRIER EFFECTS ON ALGAN/GAN HEMTS ............................................45 INTRODUCTION ......................................................................................................................................... 45 EXPERIMENT SETTINGS ............................................................................................................................ 45 DC MEASUREMENTS AND NOISE SPECTRUM ANALYSIS ........................................................................... 46 CONCLUSIONS .......................................................................................................................................... 48 CHAPTER VII: SUMMARY AND CONCLUSIONS ..........................................................................49 REFERENCES ......................................................................................................................................51