RELIABILITY STUDY OF GAN-BASED HIGH ELECTRON MOBILITY TRANSISTORS By LU LIU A DISSERTATION PRESENTED TO THE GRADUATE SCHOOL OF THE UNIVERSITY OF FLORIDA IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY UNIVERSITY OF FLORIDA

3 Dedicated to my loving mother and wife for their love and constant support 4 ACKNOWLEDGMENTS First of all, I would like to appreciate my advisor and supervisory committee chair, Dr. Fan Ren. Thanks for his broad and profound knowledge, patience and encouragement through my Ph.D. study. The completion of this work would not be possible without the guidance from Dr. Fan Ren. He has always been there to provide technical and personal support whenever I had problems. He has treated me like his kid and the group like a family, and provided an excellent academic atmosphere for me to perform my research. His education and dedication in the past four years have been priceless and will benefit my future life. I also would like to express my sincere gratitude to the rest of my committee members, Dr. their suggestions and efforts to improve my proficiency in my research area.