WILLIAM LIU, PhD, is a senior member of the technical staff at Texas Instruments, where he has worked since obtaining his PhD in electrical engineering from Stanford University in 1991. Dr. Liu has been TI's lead contact in mentoring the development of BSIM4 model equations with UC Berkeley, and has been in charge of the modeling development for LDMOS/DEMOS and RF-CMOS in TI's SPICE Modeling Laboratory. Dr. Liu has authored/coauthored five book chapters, and has written more than fifty journal papers on modeling, device characterization, and fabrication. Dr. Liu has also published two books on III-V device technologies. Dr. Liu holds sixteen U.S. patents and is a senior member of IEEE.