Dr. Stephen Bayne, Vice Chancellor for Innovation and Collaboration, Executive Director of the Institute for Critical Infrastructure Security and John R. Bradford Endowed Chair in Engineering at Texas Tech University will give a seminar titled "Semiconductor Opening Device Characterizations, Package Comparisons, and TCAD Modeling for Pulsed Power Systems" to the interested faculty and students at Discovery Park.

Abstract

Semiconductor opening switch (SOS) diodes and drift step recovery diodes (DSRDs) are viable options for opening devices in pulsed power electronic systems, enabling the generation of high-power nanosecond pulses. SOS diodes rely on an opening effect to transfer power to a parallel load instead of closing switch technology for energy transfer. This work characterizes and evaluates the performance of silicon SOS diodes with varying doping profile gradients and a commercially produced SiC DSRD. For the Si SOS diode, a double-loop LC testbed was designed to pulse SOS diodes to observe the SOS opening effect. Six doping profiles were compared, each with three different active area sizes. Following this, three custom-designed packages were developed to house the devices and compared in terms of performance. Measurements were taken with single and series stacks of two and three devices to compare peak power and energy efficiency. COMSOL Multiphysics models were used to assess the thermal behavior of each package design during single pulse and repetition rate operation. The results highlight a strong electrical and thermal performance optimization dependence on the doping profile and package thermal resistance, respectively. The SiC DSRD is first characterized in transient and DC conditions to extrapolate device and material properties. A custom testbed was developed to rapidly alter discrete capacitance and inductance values to perform the transient characterizations. This flexibility allows for a broader range of sweep conditions to be tested. Based on these characterizations, a TCAD model is generated in Silvaco Victory Device. The model aims to converge on the measured values from the physical device through an iterative optimization process. Once optimized, this model will serve as a basis for high-voltage SiC SOS diode modeling.

Bio

Dr. Bayne is a professor and previous interim Dean for the Whitacre College of Engineering and previous Department Chair for Electrical and Computer Engineering at Texas Tech and has several years of experience in leadership and technical research. Before joining Texas Tech, he was chief of the directed energy branch at the Army Research Lab, where he managed three teams consisting of engineers, technicians and support staff. In 2009, Dr. Bayne joined Texas Tech and was named department chair in 2021, where he led a team of 28 faculty and instructors and was responsible for the recruitment and retention of undergraduate and graduate students. As a department chair, he managed the budget, conducted annual reviews for faculty and staff and was responsible for recruiting new faculty into the department. An active researcher in the department, Bayne brought in more than $32,691,998 ($11,541,066 credited) in research funding to Texas Tech and established a robust energy research program. With more than 219 publications, a book and a book chapter to his credit, Dr. Bayne also has two U.S. patents. He has earned several research and teaching awards, most notably the Barnie E. Rushing, Jr. Faculty Distinguished Research Award STEM Disciplines; TTU Lockheed Martin Excellence in Engineering Teaching award; Army Greatest Invention Award; and the Army Research Lab Achievement Award for Engineering.advisory panels. He received his Ph.D. in engineering mechanics from University of Minnesota in 1985.