Oxide semiconductors' unique properties – a wide bandgap, reasonably high electron mobility, and ease of bulk and thin film preparation – make them prime material candidates for a variety of electronic devices. In this talk, I will describe my group's recent work on amorphous and crystalline oxide semiconductors for back end of line (BEOL) thin film circuitry and for high-voltage ultra-wide bandgap (UWBG) power devices, respectively. First, we exploit the thermodynamics of interfacialin situredox reactions with amorphous zinc tin oxide (a-ZTO) semiconductor to make MISFETs, MESFETs, Schottky diodes, and resistive memory devices that can be monolithically integrated with silicon CMOS. We demonstrate rectifiers that can harvest RFID wireless power and inverters that are compatible with low voltage silicon ICs. Furthermore, we develop novel, scalable atomic layer deposition processes to realize high-qualitya-ZTO semiconductor films, high-kAl2O3gate insulators and passivation layers, and Al:ZnO source/drain electrodes. Combining an innovative electro-hydro-dynamic jetting process with additive and subtractive selective area ALD, we realize thin film transistors with channel lengths below the ink-jet printing limit. I'll also describe our recent work on p-type oxide TFTs using Cu2O, and explain the key challenges in device architecture and materials physics that limit p-TFT performance. Finally, I'll explain how we've taken the learning from thin film oxides and used it to realize ultra-stable ohmic contacts and MOS capacitors to crystalline beta-phase gallium oxide, an ultra-wide bandgap semiconductor of interest for multi-kV power devices.
Bio: Dr. Rebecca Lorenz (Becky) Peterson is an Associate Professor at the University of Michigan, with faculty appointments in Electrical and Computer Engineering, in Materials Science and Engineering, and in Applied Physics. She also serves as Director of the University of Michigan's Lurie Nanofabrication Facility. Prior to joining University of Michigan, she received her PhD in electrical engineering from Princeton University, and then was a post-doctoral researcher at the Cavendish Laboratory, Department of Physics, and an Associate Lecturer at Newnham College at Cambridge University, UK. In fall 2019, she was on sabbatical as a Visiting Scientist at the Paul-Drude-Institut für Festkörperelektronik in Berlin. Dr. Peterson is the recipient of several awards including the University of Michigan's 2018 Henry Russel Award, an NSF CAREER award in 2017 and a DARPA Young Faculty Award in 2014. She is a Senior Member of IEEE. She chaired the Optoelectronics, Displays and Imaging Systems sub-committee of the 2020 IEEE International Electron Devices Meeting (IEDM), is Technical Program Chair of the 2021 Device Research Conference, and is Treasurer of the Electronic Materials Conference. For more information, see eecs.umich.edu/~blpeters