Aug 7 (Fri): "InP Based MOS-HEMTs for Beyond 5G Amplifiers," Brian Markman, ECE PhD Defense

https://ucsb.zoom.us/j/98605850118

ABSTRACT

InP-based transistors are of interest for future high-frequency communication systems. Specifically, high current gain cutoff frequency transistors are necessary for future low noise, mm-wave communication systems. To increase the current gain cutoff frequency, the transconductance must be increased and thus the gate-channel capacitance must be increased. Currently InP-based HEMTs, which dominate the space, are limited by high gate leakage and cannot be further scaled. Replacing the wide bandgap gate insulator common to HEMTs with a high-k gate dielectric common to MOSFETs truncates thermionic leakage and reduces tunneling leakage facilitating further gate-insulator scaling. The improved gate-channel capacitance enables higher transconductance and higher current gain cutoff frequency while simultaneously improving electrostatics which reduces short channel effects and increases the power gain cutoff frequency. This talk will discuss intrinsic channel design of quantum well field effect devices and demonstrate three generations of MOS-HEMTs for mm-wave applications. A bottom up, regrowth-based process is demonstrated which enables reduced source-resistance and increased extrinsic transconductance. Finally, process modules necessary for a future self-aligned process flow will be discussed and initial data demonstrated.

BIO

Brian Markman is in Professor Mark Rodwell’s high frequency electronics group. His research focuses on InP-based, high frequency MOS devices. While at UCSB he has worked on high frequency MOS-HEMTs, low power tunneling field effect transistors, and confined epitaxial lateral overgrowth (CELO). Brian graduated from Penn State University in 2015 with a degree in Materials Science and Engineering and a focus on electronic materials.

Hosted by: Professor Mark Rodwell

Submitted by: Brian Markman <brianmarkman@ucsb.edu>