Development of high power semiconductor devices based on alpha-Ga2O3 and its ternary compounds grown via mist CVD

Recently, Ga2O3 has emerged as a promising material for the next-generation high power semiconductor devices due to its ultra-wide band gaps (~5 eV), high predicted break down field and Baliga’s Figure of Merit. Among Ga2O3 polymorphs, the beta-phase is gaining momentum in the research community at the moment due to commercial availability of high-quality bulk substrates. On the other hand, alpha-phase Ga2O3 single crystals can be readily grown via cost-effective atmospheric-pressure mist chemical vapor deposition (mist CVD) on c-plane sapphire substrates. More importantly, Ga can alloy with numerous other metals (Al, Cr, In, Fe, Rh) to form alpha-phase corundum-structure oxide heterostructures with controllable large band offsets and low lattice mismatches, which form ideal conditions for quantum confinement effects. In addition, several corundum-structure oxides have been reported as p-type semiconductors. These main features encourage us to develop corundum-structure oxides for ultra-high power semiconductor device applications.

In this presentation, first I would like to briefly present my previous works on the growth of Sn-doped conductive alpha-Ga2O3 and the fabrication of alpha-Ga2O3 Schottky diodes and MESFETs using an one-chamber mist CVD system. Then I would like to focus on the current development of Si-doped alpha-(AlxGa1-x)2O3/alpha-(CryGa1-y)2O3 high electron mobility transistors (HEMTs) including the growth of alpha-phase ternary compounds via a two-chamber mist CVD system and the fabrication process of the HEMTs.

Dr. Giang T. Dang

Research Associate, Kochi University of Technology on August 28, 2019 at 9:00 AM in MRC 136

Giang T. Dang received a specialist degree in Physics of Semiconductors from M. V. Lomonosov Moscow State University, Moscow, Russia, in 2008 and a Ph.D. degree from Kochi University of Technology, Kochi, Japan in 2011.
He was working as a postdoctoral fellow in the MacDiarmid Institute for Advanced Materials and Nanotechnology at University of Canterbury, Christchurch, New Zealand (2012-2016) and JSPS postdoctoral fellow at Kochi University of Technology, Kochi, Japan (2016-2018). He is currently a Research Associate in the School of Systems Engineering, Kochi University of Technology, Kochi, Japan. His interests include device fabrication and characterization of wide band gap metal oxide thin films and nanostructures, in particular, alpha-Ga2O3 and its ternary compounds, for ultra-high power semiconductor devices, flat panel displays, and UV sensors.

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