Delta-doped β-(AlxGa1−x)2O3/Ga2O3 heterostructure field-effect transistors by ozone molecular beam epitaxy
Abstract
Heterojunction field-effect transistors based on the β-(AlxGa1−x)2O3/Ga2O3 heterostructure grown by ozone-assisted molecular beam epitaxy were demonstrated for the first time. Al composition ratios in the 14%–23% range were validated using x-ray diffraction on the three samples grown for this study. Electrochemical capacitance-voltage (ECV) measurements showed the presence of a charge sheet in the delta-doped (AlxGa1−x)2O3 barrier layer. Secondary ion mass spectroscopy and ECV measurements also revealed an unintentional Si peak at the (AlxGa1−x)2O3/Ga2O3 interface. Direct current (IDS-VGS) and transconductance (Gm-VGS) measurements demonstrated depletion-mode transistor operation as well as the presence of a parallel conduction channel. A one-dimensional Poisson model suggested that dopant redistribution in the delta-doped region could cause a secondary channel to form in the barrier in addition to the primary channel near the (AlxGa1−x)2O3/Ga2O3 interface under certain conditions met in these samples. Fabricated devices on sample A did not exhibit breakdown up to the measurement limit of 1100 V, with stability after ten cycles. A maximum output drain current density of 22 mA/mm was measured on sample B. Room temperature Hall measurements yielded a sheet carrier density of 1.12 × 1013 cm−2 with corresponding Hall mobility of 95 cm2/V s in sample C.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Mar 09, 2021
- Source ID
- 10.1116/6.0000932
Entities
People
- Akito Kuramata
- Alan G Jacobs
- Alyssa L. Mock
- Andrew D. Koehler
- Daiki Wakimoto
- James C. Gallagher
- Karl D. Hobart
- Kohei Sasaki
- Marko J. Tadjer
- Michael A. Mastro
- Mona Ebrish
- Travis J. Anderson
Organizations
- Novel Crystal Technology, Inc.
- Office of Naval Research
- Office of Naval Research Global
- United States Naval Research Laboratory