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Delta-doped β-(AlxGa1−x)2O3/Ga2O3 heterostructure field-effect transistors by ozone molecular beam epitaxy.
- Source :
- Journal of Vacuum Science & Technology: Part A-Vacuums, Surfaces & Films; May2021, Vol. 39 Issue 3, p1-9, 9p
- Publication Year :
- 2021
-
Abstract
- Heterojunction field-effect transistors based on the β-(Al<subscript>x</subscript>Ga<subscript>1−x</subscript>)<subscript>2</subscript>O<subscript>3</subscript>/Ga<subscript>2</subscript>O<subscript>3</subscript> 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 (Al<subscript>x</subscript>Ga<subscript>1−x</subscript>)<subscript>2</subscript>O<subscript>3</subscript> barrier layer. Secondary ion mass spectroscopy and ECV measurements also revealed an unintentional Si peak at the (Al<subscript>x</subscript>Ga<subscript>1−x</subscript>)<subscript>2</subscript>O<subscript>3</subscript>/Ga<subscript>2</subscript>O<subscript>3</subscript> interface. Direct current (I<subscript>DS</subscript>-V<subscript>GS</subscript>) and transconductance (G<subscript>m</subscript>-V<subscript>GS</subscript>) 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 (Al<subscript>x</subscript>Ga<subscript>1−x</subscript>)<subscript>2</subscript>O<subscript>3</subscript>/Ga<subscript>2</subscript>O<subscript>3</subscript> 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 × 10<superscript>13</superscript> cm<superscript>−2</superscript> with corresponding Hall mobility of 95 cm<superscript>2</superscript>/V s in sample C. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 07342101
- Volume :
- 39
- Issue :
- 3
- Database :
- Complementary Index
- Journal :
- Journal of Vacuum Science & Technology: Part A-Vacuums, Surfaces & Films
- Publication Type :
- Academic Journal
- Accession number :
- 150232959
- Full Text :
- https://doi.org/10.1116/6.0000932