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Title: Type-II band alignment for atomic layer deposited HfSiO 4 on α-Ga 2 O 3
There is increasing interest in α-polytype Ga 2 O 3 for power device applications, but there are few published reports on dielectrics for this material. Finding a dielectric with large band offsets for both valence and conduction bands is especially challenging given its large bandgap of 5.1 eV. One option is HfSiO 4 deposited by atomic layer deposition (ALD), which provides conformal, low damage deposition and has a bandgap of 7 eV. The valence band offset of the HfSiO 4 /Ga 2 O 3 heterointerface was measured using x-ray photoelectron spectroscopy. The single-crystal α-Ga 2 O 3 was grown by halide vapor phase epitaxy on sapphire substrates. The valence band offset was 0.82 ± 0.20 eV (staggered gap, type-II alignment) for ALD HfSiO 4 on α-Ga 0.2 O 3 . The corresponding conduction band offset was −2.72 ± 0.45 eV, providing no barrier to electrons moving into Ga 2 O 3 .  more » « less
Award ID(s):
1856662
PAR ID:
10399479
Author(s) / Creator(s):
; ; ; ; ; ; ; ; ;
Date Published:
Journal Name:
Journal of Vacuum Science & Technology A
Volume:
41
Issue:
2
ISSN:
0734-2101
Page Range / eLocation ID:
023205
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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