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Identification and characterization of deep nitrogen acceptors in β-Ga2O3 using defect spectroscopies.

Authors :
Ghadi, Hemant
McGlone, Joe F.
Cornuelle, Evan
Senckowski, Alexander
Sharma, Shivam
Man Hoi Wong
Singisetti, Uttam
Frodason, Ymir Kalmann
Peelaers, Hartwin
Lyons, John L.
Varley, Joel B.
Van de Walle, Chris G.
Arehart, Aaron
Ringel, Steven A.
Source :
APL Materials; Nov2023, Vol. 11 Issue 11, p1-9, 9p
Publication Year :
2023

Abstract

The ability to achieve highly resistive beta-phase gallium oxide (β-Ga<subscript>2</subscript>O<subscript>3</subscript>) layers and substrates is critical for β-Ga<subscript>2</subscript>O<subscript>3</subscript> high voltage and RF devices. To date, the most common approach involves doping with iron (Fe), which generates a moderately deep acceptor-like defect state located at EC-0.8 eV in the β-Ga<subscript>2</subscript>O<subscript>3</subscript> bandgap. Recently, there has been growing interest in alternative acceptors, such as magnesium (Mg) and nitrogen (N), due to their predicted deeper energy levels, which could avoid inadvertent charge modulation during device operation. In this work, a systematic study that makes direct correlations between the introduction of N using ion implantation and the observation of a newly observed deep level at EC-2.9 eV detected by deep-level optical spectroscopy (DLOS) is presented. The concentration of this state displayed a monotonic dependence with N concentration over a range of implant conditions, as confirmed by secondary ion mass spectrometry (SIMS). With a near 1:1 match in absolute N and EC-2.9 eV trap concentrations from SIMS and DLOS, respectively, which also matched the measured removal of free electrons from capacitance-voltage studies, this indicates that N contributes a very efficiently incorporated compensating defect. Density functional theory calculations confirm the assignment of this state to be an N (0/-1) acceptor with a configuration of Noccupying the oxygen site III [N<subscript>O(III)</subscript>]. The near ideal efficiency for this state to compensate free electrons and its location toward the midgap region of the β-Ga<subscript>2</subscript>O<subscript>3</subscript> bandgap demonstrates the potential of N doping as a promising approach for producing semi-insulating β-Ga<subscript>2</subscript>O<subscript>3</subscript>. [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
2166532X
Volume :
11
Issue :
11
Database :
Complementary Index
Journal :
APL Materials
Publication Type :
Academic Journal
Accession number :
173773445
Full Text :
https://doi.org/10.1063/5.0160541