Abstract
Cubic AlxGa1-xN/GaN heterostructures were grown by plasma-assisted molecular beam epitaxy on free-standing 3C-SiC(001). The samples consist of an unintentionally doped 600nm thick c-GaN buffer and a 30 nm c-Al0.3Ga0.7N layer. Capacitance-voltage measurements were performed on metal-oxide-semiconductor heterojunction structure using SiO 2 as an insulator. A depth profile of the net donor concentration NCV of the grown sample was measured, demonstrating a clear carrier accumulation at the heterojunction. By electron holography in a transmission electron microscope the potential profile was measured and a free electron concentration of 5.1 × 1011 cm-2 was estimated at the c-Al xGa1-xN/ GaN interface. Using a one-dimensional (1D) Poisson simulator the results of both techniques are compared and a conduction-to-valence band offset ratio of about 4 : 1 for the cubic Al xGa1-xN/GaN interface is estimated, which promotes the electron accumulation. Our results demonstrate that the two-dimensional electron gas (2DEG) in cubic AlxGa1-xN/GaN heterostructures can be achieved without the need of polarization effects and is due to the residual background doping in the AlxGa1-xN and GaN.
| Original language | English (US) |
|---|---|
| Article number | 08JN04 |
| Journal | Japanese Journal of Applied Physics |
| Volume | 52 |
| Issue number | 8 PART 2 |
| DOIs | |
| State | Published - Aug 2013 |
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ASJC Scopus subject areas
- Engineering(all)
- Physics and Astronomy(all)
Cite this
Capacitance voltage characteristics and electron holography on cubic AlGaN/GaN heterojunctions. / As, Donat J.; Zado, Alexander; Wei, Qiyang Y.; Li, Ti; Huang, Jingyi Y.; Ponce, Fernando.
In: Japanese Journal of Applied Physics, Vol. 52, No. 8 PART 2, 08JN04, 08.2013.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Capacitance voltage characteristics and electron holography on cubic AlGaN/GaN heterojunctions
AU - As, Donat J.
AU - Zado, Alexander
AU - Wei, Qiyang Y.
AU - Li, Ti
AU - Huang, Jingyi Y.
AU - Ponce, Fernando
PY - 2013/8
Y1 - 2013/8
N2 - Cubic AlxGa1-xN/GaN heterostructures were grown by plasma-assisted molecular beam epitaxy on free-standing 3C-SiC(001). The samples consist of an unintentionally doped 600nm thick c-GaN buffer and a 30 nm c-Al0.3Ga0.7N layer. Capacitance-voltage measurements were performed on metal-oxide-semiconductor heterojunction structure using SiO 2 as an insulator. A depth profile of the net donor concentration NCV of the grown sample was measured, demonstrating a clear carrier accumulation at the heterojunction. By electron holography in a transmission electron microscope the potential profile was measured and a free electron concentration of 5.1 × 1011 cm-2 was estimated at the c-Al xGa1-xN/ GaN interface. Using a one-dimensional (1D) Poisson simulator the results of both techniques are compared and a conduction-to-valence band offset ratio of about 4 : 1 for the cubic Al xGa1-xN/GaN interface is estimated, which promotes the electron accumulation. Our results demonstrate that the two-dimensional electron gas (2DEG) in cubic AlxGa1-xN/GaN heterostructures can be achieved without the need of polarization effects and is due to the residual background doping in the AlxGa1-xN and GaN.
AB - Cubic AlxGa1-xN/GaN heterostructures were grown by plasma-assisted molecular beam epitaxy on free-standing 3C-SiC(001). The samples consist of an unintentionally doped 600nm thick c-GaN buffer and a 30 nm c-Al0.3Ga0.7N layer. Capacitance-voltage measurements were performed on metal-oxide-semiconductor heterojunction structure using SiO 2 as an insulator. A depth profile of the net donor concentration NCV of the grown sample was measured, demonstrating a clear carrier accumulation at the heterojunction. By electron holography in a transmission electron microscope the potential profile was measured and a free electron concentration of 5.1 × 1011 cm-2 was estimated at the c-Al xGa1-xN/ GaN interface. Using a one-dimensional (1D) Poisson simulator the results of both techniques are compared and a conduction-to-valence band offset ratio of about 4 : 1 for the cubic Al xGa1-xN/GaN interface is estimated, which promotes the electron accumulation. Our results demonstrate that the two-dimensional electron gas (2DEG) in cubic AlxGa1-xN/GaN heterostructures can be achieved without the need of polarization effects and is due to the residual background doping in the AlxGa1-xN and GaN.
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UR - http://www.scopus.com/inward/citedby.url?scp=84883145898&partnerID=8YFLogxK
U2 - 10.7567/JJAP.52.08JN04
DO - 10.7567/JJAP.52.08JN04
M3 - Article
VL - 52
JO - Japanese Journal of Applied Physics, Part 1: Regular Papers & Short Notes
JF - Japanese Journal of Applied Physics, Part 1: Regular Papers & Short Notes
SN - 0021-4922
IS - 8 PART 2
M1 - 08JN04
ER -