Measurement of spontaneous polarization charge in C-face 3C-SiC/6H-SiC heterostructure with two-dimensional electron gas by capacitance-voltage method

AbstractPlanar Pt/AlGaN/GaN Schottky barrier diodes (SBDs) have been characterized by capacitance-voltage and capacitance deep-level optical spectroscopy measurements, compared to reference Pt/GaN:Si SBDs. Two specific deep levels are found to be located at ∼1.70 and ∼2.08 eV below the conduction band, which are clearly different from deep-level defects (Ec - 1.40, Ec - 2.64, and Ec - 2.90 eV) observed in the Pt/GaN:Si SBDs. From the diode bias dependence of the steady-state photocapacitance, these levels are believed to stem from a two-dimensional electron gas (2DEG) region at the AlGaN/GaN hetero-interface. In particular, the 1.70 eV level is likely to act as an efficient generation-recombination center of 2DEG carriers.

Download Full-text

Perturbation of charges in AlGaN/GaN heterostructures studied by nanoscale capacitance-voltage technique

MRS Proceedings ◽

10.1557/proc-0892-ff17-01 ◽

2005 ◽

Vol 892 ◽

Author(s):

Goutam Koley ◽

Lakshminarayanan Lakshmanan

Keyword(s):

Electron Gas ◽

Two Dimensional ◽

Dimensional Electron ◽

Two Dimensional Electron Gas ◽

Dc Voltage ◽

Surface And Interface ◽

Voltage Sweep ◽

Uv Illumination ◽

Capacitance Voltage ◽

Dimensional Electron Gas

AbstractPerturbation of charges at the surface and interface of AlGaN/GaN heterostructures has been studied by quantitative nanoscale capacitance-voltage (C-V) measurements. The nanoscale C-V curves were found to have different slopes in the forward and reverse directions. These measurements indicate a change in confinement of the two-dimensional electron gas (2DEG) at the AlGaN/GaN interface depending on the direction of the dc voltage sweep during C-V measurements, which can be explained by surface state charging and discharging during the bias sweep. Under UV illumination, the density of the 2DEG increased significantly as inferred from the increase in threshold voltage of the nanoscale C-V scans, and no change in 2DEG confinement, depending on the direction of the bias sweep, was observed.

Download Full-text

Nanoscale Capacitance-Voltage Characterization of Two-Dimensional Electron Gas in AlGaN/GaN Heterostructures

Japanese Journal of Applied Physics ◽

10.1143/jjap.44.l1348 ◽

2005 ◽

Vol 44 (No. 44) ◽

pp. L1348-L1351 ◽

Cited By ~ 5

Author(s):

G. Koley ◽

L. Lakshmanan ◽

N. Tipirneni ◽

M. Gaevski ◽

A. Koudymov ◽

...

Keyword(s):

Electron Gas ◽

Two Dimensional ◽

Dimensional Electron ◽

Two Dimensional Electron Gas ◽

Capacitance Voltage ◽

Dimensional Electron Gas

Download Full-text

Observation of Polarization and Two-Dimensional Electron Gas in AlGaN/GaN Heterostructure Using Scanning Nonlinear Dielectric Microscopy

ISTFA 2015: Conference Proceedings from the 41st International Symposium for Testing and Failure Analysis ◽

10.31399/asm.cp.istfa2015p0333 ◽

2015 ◽

Author(s):

K. Hirose ◽

N. Chinone ◽

Y. Cho

Keyword(s):

Spontaneous Polarization ◽

Electron Gas ◽

Two Dimensional ◽

Dimensional Electron ◽

Two Dimensional Electron Gas ◽

Nonlinear Dielectric ◽

Piezoelectric Polarization ◽

Polarization Profile ◽

Dimensional Electron Gas ◽

Gan Heterostructure

Abstract We measured AlGaN/GaN heterostructure using scanning nonlinear dielectric microscopy (SNDM) [1], which can measure both carrier and polarization profile in AlGaN/GaN heterostructure. As a result, GaN spontaneous polarization and AlGaN polarization which is sum of spontaneous polarization and piezoelectric polarization were clearly distinguished. Two dimensional electron gas (2DEG) was observed at the AlGaN/GaN interface. This results show that SNDM is useful method for evaluation of 2DEG profile and polarization profile in AlGaN/GaN heterostructure.

Download Full-text

Visualization of Polarization and Two Dimensional Electron Gas Distribution in AlGaN/GaN Heterostructure Using Scanning Nonlinear Dielectric Microscopy

Materials Science Forum ◽

10.4028/www.scientific.net/msf.858.1182 ◽

2016 ◽

Vol 858 ◽

pp. 1182-1185

Author(s):

Kotaro Hirose ◽

Norimichi Chinone ◽

Yasuo Cho

Keyword(s):

Spontaneous Polarization ◽

Electron Gas ◽

Two Dimensional ◽

Dimensional Electron ◽

Gas Distribution ◽

Two Dimensional Electron Gas ◽

Nonlinear Dielectric ◽

Polarization Profile ◽

Dimensional Electron Gas ◽

Gan Heterostructure

AlGaN/GaN heterostructure was observed using scanning nonlinear dielectric microscopy, which can measure both carrier and polarization profile in AlGaN/GaN heterostructure. As a result, GaN spontaneous polarization and AlGaN polarization which was sum of spontaneous polarization and piezoelectric polarization were clearly distinguished. Moreover, two dimensional electron gas was observed at the AlGaN/GaN interface. These results show that scanning nonlinear dielectric microscopy is useful method for evaluation of two dimensional electron gas profile and polarization profile in AlGaN/GaN heterostructure.

Download Full-text