Deep-Level Characterization of Free-Standing HVPE-grown GaN Substrates Using Transparent Conductive Polyaniline Schottky Contacts

2011 ◽  
Vol 1309 ◽  
Author(s):  
Yoshitaka Nakano ◽  
Nobuyuki Matsuki ◽  
Mickael Lozac’h ◽  
Kazuaki Sakoda ◽  
Masatomo Sumiya
Keyword(s):  
Deep Level ◽  
Chemical Vapor ◽  
Deep Levels ◽  
Schottky Contacts ◽  
Hydride Vapor Phase Epitaxy ◽  
Organic Chemical ◽  
Free Standing ◽  
Low Concentrations ◽  
Metal Organic ◽  
Conductive Polyaniline

ABSTRACTWe have investigated electronic deep levels in free-standing n-GaN substrates grown by hydride vapor phase epitaxy (HVPE), by means of a steady-state photo-capacitance spectroscopy technique, using transparent conductive polyaniline Schottky contacts. Two specific deep levels located at ~1.7 and ~3.1 eV below the conduction band were revealed to be significantly reduced compared to those in n-GaN layers grown by metal-organic chemical vapor deposition. This difference between them is probably due to extremely low concentrations of threading dislocations and residual C impurities in the HVPE-grown n-GaN substrates.

Electron Irradiation Induced Trap In N-Type Gan

1997 ◽  
Vol 482 ◽  
Author(s):  
Z-Q. Fang ◽  
J. W. Hemsky ◽  
D. C. Look ◽  
M. P. Mack ◽  
R. J. Molnar ◽  
...  
Keyword(s):  
Electron Irradiation ◽  
Deep Level Transient Spectroscopy ◽  
Deep Level ◽  
Chemical Vapor ◽  
Hydride Vapor Phase Epitaxy ◽  
Organic Chemical ◽  
Electric Field Effects ◽  
Metal Organic ◽  
Transient Spectroscopy ◽  
Organic Chemical Vapor Deposition

AbstractA 1-MeV-electron-irradiation (EI) induced trap at Ec-0.18 eV is found in n-type GaN by deep level transient spectroscopy (DLTS) measurements on Schottky barrier diodes, fabricated on both metal-organic-chemical-vapor-deposition and hydride-vapor-phase-epitaxy material grown on sapphire. The 300-K carrier concentrations of the two materials are 2.3 × 1016 cm−3 and 1.3 × 1017 cm−3, respectively. Up to an irradiation dose of 1 × 1015 cm−2, the electron concentrations and pre-existing traps in the GaN layers are not significantly affected, while the EI-induced trap is produced at a rate of at least 0.2 cm−1. The DLTS peaks in the two materials are shifted slightly, possibly due to electric-field effects. Comparison with theory suggests that the defect is most likely associated with the N vacancy or Ga interstitial.

Deep Level Centers in Carbon-Doped High Resistivity GaN

2014 ◽  
Vol 997 ◽  
pp. 492-495
Author(s):  
Huan Cui ◽  
Li Wu Lu ◽  
Ling Sang ◽  
Bai He Chen ◽  
Zhi Wei He ◽  
...  
Keyword(s):  
Deep Level ◽  
Chemical Vapor ◽  
Deep Levels ◽  
Hall Measurement ◽  
High Resistivity ◽  
Organic Chemical ◽  
Carbon Doped ◽  
Metal Organic ◽  
High Level ◽  
Organic Chemical Vapor Deposition

The deep levels of carbon doped high resistivity (HR) GaN samples grown by metal-organic chemical vapor deposition (MOCVD) has been investigated using thermally stimulated current (TSC) spectroscopy and high temperature (HT) Hall measurement. Two different thickness of 100 and 300 nm were used to be compared. It was found that four distinct deep levels by TSC and one deep level by HT Hall measurement were observed in both samples, which means great help for the decrease of leakage current and lifetime limitations of device utilizing the structure. The activation energy of these levels was calculated and their possible origins were also proposed. The low temperature traps, might be related to VN, 0.50 and 0.52eV related to incorporate a high level carbon, 0.57eV related to VGa, 0.59eV related to CGaor NGa, 0.91 and 0.97eV related to interstitial N1.

Photoluminescence study of deep-level defects in undoped GaN

2001 ◽  
Vol 693 ◽  
Author(s):  
M. A. Reshchikov ◽  
H. Morkoç ◽  
S. S. Park ◽  
K. Y. Lee
Keyword(s):  
Deep Level ◽  
Broad Band ◽  
Chemical Vapor ◽  
Hydride Vapor Phase Epitaxy ◽  
Organic Chemical ◽  
Metal Organic ◽  
Identical Position ◽  
Lift Off ◽  
The One ◽  
Organic Chemical Vapor Deposition

AbstractWe studied photoluminescence (PL) and PL excitation (PLE) spectra in a large number of undoped GaN layers grown on sapphire by molecular beam epitaxy (MBE), metal-organic chemical vapor deposition (MOCVD) and hydride vapor phase epitaxy (HVPE). The HVPE-grown GaN layers with thickness of ~200 m m were separated from the sapphire substrate by laser lift-off and represented bulk freestanding templates of very high quality. Identical position and shape of the YL band were reproduced in many samples grown by MBE and MOCVD: maximum at ~2.23 eV and full width at half maximum (FWHM) of about 460 meV at room temperature. However, in some samples the band maximum was observed at about 2.0 eV. The freestanding templates reveal a broad band (FWHM=530-680 meV) whose position depends on excitation energy and intensity, varying from 2.22 eV to 2.47 eV. PLE spectra taken from various samples represented a broad band with apparent maximum at about 3.3 eV. For below-gap excitation, the intensity of the YL band was independent of temperature except for the one in the freestanding template. The latter was temperature independent above 60 K, however at lower temperatures the PL intensity decreased by 5 times. An activation energy of 15 meV has been determined that is related to a barrier in the adiabatic potential in the excited state of the defect.

scholarly journals Fabrication of Pyramid Structure Substrate Utilized for Epitaxial Growth Free-Standing GaN

Crystals ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 547 ◽  
Author(s):  
Ruixian Yu ◽  
Baoguo Zhang ◽  
Lei Zhang ◽  
Yongzhong Wu ◽  
Haixiao Hu ◽  
...  
Keyword(s):  
Sapphire Substrate ◽  
Chemical Vapor ◽  
Hydride Vapor Phase Epitaxy ◽  
Organic Chemical ◽  
Free Standing ◽  
Wurtzite Crystal Structure ◽  
Pyramid Structure ◽  
Metal Organic ◽  
Pyramid Structures ◽  
Organic Chemical Vapor Deposition

Metal–organic chemical vapor deposition (MOCVD)-grown GaN on sapphire substrate was etched by hot phosphoric acids. Pyramid structures were obtained in the N-polar face of the MOCVD–GaN. Details of the formation process and morphology of the structures were discussed. The crystallographic plane index of the pyramid facet was calculated dependent on the symmetry of the wurtzite crystal structure and the tilt angle. The substrates with pyramid structures were utilized in subsequent hydride vapor phase epitaxy (HVPE) growth of GaN. Free-standing crystals were obtained, while HVPE-grown GaN achieved a certain thickness. Raman spectroscopy was employed to obtain the stress conditions of the HVPE–GaN without and with sapphire substrate. The mechanism of the self-separation process was discussed. This facile wet etching method may provide a simple way to acquire free-standing GaN by HVPE growth.

scholarly journals Review of GaN Thin Film and Nanorod Growth Using Magnetron Sputter Epitaxy

2020 ◽  
Vol 10 (9) ◽  
pp. 3050 ◽  
Author(s):  
Aditya Prabaswara ◽  
Jens Birch ◽  
Muhammad Junaid ◽  
Elena Alexandra Serban ◽  
Lars Hultman ◽  
...  
Keyword(s):  
Thin Film ◽  
Chemical Vapor ◽  
Hydride Vapor Phase Epitaxy ◽  
Alternative Methods ◽  
Organic Chemical ◽  
Large Area ◽  
Material Quality ◽  
Pulsed Dc ◽  
Metal Organic ◽  
Magnetron Sputter

Magnetron sputter epitaxy (MSE) offers several advantages compared to alternative GaN epitaxy growth methods, including mature sputtering technology, the possibility for very large area deposition, and low-temperature growth of high-quality electronic-grade GaN. In this article, we review the basics of reactive sputtering for MSE growth of GaN using a liquid Ga target. Various target biasing schemes are discussed, including direct current (DC), radio frequency (RF), pulsed DC, and high-power impulse magnetron sputtering (HiPIMS). Examples are given for MSE-grown GaN thin films with material quality comparable to those grown using alternative methods such as molecular-beam epitaxy (MBE), metal–organic chemical vapor deposition (MOCVD), and hydride vapor phase epitaxy (HVPE). In addition, successful GaN doping and the fabrication of practical devices have been demonstrated. Beyond the planar thin film form, MSE-grown GaN nanorods have also been demonstrated through self-assembled and selective area growth (SAG) method. With better understanding in process physics and improvements in material quality, MSE is expected to become an important technology for the growth of GaN.

Characteristics of Alpha-Radiation-Induced Deep Level Defects in p-Type InP Grown by Metal-Organic Chemical Vapor Deposition

1998 ◽  
Vol 37 (Part 1, No. 8) ◽  
pp. 4595-4602 ◽  
Author(s):  
Aurangzeb Khan ◽  
Mohd Zafar Iqbal ◽  
Umar Saeed Qurashi ◽  
Masafumi Yamaguchi ◽  
Nasim Zafar ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Deep Level ◽  
Chemical Vapor ◽  
Organic Chemical ◽  
Alpha Radiation ◽  
Metal Organic ◽  
Radiation Induced ◽  
P Type ◽  
Organic Chemical Vapor Deposition

As-grown deep-level defects in n-GaN grown by metal–organic chemical vapor deposition on freestanding GaN

2012 ◽  
Vol 112 (5) ◽  
pp. 053513 ◽  
Author(s):  
Shang Chen ◽  
Unhi Honda ◽  
Tatsunari Shibata ◽  
Toshiya Matsumura ◽  
Yutaka Tokuda ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Deep Level ◽  
Chemical Vapor ◽  
Organic Chemical ◽  
Metal Organic ◽  
Organic Chemical Vapor Deposition
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