Deep Trap Characterization In GaN Using Thermal And Optical Admittance Spectroscopy

1997 ◽  
Vol 482 ◽  
Author(s):  
A. Krtschil ◽  
H. Witte ◽  
M. Lisker ◽  
J. Christen ◽  
U. Birkle ◽  
...  

AbstractDeep defect levels and the optical as well as thermal transitions of carriers from the levels into the corresponding bands were analyzed using Thermal and Optical Admittance Spectroscopy. High resistivity GaN-layers grown by MBE and heterostructures consisting of n-type GaN-layers grown with Low Pressure Chemical Vapor Deposition on 6H-SiC substrates are investigated. In the MBE-grown GaN layers we determine deep electron traps with thermal activation energies of EA=(0.45±0.04)eV and EA=(0.65±0.03)eV. Furthermore, three different kinds of optical transitions were distinguished by Optical Admittance Spectroscopy: near band gap transitions including the transition between the valence band and a shallow donor 50meV below the conduction band, a peak at 2.1eV associated with the yellow photoluminescence band and various deep level-band transitions in the infrared region.The high sensitivity of the TAS to interface defect states was used to investigate GaN/SiC heterostructures. We found an interface defect state at 70 … 90meV. Furthermore, one level was obtained originating from the epitaxial GaN-layer having an activation energy of 63±3meV. A defect distribution was identified in the p-type SiC-substrate with activation energies between 160meV and 180meV.

2014 ◽  
Vol 997 ◽  
pp. 492-495
Author(s):  
Huan Cui ◽  
Li Wu Lu ◽  
Ling Sang ◽  
Bai He Chen ◽  
Zhi Wei He ◽  
...  

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.


2006 ◽  
Vol 911 ◽  
Author(s):  
Nguyen Tien Son ◽  
Patrick Carlsson ◽  
Björn Magnusson ◽  
Erik Janzén

AbstractElectron paramagnetic resonance was used to study defects in high-purity semi-insulating (HPSI) substrates grown by high-temperature chemical vapor deposition and physical vapor transport. Deep level defects associated to different thermal activation energies of the resistivity ranging from ~0.6 eV to ~1.6 eV in HPSI substrates are identified and their roles in carrier compensation processes are discussed. Based on the results obtained in HPSI materials, we discuss the carrier compensation processes in vanadium-doped SI SiC substrates and different activation energies in the material.


2006 ◽  
Vol 527-529 ◽  
pp. 505-508
Author(s):  
W.C. Mitchel ◽  
William D. Mitchell ◽  
S.R. Smith ◽  
G.R. Landis ◽  
A.O. Evwaraye ◽  
...  

A variety of 4H-SiC samples from undoped crystals grown by the physical vapor transport technique have been studied by temperature dependent Hall effect, optical and thermal admittance spectroscopy and thermally stimulated current. In most samples studied the activation energies were in the range 0.9 - 1.6 eV expected for commercial grade HPSI 4H-SiC. However, in several samples from developmental crystals a previously unreported deep level at EC-0.55 ± 0.01 eV was observed. Thermal admittance spectroscopy detected one level with an energy of about 0.53 eV while optical admittance spectroscopy measurements resolved two levels at 0.56 and 0.64 eV. Thermally stimulated current measurements made to study compensated levels in the material detected several peaks at energies in the range 0.2 to 0.6 eV.


2005 ◽  
Vol 483-485 ◽  
pp. 377-380 ◽  
Author(s):  
Evgenia V. Kalinina ◽  
G. Kholuyanov ◽  
G. Onushkin ◽  
D.V. Davydov ◽  
Anatoly M. Strel'chuk ◽  
...  

The influence of the irradiation with neutrons, Kr+ (245 MeV) and Bi+ (710 MeV) ions on the optical and electrical properties of high-resistivity, high-purity 4H-SiC epitaxial layers grown by chemical vapor deposition was investigated using photoluminescence and deep-level transient spectroscopy. Electrical characteristics were studied using Al and Cr Schottky barriers as well as p+-n-n+ diodes fabricated by Al ion implantation on this epitaxial layers. It was found that both "light" neutrons and high energy heavy ions introduced identical defect centers in 4H-SiC. So, even at extremely high density of the ionization energy of 34 keV/nm, typical for Bi+ ion bombardment, damage structure formation in SiC single crystal is governed by energy loss in elastic collisions.


2002 ◽  
Vol 719 ◽  
Author(s):  
Masashi Kato ◽  
Masaya Ichimura ◽  
Eisuke Arai ◽  
Shigehiro Nishino

AbstractEpitaxial layers of 4H-SiC are grown on (0001) substrates inclined toward <1120> and <1100> directions. Defects in these films are characterized by deep level transient spectroscopy (DLTS) in order to clarify the dependence of concentrations and activation energies on substrate inclination. DLTS results show no such dependence on substrate inclination but show thickness dependence of the concentration.


1997 ◽  
Vol 482 ◽  
Author(s):  
Z-Q. Fang ◽  
J. W. Hemsky ◽  
D. C. Look ◽  
M. P. Mack ◽  
R. J. Molnar ◽  
...  

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.


1995 ◽  
Vol 395 ◽  
Author(s):  
X. Zhang ◽  
P. Kung ◽  
D. Walker ◽  
A. Saxler ◽  
M. Razeghi

ABSTRACTWe report the growth and photoluminescence characterization of GaN grown on different substrates and under different growth conditions using metalorganic chemical vapor deposition. The deep-level yellow luminescence centered at around 2.2eV is attributed to native defect, most possibly the gallium vacancy. The yellow luminescence can be substantially reduced By growing GaN under Ga-rich condition or doping GaN with Ge or Mg.


2015 ◽  
Vol 3 (31) ◽  
pp. 8074-8079 ◽  
Author(s):  
Changyong Lan ◽  
Chun Li ◽  
Yi Yin ◽  
Huayang Guo ◽  
Shuai Wang

Single-crystalline GeS nanoribbons were synthesized by chemical vapor deposition for the first time. The nanoribbon photodetectors respond to the entire visible incident light with a response edge at around 750 nm and a high responsivity, indicating their promising application for high performance broadband visible-light photo-detection.


2000 ◽  
Vol 88 (5) ◽  
pp. 2564-2569 ◽  
Author(s):  
D. J. Kim ◽  
D. Y. Ryu ◽  
N. A. Bojarczuk ◽  
J. Karasinski ◽  
S. Guha ◽  
...  

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