Electrical and Optical Properties of 1 MeV-electron irradiated AlxGa1-xN

2004 ◽  
Vol 831 ◽  
Author(s):  
Michael R. Hogsed ◽  
Mo Ahoujja ◽  
Mee-Yi Ryu ◽  
Yung Kee Yeo ◽  
James C. Petrosky ◽  
...  

ABSTRACTThe optical and electrical properties of Si doped GaN and Al0.20Ga0.80N films irradiated with 1 MeV electrons at a fluence of 1×1017 cm−2 are investigated using cathodoluminescence (CL), variable-temperature Hall-effect, and deep level transient spectroscopy (DLTS) measurements. The CL spectra measured at 6 K show peak luminescence intensity of the near band edge decreases, on average, by 50% after electron irradiation, indicating the creation of non-radiative recombination centers which are stable at room temperature. At room temperature, the free carrier concentration decreases significantly in both the GaN and AlGaN samples following the irradiation, and the carrier removal rate depends strongly on the initial carrier concentration. DLTS measurements show three electron traps in the as-grown Al0.20Ga0.80N. Following 1 MeV electron irradiation of the Al0.20Ga0.80N sample, three additional electron traps labeled R2, R3, and R4 are observed. The first two traps appear to correspond to radiation-induced traps reported in GaN while the latter appears to be unique to AlGaN.

2015 ◽  
Vol 242 ◽  
pp. 308-311 ◽  
Author(s):  
Nikolai Yarykin ◽  
Jörg Weber

The spectrum of defects produced by 5 MeV electron irradiation in oxygen-lean p-type silicon strongly contaminated with interstitial copper (Cui) is studied using the deep-level transient spectroscopy. It is observed that the room-temperature irradiation creates a large amount of CuPL centers (complexes including one substitutional and three interstitial Cu atoms). The analysis shows that this process is govern by formation of the substitutional copper atoms due to the direct reaction between irradiation-induced vacancies and mobile Cui species. This reaction consumes nearly all irradiation-induced vacancies and affects strongly the standard spectrum of radiation defects.


1996 ◽  
Vol 442 ◽  
Author(s):  
Akira Ito ◽  
Hiroyuki Iwata ◽  
Yutaka Tokuda

AbstractThe change of the concentration of electron traps in n-type Si induced by P+ implantation (300keV, l×109 cm−2) with subsequent H+-implantation has been studied by deep level transient spectroscopy. H+-implantation is performed at room temperature to a dose of 2×1010cm−2 in the range 30 to 120keV. First P+ implantation induces six electron traps (Ec-0.12, 0.15, 0.21, 0.26, 0.39, 0.49eV). H+-implantation additionally induces an electron trap (Ec-0.32eV) which is related to hydrogen. The subsequent H+-implantation partly decreases the concentration of the electron traps induced by P+ implantation, although it increases the concentrations near the H+ projected range. 30 keV H+-implantation is mdst effective to reduce the trap concentration. The reduction of the concentration of the traps is ascribed to the reaction of pre-existing defects with interstitial or vacancy defects formed by subsequent H+-implantation.


2004 ◽  
Vol 815 ◽  
Author(s):  
A. O. Evwaraye ◽  
S. R. Smith ◽  
W. C. Mitchel ◽  
G. C. Farlow ◽  
M. A. Capano

AbstractArgon ions (Ar+) were implanted into n-type 4H-SiC epitaxial layers at 600 °C. The energy of the ions was 160 keV and at a dose of 2 × 1016 cm−2. After post-implantation annealing at 1600 °C, Schottky diodes were fabricated on the ion implanted samples. Bulk n-type 4H-SiC samples were irradiated at room temperature with 1 MeV electrons at doses of 1 × 1016 to 5.1 × 1017 el/cm2. The current density of the beam was 0.91 μA/cm2. Deep Level Transient Spectroscopy (DLTS) was used to characterize the induced defects. DLTS studies of Ar+ implanted samples showed six defect levels at EC – 0.18 eV, EC – 0.23eV, EC – 0.31eV, EC – 0.38 eV, EC – 0.72 eV, and EC – 0.81 eV. Z1/Z2 defect is the dominant defect in the electron irradiated sample and anneals out completely after 10 minutes at 1000 °C. However, Z1/Z2 defect in Ar+ implanted samples was stable up to 1600 °C. It is suggested that the annealing behavior of Z1/Z2 depends on the source of its formation.


2007 ◽  
Vol 131-133 ◽  
pp. 485-490
Author(s):  
Łukasz Gelczuk ◽  
Grzegorz Jóźwiak ◽  
Marcin Motyka ◽  
Maria Dąbrowska-Szata

The studies of electrical activity of deep electron traps and the optical response of partially-strain relaxed InxGa1-xAs layers (x=5.5%, 7.7% and 8.6%) grown by metalorganic vapourphase epitaxy (MOVPE) have been performed by means of deep-level transient spectroscopy (DLTS) and photoreflectance (PR). DLTS measurements revealed two electron traps. One of the trap has been attributed to electron states at α-type misfit dislocations. The other trap has been ascribed to the EL2 point defect. The PR spectra at room temperature were measured and analysed. By applying the results of theoretical calculations which include excitonic and strain effects, we were able to estimate the extent of strain relaxation and the values of residual strain in the partially relaxed epitaxial layers.


1998 ◽  
Vol 510 ◽  
Author(s):  
Min Gong ◽  
C. D. Beling ◽  
S. Fung ◽  
G. Brauer ◽  
H. Wirth ◽  
...  

AbstractTwo deep levels, located at Ev+0.26eV and Ec-0.44eV, in Al-implanted n-type samples and one at Ev+0.48eV in p-type samples have been observed by the deep level transient spectroscopy. The level of is identified as the shallower aluminum-acceptor. The 1.7 MeV electron-irradiation, used as a probe to distinguish the implantation induced deep-levels, induces at least six electron traps in the n-SiC and one hole-trap in the p-type material. The peak positions of these deep-levels in DLTS spectra are quite different from those induced by Al-implantation. This result suggests that various damages are formed after heavy ion (Al) and light particle (e) irradiation.


2015 ◽  
Vol 242 ◽  
pp. 302-307
Author(s):  
Nikolai Yarykin ◽  
Jörg Weber

The spectrum of defects produced by 5 MeV electron irradiation at room temperature in the oxygen-lean p-type silicon strongly contaminated with interstitial copper (Cui) is studied using the deep-level transient spectroscopy. It is observed that the interstitial carbon defects (Ci), which are abundant in irradiated copper-free samples, are not detected directly after irradiation. The phenomenon is attributed to the formation of a {Cui, Ci} complexes which exhibit no deep levels in the lower half of the band gap. The complexes are shown to dissociate under anneals at 300-340 K resulting in the appearance of the Ci species.


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.


2008 ◽  
Vol 607 ◽  
pp. 134-136
Author(s):  
Y.J. Zhang ◽  
Ai Hong Deng ◽  
You Wen Zhao ◽  
J. Yu ◽  
X.X. Yu ◽  
...  

Positron annihilation lifetime (PAL) spectroscopy,photo-induced current transient spectroscopy (PICTS) and thermally stimulated current (TSC) have been employed to study the formation of compensation defects and their evolvement under iron phosphide (IP) ambience or pure phosphide (PP) ambience. In the formation of IP SI-InP, the diffusion of Fe atoms suppresses the formation of some open-volume defects. As to PP SI-InP, VInH4 complexes dissociate into acceptor vacancies VInHn(n-3)(n=0,1,2,3), which compensate residual donor type defects and make the sample semi-insulating. Electron irradiation-induced deep level defects have been studied by TSC in PP and IP SI-InP, respectively. In contrast to a high concentration of irradiation-induced defects in as-grown and PP annealed InP, IP SI-InP has a very low concentration of defects.


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