Electrical characterization of alpha radiation-induced defects in p-GaAs grown by metal-organic chemical-vapor deposition
Abstract
Investigations of the alpha particle irradiation-induced defects in low-pressure metal-organic chemical-vapor deposition grown p-GaAs have been carried out. By employing deep-level transient spectroscopy, at least seven radiation-induced deep-level defects have been observed in the lower half of the band gap in the temperature range of 12-475 K. Double-correlation deep-level transient spectroscopy measurements show three prominent levels: two known radiation-induced levels namely, H{alpha}1 and H{alpha}5, and one inadvertent center HSA, present before irradiation, to exhibit a significant dependence of thermal emission rate on the junction electric field. For H{alpha}1 and HSA the field-enhanced emission data are well fitted with a Poole-Frenkel model, using a three-dimensional square-well potential with radius r=3.2 and 1.43 nm, respectively. The field effect for H{alpha}5 has been explained by a square-well potential in combination with a phonon-assisted tunneling process. Detailed data on the carrier capture cross section for all three levels have been obtained. The hole capture cross section for the levels H{alpha}1 and H{alpha}5 are found to be temperature independent, while for HSA, the hole capture data show a dependence on temperature. The dependence of hole capture cross section of HSA on temperature has been explained in terms of multiphonon capture mechanism, yielding a capture barriermore »
- Authors:
- Semiconductor Physics Laboratory, Department of Physics, Quaid-I-Azam University, Islamabad 45320 (Pakistan)
- Publication Date:
- OSTI Identifier:
- 20982762
- Resource Type:
- Journal Article
- Resource Relation:
- Journal Name: Journal of Applied Physics; Journal Volume: 101; Journal Issue: 6; Other Information: DOI: 10.1063/1.2710298; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 36 MATERIALS SCIENCE; ALPHA PARTICLES; CAPTURE; CHARGE CARRIERS; CHEMICAL VAPOR DEPOSITION; CROSS SECTIONS; DEEP LEVEL TRANSIENT SPECTROSCOPY; ELECTRIC FIELDS; ENERGY GAP; FIELD EMISSION; GALLIUM ARSENIDES; HOLES; IRRADIATION; PHONONS; SQUARE-WELL POTENTIAL; TEMPERATURE RANGE 0000-0013 K; TEMPERATURE RANGE 0013-0065 K; TEMPERATURE RANGE 0065-0273 K; TEMPERATURE RANGE 0273-0400 K; TEMPERATURE RANGE 0400-1000 K; TUNNEL EFFECT
Citation Formats
Naz, Nazir A., Qurashi, Umar S., and Iqbal, M. Zafar. Electrical characterization of alpha radiation-induced defects in p-GaAs grown by metal-organic chemical-vapor deposition. United States: N. p., 2007.
Web. doi:10.1063/1.2710298.
Naz, Nazir A., Qurashi, Umar S., & Iqbal, M. Zafar. Electrical characterization of alpha radiation-induced defects in p-GaAs grown by metal-organic chemical-vapor deposition. United States. doi:10.1063/1.2710298.
Naz, Nazir A., Qurashi, Umar S., and Iqbal, M. Zafar. Thu .
"Electrical characterization of alpha radiation-induced defects in p-GaAs grown by metal-organic chemical-vapor deposition". United States.
doi:10.1063/1.2710298.
@article{osti_20982762,
title = {Electrical characterization of alpha radiation-induced defects in p-GaAs grown by metal-organic chemical-vapor deposition},
author = {Naz, Nazir A. and Qurashi, Umar S. and Iqbal, M. Zafar},
abstractNote = {Investigations of the alpha particle irradiation-induced defects in low-pressure metal-organic chemical-vapor deposition grown p-GaAs have been carried out. By employing deep-level transient spectroscopy, at least seven radiation-induced deep-level defects have been observed in the lower half of the band gap in the temperature range of 12-475 K. Double-correlation deep-level transient spectroscopy measurements show three prominent levels: two known radiation-induced levels namely, H{alpha}1 and H{alpha}5, and one inadvertent center HSA, present before irradiation, to exhibit a significant dependence of thermal emission rate on the junction electric field. For H{alpha}1 and HSA the field-enhanced emission data are well fitted with a Poole-Frenkel model, using a three-dimensional square-well potential with radius r=3.2 and 1.43 nm, respectively. The field effect for H{alpha}5 has been explained by a square-well potential in combination with a phonon-assisted tunneling process. Detailed data on the carrier capture cross section for all three levels have been obtained. The hole capture cross section for the levels H{alpha}1 and H{alpha}5 are found to be temperature independent, while for HSA, the hole capture data show a dependence on temperature. The dependence of hole capture cross section of HSA on temperature has been explained in terms of multiphonon capture mechanism, yielding a capture barrier of 0.13 eV and {sigma}({infinity})=1.5x10{sup -14} cm{sup 2}. These analyses lead us to conclude that the levels H{alpha}1 and HSA are associated with a charged center, while the level H{alpha}5 is most likely a substitutional defect in GaAs.},
doi = {10.1063/1.2710298},
journal = {Journal of Applied Physics},
number = 6,
volume = 101,
place = {United States},
year = {Thu Mar 15 00:00:00 EDT 2007},
month = {Thu Mar 15 00:00:00 EDT 2007}
}
-
This paper reports a detailed study of the effects of irradiation and thermal annealing on deep levels in Rh-doped p-type GaAs grown by low-pressure metal-organic chemical-vapor deposition, using deep level transient spectroscopy (DLTS) technique. It is found upon irradiation with alpha particles that, in addition to the radiation-induced defect peaks, all the Rh-related peaks observed in majority, as well as minority-carrier emission DLTS scans show an increase in their respective concentrations. The usually observed {alpha}-induced defects H{alpha}1, H{alpha}2, and H{alpha}3 are found to have lower introduction rates in Rh-doped samples, as compared to reference samples (not doped with Rh). Alpha-irradiationmore »
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Comparison of electrical properties and deep traps in p-Al{sub x}Ga{sub 1-x}N grown by molecular beam epitaxy and metal organic chemical vapor deposition
The electrical properties, admittance spectra, microcathodoluminescence, and deep trap spectra of p-AlGaN films with an Al mole fraction up to 45% grown by both metal organic chemical vapor deposition (MOCVD) and molecular beam epitaxy (MBE) were compared. The ionization energy of Mg increases from 0.15 to 0.17 eV in p-GaN to 0.3 eV in 45% Al p-AlGaN. In p-GaN films grown by MBE and MOCVD and in MOCVD grown p-AlGaN, we observed additional acceptors with a concentration an order lower than that of Mg acceptors, with a higher hole capture cross section and an ionization energy close to that ofmore » -
As-grown deep-level defects in n-GaN grown by metal-organic chemical vapor deposition on freestanding GaN
Traps of energy levels E{sub c}-0.26 and E{sub c}-0.61 eV have been identified as as-grown traps in n-GaN grown by metal-organic chemical vapor deposition by using deep level transient spectroscopy of the Schottky contacts fabricated by resistive evaporation. The additional traps of E{sub c}-0.13 and E{sub c}-0.65 eV have been observed in samples whose contacts are deposited by electron-beam evaporation. An increase in concentration of the E{sub c}-0.13 and E{sub c}-0.65 eV traps when approaching the interface between the contact and the GaN film supports our argument that these traps are induced by electron-beam irradiation. Conversely, the depth profiles ofmore »