Effects of irradiation and annealing on deep levels in rhodium-doped p-GaAs grown by metal-organic chemical-vapor deposition

Journal Article · Wed Jun 01 00:00:00 EDT 2011 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.3575328· OSTI ID:21538410

Naz, Nazir A; Qurashi, Umar S; Iqbal, M Zafar ^[1]

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1. Semiconductor Physics Laboratory, Department of Physics, Quaid-i-Azam University, Islamabad 45320 (Pakistan)

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-irradiation has been found to decompose the two minority carrier emitting bands (one at low temperature {approx}150 K and the other at {approx}380 K) observed prior to irradiation into distinct peaks corresponding to deep levels Rh1 and Rh2 and EL2 and Rh3, respectively. A similar effect is also observed for the majority-carrier emitting band composed of hole emission from deep levels RhA and RhB, which separate out well upon irradiation. Further, from the double-correlation DLTS measurements, the emission rates of carriers from the radiation-enhanced peaks corresponding to deep levels Rh1, Rh2, Rh3, and RhC were found to be dependent on junction electric field. For RhC, the field dependence data have been analyzed in terms of the Poole-Frenkel model employing a 3-dimensional Coulomb potential with q = 2e (electronic charge). Temperature dependence of the hole capture cross-sections of the levels RhA and RhC was also studied quantitatively. The observed dependence of the hole capture cross-section of RhC on temperature can be interpreted in terms of multiphonon capture model, yielding a capture barrier of 0.2 eV and {sigma}({infinity}) = 2.3 x 10{sup -14} cm{sup 2}. The results of irradiation and isochronal thermal annealing study, in combination with the theoretical analysis of the field dependence of hole emission data, lead us to interpret the levels RhA and RhB as charged centers and probably complexes of arsenic anti-site defect (As{sub Ga}) with Rh-impurity, (As{sub Ga}-Rh). The levels Rh1 and Rh2 are also proposed to be complexes, albeit of a different type, of arsenic anti-site defects (As{sub Ga}) and Rh-impurity (As{sub Ga}-Rh), while the level RhC is likely to be a doubly-charged complex center composed of arsenic interstitial (I{sub As}) and Rh-impurity (I{sub As}-Rh).

• OSTI ID: 21538410
• Journal Information: Journal of Applied Physics, Vol. 109, Issue 11; Other Information: DOI: 10.1063/1.3575328; (c) 2011 American Institute of Physics; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
36 MATERIALS SCIENCE
ACTIVATION ENERGY
ALPHA PARTICLES
ANNEALING
CAPTURE
CHEMICAL VAPOR DEPOSITION
COULOMB FIELD
CROSS SECTIONS
CRYSTAL DEFECTS
DEEP LEVEL TRANSIENT SPECTROSCOPY
DOPED MATERIALS
ELECTRON BEAMS
EMISSION
GALLIUM ARSENIDES
IMPURITIES
INTERSTITIALS
LAYERS
PHYSICAL RADIATION EFFECTS
P-TYPE CONDUCTORS
RHODIUM ADDITIONS
TEMPERATURE DEPENDENCE
ALLOYS
ARSENIC COMPOUNDS
ARSENIDES
BEAMS
CHARGED PARTICLES
CHEMICAL COATING
CRYSTAL STRUCTURE
DEPOSITION
ELECTRIC FIELDS
ENERGY
GALLIUM COMPOUNDS
HEAT TREATMENTS
IONIZING RADIATIONS
LEPTON BEAMS
MATERIALS
PARTICLE BEAMS
PLATINUM METAL ALLOYS
PNICTIDES
POINT DEFECTS
RADIATION EFFECTS
RADIATIONS
RHODIUM ALLOYS
SEMICONDUCTOR MATERIALS
SPECTROSCOPY
SURFACE COATING
TRANSITION ELEMENT ALLOYS