Radiation-induced deep levels in n-type GaAs grown by metal-organic chemical-vapor deposition

• Published in: Physica. B, Condensed matter Vol. 404; no. 23-24; pp. 4981 - 4983
• Main Authors: Naz, Nazir A., Qurashi, Umar S., Zafar Iqbal, M.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.12.2009
• Subjects: Deep levels; DLTS; GaAs; Irradiation; MOCVD; Irradiation; GaAs; MOCVD; Deep levels; DLTS
• ISSN: 0921-4526; 1873-2135
• DOI: 10.1016/j.physb.2009.08.204

We report a comprehensive study of deep levels in the entire band gap of alpha-irradiated n-type GaAs, grown by metal-organic vapor phase epitaxy (MOVPE), over a wide temperature scan range of 12–475K. Deep level transient spectroscopy (DLTS) reveals the presence of, at least, seven radiation-induced deep level defects at energy positions Ec−0.05eV, Ec−0.14eV, Ec−0.19eV, Ec−0.34eV, Ec−0.38eV, Ec−0.59eV and Ec−0.69eV in the upper-half of the band gap, while two radiation-induced defects at energy positions Ev+0.54eV and Ev+0.77eV were observed in the lower-half band gap. Some significant differences have been observed with respect to the published work on Schottky barrier diodes. Detailed data on the emission rates, capture cross-sections and introduction rates of the radiation-induced defects are presented. The majority carrier emitting levels at Ec−0.05eV and Ec−0.14eV have been found to have electric-field-dependent emission rate signatures.