Identification of electron-irradiation defects in semi-insulating GaAs by normalized thermally stimulated current measurements

Abstract

Primary defects induced by 1 MeV electron irradiation have been quantitatively studied in semi-insulating ͑SI͒ GaAs by using normalized thermally stimulated current spectroscopy, a new technique. Defects identical to ͑or similar to͒ those known in the thermally stimulated current literature as T 6 *(0.13 eV), T 5 ͑0.34 eV͒, and T 4 ͑0.31 eV͒ are produced at rates 0.70, 0.08, and 0.23 cm Ϫ1 , respectively; T 5 is also a strong trap in unirradiated SI GaAs. The defects T 6 * and T 4 correspond closely to the irradiation-induced traps E2͑0.14 eV͒ and E3͑0.30 eV͒, studied extensively by deep-level transient spectroscopy and Hall-effect measurements and assigned to the As vacancy. We thus infer that traps T 6 * and T 4 ͑and probably also T 5 ͒ in SI GaAs have As-vacancy character. ͓S0163-1829͑97͒04503-7͔

Electron Irradiation Induced Trap In N-Type Gan

“…energy necessary to displace an atom will be a few hundred keV; thus the common choice of 1-MeV irradiation will produce only one, or at most a few, displacements and no massive damage, such as is often found with heavy-ion irradiation. In the case of El induced defects in GaAs, either semiconducting or semi-insulating, it was concluded that the major defects induced by 1-MeV electrons are associated with the displacement of As atoms, resulting in As Frenkel pairs, VA.-Asi [11,13]. The EI-induced trap E3 in n-type GaAs, mentioned above, has a thermal activation energy of 0.3 eV, with a Franck-Condon shift of 0.2 eV, and is believed to be related to the As Frenkel pair [11].…”

“…Based on the effects of 270-keV N 2 1 implantation and annealing, two deep centers, with activation energies of 0.60 eV and 0.67 eV, are believed to be N antisite and N interstitial, respectively [9]. Although vacancy defects in Si [10] and GaAs [11][12][13] induced by high-energy electron irradiation (EI) have been extensively studied in the past, only two, recent studies have been conducted in GaN [14,15], to our knowledge. In the first of these, Linde et al [14] used optically detected magnetic resonance of a photoluminescence band at 0.93 eV, produced by 2.5-MeV-electron irradiation, to obtain a tentative identification of a Gainterstitial complex.…”

Thermally stimulated current spectroscopy of high-purity semi-insulating 4H-SiC substrates

“…1,2 To control the material quality, it is important to understand the nature of the deep traps in the SI material. To this end, we have successfully applied thermally stimulated current (TSC) spectroscopy, which is known to be a very sensitive technique for investigating point-defect and impurity-related traps in various SI semiconductors, such as HPSI GaAs and InP, [3][4][5] and carbon-doped SI-GaN. 6 In this paper, we present (1) the fundamentals of TSC spectroscopy; (2) typical TSC spectra measured on two types of HPSI 4H-SiC material, grown by physical vapor transport (PVT) 1 and high-temperature chemical vapor deposition (HTCVD); 2 and (3) theoretical fitting of a dominant hole trap (peaking at ϳ150 K) related to boron.…”

Deep centers in undoped semi-insulating InP

“…5,6 Although the application of the TSC technique to Fe-doped InP has revealed at least six traps in the range 80 to 250K, 7-9 the connection of these deep centers with particular point defects in SI InP is still not clear. 5,6 Although the application of the TSC technique to Fe-doped InP has revealed at least six traps in the range 80 to 250K, 7-9 the connection of these deep centers with particular point defects in SI InP is still not clear.…”