Defect-Related Donors, Acceptors, and Traps in GaN

✍ Scribed by D.C. Look

• Publisher: John Wiley and Sons
• Year: 2001
• Tongue: English
• Weight: 108 KB
• Volume: 228
• Category: Article
• ISSN: 0370-1972
• DOI: 10.1002/1521-3951(200111)228:1<293::aid-pssb293>3.0.co;2-f

✦ Synopsis

Point defects have been created in GaN by various types of irradiation: electrons (1 and 2.5 MeV, and the spectrum from 90 Sr); protons (0.15 MeV, 2 MeV, and 24 GeV); He ions (5.4 MeV); g-rays ( 60 Co); and sputtering and e-beam deposition of metals. They have been studied by temperaturedependent Hall-effect measurements (T-Hall), deep-level transient spectroscopy (DLTS), optically detected magnetic resonance (ODMR), positron annihilation spectroscopy (PAS), and photoluminescence (PL). Confirmed defect energies, and firm or tentative defect assignments, are as follows: T-Hall (donor at 0.06 eV, V N ); DLTS (electron trap at 0.18 eV (thermal 0.06 eV), V N ; electron trap at 0.9 eV, N I or Ga I -X); ODMR (Ga I and Ga I -X); PAS (V Ga ); PL (0.85 eV band with 0.88 eV zero-phonon line, O N or O N -Ga I ; 0.93 eV band; 3.37 eV line; 3.39 eV line). Many of these defect signatures have also been observed in as-grown GaN. Dislocations, of the threading-edge type, are found to be acceptor-like in n-type GaN.