Experimental elucidation of vacancy complexes associated with hydrogen ion-induced splitting of bulk GaN

Journal Article · Mon Mar 15 00:00:00 EDT 2010 · Physical Review. B, Condensed Matter and Materials Physics

DOI:https://doi.org/10.1103/PHYSREVB.81.115205· OSTI ID:21366704

Moutanabbir, O; Scholz, R; Goesele, U; Guittoum, A; Jungmann, M; Butterling, M; Krause-Rehberg, R; Anwand, W; Egger, W; Sperr, P ^[1]

---

1. Max Planck Institute of Microstructure Physics, Weinberg 2, Halle (Saale) 06120 (Germany)

We present a detailed study of the thermal evolution of H ion-induced vacancy related complexes and voids in bulk GaN implanted under ion-cut conditions. By using transmission electron microscopy, we found that the damage band in as-implanted GaN is decorated with a high density of nanobubbles of approx1-2 nm in diameter. Variable energy Doppler broadening spectroscopy showed that this band contains vacancy clusters and voids. In addition to vacancy clusters, the presence of V{sub Ga}, V{sub Ga}-H{sub 2}, and V{sub Ga}V{sub N} complexes was evidenced by pulsed low-energy positron lifetime spectroscopy. Subtle changes upon annealing in these vacancy complexes were also investigated. As a general trend, a growth in open-volume defects is detected in parallel to an increase in both size and density of nanobubbles. The observed vacancy complexes appear to be stable during annealing. However, for temperatures above 450 deg. C, unusually large lifetimes were measured. These lifetimes are attributed to the formation of positronium in GaN. Since the formation of positronium is not possible in a dense semiconductor, our finding demonstrates the presence of sufficiently large open-volume defects in this temperature range. Based on the Tao-Eldrup model, the average lattice opening during thermal annealing was quantified. We found that a void diameter of 0.4 nm is induced by annealing at 600 deg. C. The role of these complexes in the subsurface microcracking is discussed.

• OSTI ID: 21366704
• Journal Information: Physical Review. B, Condensed Matter and Materials Physics, Vol. 81, Issue 11; Other Information: DOI: 10.1103/PhysRevB.81.115205; (c) 2010 The American Physical Society; ISSN 1098-0121
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ANNEALING
COMPLEXES
CRYSTAL DEFECTS
DENSITY
DOPPLER BROADENING
GALLIUM NITRIDES
HYDROGEN IONS
ION IMPLANTATION
LIFETIME
PHYSICAL RADIATION EFFECTS
POINT DEFECTS
POSITRONIUM
POSITRONS
SEMICONDUCTOR MATERIALS
SPECTROSCOPY
TEMPERATURE RANGE
TEMPERATURE RANGE 0400-1000 K
TRANSMISSION ELECTRON MICROSCOPY
VACANCIES
ANTILEPTONS
ANTIMATTER
ANTIPARTICLES
CHARGED PARTICLES
CRYSTAL STRUCTURE
ELECTRON MICROSCOPY
ELEMENTARY PARTICLES
FERMIONS
GALLIUM COMPOUNDS
HEAT TREATMENTS
IONS
LEPTONS
LINE BROADENING
MATERIALS
MATTER
MICROSCOPY
NITRIDES
NITROGEN COMPOUNDS
PHYSICAL PROPERTIES
PNICTIDES
RADIATION EFFECTS