Growth kinetics and electronic properties of unintentionally doped semi-insulating GaN on SiC and high-resistivity GaN on sapphire grown by ammonia molecular-beam epitaxy

Journal Article · Sat May 15 04:00:00 EDT 2010 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.3415527· OSTI ID:21476252

Tang, H; Rolfe, S; Bardwell, J A; Raymond, S ^[1]; Fang, Z Q ^[2]

---

1. Institute for Microstructural Sciences, National Research Council Canada, Ottawa, Ontario K1A 0R6 (Canada)
2. Semiconductor Research Center, Wright State University, Dayton, Ohio 45435 (United States)

Growth of unintentionally doped (UID) semi-insulating GaN on SiC and highly resistive GaN on sapphire using the ammonia molecular-beam epitaxy technique is reported. The semi-insulating UID GaN on SiC shows room temperature (RT) resistivity of 10{sup 11} {Omega} cm and well defined activation energy of 1.0 eV. The balance of compensation of unintentional donors and acceptors is such that the Fermi level is lowered to midgap, and controlled by a 1.0 eV deep level defect, which is thought to be related to the nitrogen antisite N{sub Ga}, similar to the ''EL2'' center (arsenic antisite) in unintentionally doped semi-insulating GaAs. The highly resistive GaN on sapphire shows RT resistivity in range of 10{sup 6}-10{sup 9} {Omega} cm and activation energy varying from 0.25 to 0.9 eV. In this case, the compensation of shallow donors is incomplete, and the Fermi level is controlled by levels shallower than the 1.0 eV deep centers. The growth mechanisms for the resistive UID GaN materials were investigated by experimental studies of the surface kinetics during growth. The required growth regime involves a moderate growth temperature range of 740-780 deg. C, and a high ammonia flux (beam equivalent pressure of 1x10{sup -4} Torr), which ensures supersaturated coverage of surface adsorption sites with NH{sub x} radicals. Such highly nitrogen rich growth conditions lead to two-dimensional layer by layer growth and reduced oxygen incorporation.

• OSTI ID: 21476252
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 10 Vol. 107; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ACTIVATION ENERGY
ADSORPTION
AMMONIA
ARSENIC COMPOUNDS
ARSENIDES
CARBIDES
CARBON COMPOUNDS
CORUNDUM
CRYSTAL GROWTH
CRYSTAL GROWTH METHODS
DOPED MATERIALS
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ENERGY
ENERGY LEVELS
ENERGY RANGE
EPITAXY
EV RANGE
FERMI LEVEL
GALLIUM ARSENIDES
GALLIUM COMPOUNDS
GALLIUM NITRIDES
HYDRIDES
HYDROGEN COMPOUNDS
LAYERS
MATERIALS
MINERALS
MOLECULAR BEAM EPITAXY
NITRIDES
NITROGEN COMPOUNDS
NITROGEN HYDRIDES
OXIDE MINERALS
PHYSICAL PROPERTIES
PNICTIDES
RADICALS
SAPPHIRE
SEMICONDUCTOR MATERIALS
SILICON CARBIDES
SILICON COMPOUNDS
SORPTION
SURFACES
TEMPERATURE RANGE
TEMPERATURE RANGE 0273-0400 K