Optoelectronic and structural properties of high-quality GaN grown by hydride vapor phase epitaxy

Conference · Fri Nov 01 04:00:00 EST 1996

OSTI ID:394950

Molnar, R J; Aggarwal, R; Liau, Z L; Brown, E R; Melngailis, I ^[1]; Goetz, W; Romano, L T; Johnson, N M ^[2]

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1. Massachusetts Inst. of Tech., Lexington, MA (United States). Lincoln Lab.
2. Xerox Palo Alto Research Center, CA (United States)

Gallium nitride (GaN) films have been grown by hydride vapor phase epitaxy (HVPE) in a vertical reactor design. The authors report on GaN growth directly on sapphire using a GaCl surface pretreatment. The electrical properties of these films compare favorably with the highest values reported in the literature for GaN. Specifically, a room temperature Hall mobility as high as 540 cm{sup 2}/V{center_dot}s, with a corresponding carrier concentration of 2 {times} 10{sup 17} cm{sup {minus}3}, have been attained. Additionally, the vertical reactor design has assisted in reducing nonuniformities in both film thickness as well as in transport properties due to depletion effects, as compared with horizontal designs. The dislocation density in these films has been determined by plan-view transmission electron microscopy to be {approximately} 3 {times} 10{sup 8} cm{sup {minus}2}. Photoluminescence spectra obtained at 2 K show intense, sharp, near-band edge emission with minimal deep level emissions.Stimulated emission has been observed in these films, utilizing a nitrogen laser pump source ({lambda} = 337.1 nm) with a threshold pump power of {approximately} 0.5 MW/cm{sup 2}. These results suggest that HVPE is viable for the growth of high-quality nitride films, particularly for the subsequent homoepitaxial overgrowth of device structures by other growth methods such as OMVPE and MBE.

• OSTI ID: 394950
• Report Number(s): CONF-951155--; ISBN 1-55899-298-7
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
42 ENGINEERING
CARRIER DENSITY
CHEMICAL VAPOR DEPOSITION
CRYSTAL STRUCTURE
DISLOCATIONS
ELECTRICAL PROPERTIES
ELECTRON DIFFRACTION
GALLIUM CHLORIDES
GALLIUM NITRIDES
HALL EFFECT
INTERFACES
LIGHT EMITTING DIODES
MATERIALS
OPTICAL PROPERTIES
PHOTOLUMINESCENCE
SAPPHIRE
STIMULATED EMISSION
SUBSTRATES
TRANSMISSION ELECTRON MICROSCOPY
X-RAY DIFFRACTION
ZINC OXIDES