Structural defects in heteroepitaxial and homoepitaxial GaN
- Lawrence Berkeley Lab., CA (United States). Materials Science Div.; and others
The microstructure and characterization defects of heteroepitaxial GaN films grown on sapphire using molecular beam epitaxy (MBE) and metal-organic-chemical-vapor-deposition (MOCVD) methods and of homoepitaxial GaN grown on bulk substrates are described based on transmission electron microscopy (TEM), x-ray diffraction, and cathodoluminescence (CL) studies. The difference in arrangement of dislocations along grain boundaries and the influence of buffer layers on the quality of epitaxial films is described. The structural quality of GaN epilayers is compared to that of bulk GaN crystals grown from dilute solution of atomic nitrogen in liquid gallium. The full width at half maximum (FWHM) of the x-ray rocking curves for these crystals was in the range of 20--30 arc sec, whereas for the heteroepitaxially grown GaN the FWHM was in the range of 5--20 arc min. Homoepitaxial MBE grown films had FWHMs of about 40 arc sec. The best film quality was obtained for homoepitaxial films grown using MOCVD; these samples were almost free from extended defects. For the bulk GaN crystals a substantial difference in crystal perfection was observed for the opposite sides of the plates shaped normal to the c direction. A large difference in crystal stoichiometry was also observed within different sublayers of the crystals. Based on convergent beam electron diffraction and cathodoluminescence, it is proposed that Ga{sub N} antisite defects are related to the yellow luminescence observed in these crystals.
- DOE Contract Number:
- AC03-76SF00098
- OSTI ID:
- 394975
- Report Number(s):
- CONF-951155-; ISBN 1-55899-298-7; TRN: IM9648%%52
- Resource Relation:
- Conference: Fall meeting of the Materials Research Society (MRS), Boston, MA (United States), 27 Nov - 1 Dec 1995; Other Information: PBD: 1996; Related Information: Is Part Of Gallium nitride and related materials; Ponce, F.A. [ed.] [Xerox Palo Alto Research Center, CA (United States)]; Dupuis, R.D. [ed.] [Univ. of Texas, Austin, TX (United States)]; Nakamura, S. [ed.] [Nichia Chemical Industries, Tokushima (Japan)]; Edmond, J.A. [ed.] [Cree Research, Inc., Durham, NC (United States)]; PB: 993 p.; Materials Research Society symposium proceedings, Volume 395
- Country of Publication:
- United States
- Language:
- English
Similar Records
Proton irradiation effects on minority carrier diffusion length and defect introduction in homoepitaxial and heteroepitaxial n-GaN [Proton irradiation effects on minority carrier diffusion length and defect introduction in homoepitaxial n-GaN]
Molecular beam homoepitaxy of N-polar AlN: Enabling role of aluminum-assisted surface cleaning
Related Subjects
42 ENGINEERING NOT INCLUDED IN OTHER CATEGORIES
GALLIUM NITRIDES
CHEMICAL VAPOR DEPOSITION
PHYSICAL VAPOR DEPOSITION
MICROSTRUCTURE
CRYSTAL DEFECTS
OPTICAL PROPERTIES
LIGHT EMITTING DIODES
SEMICONDUCTOR MATERIALS
SAPPHIRE
MOLECULAR BEAM EPITAXY
ORGANOMETALLIC COMPOUNDS
TRANSMISSION ELECTRON MICROSCOPY
X-RAY DIFFRACTION
CATHODOLUMINESCENCE
BURGERS VECTOR
DISLOCATIONS
GRAIN BOUNDARIES
STACKING FAULTS