The microstructural study of aluminum nitride thin films: Epitaxy on the two orientations of sapphire and texturing on Si
- North Carolina State Univ., Raleigh, NC (United States). Dept. of Materials Science and Engineering
- Northwestern Univ., Evanston, IL (United States). Center for Quantum Devices
The microstructural study of wide-band gap semiconductor AlN thin films grown on (0001) and (10{bar 1}2) sapphire and (111), (100) Si was carried out using plan-view and cross-sectional high-resolution electron microscopy and x-ray diffraction. The films were grown by MOCVD from TMAl + NH{sub 3} + N{sub 2} gas mixture. Epitaxial relationship for AlN grown on (0001) {alpha}-Al{sub 2}O{sub 3} was determined to be the following: (0001){sub AlN} {parallel} (0001){sub sap} with the 30{degree} in-plane rotation--[01{bar 1}0]{sub AlN} {parallel} [{bar 1}2{bar 1}0]{sub sap}. The authors report also TEM observation of the following epitaxial relationship of the AlN/(10{bar 1}2){alpha}-Al{sub 2}O{sub 3} heterostructure: (11{bar 2}0){sub AlN} {parallel} (10{bar 1}2){sub sap}; [0001]{sub AlN} {parallel} [{bar 1}011]{sub sap} and [1{bar 1}00]{sub AlN} {parallel} [1{bar 2}10]{sub sap}. These epitaxial relationships were determined to be controlled by the bonding of Al and O ions at the interface. The study of interfaces and the defects present in the film was also carried out. Main type of defects were established to be inverted domain boundaries, misfit and threading dislocations--in the films on (0001) sapphire, and stacking faults of high density in the films on (10{bar 1}2) sapphire. The epitaxial AlN films on (0001) sapphire, and stacking faults of high density in the films on (10{bar 1}2) sapphire. The epitaxial AlN films on (001) sapphire contained dislocation density about 10{sup 10} cm{sup {minus}2} and exhibited device quality electrical characteristics. The films on both orientations of Si were found to be highly <0001> textured polycrystalline.
- OSTI ID:
- 394980
- Report Number(s):
- CONF-951155--; ISBN 1-55899-298-7
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
42 ENGINEERING
ALUMINIUM NITRIDES
AMMONIA
BURGERS VECTOR
CHEMICAL VAPOR DEPOSITION
DISLOCATIONS
ELECTRON DIFFRACTION
HYDROGEN
LASERS
LIGHT EMITTING DIODES
MICROSTRUCTURE
ORGANOMETALLIC COMPOUNDS
ORIENTATION
SEMICONDUCTOR MATERIALS
STACKING FAULTS
SUBSTRATES
TRANSMISSION ELECTRON MICROSCOPY
X-RAY DIFFRACTION