MOVPE growth of high electron mobility AlGaN/GaN heterostructures
- Advanced Technology Materials, Inc., Danbury, CT (United States)
- Electronic and Optical materials Branch, Wright-Patterson AFB, OH (United States)
The authors have fabricated Al{sub x}Ga{sub 1{minus}x}N/GaN heterostructures with high two-dimensional electron gas (2DEG) mobilities and high sheet carrier densities by metalorganic vapor phase epitaxy (MOVPE). The 2DEG sheet density and mobility exhibit a compositional dependence on the Al fraction of the electron donor layer. The highest mobility (5,750 cm{sup 2}/Vs at 16K) was measured in a sample with x = 0.15 that had a sheet carrier density of 8.5 {times} 10{sup 12} cm{sup {minus}2}. The undoped Al{sub x}Ga{sub 1{minus}x}N layers have low background carrier concentrations and can be intentionally doped n-type using SiH{sub 4}. The effect of intentional n-type doping of the Al{sub x}Ga{sub 1{minus}x}N donor layer on the electrical properties of the 2DEG was studied in structures that included an undoped Al{sub x}Ga{sub 1{minus}x}N spacer layer of varying thickness. Higher 2DEG mobilities were obtained when a 100{angstrom} thick undoped layer was included in the structure due to spatial separation of the 2DEG from ionized impurities in the doped Al{sub x}Ga{sub 1{minus}x}N. These initial results demonstrate that the electrical properties of Al{sub x}Ga{sub 1{minus}x}N/GaN heterostructures can be controlled by intentional doping and appropriate layer design.
- OSTI ID:
- 394952
- 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
CARRIER DENSITY
CHEMICAL VAPOR DEPOSITION
COMPOSITE MATERIALS
CRYSTAL STRUCTURE
DOPED MATERIALS
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ELECTRON MOBILITY
ELECTRONIC EQUIPMENT
EXPERIMENTAL DATA
GALLIUM NITRIDES
HALL EFFECT
HYDROGEN
INTERFACES
ORGANOMETALLIC COMPOUNDS
SAPPHIRE
SEMICONDUCTOR MATERIALS
SILICON
X-RAY DIFFRACTION