Isotype InGaN/GaN heterobarrier diodes by ammonia molecular beam epitaxy

Journal Article · Sun Feb 07 04:00:00 EST 2016 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4941323· OSTI ID:22494997

Fireman, Micha N.; Browne, David A.; Speck, James S. ^[1]; Mishra, Umesh K. ^[2]

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1. Materials Department, University of California, Santa Barbara, California 93106 (United States)
2. Electrical and Computer Engineering Department, University of California, Santa Barbara, California 93106 (United States)

The design of isotype InGaN/GaN heterobarrier diode structures grown by ammonia molecular beam epitaxy is presented. On the (0001) Ga-polar plane, a structure consisting of a surface n{sup +} GaN contact layer, followed by a thin InGaN layer, followed by a thick unintentionally doped (UID) GaN layer, and atop a buried n{sup +} GaN contact layer induces a large conduction band barrier via a depleted UID GaN layer. Suppression of reverse and subthreshold current in such isotype barrier devices under applied bias depends on the quality of this composite layer polarization. Sample series were grown under fixed InGaN growth conditions that varied either the UID GaN NH{sub 3} flow rate or the UID GaN thickness, and under fixed UID GaN growth conditions that varied InGaN growth conditions. Decreases in subthreshold current and reverse bias current were measured for thicker UID GaN layers and increasing InGaN growth rates. Temperature-dependent analysis indicated that although extracted barrier heights were lower than those predicted by 1D Schrödinger Poisson simulations (0.9 eV–1.4 eV for In compositions from 10% to 15%), optimized growth conditions increased the extracted barrier height from ∼11% to nearly 85% of the simulated values. Potential subthreshold mechanisms are discussed, along with those growth factors which might affect their prevalence.

• OSTI ID: 22494997
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 5 Vol. 119; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
AMMONIA
DOPED MATERIALS
GALLIUM NITRIDES
MOLECULAR BEAM EPITAXY
POLARIZATION
SIMULATION