Mechanism of carrier injection in (Ni/Au)/p-Al{sub x}Ga{sub 1-x}N:Mg(0{<=}x<0.1) Ohmic contacts

Journal Article · Mon Oct 19 00:00:00 EDT 2009 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.3242420· OSTI ID:21294374

Nikishin, S; Chary, I; Borisov, B; Kuryatkov, V ^[1]; Kudryavtsev, Yu; Asomoza, R ^[2]; Karpov, S Yu ^[3]; Holtz, M ^[4]

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1. Department of Electrical and Computer Engineering and Nano Tech Center, Texas Tech University, Lubbock, Texas 79409 (United States)
2. SIMS Laboratory of SEES, CINVESTAV, Mexico D.F.07300 (Mexico)
3. STR Group, Soft-Impact, Ltd., St. Petersburg 194156 (Russian Federation)
4. Department of Physics and Nano Tech Center, Texas Tech University, Lubbock, Texas 79409 (United States)

We report the mechanism of current injection in (Ni/Au)/p-Al{sub x}Ga{sub 1-x}N:Mg(0{<=}x<0.1) Ohmic contacts based on the temperature dependence of hole concentrations (p) and specific contact resistance ({rho}{sub c}). The injection mechanism is found to be thermionic emission in all cases. A model is developed to describe the temperature dependences of p and {rho}{sub c} for Mg concentrations from 10{sup 19} to 10{sup 20} cm{sup -3}. The model takes into account splitting in the valence band structure, hole activation energy, and Schottky barrier height. For GaN (AlGaN) these are found to be 132-140 (135-150) meV and 66-88 (84-93) meV, respectively.

• OSTI ID: 21294374
• Journal Information: Applied Physics Letters, Vol. 95, Issue 16; Other Information: DOI: 10.1063/1.3242420; (c) 2009 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ACTIVATION ENERGY
ALUMINIUM NITRIDES
CHARGE CARRIERS
GALLIUM NITRIDES
GOLD
HOLES
MAGNESIUM
NICKEL
SEMICONDUCTOR MATERIALS
TEMPERATURE DEPENDENCE
THERMIONIC EMISSION