Dual passivation of GaAs (110) surfaces using O{sub 2}/H{sub 2}O and trimethylaluminum

Journal Article · Sat Dec 28 00:00:00 EST 2013 · Journal of Chemical Physics

DOI:https://doi.org/10.1063/1.4852155· OSTI ID:22220208

Kent, Tyler J.; Edmonds, Mary ^[1]; Chagarov, Evgueni ^[2]; Droopad, Ravi ^[3]; Kummel, Andrew C. ^[1]

---

1. Materials Science and Engineering Program, University of California, San Diego, La Jolla, California 92093 (United States)
2. Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California 92093 (United States)
3. Department of Physics, Texas State University, San Marcos, Texas 78666 (United States)

The nucleation and passivation of oxide deposition was studied on defect-free GaAs (110) surfaces to understand passivation of surfaces containing only III-V heterobonds. The passivation process on GaAs (110) was studied at the atomic level using scanning tunneling microscopy while the electronic structure was determined by scanning tunneling spectroscopy (STS). The bonding of the oxidant and reductant were modeled with density functional theory. To avoid Fermi level pinning during gate oxide atomic layer deposition, a dual passivation procedure was required using both a reductant, trimethylaluminum (TMA), and an oxidant, O{sub 2} or H{sub 2}O. Dosing GaAs (110) with TMA resulted in the formation of an ordered complete monolayer of dimethylaluminum which passivates the group V dangling bonds but also forms metal-metal bonds with conduction band edge states. These edge states were suppressed by dosing the surface with oxidants O{sub 2} or H{sub 2}O which selectively react with group III-aluminum bonds. The presence of an ordered Al monolayer with a high nucleation density was indirectly confirmed by XPS and STS.

• OSTI ID: 22220208
• Journal Information: Journal of Chemical Physics, Vol. 139, Issue 24; Other Information: (c) 2013 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
36 MATERIALS SCIENCE
ALUMINIUM
DENSITY
DENSITY FUNCTIONAL METHOD
DEPOSITION
ELECTRONIC STRUCTURE
FERMI LEVEL
GALLIUM ARSENIDES
OXIDES
PASSIVATION
SCANNING TUNNELING MICROSCOPY
SEMICONDUCTOR MATERIALS
SURFACES
TUNNEL EFFECT
X-RAY PHOTOELECTRON SPECTROSCOPY