Electrical and physical characterization of the Al{sub 2}O{sub 3}/p-GaSb interface for 1%, 5%, 10%, and 22% (NH{sub 4}){sub 2}S surface treatments

Journal Article · Mon Oct 20 00:00:00 EDT 2014 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4899123· OSTI ID:22350970

Peralagu, Uthayasankaran; Thayne, Iain G. ^[1]; Povey, Ian M.; Carolan, Patrick; Lin, Jun; Hurley, Paul K. ^[2]; Contreras-Guerrero, Rocio; Droopad, Ravi ^[3]

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1. School of Engineering, University of Glasgow, Glasgow, G12 8LT (United Kingdom)
2. Tyndall National Institute, University College Cork, Lee Maltings, Prospect Row, Cork (Ireland)
3. Ingram School of Engineering, Texas State University, San Marcos, Texas 78666 (United States)

In this work, the impact of ammonium sulfide ((NH{sub 4}){sub 2}S) surface treatment on the electrical passivation of the Al{sub 2}O{sub 3}/p-GaSb interface is studied for varying sulfide concentrations. Prior to atomic layer deposition of Al{sub 2}O{sub 3}, GaSb surfaces were treated in 1%, 5%, 10%, and 22% (NH{sub 4}){sub 2}S solutions for 10 min at 295 K. The smallest stretch-out and flatband voltage shifts coupled with the largest capacitance swing, as indicated by capacitance-voltage (CV) measurements, were obtained for the 1% treatment. The resulting interface defect trap density (D{sub it}) distribution showed a minimum value of 4 × 10{sup 12 }cm{sup −2}eV{sup −1} at E{sub v} + 0.27 eV. Transmission electron microscopy and atomic force microscopy examination revealed the formation of interfacial layers and increased roughness at the Al{sub 2}O{sub 3}/p-GaSb interface of samples treated with 10% and 22% (NH{sub 4}){sub 2}S. In combination, these effects degrade the interface quality as reflected in the CV characteristics.

• OSTI ID: 22350970
• Journal Information: Applied Physics Letters, Vol. 105, Issue 16; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ALUMINIUM OXIDES
ATOMIC FORCE MICROSCOPY
CAPACITANCE
CRYSTAL DEFECTS
DENSITY
DISTRIBUTION
ELECTRIC CONDUCTIVITY
ELECTRIC POTENTIAL
GALLIUM ANTIMONIDES
INTERFACES
LAYERS
PASSIVATION
ROUGHNESS
SURFACE TREATMENTS
SURFACES
TRANSMISSION ELECTRON MICROSCOPY
TRAPS