Effective passivation of In{sub 0.2}Ga{sub 0.8}As by HfO{sub 2} surpassing Al{sub 2}O{sub 3} via in-situ atomic layer deposition

Journal Article · Mon Oct 22 00:00:00 EDT 2012 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4762833· OSTI ID:22080504

Chang, Y H; Chiang, T H ^[1]; Lin, C A; Liu, Y T; Lin, H Y; Huang, M L; Kwo, J ^[2]; Lin, T D; Hong, M ^[3]; Pi, T W ^[4]

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1. Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan (China)
2. Department of Physics, National Tsing Hua University, Hsinchu 30013, Taiwan (China)
3. Graduate Institute of Applied Physics and Department of Physics, National Taiwan University, Taipei 10617, Taiwan (China)
4. National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan (China)

High {kappa} gate dielectrics of HfO{sub 2} and Al{sub 2}O{sub 3} were deposited on molecular beam epitaxy-grown In{sub 0.2}Ga{sub 0.8}As pristine surface using in-situ atomic-layer-deposition (ALD) without any surface treatment or passivation layer. The ALD-HfO{sub 2}/p-In{sub 0.2}Ga{sub 0.8}As interface showed notable reduction in the interfacial density of states (D{sub it}), deduced from quasi-static capacitance-voltage and conductance-voltage (G-V) at room temperature and 100 Degree-Sign C. More significantly, the midgap peak commonly observed in the D{sub it}(E) of ALD-oxides/In{sub 0.2}Ga{sub 0.8}As is now greatly diminished. The midgap D{sub it} value decreases from {>=}15 Multiplication-Sign 10{sup 12} eV{sup -1} cm{sup -2} for ALD-Al{sub 2}O{sub 3} to {approx}2-4 Multiplication-Sign 10{sup 12} eV{sup -1} cm{sup -2} for ALD-HfO{sub 2}. Further, thermal stability at 850 Degree-Sign C was achieved in the HfO{sub 2}/In{sub 0.2}Ga{sub 0.8}As, whereas C-V characteristics of Al{sub 2}O{sub 3}/p-In{sub 0.2}Ga{sub 0.8}As degraded after the high temperature annealing. From in-situ x-ray photoelectron spectra, the AsO{sub x}, which is not the oxidized state from the native oxide, but is an induced state from adsorption of trimethylaluminum and H{sub 2}O, was found at the ALD-Al{sub 2}O{sub 3}/In{sub 0.2}Ga{sub 0.8}As interface, while that was not detected at the ALD-HfO{sub 2}/In{sub 0.2}Ga{sub 0.8}As interface.

• OSTI ID: 22080504
• Journal Information: Applied Physics Letters, Vol. 101, Issue 17; Other Information: (c) 2012 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
ADSORPTION
ALUMINIUM OXIDES
ANNEALING
ARSENIC COMPOUNDS
DEPOSITION
DIELECTRIC MATERIALS
GALLIUM COMPOUNDS
HAFNIUM OXIDES
INDIUM COMPOUNDS
INTERFACES
LAYERS
MOLECULAR BEAM EPITAXY
PASSIVATION
SEMICONDUCTOR MATERIALS
STABILITY
SURFACE TREATMENTS
SURFACES
TEMPERATURE RANGE 0273-0400 K
THIN FILMS
X-RAY PHOTOELECTRON SPECTROSCOPY