Al{sub 2}O{sub 3}/GeO{sub x}/Ge gate stacks with low interface trap density fabricated by electron cyclotron resonance plasma postoxidation

Journal Article · Mon Mar 14 00:00:00 EDT 2011 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.3564902· OSTI ID:21518328

Zhang, R; Iwasaki, T; Taoka, N; Takenaka, M; Takagi, S ^[1]

---

1. School of Engineering, University of Tokyo, 2-11-16 Yayoi, Bunkyo-ku, Tokyo 113-8656 (Japan)

An electron cyclotron resonance (ECR) plasma postoxidation method has been employed for forming Al{sub 2}O{sub 3}/GeO{sub x}/Ge metal-oxide-semiconductor (MOS) structures. X-ray photoelectron spectroscopy and transmission electron microscope characterizations have revealed that a GeO{sub x} layer is formed beneath the Al{sub 2}O{sub 3} capping layer by exposing the Al{sub 2}O{sub 3}/Ge structures to ECR oxygen plasma. The interface trap density (D{sub it}) of Au/Al{sub 2}O{sub 3}/GeO{sub x}/Ge MOS capacitors is found to be significantly suppressed down to lower than 10{sup 11} cm{sup -2} eV{sup -1}. Especially, a plasma postoxidation time of as short as 10 s is sufficient to reduce D{sub it} with maintaining the equivalent oxide thickness (EOT). As a result, the minimum D{sub it} values and EOT of 5x10{sup 10} cm{sup -2} eV{sup -1} and 1.67 nm, and 6x10{sup 10} cm{sup -2} eV{sup -1} and 1.83 nm have been realized for Al{sub 2}O{sub 3}/GeO{sub x}/Ge MOS structures with p- and n-type substrates, respectively.

• OSTI ID: 21518328
• Journal Information: Applied Physics Letters, Vol. 98, Issue 11; Other Information: DOI: 10.1063/1.3564902; (c) 2011 American Institute of Physics; ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ALUMINIUM OXIDES
CAPACITORS
ELECTRIC CONDUCTIVITY
ELECTRON CYCLOTRON-RESONANCE
GERMANIUM
GERMANIUM COMPOUNDS
GERMANIUM OXIDES
LAYERS
MOS SOLAR CELLS
OXYGEN
PLASMA
SEMICONDUCTOR MATERIALS
SILICON OXIDES
SUBSTRATES
SURFACE POTENTIAL
THICKNESS
TRANSMISSION ELECTRON MICROSCOPY
TRAPS
X-RAY PHOTOELECTRON SPECTROSCOPY
ALUMINIUM COMPOUNDS
CHALCOGENIDES
CYCLOTRON RESONANCE
DIMENSIONS
DIRECT ENERGY CONVERTERS
ELECTRICAL EQUIPMENT
ELECTRICAL PROPERTIES
ELECTRON MICROSCOPY
ELECTRON SPECTROSCOPY
ELEMENTS
EQUIPMENT
MATERIALS
METALS
MICROSCOPY
NONMETALS
OXIDES
OXYGEN COMPOUNDS
PHOTOELECTRIC CELLS
PHOTOELECTRON SPECTROSCOPY
PHOTOVOLTAIC CELLS
PHYSICAL PROPERTIES
POTENTIALS
RESONANCE
SILICON COMPOUNDS
SOLAR CELLS
SOLAR EQUIPMENT
SPECTROSCOPY