High capacitance density MIS capacitor using Si nanowires by MACE and ALD alumina dielectric

Journal Article · Tue Jun 28 00:00:00 EDT 2016 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4954883· OSTI ID:22596645

Leontis, I.; Botzakaki, M. A.; Georga, S. N. ^[1]

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1. Department of Physics, University of Patras, 26 504 Rion (Greece)

High capacitance density three-dimensional (3D) metal-insulator-semiconductor (MIS) capacitors using Si nanowires (SiNWs) by metal-assisted chemical etching and atomic-layer-deposited alumina dielectric film were fabricated and electrically characterized. A chemical treatment was used to remove structural defects from the nanowire surface, in order to reduce the density of interface traps at the Al{sub 2}O{sub 3}/SiNW interface. SiNWs with two different lengths, namely, 1.3 μm and 2.4 μm, were studied. A four-fold capacitance density increase compared to a planar reference capacitor was achieved with the 1.3 μm SiNWs. In the case of the 2.4 μm SiNWs this increase was ×7, reaching a value of 4.1 μF/cm{sup 2}. Capacitance-voltage (C-V) measurements revealed that, following a two-cycle chemical treatment, frequency dispersion at accumulation regime and flat-band voltage shift disappeared in the case of the 1.3 μm SiNWs, which is indicative of effective removal of structural defects at the SiNW surface. In the case of the 2.4 μm SiNWs, frequency dispersion at accumulation persisted even after the two-step chemical treatment. This is attributed to a porous Si layer at the SiNW tops, which is not effectively removed by the chemical treatment. The electrical losses of MIS capacitors in both cases of SiNW lengths were studied and will be discussed.

• OSTI ID: 22596645
• Journal Information: Journal of Applied Physics, Vol. 119, Issue 24; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ALUMINIUM OXIDES
BUILDUP
CAPACITANCE
CAPACITORS
COMPARATIVE EVALUATIONS
DENSITY
DIELECTRIC MATERIALS
ELECTRIC POTENTIAL
ETCHING
FILMS
INTERFACES
LAYERS
LENGTH
METALS
NANOWIRES
POROUS MATERIALS
SEMICONDUCTOR MATERIALS
SILICON
THREE-DIMENSIONAL CALCULATIONS