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Title: Improving metal/semiconductor conductivity using AlO{sub x} interlayers on n-type and p-type Si

Thermal atomic layer deposition was used to form ultra-thin interlayers in metal/interlayer/ semiconductor Ohmic contacts on n-type and p-type Si. AlO{sub x} of thickness 1–2 nm was deposited at 120 °C on Si substrates prior to metallization, forming Ni/AlO{sub x}/Si contacts. Conductivity improved by two orders of magnitude but the contacts remained rectifying. When they were annealed at 200 °C, the conductivity increased by another order of magnitude and the samples became Ohmic. A minimum specific contact resistivity of 1.5 × 10{sup −4} Ω-cm{sup 2} was obtained for structures based on lightly doped (10{sup 15 }cm{sup −3}) Si substrates. Existing models that describe Fermi level de-pinning do not fully explain our results, which are however consistent with other experimental data in the literature.
Authors:
; ; ; ; ;  [1]
  1. School of Electronic and Electrical Engineering, Newcastle University, Newcastle Upon Tyne NE17RU (United Kingdom)
Publication Date:
OSTI Identifier:
22314675
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 105; Journal Issue: 5; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ALUMINIUM OXIDES; DOPED MATERIALS; FERMI LEVEL; METALS; NICKEL; SEMICONDUCTOR MATERIALS; SILICON; SUBSTRATES