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Preparation and characterisation of aluminium zirconium oxide for metal‐oxide‐semiconductor capacitor
Author(s) -
Quah Hock Jin,
Hassan Zainuriah,
Lim Way Foong
Publication year - 2020
Publication title -
international journal of energy research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.808
H-Index - 95
eISSN - 1099-114X
pISSN - 0363-907X
DOI - 10.1002/er.5693
Subject(s) - tetragonal crystal system , materials science , passivation , oxide , analytical chemistry (journal) , zirconium , aluminium , dielectric , monoclinic crystal system , alloy , metal , layer (electronics) , metallurgy , crystallography , composite material , chemistry , optoelectronics , crystal structure , chromatography
Summary A functional type metal‐oxide‐semiconductor (MOS) based capacitor was fabricated and studied by using aluminium zirconium oxide (Al x Zr y O z ) as a potential high dielectric constant ( k ) gate oxide, which was transformed from as‐sputtered Al‐Zr alloy after undergoing a wet oxidation at 400°C, 600°C, 800°C, and 1000°C in the presence of nitrogen as a carrier gas. A mixture of tetragonal ZrO 2 ‐monoclinic Al x Zr y O z phases were present at 600°C while stablized tetragonal Al x Zr y O z phases were detected at higher temperatures with a minute micro strain change. The largest k value (21) was obtained by the film oxidised at 600°C, followed by 800°C while the lowest one at 1000°C. The discrepancy was due to the absence of tetragonal ZrO 2 in the latter films. The attainment of a k value closer to the reported value for ZrO 2 at 600°C suggested that the tetragonal ZrO 2 phase was one of the factors yielding a high k value at 600°C. However, further investigation was required for this sample because the slow trap density and total interface trap density was high despite a high k value, mainly attributed to the presence of negatively charged traps as the scattering centre in the film. The film obtained at 1000°C was not encourageable to be deployed as a passivation layer for Si MOS device due to its low k controlled by the thick interfacial layer.