Enhancement of effective dielectric constant using high-temperature mixed and sub-nano-laminated atomic layer deposited Y2O3/Al2O3 on GaAs(001)

• Published in: Microelectronic engineering Vol. 178; pp. 271 - 274
• Main Authors: Lin, K.Y., Young, L.B., Cheng, C.K., Chen, K.H., Lin, Y.H., Wan, H.W., Cai, R.F., Lo, S.C., Li, M.Y., Kwo, J., Hong, M.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 25.06.2017; Elsevier BV
• Subjects: Aluminum oxide; Annealing; Atomic layer deposition; Atomic layer epitaxy; Atomic structure; Capacitance-voltage characteristics; Chemical compounds; Diffraction; GaAs; Gallium arsenide; High temperature; High κ; Laminates; Leakage current; Metal oxides; MOS; Multilayers; Permittivity; Scanning electron microscopy; Semiconductor devices; Sub-nano-laminated; Substrates; Synchrotron radiation; Y2O3; Yttrium oxide; MOS; High κ; Sub-nano-laminated; Atomic layer deposition; Y2O3; GaAs
• ISSN: 0167-9317; 1873-5568
• DOI: 10.1016/j.mee.2017.05.018

In-situ atomic layer deposition (ALD) Y2O3/Al2O3 in bi-layered and sub-nano-laminated structures were stacked on pristine GaAs(001) substrates for fabricating metal-oxide-semiconductor capacitors. The bi-layered Y2O3/Al2O3 showed an enhanced effective dielectric constant from 11.1 to 15.6 in capacitance-voltage characteristics with post deposition annealing to 900°C. No new oxide phase formed as carefully examined using synchrotron radiation X-ray diffraction and cross-sectional high-resolution scanning tunneling electron microscopy. We designed and grew sub-nano-laminated Y2O3/Al2O3 multi-layers to simulate the mixing of gate oxides, and observed an enhanced dielectric constant of 14.8 for the as-deposited sample. Both high-temperature mixed and sub-nano-laminated ALD Y2O3/Al2O3 exhibit high dielectric constant, low leakage current ~10−8A/cm2 and low interfacial trap density with GaAs(001), promising for high κ applications in future GaAs metal-oxide-semiconductor devices. [Display omitted] •High dielectric constant (κ) in 900°C annealed ALD Y2O3/Al2O3 bi-layer•High κ in ALD sub-nano-laminated (super-cycled) Y2O3/Al2O3 multi-layers•Enhancement of dielectric constant without new structure formation•Excellent CVs with low leakage current for Y2O3/Al2O3 on GaAs(001)