A novel approach of using a MBE template for ALD growth of high-庥 dielectrics
Journal
Journal of Crystal Growth
Journal Issue
SPEC. ISS.
Pages
378-380
Date Issued
2007
Author(s)
Abstract
We have employed molecular beam epitaxy (MBE) to grow high κ dielectric nano-thick films of Al2O3 and HfO2 on Si (1 0 0) as templates to suppress effectively the formation of the oxide/Si interfacial layer during the subsequent atomic layer deposition (ALD) growth for Al2O3. We show marked improvements of electrical performance of the ALD+MBE composite oxides. A first bi-layer composite of ALD Al2O3 1.9 nm/MBE Al2O3 1.4 nm showed a dielectric constant of 9.1 with an equivalent oxide thickness (EOT) of 1.41 nm. The interfacial trap density Dit was 2.2×1011 cm-2 eV-1 as deduced from the conductance method, with the leakage current density being 2.4×10-2 A/cm2 at Vfb-1 V. The second bi-layer of ALD Al2O3 3.0 nm/MBE HfO2 2.0 nm showed a dielectric constant of 11.5 and an EOT of 1.7 nm. The Dit was estimated to be 2×1011 cm-2 eV-1 with the leakage being 1.1×10-4 A/cm2 at Vfb+1 V. © 2007 Elsevier B.V. All rights reserved.
Type
journal article