TY - GEN

T1 - Growth of Epitaxial Lanthanide Oxide based Gate Dielectrics

AU - Osten, H. J.

AU - Laha, A.

AU - Bugiel, E.

AU - Schwendt, D.

AU - Fissel, A.

N1 - ACKNOWLEDGEMENTS: This paper summarizes part of the work we have been doing over the last years. We are in particular grateful to M. Czernohorsky, R. Dargis, J. Krügener, D. Tetzlaff, and J.X. Wang for their various contributions. We are also grateful to our partners all over the world for their support and collaboration. Part of this work was supported by the German Federal Ministry of Education and Research (BMBF) under the KrisMOS and the MegaEpos projects

PY - 2009

Y1 - 2009

N2 - Many materials systems are currently under consideration as potential replacements for SiO2 as the gate dielectric material for sub-0.1 μm CMOS technology. We present results for crystalline gadolinium oxides on silicon in the cubic bixbyite structure grown by solid source molecular beam epitaxy. On Si(100), crystalline Gd2O3 grows usually as (110)-oriented domains, with two orthogonal in-plane orientations. Layers grown under best vacuum conditions often exhibit poor dielectric properties due to the formation of crystalline interfacial silicide inclusions. Additional oxygen supply during growth improves the dielectric properties significantly. Layers grown by an optimized MBE process display a sufficiently high-K value to achieve equivalent oxide thickness values < 1 nm, combined with ultralow leakage current densities, good reliability, and high electrical breakdown voltage. A variety of MOS capacitors and field effect transistors has been fabricated based on these layers. Efficient manipulation of Si(100) 4° miscut substrate surfaces can lead to single domain epitaxial Gd2O3 layer. Such epi-Gd2O3 layers exhibited significant lower leakage currents compared to the commonly obtained epitaxial layers with two orthogonal domains. For capacitance equivalent thicknesses below 1 nm, this differences disappear, indicating that for ultrathin layers direct tunneling becomes dominating.

AB - Many materials systems are currently under consideration as potential replacements for SiO2 as the gate dielectric material for sub-0.1 μm CMOS technology. We present results for crystalline gadolinium oxides on silicon in the cubic bixbyite structure grown by solid source molecular beam epitaxy. On Si(100), crystalline Gd2O3 grows usually as (110)-oriented domains, with two orthogonal in-plane orientations. Layers grown under best vacuum conditions often exhibit poor dielectric properties due to the formation of crystalline interfacial silicide inclusions. Additional oxygen supply during growth improves the dielectric properties significantly. Layers grown by an optimized MBE process display a sufficiently high-K value to achieve equivalent oxide thickness values < 1 nm, combined with ultralow leakage current densities, good reliability, and high electrical breakdown voltage. A variety of MOS capacitors and field effect transistors has been fabricated based on these layers. Efficient manipulation of Si(100) 4° miscut substrate surfaces can lead to single domain epitaxial Gd2O3 layer. Such epi-Gd2O3 layers exhibited significant lower leakage currents compared to the commonly obtained epitaxial layers with two orthogonal domains. For capacitance equivalent thicknesses below 1 nm, this differences disappear, indicating that for ultrathin layers direct tunneling becomes dominating.

KW - Gadolinium oxide

KW - Gate dielectrics

KW - High-k materials

KW - Molecular beam epitaxy

UR - http://www.scopus.com/inward/record.url?scp=77951440374&partnerID=8YFLogxK

U2 - 10.1109/ICSCS.2009.5414212

DO - 10.1109/ICSCS.2009.5414212

M3 - Conference contribution

AN - SCOPUS:77951440374

SN - 9781424443987

BT - 2009 3rd International Conference on Signals, Circuits & Systems

T2 - 3rd International Conference on Signals, Circuits and Systems, SCS 2009

Y2 - 6 November 2009 through 8 November 2009

ER -