The DX centre
T.N. Morgan
Semiconductor Science and Technology
We show that a thin epitaxial strontium oxide (SrO) interfacial layer enables scaling of titanium nitride/hafnium oxide high-permittivity (high-k) gate stacks for field-effect transistors on silicon. In a low-temperature gate-last process, SrO passivates Si against SiO2 formation and silicidation and equivalent oxide thickness (EOT) of 5 is achieved, with competitive leakage current and interface trap density. In a gate-first process, Sr triggers HfO2-SiO2 intermixing, forming interfacial high-k silicate containing both Sr and Hf. Combined with oxygen control techniques, we demonstrate an EOT of 6 with further scaling potential. In both cases, Sr incorporation results in an effective workfunction that is suitable for n-channel transistors. © 2011 Elsevier B.V. All rights reserved.
T.N. Morgan
Semiconductor Science and Technology
Julien Autebert, Aditya Kashyap, et al.
Langmuir
J.H. Stathis, R. Bolam, et al.
INFOS 2005
Zelek S. Herman, Robert F. Kirchner, et al.
Inorganic Chemistry