Solid-State Electronics, Vol.60, No.1, 89-92, 2011
Introduction of local tensile strain on Ge substrates by SiGe stressors selectively grown on wet chemically recessed regions for strained Ge-nMOSFETs
Introduction of tensile strain into Ge substrates was demonstrated by forming embedded SiGe stressors on the recessed regions formed by an anisotropic wet chemical etching process for strained Ge-nMOSFETs having high electron mobility. A damage-free and well controlled anisotropic wet chemical etching process is developed in order to avoid plasma-induced damages in a conventional RIE process. The uni-axial tensile strain over 1% near the Ge recess-edge regions, which is induced by the embedded SiGe stressors, is also demonstrated for the first time. These results suggest that higher electron mobility than the upper-limit for a Si-MOSFET is obtainable in short channel strained Ge-nMOSFETs with the embedded SiGe stressors. (C) 2011 Elsevier Ltd. All rights reserved.
Keywords:SiGe;Ge;Stressor;Tensile strain;Anisotropic etching;Wet etching;Selective epitaxial growth;SEG