Pattern-dependent anisotropic stress evaluation in SiGe epitaxially grown on a Si substrate with selective Ar+ ion implantation using oil-immersion Raman spectroscopy

Biaxial stress states in SiGe stripes on Si substrates fabricated by a novel selective Ar+ ion implantation technique were evaluated by oil-immersion Raman spectroscopy. The oil-immersion technique is appropriate for the measurement of strain induced in nanostructure devices, because it has a higher spatial resolution than conventional Raman spectroscopy and can evaluate anisotropic stress states owing to the excitation of multiple optical phonon modes. Results indicate that quasi-uniaxial stress states exist in SiGe layers in unimplanted Si areas, which depends on the stripe-width ratio of implanted and unimplanted areas, and that quasi-uniaxial stress states are successfully induced in SiGe by the present technique, which can be considered as the channel materials of high-performance transistors.