Synthesis of strained SiGe on Si(100) by pulsed laser induced epitaxy

Pulsed laser induced epitaxy (PLIE), based oil melting/solidification processes induced by nanosecond laser pulses, is used to synthesize pseudomorphic Si(1-x)Ge(x) epilayers from 20 to 80 nm thick Ge layers evaporated on a Si(100) wafer Ge concentration and strain are characterized by transient reflectivity, energy dispersive X-ray analysis and X-ray diffraction from symmetric (004) and asymmetric (224) reflections For a low Ge thickness or a high laser fluence, PLIE builds up only a pseudomorphic strained Si(1-x)Ge(x) layer with a graded Ge composition reaching x approximate to 19% near the surface When the Ge amount is in excess to achieve this situation. PLIE forms additionally a relaxed Si(1-x)Ge(x) layer with x values up to approximate to 40% over the previous pseudomorphic layer. (c) 2009 Elsevier B.V. All rights reserved