Integration of functional epitaxial oxides into silicon:: From high-K application to nancistructures

The authors will present results for crystalline lanthanide oxides on silicon with the Ln(2)O(3) composition (Ln=Pr, lqd, and Gd) in the cubic bixbyite structure grown by solid state molecular beam epitaxy. On Si(100) oriented surfaces, crystalline Ln(2)O(3) grows 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. Experimental results for Ln(2)O(3)-based metal-oxide-semiconductor (MOS) capacitors grown under optimized conditions show that these layers are excellent candidates for application as very thin high-K materials replacing SiO2 in future MOS devices. In addition, they will present a new approach for nanostructure formation which is based on solid-phase epitaxy of the Si quantum well combined with simultaneous vapor-phase epitaxy of the insulator on top of the quantum well. Ultrathin single-crystal line Si buried in a single-crystalline insulator matrix with sharp interfaces was obtained by this approach on Si(III). Finally, the incorporation of crystalline Si islands into single-crystalline oxide layers will be demonstrated. (c) 2007 American Vacuum Society.