Solid phase epitaxy recrystallization by laser annealing

Abstract

Methods (70) are described for fabricating shallow and abrupt gradient drain extensions for MOS type transistors, in which a solid phase epitaxial recrystallization is performed within the drain extensions utilizing a laser SPER annealing process in the manufacture of semiconductor products. One method (70) includes a preamorphizing process (74) of implanting a heavy ion species such as Germanium deep into an extension region of a substrate adjacent a channel region of the substrate to form a deep amorphized region, then implanting boron or another such dopant species into an extension region of the substrate adjacent the channel region. The implanted dopant is then preannealed (78) at a low temperature to set the junction depth and doping concentration. The extensions and/or the deep source/drain regions are subsequently annealed (84) with a laser at a high temperature providing a solid phase epitaxial recrystallization in the regions proximate the channel region to achieve ultra high doping concentrations and activation levels with an abrupt gradient.

Dependencies are inferred from the claim text.