Thermal Stability and Dopant Segregation for Schottky Diodes With Ultrathin Epitaxial $\hbox{NiSi}_{2 - y}$

Abstract

The Schottky barrier height (SBH) of an ultrathin epitaxial NiSi <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2-y</sub> film grown on Si(100) is modified significantly by means of dopant segregation (DS). The DS process begins with the NiSi <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2-y</sub> formation and is followed by dopant implantation and drive-in annealing. The rapid lattice restoration and superior morphological stability upon heat treatment up to 800°C allow the epitaxial NiSi <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2-y</sub> film to take full advantage of the DS process. For drive-in annealing below 750°C , the effective SBH is altered to ~ 0.9-1 eV for both electrons and holes by B-DS and As-DS, respectively, without deteriorating the integrity of the NiSi <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2-y</sub> film.