Effects of Carbon on Schottky Barrier Heights of NiSi Modified by Dopant Segregation

Abstract

The presence of carbon at the interface between NiSi and Si has been found to participate in the process of modification of effective Schottky barrier heights using the dopant segregation (DS) method. Carbon alone results in an increased phi <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">bn</sub> from 0.7 to above 0.9 eV. Boron diffusion in NiSi is inhibited by carbon, and no B-DS at the NiSi/Si interface occurs below 600degC. Above this temperature, B-DS at this interface is evident thus keeping phi <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">bn</sub> high. The presence of interfacial carbon leads to an increased interfacial As concentration resulting in beneficial effects in tuning phi <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">bp</sub> above 1.0 eV by As-DS.