Contact Resistance Reduction Technology Using Aluminum Implant and Segregation for Strained p-FinFETs With Silicon–Germanium Source/Drain

Abstract

We have demonstrated the introduction of an additional aluminum (Al) implant step in the fabrication of strained p-FinFETs with silicon-germanium (SiGe) source/drain (S/D). Al is implanted. into the p <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">+</sup> -SiGe S/D region at energy of 10 keV and a dose of 2 × 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">14</sup> atoms/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> , followed by its segregation at the NiSiGe/p <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">+</sup> -SiGe S/D interface during germanosilicidation. The presence of Al at this interface leads to lowering of the effective Schottky barrier height for hole conduction, which, in essence, lowers the S/D contact resistance R <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">C</sub> · R <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">C</sub> is a dominant component of the FinFET parasitic series resistance R <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">SD</sub> , which is lowered by approximately 25% using this technology, correspondingly leading to a substantial increase in the saturation drive current. The novel Al-segregated NiSiGe/p <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">+</sup> -SiGe S/D contact junction in p-FinFETs does not degrade short-channel effects or the NiSiGe film morphology.