High-Performance Schottky Contact Quantum-Well Germanium Channel pMOSFET With Low Thermal Budget Process

Abstract

We present a high-performance Si/Ge/Si p-channel metal-oxide-semiconductor field-effect transistor (pMOSFET) with a NiSiGe Schottky junction source/drain (S/D) formed through microwave-activated annealing. A Schottky contact S/D is preferable, because the lower process temperature is beneficial for eliminating Ge diffusion. The fabricated NiSiGe Schottky junction exhibited a high effective barrier height (Φ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Bn</sub> ) of 0.69 eV for electrons, resulting in a high junction current ratio of more than 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">5</sup> at the applied voltage of |Va| = 1 V. Our quantum-well pMOSFET exhibited a high I <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ON</sub> /I <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">OFF</sub> ratio of ~10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">7</sup> (I <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">S</sub> ) and a moderate subthreshold swing of 166 mV/decade.