Improved Electrical Characteristics of ~0.5 nm EOT Ge pMOSFET With GeON Interfacial Layer Formed by NH3 Plasma and Microwave Annealing Treatments

Abstract

A hole mobility of ~650 cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> /V-s at N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">inv</sub> = ~ 0.4 × 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">12</sup> cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-2</sup> , a gate leakage current density of ~10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-5</sup> A/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> at V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">G</sub> = V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">FB</sub> + 1 V, and an equivalent oxide thickness of ~0.5 nm in Ge pMOSFETs are simultaneously achieved by using the GeON interfacial layer (IL) formed with NH <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> plasma and microwave annealing (MWA) treatments. The high performance can be attributed to the O-N polar covalent bonds in GeON, which is efficiently annealed by the MWA to increase the Ge oxidation sate in the IL. Ge out diffusion or GeO desorption can be suppressed by an MWA thanks to less thermal budget.