Gate-First Metal-Gate/High-$k$ n-MOSFETs With Deep Sub-nm Equivalent Oxide Thickness (0.58 nm) Fabricated With Sulfur-Implanted Schottky Source/Drain Using a Low-Temperature Process

Abstract

Gate-first high- <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">k</i> /metal-gate n-MOSFETs with a deep subnanometer (sub-nm) equivalent oxide thickness (EOT) of 0.58 nm were successfully fabricated with Schottky source/drain contacts using a low-temperature process. The key to achieving such a thin EOT is the use of a low-temperature process for the NiSi Schottky source/drain formation. A sulfur implantation technique was used to overcome the Schottky barrier height between Si and NiSi, which is the main problem in NiSi Schottky source/drain fabrication. The advantage of Schottky source/drain MOSFETs over conventional source/drain MOSFETs was successfully demonstrated.