Low temperature source/drain epitaxy and functional silicides: essentials for ultimate contact scaling
Clément Porret, J.-L. Everaert, Marc Schaekers, Lars‐Åke Ragnarsson, Andriy Hikavyy, Erik Rosseel, Gianluca Rengo, Roger Loo, Rami Khazaka, Michael Givens, Xiaoyu Piao, S. Mertens, N. Heylen, Hans Mertens, C. Toledo De Carvalho Cavalcante, Gunther Sterckx, S. Brus, Ankit Nalin Mehta, M. Korytov, D. Batuk, Paola Favia, R. Langer, Geoffrey Pourtois, J. Swerts, E. Dentoni Litta, Naoto Horiguchi
Abstract
Low temperature Si <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1-x</inf> Ge <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</inf> source-drain epitaxy processes are associated with exploratory contact metals to identify stacks alleviating access resistance issues in modern logic devices. TiN/W metal-to-metal interfaces featuring contact resistivities <5 × 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-10</sup> Ω.cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> demonstrate the resolution of the test vehicle and extraction methods. Amongst the different systems investigated, Sc/Si:P yields $\sim1.3 \times 10^{-9} \Omega \cdot cm^{2}$, which represents a ~35% reduction with respect to the Ti/Si:P reference. This confirms that doping levels in Si:P are sufficient to achieve significant performance gains. Analyses of Sc/Si:P stacks reveal the material properties and reaction mechanisms responsible for the contact resistivity reduction.