-A A +A
The downscaling of CMOS transistors requires high active dopant concentrations in the source and drain terminals to minimize contact resistance. Pulsed laser annealing is an attractive option as it enables to locally reach, typically ~100 nm below the surface, high temperatures (e.g. above the melt threshold), with extremely fast temperature ramps (>109 °C/s). Structural investigations have already allowed to identify the best conditions to obtain fully strained and defect-free undoped SiGe layers by liquid phase epitaxial regrowth (LPER). In this work, we report on the electrical properties of laser annealed 30 nm-thick boron-doped strained-Si0.7Ge0.3 layers. These layers were CVD grown on p-type bulk Si (100), with three different boron concentrations probed at: 7.3x1019 (A), 1.4x1020 (B) and 2.3x1020 cm-3 (C). Electrical properties were evaluated thanks to an algorithm comparing Hall parameters calculated from boron and germanium SIMS profiles with the corresponding Hall effect measurements. Germanium redistribution occurring during laser annealing in melt conditions was taken into account through Hall scattering factor variations. For the as-grown layers, activations rates of ~100%, ~80% and ~60% were found, without any significant carrier mobility degradation. These layers were annealed in a SCREEN-LT3100 platform, equipped with a pulsed laser operating at 308 nm (XeCl laser), with a pulse duration around 160 ns and energy densities ranging from 1.20 to 2.40 J/cm2. The different laser regime transitions as well as the strain state were studied thanks to surface, structural and chemical characterizations, in addition to electrical …
Publication date: 
29 May 2023

Richard Daubriac, Rémi Demoulin, Sébastien Kerdilès, P Acosta-Alba, M Opprecht, JM Hartmann, Léa Dagault, Michałowski Piotr, Francesca Chiodi, Obaïd-Allah Adami, Dominique Débarre, Emmanuel Scheid, Etienne Talbot, Antonio Mio, Damiano Ricciarelli, Gaetano Calogero, Antonino La Magna, Fuccio Cristiano

Biblio References: 
2023 E-MRS Spring Meeting