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In this work, a barrier-induced phase modulation scheme to realize an ultra-thin and conformal epitaxial NiSi 2 film for wrapped-around contact beyond the 7 nm technology node, is proposed and experimentally demonstrated. The 1 nm thick Al 2 O 3 barrier inserted between the Ni film and the substrate can limit the amount of nickel diffusing into silicon and establish an initial Si-rich region consisted of only a few atomic layers during a rapid thermal annealing treatment, so that NiSi 2 can grow epitaxially as the first phase at a temperature as low as 600 °C. Additionally, thanks to the barrier layer, a relatively thick (50 nm) Ni film can be used, which not only ensures the continuity of NiSi 2 formed on sidewalls of three-dimensional structures, but also reduces the process complexity. As a result, a conformal 3.3 nm NiSi 2 shell with Φ Bn =0.33 eV is successfully obtained on Si fins.

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