Conformal Deposition of Conductive Single-Crystalline Cobalt Silicide Layer on Si Wafer via a Molecular Approach

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Lin, T. H.
Margossian, T.
Zheng, L. Q.
Kumar, S.
Marozau, I.
Sereda, O.
et al.
The realization of metal-semiconductor contacts plays a significant role in ultrascaled integrated circuits. Here, we establish a low-temperature molecular approach for the conformal deposition of a 20 nm Co-rich layer on Si (100) wafers by reaction in solution of Co-2(CO)(8) with SiH4. Postannealing at 850 degrees C under vacuum (similar to 10(-5) mbar) yields a crystalline CoSi2 film with a lower surface roughness (R-rms = 5.3 nm) by comparison with the conventional physical method; this layer exhibiting a metallic conductive behavior (ohmic behavior) with a low resistivity (rho = 11.6 mu Omega cm) according to four-point probe measurement. This approach is applicable to trench-structured wafers, showing the conformal layer deposition on 3D structures and showcasing the potential of this approach in modern transistor technology.
Publication Reference
Chemistry of Materials, vol. 30 (6), pp. 2168-2173, Mar 2018.