Effects of Ni Film Thickness on the Properties of Ni-Based Silicides Formed on Both Highly Doped n- and p-Si Substrate

Ni-based silicides continue to play an indispensable role during the remarkable development of microelectronics. In this work, on both highly boron (B)-doped n-Si and phosphorus (P)-doped p-Si substrate, the effects of the thickness of initial Ni films on Ni-based silicides properties are investigated comprehensively. Ni films with varying thicknesses from 1-10 nm are deposited followed by rapid thermal annealing (RTP) to form Ni-based silicides. Sheet resistance, phase identity, thermal stability and dopant redistribution are versatilely characterized by four-point probe, X-ray diffraction (XRD), Raman spectroscopy, Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM) and Secondary Ion Mass Spectroscopy (SIMS). It is found that the dopants tend to segregate at silicides/Si interface when the thickness of Ni films is 3 nm or less, which is paramount beneficial to reduce effective Schottky barrier heights (SBHs) thus lowering specific contact resistivity (rho(c)). (C) 2020 The Electrochemical Society ("ECS"). Published on behalf of ECS by IOP Publishing Limited.