New insights on Ni-Si system for microelectronics applications

Metal silicides and their nanostructures have been found to be suitable candidates for device manufacturing in contemporary microelectronics industries to reduce contact resistance in gate electrodes and source/drain contacts. Nickel monosolicide (NiSi), in particular, has been found to be highly conducting (with resistivity in the range 10.5–18 μΩ-cm, smallest among all Nickel Silicides), hence most suitable silicide for microelectronic devices. However, due to poor thermal stability, Nickel monoslicide phase transforms to various resistive phases in the phase diagram (like Ni2Si, NiSi2, etc.). Considering its importance to the microelectronics industry, and to provide a ready reference to the researchers working in this area, a cogent and focused review of various experimental approaches to synthesize low resistance Nickel monosolicide (NiSi) material has been presented. Two synthesis schemes have been discussed in detail: thermal annealing and ion beam irradiation. Both the schemes have been critically compared, and suggestions on using one or the other synthesis method have been proposed. Finally, a short discussion on the status of understanding the stability of Nickel monosilicide and the various means to address it have also been elaborated.