Formation and Stability of NI(PT) Silicide on (100)SI and (111)SI

Abstract

The effect of a small amount of Pt (5 at.%) on the thermal stability of NiSi film on (100)Si and (111 )Si has been investigated. Rutherford back scattering, Scanning Electron Microscopy, and X-ray diffraction have been used to study the formation, microstructure and orientation of the silicide. The addition of platinum results in increasing the disilicide nucleation temperature to 900°C and thus leads to a better stability of NiSi at high IC processing temperatures. The presence of Pt also induced a texture of the NiSi film both on (11 1)Si and (100)Si. The increase in thermal stability is explained in terms of nucleation controlled reaction concept and should open new possibilities for the use of NiSi in self aligned silicidation. The redistribution of Pt in the silicide is examined and explained in terms of kinetics and thermodynamics considerations. The addition of Pt also increases the temperature of agglomeration of NiSi.

Lateral growth of NiSi at the θ-Ni2Si/Si(100) interface: Experiments and modelling

“…They also highlight that the formation of the NiSi phase starts by nucleation and lateral growth at the θ-Ni2Si/Si interface during the reaction of Ni(10 at.% Pt) films with Si. Our TEM results provide thus a direct observation of the shape of the precipitates associated to the lateral growth phenomenon in contrast to former experimental results [14][15][16][17][18][19] where only partial view of lateral growth were observed. They also allow to compare experiment with models that were developed for lateral growth [1] The shape of precipitates as well as their dimensions are in accordance with the existing models that are presented in Fig.…”

Atomic-scale redistribution of Pt during reactive diffusion in Ni (5% Pt)–Si contacts

“…Indeed, when the very last Ni 1_x Pt x layer reacted, some of the Pt in the Ni 1_x Pt x layer stays at the surface and the other part reaches the Ni 2 Si/NiSi interface. Experimental evidence for this process was obtained previously [23]. Another characteristic of Pt redistribution at 350 1C is that during NiSi formation, Pt is mainly located close to the middle of NiSi.…”

“…Pt thus acts like a marker for NiSi formation. The low diffusivity of Pt in NiSi is also evidenced by the high temperatures (700-800 1C) needed to obtain a homogenous redistribution of Pt in NiSi [23].…”

New salicidation technology with Ni(Pt) alloy for MOSFETs

“…A decrease in the free energy ( ) term is due to the formation of a pseudobinary silicide solution Ni(Pt)Si which has a lower free energy (NiSi and PtSi are both orthorhombic silicides). The strong tendency of Ni(Pt)Si to be in texture on Si(100) was ascribed to lower the interfacial energy of Ni(Pt)Si on Si and therefore increases the [4], [8]. The Ni(Pt) salicidation scheme was integrated onto PMOSFETs.…”