Atomic-scale redistribution of Pt during reactive diffusion in Ni (5% Pt)-Si contacts.
The NiSi silicide that forms by reactive diffusion between Ni and Si active regions of nanotransistors is used nowadays as contacts in nanoelectronics because of its low resistivity. Pt is added to the Ni film in order to stabilise the NiSi phase against the formation of the high-resistivity NiSi(2) phase and agglomeration. In situ X-ray diffraction (XRD) experiments performed on material aged at 350 degrees C (under vacuum) showed the complete consumption of the Ni (5 at% Pt) phase, the regression of Ni(2)Si phase as well as the growth of the NiSi phase after 48 min. Pt distribution for this heat treatment has been analysed by laser-assisted tomographic atom probe (LATAP). An enrichment of platinum in the middle of the NiSi phase suggests that Pt is almost immobile during the growth of NiSi at the two interfaces: Ni(2)Si/NiSi and NiSi/Si. In the peak, platinum was found to substitute for Ni in the NiSi phase. Very small amounts of Pt were also found in the Ni(2)Si phase close to the surface and at the NiSi/Si interface.
Cojocaru-Mirédin
O
O
Université de Rouen, GPM, UMR CNRS 6634 BP 12, Avenue de l'Université, 76801 Saint Etienne de Rouvray, France.
Cadel
E
E
Blavette
D
D
Mangelinck
D
D
Hoummada
K
K
Genevois
C
C
Deconihout
B
B