Interfacial reactions of Ni on Si0.76Ge0.24 and Si by pulsed laser annealing

High-resolution transmission electron microscopy of silicide formation and morphology development of Ni/Si and Ni/Si1−xGex

“…Similar Ge segregation effects have also been reported previously for Ti, Co, and Ni silicidation on SiGe. 2,3,13,23 Because the heats of formation for NiSi and NiGe are about Ϫ45 kJ/mol and Ϫ32 kJ/mol, respectively, 24 Ni tends to react preferentially with Si, expelling Ge from the Ni(Si 1-x Ge x ) and into the interface and the Si 0.8 Ge 0.2 substrate. Figure 8 shows two plan-view images of a Ni/Si 0.8 Ge 0.2 sample annealed at 700°C.…”

“…Island structures and Ge segregation have been observed following high-temperature annealing treatments. [11][12][13] The failure of the Ni/Si 1-x Ge x system to form a uniform, low-resistivity silicide was ascribed to the higher heat of formation of Ni-Si compared to that for Ni-Ge, but little has been reported on the growth mechanisms and microstructural development of nickel germanosilicide.…”

Interfacial reactions of Co/Si0.76Ge0.24 and Co(Si0.76Ge0.24)/Si0.76Ge0.24 by pulsed KrF laser annealing

“…Strain relaxation might be induced by the chemical inhomogeneities, e.g., Ge segregation, and defects present in the interface between the germanosilicide and the unreacted Si 1−x Ge x film. 7,17,[26][27][28] At 0.6 J/cm 2 three germanosilicide layers were still present, and some Ge further diffused to the Si substrate, indicating that the melting depth exceeded the total thickness of the asdeposited Co layer (∼25 nm) and the as-grown Si 0.76 Ge 0.24 film (∼150 nm). Meanwhile the inhomogeneous distribution of Co in the reacted region was significantly improved.…”

“…31 For Ni and Pd on Si 1−x Ge x pulsed KrF laser annealing has been found to effectively prevent Ge segregation out of the germanosilicide, the formation of agglomeration structure, and the occurrence of strain relaxation. [26][27][28] Strain relaxation is possibly induced by the chemical inhomogeneities and defects present in the interface between the germanosilicide and the unreacted Si 1−x Ge x film. 7 In a salicide formation technique CoSi 2 has received much attention because it can significantly reduce the contact resistivity of Si devices and act as a solid diffusion source to form shallow junction.…”

Study of nickel silicide contact on Si/Si1-xGex

“…This is due to more nickel germanosilicide agglomerate and micro-void formation in the samples as the Ge mole fraction increases as observed by the SEM. These phenomena are attributed to the lower heat formation for metal-Ge than for metal-Si [10]. For the samples, the increases slightly as the Ge fraction increases.…”