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[en] A two-step process of Ni silicide formed on bulk silicon, and the effects of different process conditions, including two-step RTA temperature and time, selective etching, and process protective nitrogen gas on the properties of the Ni silicide film have been studied. In particular, the experiments show that the quality of NiSi film is very sensitive to the process conditions of the first RTA. The experiments also show that the quality of the film is very sensitive to the flow of protective nitrogen gas. The corresponding mechanisms are discussed.
[en] The post-silicide of dopant segregation process for adjusting NiSi/n-Si SBH (Schottky barrier height) is described. Adopting the analysis of the I-V characteristic curve and extrapolating the SBH of NiSi/n-Si Schottky junction diodes (NiSi/n-Si SJDs), the effects of different of process parameters dopant segregation, including segregation anneal temperature and dopant implant dose, on the properties of the NiSi/n-Si SJDs have been studied, and the corresponding mechanisms are discussed.
[en] The growth kinetics of NiSi has been evaluated by depositing a Ni film on a <111> and <100> Si substrates. By X-ray diffraction and MeV annealing Ni2Si is formed first, while NiSi appears only after the total exhaustion of the Ni film. It has been found that, on both Si substrates, the thickness of NiSi increases with the square root of time; different growth rates have been observed for the two different Si orientations. The two competing mechanisms of Ni diffusion through NiSi by grain boundary and by substitutional processes are correlated with the different microcrystalline structure of the NiSi silicide layers grown on different Si oriented substrates
[en] Hot compression tests of Cu–Ni–Si alloy with high Ni and Si contents were carried out on Gleeble-3800 thermal simulator in the deformation temperature of 750 °C ∼ 950 °C, strain rate of 0.01 ∼ 10 s−1 and deformation amount of 70%. Subsequently, constitutive equation based on Arrhenius-type constitutive model considering strain effect was established, and the average absolute relative error and correlation coefficient R were 7.34% and 0.991. Then, hot Processing map was obtained by combining the power dissipation and instability maps, and the suitable processing conditions could be predicted. Based on the results of these experimental and theoretical investigations on the hot deformation behavior of Cu–Ni–Si alloys, Multi-direction compression (MDC) was carried out at 860 °C and corresponding strain of single pass and accumulated 24 passes 0.4 and 9.6 respectively. The resulted microstructure consisted of fine matrix grains with a diameter of 3.02 μm and well dispersed Ni31Si12 particles 0.62 μm, suggesting that the results of thermal simulator and corresponding calculation were credible for guiding the thermo-mechanical processing parameters of Cu–Ni–Si alloys. (paper)
[en] Highlights: • Si@NiSi2/Ni/C nanocomposites with core-shell structure were synthesized via thermal reduction process. • Si@NiSi2/Ni/C exhibited much higher capacities than Si/C and NiSi2/Si anodes. • Si@NiSi2/Ni/C anode displayed 98% capacity retention after 105 cycles. • Si@NiSi2/Ni/C anode showed excellent rate capabilities. - Abstract: A Si-based alloy as the anode material in Li-ion batteries has advantages of safety and excellent performances, but poor electronic conductivity and excessive volume expansion limit the long cycle life required for practical application. In this work, in order to solve these problems, a core-shell nanocomposite has been developed, which is composed of a Si core and NiSi2/Ni shell with a carbon layer coating as the outer surface, which is referred to as a Si@NiSi2/Ni/C nanocomposite. Results show a reversible charge capacity of 1194 mA h g−1 and 98% retention after 105 cycles, which are superior to its Si/C and NiSi2/Si counterparts. Furthermore, the fabrication method used has advantages of low cost and easy operation, which make it feasible to commercialize the Si@NiSi2/Ni/C nanocomposite as the anode in a lithium-ion battery.
[en] To further the understanding of superplasticity in intermetallics, this paper presents results of experimental investigations on an intermetallic alloy based on nickel silicide. Specifically, the evolution of the microstructure and its influence on superplastic performance is discussed. In the duplex microstructure, one phase showed grain growth, and the other, grain refinement. Cavitation occurred at interphase boundaries and final failure was by interlinkage of these cavities. Superplastic behavior was influenced by changing the orientation of the tensile axis. Though a transverse orientation showed more cavitation than longitudinal, it yielded greater elongation. An increased resistance to cavity coalescence in the transverse direction played a role in the enhanced ductility. Annealing the material improved the homogeneity of the microstructure. The annealed material showed improved strain-rate sensitivity values and enhanced superplasticity
[en] By means of analyzing the I-V characteristic curve of NiSi/n-Si Schottky junction diodes (NiSi/n-Si SJDs), abstracting the effective Schottky barrier height (φB,eff) and the ideal factor of NiSi/n-Si SJDs and measuring the sheet resistance of NiSi films (RNiSi), we study the effects of different dopant segregation process parameters, including impurity implantation dose, segregation annealing temperature and segregation annealing time, on the φB,eff of NiSi/n-Si SJDs and the resistance characteristic of NiSi films. In addition, the changing rules of φB,eff and RNiSi are discussed. (semiconductor technology)
[en] A comparative experimental study of series resistance and hole mobility of pMOSFETs with silicon germanium (SiGe) junctions under various silicide techniques is carried out. It is found that using an additional germanium pre-amorphous implant process in the nickel silicide (NiSi) techniques does not affect the hole mobility. However, it increases the source/drain series resistance. On the other hand, an additional silicon capping layer process in the NiSi techniques not only improves the hole mobility, but also reduces the series resistance dramatically. Various MOSFET characterizations from the silicide techniques are mainly due to the differences in the NiSi/SiGe interface structures in those devices. (paper)
[en] An electric conductive Ni silicide nanowire (NiSi NW) embedding electric force microscopy (EFM) tip was fabricated by the dielectrophoretic method and was used to obtain electric information. Due to the geometric and electric excellence, the NiSi NW provides advantages in imaging and fabrication of the microscopy tip. A lead zirconate titanate (PZT) ferroelectric thin film was positively and negatively polarized, and the polarities were obtained by probing of the NiSi NW EFM tip to give distinctive charging information of the PZT film. Moreover, the NiSi NW EFM probing was adopted to achieve the electrical signal from the NW interconnect. The NiSi NW EFM probe confirmed the uniform electric-potential distribution through the NiSi NW interconnect with a small standard deviation. This demonstrates the feasibility of functional utilizations of the NiSi NW.
[en] We have studied a polycrystalline silicon thin-film-transistor (poly-Si TFT) process that has very low parasitic resistance by using a Ni-silicide. The poly-Si TFT characteristics having Ni-silicide source/drain region were compared with a conventional ion-doped source/drain region TFT. On reducing the source/drain parasitic resistance, the transconductance of poly-Si TFT increases. The poly-Si TFT having a Ni-silicide source/drain region shows a higher field effect mobility than conventional ion-doped source/drain region shows a higher field effect mobility than conventional ion-doped source/drain poly-Si TFT. The poly-Si TFT using a Ni-silicide source/drain exhibited a field-effect mobility of 60 cm2/Vs, and a sheet resistance at the source/drain region of 200 Ω/sq