激光熔敷Mo2Ni3Si／NiSi金属硅化物耐磨复合材料涂层组织与抗磨性能

以Ni-42Mo-28Si和Ni-36Mo-24Si(质量分数计)合金粉末为原料，利用激光熔敷技术在1Crl8Ni9Ti不锈钢基材表面制得由三元金属硅化物Mo2Ni3Si初生树枝晶和枝晶间Mo2Ni3Si／NiSi共晶组织组成的复合材料涂层，考察了涂层镍含量及Mo2Ni3Si初生相体积分数对涂层在滑动干摩擦下的耐磨性的影响．结果表明：激光熔敷Mo2Ni3Si／NiSi金属硅化物复合材料涂层在滑动干摩擦条件下具有优异的抗磨性能；随着涂层中三元金属硅化物Mo2Ni3Si初生相体积分数的增加，涂层的耐磨性提高，摩擦系数降低；激光熔敷Mo2Ni3Si／NiSi金属硅化物复合材料涂层具有良好的载荷特性．     

Enhanced formation of periodic arrays of low-resistivity NiSi nanocontacts on (0 0 1)Si0.7Ge0.3 by nanosphere lithography with a thin interposing Si layer

In this study, we demonstrated significant enhancement of the formation of low-resistivity NiSi nanocontacts with controlled size on (0 0 1)Si_0.7Ge_0.3 substrates by combining the nanosphere lithography with the use of a new Ni/a-Si bilayer nanodot structure. Low-resistivity NiSi with an average size of 78 nm was observed to be the only silicide phase formed in samples annealed at 350-800 °C. The presence of the interposing Si layer with appropriate thickness was found to effectively prevent Ge segregation and maintain the interface stability in forming NiSi nanocontacts on (0 0 1)Si_0.7Ge_0.3. As the annealing temperature was increased to 900 °C, amorphous SiO_x nanowires were observed to grow from silicide nanocontact regions. The NSL technique in conjunction with a sacrificial Si interlayer process promises to be applicable in fabricating periodic arrays of other low-resistivity silicide nanocontacts on Si_1−xGe_x substrates without complex lithography.     

Enhanced thermal stability of NiSi films on Si(1 1 1) substrates by a thin Pt interlayer

A thin interlayer of Pt can greatly enhance the thermal stability of NiSi films formed by rapid thermal annealing (RTA) on Si(1 1 1) substrates, as was revealed by X-ray diffraction (XRD) data and sheet resistance measurement. High-resolution transmission electron microscopy (HRTEM) reveals a well-defined interface between the Ni(Pt)Si film and the Si(1 1 1) substrate for the Ni/Pt/Si sample annealed at 640°C. The orientation relationship in this sample determined by selected area electron diffraction (SAED) was NiSi(1 0 0)||Si(1 1 1) and NiSi[0   0]||Si[0 1  ]. With the increase of temperature, the texture of NiSi films transform from NiSi(1 0 0)||Si(1 1 1) to NiSi(0 0 1)||Si(1 1 1). The reduction in the interfacial energy due to the formation of the (1 0 0) textured NiSi film is proposed as a possible reason for the improved thermal stability of NiSi and the transition in NiSi texture during high-temperature annealing. Detailed study on the XRD data combined with Auger electron spectra (AES) indicates PtSi and NiSi form a solid solution following Vegard's law, which adjusts the lattice constant ratio c/b to and may account for the texture of NiSi(1 0 0)||Si(1 1 1).     

Kleppa type calorimeter for the study of high temperature processes

A Kleppa type microcalorimeter was designed and constructed for the application to measure the thermal change in a reaction tube at T>1300 K. The details of new calorimeter are described. In order to verify the performance of the new calorimeter, the standard enthalpies of formation for NiSi and Ni₃Al were measured by direct synthesis in the calorimeter at T=1323 K. The enthalpies of formation obtained were −(79.3 ± 1.8) and −(189.3 ± 6.3) kJ · mol⁻¹ for NiSi and Ni₃Al, respectively. A comparison of results in the present work with available reported values has been made.     

Abnormal oxidation in nickel silicide and nickel germanosilicide in sub-micro CMOS

After post-silicidation annealing at various temperatures for 30 min,abnormal oxidation and agglomeration in nickel silicide and nickel germanosilicide are investigated under different conditions of NiSi,with As-,In-,and Sb-doped Si substrates of nickel germanosilicide without any dopants.The NiSi thickness,dopant species,doping concentration,and silicide process conditions are dominant factors for abnormal oxidation and NiSi agglomeration.Larger dopants than Si,thinner NiSi thickness and SiGe substrates,and higher dopant concentrations promote abnormal oxidation and agglomeration.