The diffusion behavior of ion-implanted arsenic and phosphorus in relaxed Si0.8Ge0.2 has been investigated. Under equilibrium, extrinsic conditions, both dopants are observed to diffuse faster in SiGe than in Si. Simulations of the measured profiles suggest that the ratio of the effective diffusivity in Si0.8Ge0.2 compared to that in Si is roughly seven for arsenic, and roughly two for phosphorus. Under transient diffusion conditions, the arsenic diffusivity in SiGe is retarded, and the magnitude of the diffusion is roughly the same as that in Si. This result suggests that it is possible to optimize the diffusion conditions to achieve n+ source/drain junctions that are as shallow in SiGe as in Si.

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SYNOPSISThe effects of various curing accelerators on the physical properties of epoxy molding compounds (EMCs) were investigated. Such properties as elasticities in rubbery and glassy regions, glass transition temperature, thermal expansion coefficient, and water absorption at 60°C of neat epoxy resins using various curing accelerators were found to be directly reflected in the properties of the EMCs that were prepared by using each resin system. However, volume resistivity and saturated water absorption at 120°C were not reflected. This was attributed to differences in the catalytic reactivity of accelerators causing different melt viscosity for the EMC, which resulted in different densities (packing degrees) and affected physical properties of molded EMC. On the other hand, it was found that the density of molded EMC was also affected by the molding conditions. To improve the physical properties of the molded EMC, in addition to proper selection of accelerators, it was very important to set the melt viscosity of the EMC as high as possible within the moldable range and to select suitable molding conditions.

Selective epitaxial germanium on silicon-on-insulator high speed photodetectors using low-temperature ultrathin Si 0.8 Ge 0.2 buffer Appl. Phys. Lett. 91, 073503 (2007); 10.1063/1.2769750Fermi-level dependent diffusion of ion-implanted arsenic in germanium AIP Conf.

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Ltd. (4026, Kuji-cho, Hitachi-shi, 319-12 Japan) *2Hitachi Chemical Co ., Ltd. (1772-1, Kanakubo, Yuuki-shi, 307 Japan) The relationship between cross-linking density and physical properties was investigated for cured epoxy resins. These resins were prepared by using poly(glycidyl ether) of o-cresol-formaldehyde novolacs having different molecular weights, a phenol-formaldehyde novolac hardener, and various accelerators. The cross-linking density of the cured resins is higher for raw epoxy resins of higher molecular weight.The density reached the highest value when 2-ethyl-4-methyl imidazole was used as an accelerator. The thermal expansion coefficient of the cured resins in rubbery state decreased with higher values of cross-linking density, while it increases in the glassy state. The elasticity values of highly cross-linked resins in glassy state are lower than those of low cross-linked resins. Furthermore, the saturated water content, water vapor permeability and diffusion coefficient and specific volume increase as the cross-linking density becomes higher. Such relationships between cross-linking density and physical properties were observed in the cured resins which were prepared by using the raw epoxy resins having different molecular weights and in the cured resins prepared by using different accelerators.