Thermal Conductivity of Rough Silicon Nanowires with Silicide Layer

Rough silicon nanowires have considered as promising building block for high efficiency thermoelectric device. We demonstrate that the thermal conductivity of rough nanowires is further reduced by forming cobalt silicide layer on their both ends. This reduction is experimentally investigated using differential 3ω method. The rough nanowire exhibits 10% reduction of thermal conductivity by forming a 100 nm thick cobalt silicide layer at both nanowire ends. To investigate the effect of silicide layer on the reduction in thermal conductivity, the theoretical analysis was performed using the nanoinclusion scattering and interfacial thermal resistance model. It found that the cobalt silicide layer reduces thermal conductivity by disturbing thermal transport in the silicon/cobalt silicide interface.