Study on Transport Properties of Silicon Nanowires

초록

Various p-type silicon nanostructures with fixed length 20 mm and thickness 40 nm but with varying width in the range from ~ 100 nm to 20 μm were prepared by the silicon process technology and their intrinsic transport property was systematically studied. Based on their Id-Vg characteristic measurements, the hole mobility (μh) and concentration (nh) were extracted for all nanostructures. For the structures of small widths (w ≤ 500 nm, nanowire-type), nh remains more or less constant at about 2.4x1017 cm-3 as width narrows down from 500 to 96 nm, while μh decreases steadily from 340 to 240 cm2V-1s-1. This behavior of mobility degradation with width narrowing is likely to originate from the enhanced surface scattering effect, but more detailed microscopic theory should be needed to explain this effect quantitatively.