Localized growth and functionalization of silicon nanowires for MEMS sensor applications

We present a mechanism for the growth of silicon nanowires (SiNW) directly from a silicon substrate or polysilicon block, without the use of a metal catalyst, silicon vapor or CVD gasses. This allows for "in place" growth of nanostructures without further need for manipulation or alignment for subsequent applications. Wires in the 2040 nm diameter range with lengths over 85 μm can be easily grown by this technique. The critical parameters in the growth of these nanowires are the surface treatment and the carrier gas used. The growth and functionalization of SiNW can enhance the sensitivity of sensor systems. Wire growth is stress driven and enhanced by surface Si atom diffusion due to the presence of hydrogen gas.