Synthesis of small diameter silicon nanowires on SiO₂ and Si₃N₄ surfaces

We report successful bottom-up synthesis of small diameter silicon nanowires (SiNW_s) on SiO₂ and Si₃N₄ surfaces. SiNW_s with diameter comparable to the diameter of the Au nano-particles (10-20 nm) were grown on these surfaces, as well as on Si substrates which are commonly used for the nanowire growth. The growth temperature for obtaining a high density of SiNWs on SiO₂ and Si ₃N₄ substrates is higher (460- 470°C) than that of the case of normal Si substrates (440°C). The growth on patterned substrates demonstrates that SiNWs can be selectively grown. Furthermore, the guided growth over metal structures is also shown to be possible. Selective growth of SiNWs on pre-patterned surfaces opens up the possibility of self-aligning SiNWs for the integration of complex device structures.