Promoted Growth of Bi Single-Crystalline Nanowires by Sidewall-Induced Compressive Stress in On-Film Formation of Nanowires

摘要

To increase the density of Bi nanowires grown by our unique on-film formation of nanowires (OFF-ON) method, we introduced a technique for enhancing compressive stress, which is the driving force for the nanowire growth. The compressive stress could be controlled by modifying the substrate structure. A combination of photolithography and a reactive ion etching technique was used to fabricate patterns on a thermally oxidized Si(100) substrate. It was found that the density of Bi nanowires grown from Bi films in 100 × 100 μm~2-sized SiO_2 patterns increases by a factor of seven over that from non-patterned substrates. Our results indicate that the density of Bi nanowires can be increased by enhanced compressive stress arising from a sidewall effect in the optimized pattern size and array.