Selective growth of ZnO nanowires with varied aspect ratios on an individual substrate

Hydrothermal zinc oxide (ZnO) nanowires (NWs) were grown on sputtered ZnO seed layer regions defined by photolithography on silicon device substrates with controlled aspect ratios of 9-26 across a single chip. We investigated the influence of seed area ratio on the morphology of ZnO NWs and demonstrated that the aspect ratio increases at lower seed area ratios. The aspect ratios were further increased to 24-34 on a single substrate with minimal debris by maintaining a photoresist layer during the ZnO NW growth. These ZnO growth and fabrication techniques pave the way to fabricate devices that require ZnO NWs with varied aspect ratios on the same substrate.