Abstract
ENGLISH ABSTRACT Vertically aligned nano-scale diamond tubes (NDTs) have been successfully grown on a rugged Polycrystalline diamond substrate. Each NDT is single crystalline with {111} twins defects inside. The formation of single crystalline nano-scale diamond tubes can be well explained by the observed coalescence mechanism of diamond dots. The aspect ratio of NDTs can be fine-tuned by bias voltage and the growth rate of NDTs increases linearly with bias voltage. This tubular structure of NDTs provides very large extended surface area to dissipate heat away and acts as fin structures on diamond. The heat dissipation performance of NDT/diamond structure is better than the flat diamond. Vertically aligned nano-scale diamond tips have been also sucessfully grown on the rugged polycrystalline diamond/Si substrates. The diamond nanotips exhibit three different morphologies (C-, cone-, and rod-like-shape) that can be monitored by varying substrate temperature and bias voltage. Nano-scale diamond tips can also be grown on the polycrystalline diamond substrates in a CH4/H2/N2 mixed plasma. This diamond nanotip seems to exhibit a tubular hole of ~ 20-50 nm in diameter along the axis at the bottom part of the nanotip. This diamond nanotips are polycrystalline at the bottom part, single crystalline at the tip end, and a mixed region in between.