Growth control of carbon nanotube using various applied electric fields for electronic device applications

The control of the growth direction of a carbon nanotube was accomplished by applying an electric field during the growth of the carbon nanotube. The effects of two types of applied bias, one is a constant DC bias, and the other is a ramp bias, on the control of the growth direction were. examined. By maintaining a constant DC bias we could control the growth direction of the carbon nanotube, however, the bridging ratio between the two electrodes was as small as 35%. We suppose that this low bridging ratio may be caused by the etching effect of hydrogen. When a ramp bias was applied, bridging ratio tended to increase with the slope of ramp bias. Under optimal conditions, the bridging ratio reached a value as high as 95%.