Catalyzed chemical vapor deposition is the most practical method for development of carbon nanotube devices. It is both scalable and compatible with integrated circuit and MEMS manufacturing processes. CVD allows high specificity of single wall or multi wall nanotubes through appropriate selection of process gasses. Carbon feedstock comes from the decomposition of a feed gas such as Methane or Ethylene.
The high stability of the feed gas prevents it from decomposing in the elevated temperatures of the furnace. Typically, decomposition will take place at 800 °C to 1000 °C for SWNT, and 550 °C to 750 °C for MWNT.
Decomposition of the feed gas occurs only at the catalyst sites, reducing amorphous carbon generated in the process. Decomposed carbon molecules then assemble into nanotubes at the catalyst nano-particle sites.
Catalyst nanoparticles can be patterned on a substrate lithographically to seed nanotube growth at intended locations. The growth of nanotubes can be caused to originate at a site of electrical connection or of mechanical significance.
Control Over Nanotube Synthesis
Carbon nanotubes have been demonstrated as enabling components of various electronic and chemical-mechanical devices functional on the molecular scale. Among these devices are chemical force sensors, gas detectors, field emission displays, molecular wires, diodes, FEDs, and single-electron transistors.
To develop these devices into manufacturable products and to gain control of device assembly on the molecular level, a practical technique for nanotube growth is needed. Relatively low temperatures of the process and the ability to pattern the catalyst material directly on device substrates make catalytic CVD the method of choice for nanotube device development. The EasyTube® was designed to put the power in the hands of our customers to create and innovate with this exciting new medium.