Hi all,

I tried to fabricate the Carbon nanotube field effect transistor (CNFET) for around half a year, however, none of them is working till now. The main problem was the source to drain current Id did not change much (less than 1 order) corresponding to the gate voltage.

I have tried different design, including 1. I used the heavily doped silicon substrate as the gate and CNT bridging two pre-patterned electrodes. (the electrode may block the electric field from the gate???)

2. I tried to disperse the CNT on top of the SiO2 on top of heavily doped silicon, and use the e-beam lithography to contact two ends of the CNT. But gate effect as well. (Although just try once)

3. I also tried the top gate design. Firstly, I disperse the CNT to bridge two pre-fabricated Au electrodes, then deposit an insulator on the top. Finally an Al gate electrode will be pattern on the top of the insulator. (Still no gate effect, although try once as well)

4. The design using the Al2O3 as insulator was also tried. The Aluminum was pattern between two prefabricate Au electrodes, then O2 plasma was used to bombard the Al to generate a thin layer of Al2O3 with around 3nm. (No gate effect as well)

Did anyone who had fabricated Carbon nanotube field effect transistor or Nanowire transistor know what the reasons are? Or is there any trick to make the CNT transistor? Any advice is highly appreciated. Thanks in advanced.

Chen