tens of nanos a plurality of carbon nano tubes may be formed depending on design of the semiconductor device so that a fine width can be easily formed also the carbon nano tube 110 is vertically grown to secure the channel length thereby improving the characteristics of the semiconductor device referring to fig2 c the insulating film 120 is formed on the substrate 100 and the inner surface and the outer surface of the gate shaped carbon nano tube pattern 110 the insulating film 120 includes a high k dielectric material for example the insulating film 120 can be formed of zirconium oxide lead zirconium titanate pzt hafnium oxides sion sio 2 si 3 n 4 taon ta 2 o 5 al 2 o 3 hfo 2 tio 2 srtio 3 ba sr tio 3 pb sr tio 3 zro 2 or a combination thereof the insulating film 120 may include an oxide film a nitride film or a carbonized film the insulating film 120 is formed by an ald process or a cvd process the above deposition processes allows the insulating film 120 to be uniformly deposited on the inner surface and the outer surface of the carbon nano tube pattern 110 the insulating film 120 may serve as a gate insulating film referring to fig2 d a catalyst layer not shown is formed on the the first insulating film and the second insulating films 120 by an ald process or a.