1. A method for forming a semiconductor device, comprising: providing a substrate structure, the substrate structure including: a substrate; an insulating layer overlying the substrate; two support structures overlying the insulating layer; a carbon nanotube supported by the support structures, the carbon nanotube including a first portion and a second portion, the first and second portions, respectively, including first end region, a channel region, and a second end region; wherein the first end region of the first portion is connected to the first end region of said second portion, the first portion having a first conductivity type and the second portion having a second conductivity type; forming a multi-layer film structure surrounding the carbon nanotube, the multi-layer film structure including a first dielectric layer, a conductive material layer, and a second dielectric layer; forming a plurality of first electrodes surrounding the multi-layer film structure at the channel region of the first portion, the plurality of first electrodes being separated from each other; forming a plurality of second electrodes surrounding the multi-layer film structure at the channel region of the second portion, the plurality of second electrodes being separated from each other; forming a third electrode surrounding the second end region of the first portion; forming a fourth electrode surrounding the second end region of the second portion; removing a portion of the multi-layer film structure to expose the first end region of the first portion and the first end region of the second portion; and forming a fifth electrode coupled to the exposed first end region of the first portion and the exposed first end region of the second portion, the fifth electrode being insulated from the conductive material layer in the multi-layer film structure; wherein, the carbon nanotube is supported on the substrate by the plurality of first electrodes, the plurality of second electrodes, the third electrode, the fourth electrode, and the fifth electrode support.