Patent ID: 8058112

Claim:
A manufacturing method of a semiconductor device comprising: designing a distance between a source electrode and a drain electrode; preparing a carbon nanotube group including both of conductive carbon nanotubes having a characteristic of a conductive material and semiconductive carbon nanotubes having a characteristic of a semiconductive material; and forming a channel layer by depositing the carbon nanotube group on a channel layer forming region at a density where the source electrode and the drain electrode are connected to each other through all of the carbon nanotube group and not connected to each other only through the conductive carbon nanotubes, wherein the preparing comprises preparing the carbon nanotube group in which the conductive carbon nanotubes accounts for 1/k of total of carbon nanotubes, and the forming the channel layer comprises: preparing a first data indicating a correspondence relationship between a short-circuit probability being a probability of a short-circuit of the source electrode and the drain electrode through carbon nanotubes and a density of carbon nanotubes for each length of carbon nanotubes; determining Ï open and Ï short by referring the first data for each length of carbon nanotubes, wherein the Ï open indicates a maximum value of a density of carbon nanotubes at which the source electrode and the drain electrode are substantially opened to each other, and the Ï short indicates a minimum value of a density of carbon nanotubes at which the source electrode and the drain electrode are substantially short-circuited to each other; determining a length of carbon nanotubes at which the Ï short is smaller than kÃ—Ï open; adjusting a length of the prepared carbon nanotube group to a length determined at the step of determining the length; and forming the channel layer by depositing the carbon nanotube group adjusted at the adjusting on the cannel layer forming region such that a density of carbon nanotubes Ï total is in a range represented by Ï short<Ï total<kÃ—Ï open.