Thin film transistor, method of manufacturing thin film transistor, display device, and electronic equipment

Abstract

A thin film transistor includes a contact layer that contains an organic semiconductor material and an acceptor material or a donor material provided between an organic semiconductor layer and a source electrode/a drain electrode.

What is claimed is: 
     
         1 . A thin film transistor,
 wherein a contact layer containing an organic semiconductor material and an acceptor material or a donor material is provided between an organic semiconductor layer and a source electrode/a drain electrode.   
     
     
         2 . The thin film transistor according to  claim 1 ,
 wherein the contact layer has the same pattern form as the organic semiconductor layer, and   wherein the source electrode/the drain electrode are stacked on the organic semiconductor layer via the contact layer.   
     
     
         3 . The thin film transistor according to  claim 2 ,
 wherein, in the contact layer, the content of the acceptor material or the donor material in a portion interposed between the organic semiconductor layer and the source electrode and a portion interposed between the organic semiconductor layer and the drain electrode is higher than the content between the source electrode and the drain electrode.   
     
     
         4 . The thin film transistor according to  claim 1 ,
 wherein the contact layer contains the acceptor material when a conductivity type of the organic semiconductor layer is a p type, and   wherein the contact layer contains the donor material when a conductivity type of the organic semiconductor layer is an n type.   
     
     
         5 . The thin film transistor according to  claim 1 ,
 wherein the contact layer contains the same organic material as that of the organic semiconductor layer.   
     
     
         6 . The thin film transistor according to  claim 1 , comprising:
 a gate electrode;   a gate insulating film that covers the gate electrode;   the organic semiconductor layer that is disposed in the state of being stacked on the gate electrode via the gate insulating film;   the contact layer that is stacked on the organic semiconductor layer; and   the source electrode/drain electrode, end portions of which are disposed on the contact layer in the state of oppositely interposing the gate electrode therebetween.   
     
     
         7 . The thin film transistor according to  claim 6 ,
 wherein, on the gate insulating film provided with the organic semiconductor layer, a protective film is provided which has a shape for covering an upper portion of the gate electrode and exposing the organic semiconductor layer portion on both sides of the gate electrode, and   wherein the contact layer is provided on the organic semiconductor layer that is at least exposed from the protective film.   
     
     
         8 . The thin film transistor according to  claim 7 ,
 wherein the protective film has openings that expose the organic semiconductor layer portion on both sides of the gate electrode, and covers the upper portion of the gate insulating film.   
     
     
         9 . The thin film transistor according to  claim 7 ,
 wherein the contact layer is divided on the protective film and the organic semiconductor layer by a step of the protective film.   
     
     
         10 . The thin film transistor according to  claim 7 ,
 wherein the contact layer is divided between the source electrode and the drain electrode in an upper portion of the protective film.   
     
     
         11 . A display device comprising:
 a thin film transistor in which a contact layer containing an organic semiconductor material and an acceptor material or a donor material is provided between an organic semiconductor layer and a source electrode/a drain electrode; and   a pixel electrode that is connected to the thin film transistor.   
     
     
         12 . Electronic equipment comprising a thin film transistor in which a contact layer containing an organic semiconductor material and an acceptor material or a donor material is provided between an organic semiconductor layer and a source electrode/a drain electrode.