Patent ID: 8431448

Claim:
A method for manufacturing an organic transistor element having an electrode provided on an organic semiconductor layer comprising: forming an organic semiconductor layer above an insulating layer; performing wet etching of the electrode into a predetermined pattern, the electrode being provided on the organic semiconductor layer, the wet etching using an iodine etching solution; and forming a doped region in the organic semiconductor layer from a surface layer of the organic semiconductor layer to a vicinity of an interface of the insulating layer, by doping the dopant into the organic semiconductor layer concurrently with the wet etching of the electrode being performed using the iodine etching solution that includes the dopant, wherein the wet etching includes one of the following: when the organic semiconductor layer has positive holes as carriers, the dopant in the iodine etching solution is an oxidizing dopant having oxidative capability, wherein the oxidizing dopant is selected from the group consisting of halogens, Lewis acids, proton acids, organic acids, transition metal compounds and electrolytic anions, and the wet etching of the electrode simultaneously oxidizes the organic semiconductor layer and forms more positive holes therein, and when the organic semiconductor layer has electrons as carriers, the dopant in the iodine etching solution is a reducing dopant having reductive capability, wherein the reducing dopant is selected from the group consisting of alkali metals, alkaline earth metals, rare earth metals, ammonium ion, alkyl group including R 4 P + , R 4 As + ,R 3 S + and acetylcholine; and the wet etching of the electrode simultaneously reduces the organic semiconductor layer and forms more electrons therein.