Organic transistor, method of forming organic transistor and organic EL display with organic transistor

1. An organic transistor comprising:

a source electrode part and a drain electrode part that are formed on a substrate, fingers of the source electrode part being interdigitated with fingers of the drain electrode part;

ribs that are selectively formed on lead segments of the source electrode part and the drain electrode part, and on finger segments located at an end of each lead segment of the source electrode part and the drain electrode part;

an organic semiconductor film that is placed in a region defined by the ribs and that connects the source electrode part and the drain electrode part; and

a gate electrode placed on the organic semiconductor film through a gate insulating film,

wherein there is a gap between a rib formed on the source electrode part and a rib formed on the drain electrode part, and the ribs serve as masking films for patterning the source electrode part and the drain electrode part.

2. The organic transistor according to claim 1 , wherein the width of the gap between the rib formed on the source electrode part and the rib formed on the drain electrode part is between 20 μm and 200 μm.

3. The organic transistor according to claim 1 , wherein a line width of parts of the electrode parts where the ribs are not placed is smaller than half of a line width of parts of the electrode parts where the ribs are placed.

4. The organic transistor according to claim 1 , wherein the ribs are water repellant.

5. An organic electroluminescent display comprising the organic transistor according to claim 1 .