Patent ID: 7510093

Claim:
A method of manufacturing a wiring substrate comprising: disposing a liquid material on a first film, the liquid material including water as a solvent and a film-forming material and covering a wet part of the first film; drying the solvent from the liquid material under atmospheric pressure to convert the liquid material into a second film, the second film covers a dry part of the first film, the dry part covering a smaller part of the first film than the area of the first film covered by the wet part; etching the first film except for the dry part of the first film, which is covered by the second film; depositing a metallic source material on one side of the dry part and a metallic drain material on a side of the dry part opposite the one side, such that the dry part of the first film, which is covered by the second film, is between the source material and the drain material, the dry part of the first film and the second film forming a barrier with a height higher than a height of either the source material and the drain material; and removing the second film so as to leave a channel between the source material and the drain material.