Patent ID: 7034453

Claim:
The organic EL display device comprising: a substrate; a plurality of pixel regions each of which has at least a first electrode, a light emitting material layer, and a second electrode laminated in this order above a principal surface of the substrate, the plurality of pixel regions are arranged two-dimensionally in the principal surface of the substrate; and a bank film formed above the principal surface of the substrate to separate respective one of the plurality of pixel regions from another of the plurality of pixel regions adjacent to the respective one of the plurality of pixel regions, the bank film has openings each of which exposes the first electrode provided for the respective one of the plurality of pixel regions, wherein the light emitting material layer is formed in the opening of the bank film to be extended to a side wall of the bank film lying along the opening in the respective one of the plurality of pixel regions, the second electrode provided for the respective one of the plurality of pixel regions is formed in common with that provided for the another of the plurality of pixel regions, and the bank film is comprised of at least one inorganic material layer and has the side wall thereof sloped at an angle less than 85 degrees with respect to the principal surface of the substrate, wherein the bank film is formed of a silicon nitride film (SiN x ), wherein a composition ratio of nitrogen x of the silicon nitride film is different between a lower side of the silicon nitride film located closer to the principal surface of the substrate and an upper side thereof further from the principal surface of the substrate opposed to the lower side thereof to decrease an etching rate thereof at the lower side thereof in comparison with that at the upper side thereof.