A method of forming a semiconductor device includes forming a molding layer and a supporter layer on a substrate including an etch stop layer, forming a mask layer on the supporter layer, forming a first edge blocking layer on the mask layer, forming a mask pattern by etching the mask layer, forming a hole, forming a lower electrode in the hole, forming a supporter mask layer on the supporter layer, forming a second edge blocking layer on the supporter mask layer, forming a supporter mask pattern by patterning the supporter mask layer, forming a supporter opening passing through the supporter layer, removing the molding layer, forming a capacitor dielectric layer and an upper electrode on the lower electrode, forming an interlayer insulating layer on the upper electrode, and planarizing the interlayer insulating layer. The hole passes through the supporter layer, the molding layer and the etch stop layer.