ELECTRON EMISSION ELEMENT, ELECTRON BEAM DEVICE, IMAGE DISPLAY DEVICE AND METHOD OF MANUFACTURING THE SAME

PROBLEM TO BE SOLVED: To provide an electron emission element which has an insulating member which is disposed on a substrate and has at least one side surface portion rising from the surface of the substrate, a gate provided to the upper surface of the insulating member, a recess portion formed just below the gate of the side surface portion, and a cathode which projects upwards from the lower edge of the recess portion and has a projecting portion having plural apex portions formed in the length direction of the lower edge, and is enhanced in electron emission characteristic.SOLUTION: A cathode 6 is formed by using a first conductive material layer 6a formed by a sputtering method under a full pressure lower than 1.0 Pa, a second conductive material layer is formed by a sputtering method under a full pressure from 1.0 Pa to 2.8 Pa, the second conductive material layer is etched, and an auxiliary apex portion 9 is formed by using the second conductive material layer left on the inner slant surface of the apex portion 8 of the projecting portion, thereby increasing the number of electron emission points.