Patent ID: 8241985
Filing Date: 2012-08-14
Classification: H01L

Abstract:
1. A method of manufacturing a semiconductor device, the semiconductor device including a well of a first conductivity type formed on a substrate; a first impurity diffusion area and a second impurity diffusion area formed on the well, separated from each other by a channel area and of a second conductivity type different from the first conductivity type; and a gate electrode formed, via a gate oxide film, above a part of the first impurity diffusion area, above the channel area and above a part of the second impurity diffusion area, wherein the gate electrode is doped with the second impurity type, and an impurity concentration of electrode edge portions located above the first and second impurity diffusion areas is lower than an impurity concentration of a portion located above the channel area, the method of manufacturing the semiconductor device comprising: forming the well; forming the gate oxide film on the well and a gate material film on the gate oxide film; and a first ion injection step of transforming the gate material film into the gate electrode and forming the first and second impurity diffusion areas on the well by providing a mask above the gate material film from outer edges of the gate material film over a predetermined width and injecting impurity ions of the second conductivity type and performing annealing in a state in which at least a part of the gate material film located within an area sandwiched by the mask and a surface of the well outside the outer edges are exposed.