Patent ID: 7663180
Filing Date: 2010-02-16
Classification: H01L

Abstract:
1. A semiconductor device comprising: a first well layer that is formed on a semiconductor substrate, the first well layer being of a first conductivity type; a first impurity diffusion layer that is formed on the first well layer, the first impurity diffusion layer being of a second conductivity type; a first element isolation insulating film that is positioned between a first region of the first well layer and the first impurity diffusion layer; a second impurity diffusion layer that is formed on the first well layer, the second impurity diffusion layer being of the second conductivity type; a third impurity diffusion layer that is formed on the first impurity diffusion layer, the third impurity diffusion layer being of the second conductivity type; a floating gate that is formed on the first region of the well layer and the first impurity diffusion layer with a gate insulating film disposed between the floating gate and the first region of the well layer, a first portion of the floating gate being positioned on a first region of the first impurity diffusion layer, the first region of the first impurity diffusion layer being positioned between the second impurity diffusion layer and the third impurity diffusion layer, a second portion of the floating gate being positioned on a second region of the first well layer, the second region of the first well layer being positioned between the second impurity diffusion layer and the first region of the first impurity diffusion layer; a source layer that is formed on the first well layer and is isolated from the first impurity diffusion layer, the source layer being of the second conductivity type; and a drain layer that is formed on the first well layer in such a manner that a third portion of the floating gate is positioned on the first region of the first well layer positioned between the source layer and the drain layer, the drain layer being in isolation from the first impurity diffusion layer and being of the second conductivity type.