US Patent 7501319 Manufacturing a semiconductor device including sidewall floating gates

A semiconductor device and a fabricating method thereof are disclosed. The semiconductor device includes polysilicon gate electrodes, a gate oxide layer, sidewall floating gates, a block oxide layer, source/drain areas, and sidewall spacers. In addition, the method includes the steps of: forming a block dielectric layer and a sacrificial layer on a semiconductor substrate; forming trenches by etching the sacrificial layer; forming sidewall floating gates on lateral faces of the trenches; forming a block oxide layer on the sidewall floating gates; forming polysilicon gate electrodes by a patterning process; removing the sacrificial layer; forming source/drain areas by implanting impurity ions into the resulting structure; injecting carriers or electric charges into the sidewall floating gates; and forming spacers on lateral faces of the polysilicon gate electrodes and the sidewall floating gates.