Patent ID: 7718483

Claim:
A method for manufacturing a non-volatile semiconductor device comprising: forming a plurality of first semiconductor portions over a substrate; forming a plurality of insulating films over said plurality of first semiconductor portions; forming a plurality of insulating structures having sidewalls inclined at a taper angle with respect to a line perpendicular to said substrate, upper surfaces of said insulating structures: having widths greater than lower surfaces of said insulating structures, and being at same heights as upper surfaces of said insulating films; removing said insulating films; selectively growing a plurality of second semiconductor portions respectively using said plurality of first semiconductor portions as seeds; removing upper portions of said plurality of second semiconductor portions to form a plurality of floating gates with substantially flat upper surfaces, said upper surfaces of said floating gates being at same heights as upper surfaces of said insulating structures; forming an insulating layer over said plurality of floating gates; and forming a control gate over said insulating layer.