Semiconductor device and method of manufacturing the same

Claim 1

A semiconductor device, comprising: a semiconductor substrate (101) of a first conductivity type; a first impurity diffusion region (109) of a second conductivity type, formed in a surface region of said semiconductor substrate; a second impurity diffusion region (110) of the second conductivity type, formed in the surface region of said semiconductor substrate (101) and separated from said first impurity diffusion region (109); a first insulating film (103) formed on the surface of said semiconductor substrate (101); and a floating gate electrode (107) and a control gate electrode (104) formed on that portion of said first insulating film (103) which corresponds to a portion of said semiconductor substrate (101) lying between said first and second impurity diffusion regions (109, 110) such that said floating gate electrode (107) and said control gate electrode (104) sandwich a second insulating film (105) therebetween; characterized in that said floating gate electrode (107) is formed on said portion of said first insulating film (103) and is positioned near said first impurity diffusion region (109), and said control gate electrode (104) is positioned near said second impurity diffusion region (110).

Claim 8

A method of manufacturing a semiconductor device, comprising the steps of: (a) forming a firstinsulating film on a semiconductor substrate of a first conductivity type; (b) forming a control gate electrode on said first insulating film; (c) forming a second insulating film on a surface of said control gate electrode; (d) depositing a conductive material over the entire surface of the resultant structure to form a conductive material layer; (e) performing anisotropic etching of said conductive material layer to remove all of said conductive material layer except those portions corresponding to the side walls of said control gate electrode; (f) selectively removing a portion of said residual conductive material layer such that said residual material layer remains only on one of the side walls of said control gate electrode, and forming a floating gate electrode from the remaining portion of said residual conductive material layer; and (g) ion-implanting an impurity of the second conductivity type into said semiconductor substrate using said control gate electrode and said floating gate electrode as masks to form first and second impurity diffusion regions in a surface region of said semiconductor substrate.

Claim 9

A method of manufacturing a semiconductor device, comprising the steps of: (a) forming a firstinsulating film on a semiconductor substrate of a first conductivity type; (b) forming a control gate electrode on said first insulating film; (c) forming a second insulating film on a surface of said control gate electrode; (d) depositing a conductive material over the entire surface of the resultant structure to form a conductive material layer; (e) performing anisotropic etching of said conductive material layer to remove all of said conductive material layer except those portions corresponding to the side walls of said control gate electrode; (f) selectively removing a portion of said residual conductive material layer such that said residual material layer remains only on one of the side walls of said control gate electrode, and forming a floating gate electrode from the remaining portion of said residual conductive material layer; and (g) ion-implanting an impurity of the second conductivity type into said semiconductor substrate using said control gate electrode and said floating gate electrode as masks to form first and second impurity diffusion regions in a surface region of said semiconductor substrate.

Claim 11

A method of manufacturing a semiconductor device, comprising the steps of: (a) forming a first insulating film on a semiconductor substrate of a first conductivity type; (b) forming first and second gate electrodes on said first insulating film; (c) forming second and third insulating films on said first and second gate electrodes, respectively; (d) depositing a conductive material over the entire surface of the resultant structure to form a conductive material layer; (e) performing anisotropic etching to remove said conductive layer except for portions thereof corresponding to the side walls of said first and second gate electrodes; (f) ion-implanting an impurity of the second conductivity type in said semiconductor substrate using said first and second gate electrodes and the residual portions of said conductive material layer as masks; (g) selectively removing said residual portions of the conductive material layer to leave said residual portions on only one side of the side walls of said first gate electrode, and forming a third gate electrode from a remaining portion of the conductive material layer; and (h) ion-implanting an impurity of the second conductivity type in said semiconductor substrate using said first, second, and third gate electrodes as masks to form first, second, third, and fourth impurity diffusion regions in a surface region of said semiconductor substrate.

Claim 12

A method of manufacturing a semiconductor device, comprising the steps of: (a) forming a first insulating film on a semiconductor substrate of a first conductivity type; (b) forming first and second gate electrodes on said first insulating film; (c) forming second and third insulating films on said first and second gate electrodes, respectively; (d) depositing a conductive material over the entire surface of the resultant structure to form a conductive material layer; (e) performing anisotropic etching to remove said conductive layer except for portions thereof corresponding to the side walls of said first and second gate electrodes; (f) ion-implanting an impurity of the second conductivity type in said semiconductor substrate using said first and second gate electrodes and the residual portions of said conductive material layer as masks; (g) selectively removing said residual portions of the conductive material layer to leave said residual portions on only one side of the side walls of said first gate electrode, and forming a third gate electrode from a remaining portion of the conductive material layer; and (h) ion-implanting an impurity of the second conductivity type in said semiconductor substrate using said first, second, and third gate electrodes as masks to form first, second, third, and fourth impurity diffusion regions in a surface region of said semiconductor substrate.