Non-volatile memory and method of manufacturing the same

A manufacturing method for an electro-optic device including a non-volatile memory, comprising the steps of:

• forming a semiconductor film on an insulating surface;
• forming a resist pattern over the semiconductor film;
• etching the semiconductor film to form a semiconductor island having tapered side edges by decreasing a selective ratio of the semiconductor film and the resist pattern;
• forming a first insulating film on the semiconductor island;
• forming a floating gate film over a channel forming region of the semiconductor island with the first insulating film interposed therebetween, the floating gate film covering the tapered side edges of the semiconductor island;
• forming a second insulating film over the floating gate film;
• and
• forming a control gate film over the floating gate film with the second insulating film interposed therebetween, the control gate film covering the tapered side edges of the semiconductor island.

A manufacturing method for a display device including a non-volatile memory, comprising the steps of:

• forming a semiconductor film on an insulating surface;
• forming a resist pattern over the semiconductor film;
• etching the semiconductor film to form a semiconductor island having tapered side edges by decreasing a selective ratio of the semiconductor film and the resist pattern;
• forming a first insulating film on the semiconductor island;
• forming a floating gate film over a channel forming region of the semiconductor island with the first insulating film interposed therebetween, the floating gate film covering the tapered side edges of the semiconductor island;
• forming a second insulating film over the floating gate film;
• and
• forming a control gate film over the floating gate film with the second insulating film interposed therebetween, the control gate film covering the tapered side edges of the semiconductor island.