SEMICONDUCTOR DEVICE AND METHOD OF MANUFACTURING THE SAME

摘要

An insulating film made of the same material as that of a gate insulating film is formed so as to cover one sidewall of a control gate on a conducting film for floating gate. By selectively removing the conducting film for floating gate with the insulating film as a mask, a floating gate is formed from the conducting film for floating gate, and a portion of the gate insulating film is exposed at the floating gate. A nitrogen introduced portion is formed by introducing nitrogen into the exposed portion of the gate insulating film. Then, the insulating film is removed to expose an upper surface of a lateral protrusion of the floating gate. An erase gate is formed so as to face the upper surface and a side surface of the lateral protrusion.

主权项

1. A method of manufacturing a semiconductor device, comprising the steps of:
forming a gate insulating film on a main surface of a semiconductor substrate; forming a conducting film for floating gate on the gate insulating film; forming a control gate on the conducting film for floating gate with a first insulating film interposed therebetween; forming a first sidewall insulating film made of the same material as that of the gate insulating film, so as to cover one sidewall of the control gate on the conducting film for floating gate; by selectively removing the conducting film for floating gate with the first sidewall insulating film as a mask, forming a floating gate from the conducting film for floating gate, and exposing a portion of the gate insulating film at the floating gate; forming a first nitrogen introduced portion by introducing nitrogen into the exposed portion of the gate insulating film; after forming the first nitrogen introduced portion, removing the first sidewall insulating film to expose an upper surface of a lateral protrusion of the floating gate protruding laterally from a region immediately below the control gate; and forming an erase gate so as to face the upper surface and a side surface of the lateral protrusion.