Patent ID: 6773992
Filing Date: 2004-08-10
Classification: H01L

Abstract:
A method for forming a nonvolatile semiconductor device, the method comprising:a first step of selectively forming a first well region of a first conductivity type in a memory circuit portion of a semiconductor substrate having the memory circuit portion and a logic circuit portion; a second step of successively forming a first insulating film and a first conductor film over the memory circuit portion and the logic circuit portion of the semiconductor substrate; a third step of patterning the first insulating film and the first conductor film so as to leave respective regions of the first insulating film and the first conductor film contained in the memory circuit portion; a fourth step of selectively forming a second well region of the first conductivity type in the logic circuit portion of the semiconductor substrate; a fifth step of successively forming a second insulating film and a second conductor film over the first conductor film in the memory circuit portion and the second well region in the logic circuit portion; a sixth step of successively patterning the second conductor film, the second insulating film, the first conductor film, and the first insulating film contained in the memory circuit portion to form a control gate electrode from the second conductor film, form a capacitance insulating film from the second insulating film, form a floating gate electrode from the first conductor film, and form a tunnel insulating film from the first insulating film; and a seventh step of patterning respective regions of the second conductor film and the second insulating film contained in the logic circuit portion to form a gate electrode from the second conductor film and form a gate insulating film from the second insulating film.