Semiconductor device and method of manufacturing the semiconductor device

Abstract

Resistance of a gate electrode is reduced in a split gate MONOS memory configured by a fin FET. A memory gate electrode of a split gate MONOS memory is formed of a first polysilicon film, a metal film, and a second polysilicon film formed in order on a fin. A trench between fins adjacent to each other in a lateral direction of the fins is filled with a stacked film including the first polysilicon film, the metal film, and the second polysilicon instead of the first polysilicon film only.

1 - 12 . (canceled) 
     
     
         13 . A method of manufacturing a semiconductor device, the method comprising the steps of:
 (a) providing a semiconductor substrate;   (b) retracting a part of a top of the semiconductor substrate, thereby forming a plurality of protrusions that are each a portion of the semiconductor substrate, protrude from the part of the top of the semiconductor substrate, and extend in a first direction along the top of the semiconductor substrate;   (c) forming an element isolation film that fills a first trench between the protrusions adjacent to each other;   (d) forming a first gate electrode that covers tops and side faces of the protrusions with a first insulating film in between over the element isolation film;   (e) after the step (d), forming a second insulating film as a charge storage part, a first semiconductor film, and a first metal film in order over the semiconductor substrate, thereby filling a space between the protrusions arranged in a second direction orthogonal to the first direction with a stacked film including the first semiconductor film and the first metal film;   (f) processing the stacked film to form a second gate electrode including the stacked film that is adjacent to one side face of the first gate electrode with the second insulating film in between, and covers the tops and the side faces of the protrusions with the second insulating film in between; and   (g) forming source and drain regions in a surface of each of the protrusions beside a pattern including the first gate electrode and the second gate electrode.   
     
     
         14 . The method according to  claim 13 ,
 wherein in the step (e), the second insulating film, the first semiconductor film, the first metal film, and a second semiconductor film are formed in order over the semiconductor substrate, thereby the space between the protrusions arranged in the second direction is filled with a stacked film including the first semiconductor film, the first metal film, and the second semiconductor film;   the method further comprising the step of:   (h) after the step (g), siliciding a top of the second semiconductor film.   
     
     
         15 . The method according to  claim 13 ,
 wherein in the step (e), the second insulating film, the first semiconductor film, the first metal film, and a second semiconductor film are formed in order over the semiconductor substrate, thereby the space between the protrusions arranged in the second direction is filled with the stacked film including the first semiconductor film, the first metal film, and the second semiconductor film,   the method further comprising the steps of:   (h) after the step (g), removing the second semiconductor film to form a second trench over the second insulating film; and   (i) after the step (h), filling the second trench with a second metal film.