Patent ID: 8497184
Filing Date: 2013-07-30
Classification: H01L

Abstract:
1. A method for manufacturing a semiconductor device, comprising: forming a first conductor layer containing silicon on a surface of a semiconductor layer via a tunnel insulating film; forming an isolation trench extending from a surface of the first conductor layer to the semiconductor layer to form a plurality of conductive plates serving as floating gate electrodes on the tunnel insulating film, the conductive plates being formed from the first conductor layer and spaced from each other by a prescribed width; filling the isolation trench with an element insulation insulating film from bottom of the isolation trench to an intermediate portion of a side surface of each of the conductive plates; forming a silicon nitride film on an exposed surface of the each of the conductive plates not covered with the element insulation insulating film while maintaining a spacing between the plurality of spaced conductive plates with the silicon nitride film at a width comparable to or larger than the prescribed width, the silicon nitride film being formed by nitridizing the silicon contained in the spaced conductive plates by a nitrogen radical generated by exciting a raw material gas containing a nitrogen element; and forming a second conductive layer serving as a control gate electrode above the spaced conductive plates with the silicon nitride film and the element insulation insulating film buried in the isolation trench, the second conductive layer filling the spacing maintained at the width comparable to or larger than the prescribed width between the spaced conductive plates, further comprising: forming the floating gate electrode and the control gate electrode by selectively etching a structure of the plurality of conductive plates buried with the second conductor layer serving as the control gate electrode to expose a side surface perpendicular to the isolation trench; and performing oxynitridation treatment on the side surface to simultaneously form a silicon oxynitride film: on each of the side surfaces; at an interface between the silicon nitride film and the floating gate electrode; and at an interface between the silicon nitride film and the control gate electrode.