Nonvolatile semiconductor memory device and method of fabricating the same

摘要

In one embodiment, a nonvolatile semiconductor memory device includes a substrate; a tunnel insulating film on the substrate; a charge storage layer on the tunnel insulating film; a block insulating film on the charge storage layer; a first element isolation insulating film in an element isolation trench in the substrate, having a bottom surface lower than an interface between the substrate and the tunnel insulating film, and having a top surface lower than an interface between the charge storage layer and the block insulating film; a second element isolation insulating film on the first element isolation insulating film, protruding to a top surface of the block insulating film, in contact with a side surface of the block insulating film, and having a higher Si concentration than the block insulating film; and a control gate electrode on the block insulating film and on the second element isolation insulating film.

主权项

1. A nonvolatile semiconductor memory device comprising:
a semiconductor substrate comprising an element isolation trench; a tunnel insulating film on the semiconductor substrate; a charge storage layer on the tunnel insulating film; a block insulating film on the charge storage layer; a first element isolation insulating film in the element isolation trench, the first element isolation insulating film having a bottom surface lower in level than an interface where the semiconductor substrate and the tunnel insulating film are in contact with each other, the first element isolation insulating film having a top surface lower in level than an interface where the charge storage layer and the block insulating film are in contact with each other; a second element isolation insulating film on the first element isolation insulating film, the second element isolation insulating film protruding to a top surface of the block insulating film and being in contact with a side surface of the block insulating film, the second element isolation insulating film having a higher Si concentration than the block insulating film; and a control gate electrode on the block insulating film and on the second element isolation insulating film.