Abstract: A nonvolatile semiconductor memory including a semiconductor substrate having an upper surface; a plurality of memory cell transistors formed in the semiconductor substrate, each memory cell transistor including a gate electrode having a gate insulating layer on the upper surface of the semiconductor substrate, a floating gate electrode layer on the gate insulating layer, an inter-gate insulating layer on the floating gate electrode layer, and a control gate electrode layer on the inter-gate insulating layer; a first oxide-based insulating film formed above the upper surface of the semiconductor substrate between the gate electrodes, and including an upper surface as high or higher than that of the floating gate electrode layer but lower than that of the control gate electrode layer; a nitride-based insulating film containing boron formed on the first oxide-based insulating film and the control gate layer; and a second oxide-based insulating film formed on the nitride-based insulating film.

Abstract: A nonvolatile semiconductor memory including a semiconductor substrate having an upper surface; a plurality of memory cell transistors formed in the semiconductor substrate, each memory cell transistor including a gate electrode having a gate insulating layer on the upper surface of the semiconductor substrate, a floating gate electrode layer on the gate insulating layer, an inter-gate insulating layer on the floating gate electrode layer, and a control gate electrode layer on the inter-gate insulating layer; a first oxide-based insulating film formed above the upper surface of the semiconductor substrate between the gate electrodes, and including an upper surface as high or higher than that of the floating gate electrode layer but lower than that of the control gate electrode layer; a nitride-based insulating film containing boron formed on the first oxide-based insulating film and the control gate layer; and a second oxide-based insulating film formed on the nitride-based insulating film.