SEMICONDUCTOR DEVICE AND METHOD OF MANUFACTURING SAME

摘要

To provide a semiconductor device with nonvolatile memory, having improved performance.;A memory cell has control and memory gate electrodes on a semiconductor substrate via an insulating film and another insulating film having first, second, and third films stacked one after another in order of mention, respectively. The memory and control gate electrodes are adjacent to each other via the stacked insulating film. The second insulating film has a charge accumulation function. The first and third insulating films each have a band gap greater than that of the second insulating film. An inner angle of the second insulating film between a portion extending between the semiconductor substrate and the memory gate electrode and a portion extending between the control gate electrode and the memory gate electrode is ≧90°. An inner angle of the corner portion between the lower surface and the side surface of the memory gate electrode is <90°.

主权项

1. A semiconductor device having a memory cell of a nonvolatile memory, comprising:
a semiconductor substrate, a first gate electrode formed over the semiconductor substrate via a first gate insulating film and including the memory cell, and a second gate electrode formed over the semiconductor substrate via a stacked insulating film, adjacent to the first gate electrode via the stacked insulating film, and including the memory cell, wherein the stacked insulating film extends over between the semiconductor substrate and the second gate electrode and between the first gate electrode and the second gate electrode, wherein the stacked insulating film has a a first insulating film, a second insulating film over the first insulating film, and a third insulating film over the second insulating film; wherein the second insulating film is an insulating film having a charge accumulation function and the band gap of each of the first insulating film and the third insulating film is greater than the band gap of the second insulating film; wherein an angle made between a portion of the second insulating film extending between the semiconductor substrate and the second electrode and a portion of the second insulating film extending between the first gate electrode and the second gate electrode is 90° or greater; and wherein an inner angle of a first corner portion formed by a first surface of the second gate electrode on a side facing to the semiconductor substrate and a second surface of the second gate electrode on a side facing to the first gate electrode is less than 90°.