Semiconductor integrated circuit device and a method of manufacturing the same
A semiconductor device having a nonvolatile memory cell which includes a semiconductor substrate, a first insulating film formed over the semiconductor substrate, a control electrode formed over the first insulating film, the first insulating film acting as a gate insulator for the control gate electrode, a second insulating film formed over the semiconductor substrate, and a memory gate electrode formed over the second insulating film and being adjacent to the control gate electrode, the second insulating film acting as a gate insulator for the memory gate electrode and featuring a non-conductive charge trap film, the control gate electrode having a different type conductivity than that of the memory gate electrode. A manufacturing technique for a semiconductor device including a nonvolatile memory cell having control gate and memory gate electrodes is also featured.
1. A semiconductor device having a nonvolatile memory cell, comprising:
a first semiconductor region and a second semiconductor region formed in a semiconductor substrate;
a channel forming region formed in the semiconductor substrate and arranged between the first semiconductor region and the second semiconductor region;
a first gate insulating film formed over the channel forming region, the first gate insulating film arranged on a side of the first semiconductor region;
a first gate electrode formed over the first insulating film;
a second gate insulating film comprised of a non-conductive charge trap film formed over the channel forming region, the second gate insulating film arranged on a side of the second semiconductor region; and
a second gate electrode formed over the second insulating film and being adjacent to the first gate electrode,
wherein injecting holes into the non-conductive charge trap film is performed by applying negative voltage to the first gate electrode and the second gate electrode and applying positive voltage to the second semiconductor region.
2. A semiconductor device according to the claim 1 ,
wherein the non-conductive charge trap film is comprised of a silicon nitride film.
3. A semiconductor device according to claim 1 ,
wherein the second gate insulating film includes:
a first insulating film formed over the channel forming region, the first insulating film arranged on a side of the second semiconductor region;
the non-conductive charge trap film formed over the first insulating film; and
a second insulating film formed over the non-conductive charge trap film.
4. A semiconductor device according to the claim 3 ,
wherein a thickness of the first gate insulating film is greater than that of the first insulating film.
5. A semiconductor device according to the claim 1 ,
wherein injecting holes into the non-conductive charge trap film is performed by applying first negative voltage to the first gate electrode and second negative voltage to the second gate electrode,
wherein the first negative voltage in absolute value is smaller than the second negative voltage in absolute value.
6. A semiconductor device according to the claim 5 ,
wherein injecting holes into the non-conductive charge trap film is performed by applying a third negative voltage to the semiconductor substrate, and
wherein the first negative voltage in absolute value is smaller than the third negative voltage in absolute value.
7. A semiconductor device having a memory cell, comprising:
a first semiconductor region and a second semiconductor region formed in a semiconductor substrate;
a channel forming region formed in the semiconductor substrate and arranged between the first semiconductor region and the second semiconductor region;
a first insulating film formed over the channel forming region, the first insulating film arranged on a side of the first semiconductor region;
a first gate electrode formed over the first insulating film;
a second insulating film formed over the channel forming region, the second insulating film arranged on a side of the second semiconductor region;
a non-conductive charge trap film formed over the second insulating film; and
a second gate electrode formed over the non-conductive charge trap film and being adjacent to the first gate electrode,
wherein injecting holes into the non-conductive charge trap film is performed by applying negative voltage to the first gate electrode and the second gate electrode and applying positive voltage to the second semiconductor region.
8. A semiconductor device according to the claim 7 ,
wherein the non-conductive charge trap film is comprised of a silicon nitride film.
9. A semiconductor device according to the claim 7 ,
wherein a third insulating film is formed between the non-conductive charge trap film and the second gate electrode.
10. A semiconductor device according to the claim 7 ,
wherein a thickness of the first insulating film is greater than that of the second insulating film.
11. A semiconductor device according to the claim 7 ,
wherein injecting holes into the non-conductive charge trap film is performed by applying first negative voltage to the first gate electrode and second negative voltage to the second gate electrode, and
wherein the first negative voltage in absolute value is smaller than the second negative voltage in absolute value.