Non-volatile semiconductor device and method of fabricating embedded non-volatile semiconductor memory device with sidewall gate
View Patent ↗A method of manufacturing a non-volatile semiconductor memory device is provided which overcomes a problem of penetration of implanted ions due to the difference of optimal gate height in simultaneous formation of a self-align split gate type memory cell utilizing a side wall structure and a scaled MOS transistor. A select gate electrode to form a side wall in a memory area is formed to be higher than that of the gate electrode in a logic area so that the height of the side wall gate electrode of the self-align split gate memory cell is greater than that of the gate electrode in the logic area. Height reduction for the gate electrode is performed in the logic area before gate electrode formation.
1. A method of manufacturing a non-volatile semiconductor device, comprising the steps of:
forming a first gate electrode film comprising at least one kind of material successively to a first gate dielectric film above a semiconductor substrate;
fabricating the first gate electrode film to form a first gate electrode structure;
forming a second gate electrode structure having a second gate dielectric film and a second gate electrode film on one sidewall of the first gate electrode structure;
controlling the film thickness of an electrode through etch selectivity so as to decrease the thickness of the first gate electrode film by a predetermined amount in a second area not overlapping a first area forming the first and second gate structures after the step of forming the first gate electrode film; and
forming a third gate structure by fabricating the gate electrode film subjected to the control for the thickness of the electrode.
2. A method of manufacturing a non-volatile semiconductor device according to claim 1 , wherein a laminate film of a first amorphous silicon film, a-silicon oxide film and a second amorphous silicon film is used as the first gate electrode film.
3. A method of manufacturing a non-volatile semiconductor device according to claim 1 , wherein a laminate film of a polysilicon film and a silicon oxide film is used as the first gate electrode film.
4. A method of manufacturing a non-volatile semiconductor device according to claim 1 , wherein a laminate film of a polysilicon film and a silicon germanium film is used as the first gate electrode film.
5. A method of manufacturing a non-volatile semiconductor device according to claim 1 , wherein a film of a single-layered structure is used as the first gate electrode film, and
dry etching is used as the step of controlling the thickness of the electrode film.
6. A method of manufacturing a non-volatile semiconductor device according to claim 1 , wherein a film of a single-layered structure is used as the first gate electrode film, and
wet etching is used as the step of controlling the thickness of the electrode film.
7. A method of manufacturing a non-volatile semiconductor device according to claim 1 , wherein a step of controlling the film thickness of an electrode for a first gate electrode film and a step of forming a third gate electrode structure are conducted after forming the second gate electrode structure in a second area not overlapping the first area forming the first and second electrode structures.
8. A method of manufacturing a non-volatile semiconductor device according to claim 1 , wherein
a step of controlling the thickness of an electrode film of a first gate electrode film is conducted in the second area not overlapping the first area for forming the first and second gate electrode structures after forming the first gate electrode structure by fabricating the first gate electrode film, and
a step of forming the third gate electrode structure in the second area is conducted in the second region after forming the second gate electrode structure in the first area.
9. A method of manufacturing a non-volatile semiconductor device according to claim 1 , wherein
a step of controlling the film thickness of the first gate electrode film is performed in the second area not overlapping the first area forming the first and second gate electrode structures after depositing the first gate electrode film, and
a step of forming the third gate electrode structure in the second area is performed after forming the second gate electrode structure in the first area.
10. A method of manufacturing a non-volatile semiconductor device according to claim 1 , wherein
a step of controlling a film thickness of the first gate electrode film and a step of forming the third gate electrode structure are performed in the second area not overlapping the first area for forming the first and the second gate electrode structures after forming the first gate electrode structure, and then
a second gate electrode structure is formed in the first area.
11. A method of manufacturing a non-volatile semiconductor device according to claim 1 , wherein
a step of controlling the thickness of the second gate electrode film is performed, after depositing the first gate electrode film, in the second area not overlapping the first area for forming the first and second gate electrode structures, and
a step of forming the third gate electrode structure in the second area is performed after fabricating first the gate electrode film to form the first gate electrode structure in the first area.
12. A method of manufacturing a non-volatile semiconductor device according to claim 1 , wherein
a step of controlling the thickness of the first gate electrode film and a step of forming the third gate electrode structure are performed in the second area not overlapping the first area for forming the first and second gate electrode structures after depositing the first gate electrode film, and then
the first gate electrode film is fabricated to form the first gate electrode structure in the first area.