Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
144 words
A method for fabricating a semiconductor device having a recessed structure comprising the steps of: forming a second conductivity type semiconductor layer on a first conductivity type substrate wherein the second conductivity type semiconductor layer is formed by depositing a polysilicon film on the first conductivity type substrate; forming a first insulation film on the second conductivity type semiconductor layer; forming a source and a drain by removing portions of the first insulation film and the second conductivity type semiconductor layer; forming a second insulation film on an exposed surface of the substrate and the source and drain; forming a first gate on the second insulation film; forming a dielectric film on a surface of the first gate; and forming a second gate on the dielectric film, wherein the first gate fills at least the removed portion of the second conductivity type semiconductor layer.
Claim 2
Independent Claim
144 words
A method for fabricating a semiconductor device having a recessed structure comprising the steps of: forming a second conductivity type semiconductor layer on a first conductivity type substrate wherein the second conductivity type semiconductor layer is formed by depositing a polysilicon film on the first conductivity type substrate; forming a first insulation film on the second conductivity type semiconductor layer; forming a source and a drain by removing portions of the first insulation film and the second conductivity type semiconductor layer; forming a second insulation film on an exposed surface of the substrate and the source and drain; forming a first gate on the second insulation film; forming a dielectric film on a surface of the first gate; and forming a second gate on the dielectric film, wherein the first gate fills at least the removed portion of the second conductivity type semiconductor layer.
Claim 3
Dependent Claim
29 words
The method as claimed in claim 1, further comprising the step of: removing a portion of the substrate between the source and drain after forming the source and drain.
Claim 4
Dependent Claim
34 words
The method as claimed in claim 2, wherein instead of the depositing step, the second conductivity type semiconductor layer is formed by implanting a second conductivity type impurity into the first conductivity type substrate.
Claim 5
Independent Claim
177 words
A method for fabricating a semiconductor device having a recessed structure comprising the steps of: forming a second conductivity type semiconductor layer on a first conductivity type substrate wherein the second conductivity type semiconductor layer is formed by depositing a first polysilicon film of the second conductivity type on the first conductivity type substrate; forming a first insulation film on the second conductivity type semiconductor layer; forming a source and a drain by removing portions of the first insulation film and the second conductivity type semiconductor layer; forming a second insulation film on a surface of the substrate between the source and the drain and on the first insulation film; forming a second polysilicon film, an oxide type film, and a third polysilicon film on the resulting structure and on the substrate; and forming a first gate, a dielectric film, and a second gate by selectively removing the second polysilicon film, the oxide type film, and the third polysilicon film, wherein the first rate fills at least the removed portion of the second conductivity type semiconductor layer.
Claim 6
Independent Claim
177 words
A method for fabricating a semiconductor device having a recessed structure comprising the steps of: forming a second conductivity type semiconductor layer on a first conductivity type substrate wherein the second conductivity type semiconductor layer is formed by depositing a first polysilicon film of the second conductivity type on the first conductivity type substrate; forming a first insulation film on the second conductivity type semiconductor layer; forming a source and a drain by removing portions of the first insulation film and the second conductivity type semiconductor layer; forming a second insulation film on a surface of the substrate between the source and the drain and on the first insulation film; forming a second polysilicon film, an oxide type film, and a third polysilicon film on the resulting structure and on the substrate; and forming a first gate, a dielectric film, and a second gate by selectively removing the second polysilicon film, the oxide type film, and the third polysilicon film, wherein the first rate fills at least the removed portion of the second conductivity type semiconductor layer.
Claim 7
Dependent Claim
30 words
The method as claimed in claim 4, further comprising the step of: removing a portion of the substrate between the source and drain after forming the source and the drain.
Claim 8
Dependent Claim
34 words
The method as claimed in claim 5, wherein instead of the depositing step, the second conductivity type semiconductor layer is formed by implanting a second conductivity type impurity into the first conductivity type substrate.
Claim 9
Dependent Claim
15 words
The method as claimed in claim 1, wherein the dielectric film is an oxide/nitride/oxide film.
Claim 10
Dependent Claim
16 words
The method as claimed in claim 4, wherein the oxide type film is an oxide/nitride/oxide film.
Claim 11
Independent Claim
98 words
A method for fabricating a semiconductor device, comprising the steps of: forming a source and a drain separated by a channel on a substrate; forming a first insulating film on the source and the drain, the first insulating film having a hole passing through the first insulating film; forming a second insulating film on the substrate and the first insulating film; and forming a first gate, a dielectric film, and a second gate on the first and second insulating films, the first gate completely filling the channel of the substrate and the hole of the first insulating film.
Claim 12
Independent Claim
98 words
A method for fabricating a semiconductor device, comprising the steps of: forming a source and a drain separated by a channel on a substrate; forming a first insulating film on the source and the drain, the first insulating film having a hole passing through the first insulating film; forming a second insulating film on the substrate and the first insulating film; and forming a first gate, a dielectric film, and a second gate on the first and second insulating films, the first gate completely filling the channel of the substrate and the hole of the first insulating film.
Claim 13
Dependent Claim
56 words
The method as claimed in claim 9, wherein said step of forming the drain and the source includes the steps of: providing a first conductivity type substrate, implanting a second conductivity type impurity into the first conductivity type substrate, and selectively removing an upper surface region of the first conductivity type substrate to form the channel.
Claim 14
Dependent Claim
29 words
The method as claimed in claim 9, wherein a width of the hole of the first insulating film is greater than a width of the channel of the substrate.
Claim 15
Dependent Claim
31 words
The method as claimed in claim 9, wherein the hole of the first insulating film is directly above the channel of the substrate so as to form a plurality of steps.
Claim 16
Dependent Claim
52 words
The method as claimed in claim 9, wherein said step of forming the drain and the source includes the steps of: providing a first conductivity type substrate, depositing a polysilicon film of a second conductivity type on the first conductivity type substrate, and selectively removing the polysilicon film to form the channel.
Claim 17
Dependent Claim
15 words
The method as claimed in claim 9, wherein the dielectric film is an oxide/nitride/oxide film.
Claim 18
Dependent Claim
78 words
The method as claimed in claim 9, wherein said step of forming the first gate, the dielectric film, and the second gate includes the steps of: depositing a first polysilicon layer on the first and second insulting films, the first polysilicon layer completely filling the channel of the substrate and the hole of the first insulating film, depositing a thin oxide layer on the first polysilicon layer, and depositing a second polysilicon layer on the thin oxide layer.
Claim 19
Dependent Claim
55 words
The method as claimed in claim 15, wherein said step of forming the first gate, the dielectric film, and the second gate further includes the steps of: selectively removing the second polysilicon layer, the thin oxide layer and the first polysilicon layer to form the second gate, the dielectric film, and the first gate, respectively.
Claim 20
Dependent Claim
16 words
The method as claimed in claim 15, wherein the thin oxide layer is an oxide/nitride/oxide film.
Claim 21
Independent Claim
118 words
A method for fabricating a semiconductor device having a recessed structure comprising the steps of: forming a second conductivity type semiconductor region on a first conductivity type substrate; forming a first insulation film on said second conductivity type semiconductor region; forming a source and drain by etching said first insulation film and the second conductivity type semiconductor region; etching the substrate between the source and drain after forming the source and drain; forming a second insulation film on an exposed surface of the substrate and the source and drain; forming a first gate on the second insulation film; forming a dielectric film on a surface of the first gate; and forming a second gate on the dielectric film.
Claim 22
Independent Claim
118 words
A method for fabricating a semiconductor device having a recessed structure comprising the steps of: forming a second conductivity type semiconductor region on a first conductivity type substrate; forming a first insulation film on said second conductivity type semiconductor region; forming a source and drain by etching said first insulation film and the second conductivity type semiconductor region; etching the substrate between the source and drain after forming the source and drain; forming a second insulation film on an exposed surface of the substrate and the source and drain; forming a first gate on the second insulation film; forming a dielectric film on a surface of the first gate; and forming a second gate on the dielectric film.