Patent US4809075A successfully refreshed from Google Patents.
Patent US5814549A successfully refreshed from Google Patents.
US5814549A
Expired / Lapsed
US
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Method of making porous-si capacitor dram cell
Assignee: Powerchip Semiconductor Corp
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Filing: 1996-11-18
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Granted: 1998-09-29
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Expires: 2016-11-18
Abstract
Abstract A method of manufacturing porous-Si capacitors for use in semiconductor memories is disclosed herein. The present invention includes a SOG layer as an etching mask to etch a polysilicon layer to form a porous-Si structure. The etching process is performed to etch a portion of the first conductive layer and to etch away the remaining HSG-Si. Next, the residure SOG layer is removed to define a porous-Si bottom storage. Utilizing the porous-Si structure, the present invention can be used to increase the surface area of the capacitor.
Inventors
- 👤 Shye-Lin Wu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 10:35
CPC Classifications
H; H10; H10B; H10B12/00; H10B12/01; H10B12/02; H10B12/03; H10B12/033; H10B12/30; H10B12/31; H10B12/318; H10D; H10D1/00; H10D1/01; H10D1/041; H10D1/043; H10D1/60; H10D1/68; H10D1/692; H10D1/711; H10D1/716; H10D1/682
Claims Analysis
Total Claims: 37
Claim 1
Independent Claim
238 words
A method for manufacturing a porous-Si capacitor on a semiconductor substrate, said substrate having transistors formed in said semiconductor substrate, the method comprising the steps of: forming a first dielectric layer on said semiconductor substrate; forming a second dielectric layer on said first dielectric layer; etching said first dielectric layer and said second dielectric layer to define a contact hole therein; forming a first polysilicon layer on said second dielectric layer and in said contact hole; forming a HSG-Si layer on said first polysilicon layer; etching said HSG-Si layer to form separated HSG-Si islands; forming a SOG layer on said HSG-Si and said first polysilicon layer; performing a thermal curing treatment to reflow said SOG layer; etching said SOG layer to expose the top of said HSG-Si islands leaving a residual SOG layer on said first polysilicon layer; using said residual SOG layer as a mask to etch a portion of said polysilicon layer and said HSG-Si islands to form a plurality of cavities in said first polysilicon layer, said HSG-Si islands being completely removed by said etch; removing said residual SOG layer to define a porous-Si structure; patterning a photoresist on said porous-Si structure; etching said porous-Si structure to the surface of said second dielectric layer; forming a dielectric film on the surface of said porous-Si structure and said second dielectric layer; and forming a second polysilicon layer over said dielectric film to form a porous-Si capacitor.
Claim 2
Independent Claim
238 words
A method for manufacturing a porous-Si capacitor on a semiconductor substrate, said substrate having transistors formed in said semiconductor substrate, the method comprising the steps of: forming a first dielectric layer on said semiconductor substrate; forming a second dielectric layer on said first dielectric layer; etching said first dielectric layer and said second dielectric layer to define a contact hole therein; forming a first polysilicon layer on said second dielectric layer and in said contact hole; forming a HSG-Si layer on said first polysilicon layer; etching said HSG-Si layer to form separated HSG-Si islands; forming a SOG layer on said HSG-Si and said first polysilicon layer; performing a thermal curing treatment to reflow said SOG layer; etching said SOG layer to expose the top of said HSG-Si islands leaving a residual SOG layer on said first polysilicon layer; using said residual SOG layer as a mask to etch a portion of said polysilicon layer and said HSG-Si islands to form a plurality of cavities in said first polysilicon layer, said HSG-Si islands being completely removed by said etch; removing said residual SOG layer to define a porous-Si structure; patterning a photoresist on said porous-Si structure; etching said porous-Si structure to the surface of said second dielectric layer; forming a dielectric film on the surface of said porous-Si structure and said second dielectric layer; and forming a second polysilicon layer over said dielectric film to form a porous-Si capacitor.
Claim 3
Dependent Claim
12 words
The method of claim 1, wherein said first dielectric layer comprises TEOS-oxide.
Claim 4
Dependent Claim
12 words
The method of claim 1, wherein said first dielectric layer comprises BPSG.
Claim 5
Dependent Claim
12 words
The method of claim 1, wherein said second dielectric layer comprises nitride.
Claim 6
Dependent Claim
18 words
The method of claim 4, wherein said nitride has a thickness in a range of about 300-2000 angstroms.
Claim 7
Dependent Claim
20 words
The method of claim 1, wherein said first polysilicon layer has a thickness in a range of about 1000-10000 angstroms.
Claim 8
Dependent Claim
22 words
The method of claim 6, wherein said first polysilicon layer is chosen from the group of doped polysilicon or in-situ doped polysilicon.
Claim 9
Dependent Claim
61 words
The method of claim 1, wherein the etchant of said etch to etch said HSG-Si islands is chosen from the group of HBr/Cl 2 /O 2 , Cl 2 , HBr/O 2 , BCl 3 /Cl 2 , SiCl 4 /Cl 2 , SF 6 , SF 6 /Br 2 , CCl 4 /Cl 2 , CH 3 F/Cl 2 .
Claim 10
Dependent Claim
21 words
The method of claim 1, wherein said HSG-Si layer is formed to have a thickness of a range about 300-2000 angstroms.
Claim 11
Dependent Claim
21 words
The method of claim 1, wherein said SOG layer is formed to have a thickness of a range about 300-2000 angstroms.
Claim 12
Dependent Claim
96 words
The method of claim 1, wherein the etchant of said etch to etch a portion of said polysilicon layer and said HSG-Si by using said SOG as a mask is chosen from the group of C 2 F 6 , SF 6 , CF 4 +O 2 , CF 4 +Cl 2 , CF 4 +HBr, HBr/Cl 2 /O 2 , Cl 2 , HBr/O 2 , BCl 3 /Cl 2 , SiCl 4 /Cl 2 , SF 6 , SF 6 /Br 2 , CCl 4 /Cl 2 , or CH 3 F/Cl 2 .
Claim 13
Dependent Claim
21 words
The method of claim 1, wherein said dielectric film is formed of tantalum oxide(Ta 2 O 5 ), BST or PZT.
Claim 14
Dependent Claim
17 words
The method of claim 1, wherein said dielectric film is formed of a triple film of oxide/nitride/oxide.
Claim 15
Dependent Claim
18 words
The method of claim 1, wherein said dielectric film is formed of a double film of nitride/oxide film.
Claim 16
Dependent Claim
21 words
The method of claim 1, wherein said second polysilicon layer is selected from the group of doped polysilicon, in-situ doped polysilicon.
Claim 17
Independent Claim
129 words
A method of forming a porous-Si structure, said method comprising the steps of: forming a polysilicon layer over a semiconductor substrate; forming a HSG-Si layer on said polysilicon layer; etching said HSG-Si layer to form separated HSG-Si islands; forming a SOG layer on said HSG-Si and said polysilicon layer; performing a thermal curing treatment to reflow said SOG layer; etching said SOG layer to expose the top of said HSG-Si islands leaving a residual SOG layer on said polysilicon layer; using said residual SOG layer as a mask to etch a portion of said polysilicon layer and said HSG-Si islands to form a plurality of cavities in said polysilicon layer, said HSG-Si islands being completely removed by said etch; removing said residual SOG layer to define a porous-Si structure.
Claim 18
Independent Claim
129 words
A method of forming a porous-Si structure, said method comprising the steps of: forming a polysilicon layer over a semiconductor substrate; forming a HSG-Si layer on said polysilicon layer; etching said HSG-Si layer to form separated HSG-Si islands; forming a SOG layer on said HSG-Si and said polysilicon layer; performing a thermal curing treatment to reflow said SOG layer; etching said SOG layer to expose the top of said HSG-Si islands leaving a residual SOG layer on said polysilicon layer; using said residual SOG layer as a mask to etch a portion of said polysilicon layer and said HSG-Si islands to form a plurality of cavities in said polysilicon layer, said HSG-Si islands being completely removed by said etch; removing said residual SOG layer to define a porous-Si structure.
Claim 19
Dependent Claim
21 words
The method of claim 16, wherein said polysilicon layer is chosen from the group of doped polysilicon or in-situ doped polysilicon.
Claim 20
Dependent Claim
60 words
The method of claim 16, wherein the etchant of said etch to etch said HSG-Si islands is chosen from the group of HBr/Cl 2 /O 2 , Cl 2 , HBr/O 2 , BCl 3 /Cl 2 ,SiCl 4 /Cl 2 , SF 6 , SF 6 /Br 2 , CCl 4 /Cl 2 , CH 3 F/Cl 2 .
Claim 21
Dependent Claim
96 words
The method of claim 16, wherein the etchant of said etch to etch a portion of said polysilicon layer and said HSG-Si by using said SOG as a mask is chosen from the group of C 2 F 6 , SF 6 , CF 4 +O 2 , CF 4 +Cl 2 , CF 4 +HBr, HBr/Cl 2 /O 2 , Cl 2 , HBr/O 2 , BCl 3 /Cl 2 , SiCl 4 /Cl 2 , SF 6 , SF 6 /Br 2 , CCl 4 /Cl 2 , or CH 3 F/Cl 2 .
Claim 22
Independent Claim
232 words
A method for manufacturing a porous-Si capacitor (PSC) on a semiconductor substrate, said semiconductor substrate having transistors formed in said semiconductor substrate, the method comprising the steps of: forming a BPSG layer on said semiconductor substrate; forming a nitride layer on said BPSG layer; etching said BPSG layer and said nitride layer to define a contact hole therein; forming a first polysilicon layer on said nitride layer and in said contact hole; forming a HSG-Si layer on said first polysilicon layer; etching said HSG-Si layer to form separated HSG-Si islands; forming a SOG layer on said HSG-Si and said first polysilicon layer; performing a thermal curing treatment to reflow said SOG layer; etching said SOG layer to expose the top of said HSG-Si islands leaving a residual SOG layer on said first polysilicon layer; using said residual SOG layer as a mask to etch a portion of said polysilicon layer and said HSG-Si islands to form a plurality of cavities in said first polysilicon layer, said HSG-Si islands being completely removed by said etch; removing said residual SOG layer to define a porous-Si structure; patterning a photoresist on said porous-Si structure; etching said porous-Si structure to the surface of said nitride layer; forming a dielectric film on the surface of said porous-Si structure and said nitride layer; and forming a second polysilicon layer over said dielectric film to form a porous-Si capacitor.
Claim 23
Independent Claim
232 words
A method for manufacturing a porous-Si capacitor (PSC) on a semiconductor substrate, said semiconductor substrate having transistors formed in said semiconductor substrate, the method comprising the steps of: forming a BPSG layer on said semiconductor substrate; forming a nitride layer on said BPSG layer; etching said BPSG layer and said nitride layer to define a contact hole therein; forming a first polysilicon layer on said nitride layer and in said contact hole; forming a HSG-Si layer on said first polysilicon layer; etching said HSG-Si layer to form separated HSG-Si islands; forming a SOG layer on said HSG-Si and said first polysilicon layer; performing a thermal curing treatment to reflow said SOG layer; etching said SOG layer to expose the top of said HSG-Si islands leaving a residual SOG layer on said first polysilicon layer; using said residual SOG layer as a mask to etch a portion of said polysilicon layer and said HSG-Si islands to form a plurality of cavities in said first polysilicon layer, said HSG-Si islands being completely removed by said etch; removing said residual SOG layer to define a porous-Si structure; patterning a photoresist on said porous-Si structure; etching said porous-Si structure to the surface of said nitride layer; forming a dielectric film on the surface of said porous-Si structure and said nitride layer; and forming a second polysilicon layer over said dielectric film to form a porous-Si capacitor.
Claim 24
Dependent Claim
26 words
The method of claim 20, wherein said first polysilicon layer and second polysilicon layer are chosen from the group of doped polysilicon or in-situ doped polysilicon.
Claim 25
Dependent Claim
61 words
The method of claim 20, wherein the etchant of said etch to etch said HSG-Si islands is chosen from the group of HBr/Cl 2 /O 2 , Cl 2 , HBr/O 2 , BCl 3 /Cl 2 , SiCl 4 /Cl 2 , SF 6 , SF 6 /Br 2 , CCl 4 /Cl 2 , CH 3 F/Cl 2 .
Claim 26
Dependent Claim
96 words
The method of claim 20, wherein the etchant of said etch to etch a portion of said polysilicon layer and said HSG-Si by using said SOG as a mask is chosen from the group of C 2 F 6 , SF 6 , CF 4 +O 2 , CF 4 +Cl 2 , CF 4 +HBr, HBr/Cl 2 /O 2 , Cl 2 , HBr/O 2 , BCl 3 /Cl 2 , SiCl 4 /Cl 2 , SF 6 , SF 6 /Br 2 , CCl 4 /Cl 2 , or CH 3 F/Cl 2 .
Claim 27
Dependent Claim
21 words
The method of claim 20, wherein said dielectric film is formed of tantalum oxide(Ta 2 O 5 ), BST or PZT.
Claim 28
Dependent Claim
17 words
The method of claim 20, wherein said dielectric film is formed of a triple film of oxide/nitride/oxide.
Claim 29
Dependent Claim
18 words
The method of claim 20, wherein said dielectric film is formed of a double film of nitride/oxide film.
Claim 30
Independent Claim
231 words
A method for manufacturing a porous-Si capacitor on a semiconductor substrate, said semiconductor substrate having transistors formed in said semiconductor substrate, the method comprising the steps of: forming a TEOS-oxide layer on said semiconductor substrate; forming a nitride layer on said TEOS-oxide layer; etching said TEOS-oxide layer and said nitride layer to define a contact hole therein; forming a first polysilicon layer on said nitride layer and in said contact hole; forming a HSG-Si layer on said first polysilicon layer; etching said HSG-Si layer to form separated HSG-Si islands; forming a SOG layer on said HSG-Si and said first polysilicon layer; performing a thermal curing treatment to reflow said SOG layer; etching said SOG layer to expose the top of said HSG-Si islands leaving a residual SOG layer on said first polysilicon layer; using said residual SOG layer as a mask to etch a portion of said polysilicon layer and said HSG-Si islands to form a plurality of cavities in said first polysilicon layer, said HSG-Si islands being completely removed by said etch; removing said residual SOG layer to define a porous-Si structure; patterning a photoresist on said porous-Si structure; etching said porous-Si structure to the surface of said nitride layer; forming a dielectric film on the surface of said porous-Si structure and said nitride layer; and forming a second polysilicon layer over said dielectric film to form a porous-Si capacitor.
Claim 31
Independent Claim
231 words
A method for manufacturing a porous-Si capacitor on a semiconductor substrate, said semiconductor substrate having transistors formed in said semiconductor substrate, the method comprising the steps of: forming a TEOS-oxide layer on said semiconductor substrate; forming a nitride layer on said TEOS-oxide layer; etching said TEOS-oxide layer and said nitride layer to define a contact hole therein; forming a first polysilicon layer on said nitride layer and in said contact hole; forming a HSG-Si layer on said first polysilicon layer; etching said HSG-Si layer to form separated HSG-Si islands; forming a SOG layer on said HSG-Si and said first polysilicon layer; performing a thermal curing treatment to reflow said SOG layer; etching said SOG layer to expose the top of said HSG-Si islands leaving a residual SOG layer on said first polysilicon layer; using said residual SOG layer as a mask to etch a portion of said polysilicon layer and said HSG-Si islands to form a plurality of cavities in said first polysilicon layer, said HSG-Si islands being completely removed by said etch; removing said residual SOG layer to define a porous-Si structure; patterning a photoresist on said porous-Si structure; etching said porous-Si structure to the surface of said nitride layer; forming a dielectric film on the surface of said porous-Si structure and said nitride layer; and forming a second polysilicon layer over said dielectric film to form a porous-Si capacitor.
Claim 32
Dependent Claim
26 words
The method of claim 27, wherein said first polysilicon layer and second polysilicon layer are chosen from the group of doped polysilicon or in-situ doped polysilicon.
Claim 33
Dependent Claim
60 words
The method of claim 27, wherein the etchant of said etch to etch said HSG-Si islands is chosen from the group of HBr/Cl 2 /O 2 , Cl 2 , HBr/O 2 , BCl 3 /Cl 2 ,SiCl 4 /Cl 2 , SF 6 , SF 6 /Br 2 , CCl 4 /Cl 2 , CH 3 F/Cl 2 .
Claim 34
Dependent Claim
95 words
The method of claim 27, wherein the etchant of said etch to etch a portion of said polysilicon layer and said HSG-Si by using said SOG as a mask is chosen from the group of C 2 F 6 , SF 6 , CF 4 +O 2 , CF 4 +Cl 2 , CF 4 +HBr, HBr/Cl 2 /O 2 , Cl 2 , HBr/O 2 , BCl 3 /Cl 2 , SiCl 4 /Cl 2 , SF 6 , SF 6 /Br 2 , CCl 4 /Cl 2 or CH 3 F/Cl 2 .
Claim 35
Dependent Claim
21 words
The method of claim 27, wherein said dielectric film is formed of tantalum oxide(Ta 2 O 5 ), BST or PZT.
Claim 36
Dependent Claim
17 words
The method of claim 27, wherein said dielectric film is formed of a triple film of oxide/nitride/oxide.
Claim 37
Dependent Claim
18 words
The method of claim 27, wherein said dielectric film is formed of a double film of nitride/oxide film.
References Cited (Backward Citations)
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