US6066528A
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US
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Method for forming a capacitor compatible with high dielectric constant materials having two independent insulative layers
Assignee: Micron Technology Inc
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Filing: 1994-09-27
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Granted: 2000-05-23
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Expires: 2014-09-27
Abstract
Abstract The invention is a storage cell capacitor and a method for forming the storage cell capacitor having a storage node electrode comprising a barrier layer interposed between a conductive plug and an oxidation resistant layer. A thick insulative layer protects the sidewalls of the barrier layer during the deposition and anneal of a dielectric layer having a high dielectric constant. The method comprises forming the conductive plug in a thick layer of insulative material such as oxide or oxide/nitride. The conductive plug is recessed from a planarized top surface of the thick insulative layer. The barrier layer is then formed in the recess. The process is continued with a formation of a second insulative layer, a potion of which is removed to form an opening exposing a portion of the barrier layer. An oxidation resistant conductive layer is deposited in the recess and forms at least a portion the storage node electrode of the capacitor. Next a dielectric layer having a high dielectric constant is formed to overly the storage node electrode and a cell plate electrode is fabricated to overly the dielectric layer.
Inventors
- 👤 Pierre C. Fazan
- 👤 Gurtej S. Sandhu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 03:07
CPC Classifications
H; H10; H10B; H10B53/00; H10B12/00; H10B12/01; H10B12/02; H10B12/03; H10B12/033; H10B53/30; H10D; H10D1/00; H10D1/60; H10D1/68; H10D1/692; H10W; H10W20/00; H10W20/01; H10W20/031; H10W20/032; H10W20/033; H10W20/037; H10W20/046; H10W20/064; H10W20/066; H10B12/0335; H10D1/682; H10D1/696
Claims Analysis
Total Claims: 37
Claim 1
Independent Claim
96 words
A method of fabricating a capacitor electrode, comprising the following steps: a) forming a first insulative layer overlying a substrate; b) forming a contact plug electrically contacting said substrate; c) forming a barrier layer in said first insulative layer and overlying said contact plug; d) forming a second insulative layer overlying said first insulative layer and said barrier layer; and e) recessing an oxidation resistant material in said second insulative layer and in contact with said barrier layer, said oxidation resistant layer, said barrier layer and said contact plug forming a first electrode of the capacitor.
Claim 2
Independent Claim
96 words
A method of fabricating a capacitor electrode, comprising the following steps: a) forming a first insulative layer overlying a substrate; b) forming a contact plug electrically contacting said substrate; c) forming a barrier layer in said first insulative layer and overlying said contact plug; d) forming a second insulative layer overlying said first insulative layer and said barrier layer; and e) recessing an oxidation resistant material in said second insulative layer and in contact with said barrier layer, said oxidation resistant layer, said barrier layer and said contact plug forming a first electrode of the capacitor.
Claim 3
Dependent Claim
48 words
The method as specified in claim 1, further comprising the steps of: a) removing a first portion of said second insulative layer thereby increasing a surface area of said first electrode; and b) retaining a second portion of said second insulative layer in contact with said barrier layer.
Claim 4
Dependent Claim
67 words
The method as specified in claim 2, further comprising the steps of: a) creating a dielectric layer having a high dielectric constant to overly said oxidation resistant material, said oxidation resistant material and said second insulative layer prohibiting an oxidation of said barrier layer; and b) creating a second electrode overlying said dielectric layer, said first and said second electrode and said dielectric layer forming the capacitor.
Claim 5
Dependent Claim
44 words
The method as specified in claim 1, further comprising: a) forming a dielectric layer overlying said oxidation resistant layer; and b) forming a second electrode overlying said dielectric layer, said dielectric layer electrically insulating said first and said second electrodes one from the other.
Claim 6
Dependent Claim
26 words
The method as specified in claim 4, wherein said step of forming said second electrode comprises sputtering an electrically conductive material to overly said dielectric layer.
Claim 7
Dependent Claim
41 words
The method as specified in claim 4, wherein said step of forming said dielectric layer comprises the following steps: a) applying temperatures capable of oxidizing said barrier layer; and b) preventing said barrier layer from oxidizing during said step of applying.
Claim 8
Independent Claim
203 words
A method for fabricating a capacitor having a first and a second electrode, comprising the following steps: a) forming a first insulative layer overlying a substrate; b) forming an opening in said first insulative layer in order to expose said substrate; c) forming a conductive plug in said opening, said conductive plug forming a first portion of the first electrode of said capacitor; d) creating a recess in said opening between a surface of said first insulative layer and a surface of said conductive plug; e) forming a conductive barrier layer, for preventing diffusion of atoms, in said recess such that said conductive barrier layer is surrounded on sidewalls by said first insulative layer, said conductive barrier layer forming a second portion of the first electrode; f) forming a second insulative layer overlying said first insulative layer and said conductive barrier layer; g) creating an opening in said second insulative layer, said opening exposing at least a portion of said conductive barrier layer; and h) creating an oxidation resistant layer overlying said second insulative layer and said portion of said conductive barrier layer exposed in said step of creating said opening, said oxidation resistant layer forming a third portion of the first electrode.
Claim 9
Independent Claim
203 words
A method for fabricating a capacitor having a first and a second electrode, comprising the following steps: a) forming a first insulative layer overlying a substrate; b) forming an opening in said first insulative layer in order to expose said substrate; c) forming a conductive plug in said opening, said conductive plug forming a first portion of the first electrode of said capacitor; d) creating a recess in said opening between a surface of said first insulative layer and a surface of said conductive plug; e) forming a conductive barrier layer, for preventing diffusion of atoms, in said recess such that said conductive barrier layer is surrounded on sidewalls by said first insulative layer, said conductive barrier layer forming a second portion of the first electrode; f) forming a second insulative layer overlying said first insulative layer and said conductive barrier layer; g) creating an opening in said second insulative layer, said opening exposing at least a portion of said conductive barrier layer; and h) creating an oxidation resistant layer overlying said second insulative layer and said portion of said conductive barrier layer exposed in said step of creating said opening, said oxidation resistant layer forming a third portion of the first electrode.
Claim 10
Dependent Claim
59 words
The method as specified in claim 7, further comprising: a) removing at least a portion of said oxidation resistant layer overlying said second insulative layer; b) forming a dielectric layer overlying said oxidation resistant layer; and c) forming second electrode overlying said dielectric layer, said dielectric layer electrically insulating said first and said second electrodes one from the other.
Claim 11
Dependent Claim
30 words
The method as specified in claim 8, wherein the step of forming said dielectric layer comprises forming said dielectric layer with a material typified as having a high dielectric constant.
Claim 12
Dependent Claim
62 words
The method as specified in claim 8, wherein said step of forming said dielectric layer comprises depositing a high dielectric constant material comprising a material selected from the group consisting of Ba x Sr.sub.(1-x) TiO 3 , BaTiO 3 , SrTiO 3 , PbTiO 3 , Pb(Zr,Ti)O 3 , (Pb,La)(Zr,Ti)O 3 , (Pb,La)TiO 3 , KNO 3 , and LiNbO 3 .
Claim 13
Dependent Claim
46 words
The method as specified in claim 8, wherein said step of forming said dielectric layer comprises the following steps: a) providing a vapor environment; b) depositing said dielectric layer; c) applying temperatures capable of oxidizing said barrier layer; and d) preventing said barrier layer from oxidizing.
Claim 14
Dependent Claim
25 words
The method as specified in claim 8, wherein said step of forming said second electrode comprises sputtering a conductive material to overlie said dielectric layer.
Claim 15
Dependent Claim
23 words
The method as specified in claim 7, further comprising the step of planarizing said first insulative layer prior to forming said conductive plug.
Claim 16
Dependent Claim
51 words
The method as specified in claim 7, further comprising forming a low contact resistance layer interposed between said conductive plug and said barrier layer, said low contact resistance layer forming a fourth portion of the first electrode and reducing a contact resistance between said conductive plug and said conductive barrier layer.
Claim 17
Dependent Claim
35 words
The method as specified in claim 14, wherein said step of forming said low contact resistance layer comprises the step of depositing a material selected from a group consisting of refractory metals and metal nitrides.
Claim 18
Dependent Claim
28 words
The method as specified in claim 14, further comprising selecting said low contact resistance layer from a group of materials consisting of Ti, W, Co, Ta, and Mo.
Claim 19
Dependent Claim
28 words
The method as specified in claim 14, further comprising selecting said low contact resistance layer from materials which form a silicide with said polysilicon during a thermal anneal.
Claim 20
Dependent Claim
22 words
The method as specified in claim 14, further comprising performing an anneal during said step of forming said low contact resistance layer.
Claim 21
Dependent Claim
23 words
The method as specified in claim 14, further comprising performing a nitrogen anneal during said step of forming said low contact resistance layer.
Claim 22
Dependent Claim
23 words
The method as specified in claim 14, wherein said step of forming said conductive plug comprises depositing in-situ doped polysilicon in said opening.
Claim 23
Dependent Claim
30 words
The method as specified in claim 20, wherein said step of providing said recess comprises etching back a portion of said polysilicon to create said recess in said insulative layer.
Claim 24
Dependent Claim
24 words
The method as specified in claim 20, wherein said step of forming said conductive plug comprises planarizing said polysilicon to expose said insulative layer.
Claim 25
Dependent Claim
23 words
The method as specified in claim 22, further comprising the step of performing a chemical mechanical planarization to effect said step of planarizing.
Claim 26
Dependent Claim
22 words
The method as specified in claim 14, wherein said step of forming said conductive plug comprises selectively growing silicon in said opening.
Claim 27
Dependent Claim
25 words
The method as specified in claim 24, wherein said step of providing said recess comprises prohibiting said step of selectively growing silicon in said recess.
Claim 28
Dependent Claim
63 words
The method as specified in claim 7, wherein the step of forming said conductive barrier layer comprises: a) sputtering an atom diffusion prohibiting material to overly said conductive plug and said first insulation layer; and b) removing portions of said atom diffusion prohibiting material to exposes said insulative layer while retaining said atom diffusion prohibiting material in said recess overlying said conductive plug.
Claim 29
Dependent Claim
28 words
The method as specified in claim 7, wherein the step of forming said conductive barrier layer comprises forming said barrier layer with a material which prohibits silicon diffusion.
Claim 30
Dependent Claim
41 words
The method as specified in claim 7, wherein the step of forming said conductive barrier layer comprises forming said conductive barrier layer with a material selected from a group of materials consisting of refractory metals, conductive metal oxides, and metal nitrides.
Claim 31
Dependent Claim
32 words
The method as specified in claim 7, wherein said conductive barrier layer is comprised of a material selected from the group consisting of Ta, TiN, TaN, Ti, RuO 2 , and Ru.
Claim 32
Dependent Claim
58 words
The method as specified in claim 7, wherein said step of forming said first insulative layer comprises the following steps: a) depositing a first portion of said first insulative layer to overly the substrate; and b) depositing a second portion of said first insulative layer to overly said first portion, said second portion capable of prohibiting oxygen penetration.
Claim 33
Dependent Claim
65 words
The method as specified in claim 7, wherein said step of forming said second insulative layer comprises the following steps: a) depositing a first portion of said second insulative layer to overly the first insulative layer, said first portion capable of prohibiting oxygen penetration; and b) depositing a second portion of said second insulative layer to overly said first portion of said second insulative layer.
Claim 34
Dependent Claim
55 words
The method as specified in claim 31, further comprising a) removing at least a portion of said second portion of said second insulative layer prior to said step of creating an oxidation resistant layer; and b) retaining at least a portion of said first portion of said second insulative layer during said step of removing.
Claim 35
Dependent Claim
33 words
The method as specified in claim 7, wherein the step of forming said first and said second insulative layers comprises depositing a material selected from a group consisting of oxide, nitride, and oxynitride.
Claim 36
Dependent Claim
37 words
The method as specified in claim 7, wherein the step of forming said oxidation resistant layer comprises forming said oxidation resistant layer with a material selected from the group consisting of non- oxidizing materials or conductive oxides.
Claim 37
Dependent Claim
36 words
The method as specified in claim 7, wherein the step of forming said oxidation resistant layer comprises forming said oxidation resistant layer comprising a material selected from a group consisting of platinum and RuO 2 .
References Cited (Backward Citations)
US4910578A
Cited
US4903110A
Cited
US4782309A
Cited
US5046043A
Cited
US5189503A
Cited
US5387532A
Cited
US5099305A
Cited
US5049975A
Cited
US5134451A
Cited
US5005102A
Cited
US4982309A
Cited
US5053917A
Cited
US5248628A
Cited
US5293510A
Cited
US5098860A
Cited
EP0494313A1
Cited
US5111355A
Cited
US5053351A
Cited
US5198384A
Cited
US5168073A
Cited
US5401680A
Cited
US5391511A
Cited
US5162248A
Cited
US5185689A
Cited
US5187638A
Cited
US5335138A
Cited
US5381302A
Cited
US5392189A
Cited
US5506166A
Cited
US5366920A
Cited
US5340765A
Cited
US5631804A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2003-05-23 | 2003-11-22 | 2004-05-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2007-05-23 | 2007-11-22 | 2008-05-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2011-05-23 | 2011-11-22 | 2012-05-23 | $7700.00 | Window Closed / Lapsed |