Patent EP1056273A2 successfully refreshed from Google Patents.
Patent US6255159B1 successfully refreshed from Google Patents.
US6255159B1
Expired / Lapsed
US
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Method to form hemispherical grained polysilicon
Assignee: Round Rock Research LLC
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Filing: 1997-07-14
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Granted: 2001-07-03
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Expires: 2017-07-14
Abstract
Abstract A capacitor with Enhanced capacitance per cell area is provided. A container supported by a substrate is formed, followed by a first layer of undoped substantially amorphous silicon. Next, a layer of heavily doped amorphous silicon is formed on the first layer. A second layer of undoped amorphous silicon is formed on the doped layer. The layers are formed in a non-oxidizing ambient so that no oxide is formed between the layers. The structure formed is planarized to form separate containers made from the doped and undoped amorphous silicon layers. Any remaining oxide is then removed from the exterior sidewalls. Selected ones of the first and second undoped layers are seeded and annealed to convert the first and second layers to HSG. A dielectric layer and second electrode are formed to complete the cell capacitor.
Inventors
- 👤 Randhir P. S. Thakur
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 03:00
CPC Classifications
H; H10; H10B; H10B12/00; H10B12/01; H10B12/02; H10B12/03; H10B12/033; H10D; H10D1/00; H10D1/60; H10D1/68; H10D1/692; H10D1/711; H10D1/712; H10D1/716
Claims Analysis
Total Claims: 49
Claim 1
Independent Claim
124 words
A method for forming at least a portion of a capacitor in an opening in an insulative layer supported by a substrate, the opening having walls and a bottom, the method comprising the steps of: forming a layer of substantially undoped amorphous silicon in the opening; forming a layer of heavily doped silicon on the layer of substantially undoped amorphous silicon; forming another layer of substantially undoped amorphous silicon on the heavily doped layer of silicon; removing selected portions of the insulative layer to expose pillars comprising portions of the silicon layers formed on the walls of the opening; removing oxide from the pillars; seeding the undoped amorphous silicon layers; and annealing the silicon layers to convert the undoped amorphous silicon layers to HSG.
Claim 2
Independent Claim
124 words
A method for forming at least a portion of a capacitor in an opening in an insulative layer supported by a substrate, the opening having walls and a bottom, the method comprising the steps of: forming a layer of substantially undoped amorphous silicon in the opening; forming a layer of heavily doped silicon on the layer of substantially undoped amorphous silicon; forming another layer of substantially undoped amorphous silicon on the heavily doped layer of silicon; removing selected portions of the insulative layer to expose pillars comprising portions of the silicon layers formed on the walls of the opening; removing oxide from the pillars; seeding the undoped amorphous silicon layers; and annealing the silicon layers to convert the undoped amorphous silicon layers to HSG.
Claim 3
Dependent Claim
21 words
The method of claim 1 , wherein the undoped amorphous silicon layers each have a thickness between 40 and 200 angstroms.
Claim 4
Dependent Claim
23 words
The method of claim 1 , wherein the undoped amorphous silicon layers are formed at a temperature between 450 and 525 degrees Celsius.
Claim 5
Dependent Claim
24 words
The method of claim 1 , wherein the heavily doped amorphous polysilicon layer is formed at a temperature between 450 and 600 degrees Celsius.
Claim 6
Dependent Claim
28 words
The method of claim 1 , wherein the heavily doped amorphous polysilicon layer is formed with a doping level between 5×10 20 and 5×10 21 cm− 3 .
Claim 7
Dependent Claim
18 words
The method of claim 1 , wherein the oxide is removed using hydrofluoric acid, chlorine and ultraviolet light.
Claim 8
Independent Claim
147 words
A method for forming at least a portion of a capacitor in an opening in an insulative layer supported by a substrate, the opening having walls and a bottom, the method comprising the steps of: forming a layer of substantially undoped amorphous silicon in the opening; forming a layer of heavily doped silicon on the layer of substantially undoped amorphous silicon in a single processing tool in an ambient not containing significant amounts of oxygen; forming another layer of substantially undoped amorphous silicon on the heavily doped layer of silicon in a single processing tool in an ambient not containing significant amounts of oxygen; removing selected portions of the insulative layer to expose pillars comprising portions of the silicon layers formed on the walls of the opening; seeding the undoped amorphous silicon layers; and annealing the silicon layers to convert the undoped amorphous silicon layers to HSG.
Claim 9
Independent Claim
147 words
A method for forming at least a portion of a capacitor in an opening in an insulative layer supported by a substrate, the opening having walls and a bottom, the method comprising the steps of: forming a layer of substantially undoped amorphous silicon in the opening; forming a layer of heavily doped silicon on the layer of substantially undoped amorphous silicon in a single processing tool in an ambient not containing significant amounts of oxygen; forming another layer of substantially undoped amorphous silicon on the heavily doped layer of silicon in a single processing tool in an ambient not containing significant amounts of oxygen; removing selected portions of the insulative layer to expose pillars comprising portions of the silicon layers formed on the walls of the opening; seeding the undoped amorphous silicon layers; and annealing the silicon layers to convert the undoped amorphous silicon layers to HSG.
Claim 10
Independent Claim
131 words
A method for forming at least a portion of a capacitor in an opening in an insulative layer supported by a substrate, the opening having walls and a bottom, the method comprising the steps of: forming a layer of substantially undoped amorphous silicon in the opening in a hydrogen ambient; forming a layer of heavily doped silicon on the layer of substantially undoped amorphous silicon in a hydrogen ambient; forming another layer of substantially undoped amorphous silicon on the heavily doped layer of silicon in a hydrogen ambient; removing selected portions of the insulative layer to expose pillars comprising portions of the silicon layers formed on the walls of the opening; seeding the undoped amorphous silicon layers; and annealing the silicon layers to convert the undoped amorphous silicon layers to HSG.
Claim 11
Independent Claim
131 words
A method for forming at least a portion of a capacitor in an opening in an insulative layer supported by a substrate, the opening having walls and a bottom, the method comprising the steps of: forming a layer of substantially undoped amorphous silicon in the opening in a hydrogen ambient; forming a layer of heavily doped silicon on the layer of substantially undoped amorphous silicon in a hydrogen ambient; forming another layer of substantially undoped amorphous silicon on the heavily doped layer of silicon in a hydrogen ambient; removing selected portions of the insulative layer to expose pillars comprising portions of the silicon layers formed on the walls of the opening; seeding the undoped amorphous silicon layers; and annealing the silicon layers to convert the undoped amorphous silicon layers to HSG.
Claim 12
Independent Claim
67 words
A method for forming at least a portion of a stacked capacitor in an opening in an insulative layer supported by a substrate, the method comprising the steps of: forming a bottom electrode container comprising pillars of heavily doped silicon sandwiched by layers of substantially undoped amorphous silicon with no oxide layers formed between the layers; and converting the layers of substantially undoped amorphous silicon to HSG.
Claim 13
Independent Claim
67 words
A method for forming at least a portion of a stacked capacitor in an opening in an insulative layer supported by a substrate, the method comprising the steps of: forming a bottom electrode container comprising pillars of heavily doped silicon sandwiched by layers of substantially undoped amorphous silicon with no oxide layers formed between the layers; and converting the layers of substantially undoped amorphous silicon to HSG.
Claim 14
Dependent Claim
21 words
The method of claim 9 , wherein the layers of undoped silicon each have a thickness between 40 and 200 angstroms.
Claim 15
Dependent Claim
23 words
The method of claim 9 , wherein the layers of undoped silicon are formed at a temperature between 450 and 525 degrees Celsius.
Claim 16
Dependent Claim
22 words
The method of claim 9 , wherein the doped silicon layer is formed at a temperature between 450 and 600 degrees Celsius.
Claim 17
Dependent Claim
26 words
The method of claim 9 , wherein the doped silicon layer is formed with a doping level between 5×10 20 and 5×10 21 cm −3 .
Claim 18
Dependent Claim
22 words
The method of claim 9 , and further comprising the step of removing oxide from the pillars prior to the annealing step.
Claim 19
Dependent Claim
17 words
The method of claim 14 wherein the oxide is removed using hydrofluoric acid, chlorine and ultraviolet light.
Claim 20
Dependent Claim
39 words
The method of claim 9 , wherein the converting step comprises the steps of seeding at least one of the undoped silicon layers with silane at a pressure of between 10 and 20 milliTorr and annealing the bottom electrode.
Claim 21
Dependent Claim
26 words
The method of claim 9 , wherein the silicon layers are formed in a single processing tool in an ambient not containing significant amounts of oxygen.
Claim 22
Dependent Claim
19 words
The method of claim 17 , wherein the steps of forming silicon layers are performed in a hydrogen ambient.
Claim 23
Independent Claim
59 words
A method for forming a bottom electrode of a capacitor supported by a substrate, the method comprising the steps of: forming a bottom electrode container comprising pillars of heavily doped silicon sandwiched by layers of substantially undoped amorphous silicon with no oxide layers formed between the layers; and converting at least one of the layers of silicon to HSG.
Claim 24
Independent Claim
59 words
A method for forming a bottom electrode of a capacitor supported by a substrate, the method comprising the steps of: forming a bottom electrode container comprising pillars of heavily doped silicon sandwiched by layers of substantially undoped amorphous silicon with no oxide layers formed between the layers; and converting at least one of the layers of silicon to HSG.
Claim 25
Dependent Claim
36 words
The method of claim 19 , wherein at least one of the layers of undoped silicon has a thickness between 40 and 200 angstroms and is formed at a temperature between 450 and 525 degrees Celsius.
Claim 26
Dependent Claim
35 words
The method of claim 19 , wherein the doped silicon layer is formed at a temperature between 450 and 600 degrees Celsius with a doping level between 5×10 20 and 5×10 21 cm −3 .
Claim 27
Dependent Claim
36 words
The method of claim 19 , and further comprising the step of removing oxide from at least on of the layers of undoped silicon prior to the annealing step using hydrofluoric acid, chlorine and ultraviolet light.
Claim 28
Dependent Claim
39 words
The method of claim 19 , wherein the converting step comprises the steps of seeding at least one of the undoped silicon layers with silane at a pressure of between 10 and 20 milliTorr and annealing the bottom electrode.
Claim 29
Dependent Claim
27 words
The method of claim 19 , wherein the silicon layers are formed in a single processing tool in a hydrogen ambient not containing significant amounts of oxygen.
Claim 30
Dependent Claim
37 words
The method of claim 19 , wherein the step of converting comprises the steps of seeding at least one of the undoped silicon layers with germanium at between approximately 1 to 30% and annealing the bottom electrode.
Claim 31
Dependent Claim
16 words
The method of claim 19 , wherein the pillars of heavily doped silicon are n+ doped.
Claim 32
Dependent Claim
21 words
The method of claim 26 , and further comprising the step of seeding the pillars of heavily doped silicon with germanium.
Claim 33
Independent Claim
160 words
A method for forming a capacitor in an insulative layer supported by a substrate, the method comprising the steps of: removing a first portion of the insulator layer to form an opening; forming a first layer of undoped amorphous silicon on the insulative layer; forming a layer of doped amorphous silicon on the first layer of silicon; forming a second layer of undoped amorphous silicon on the doped layer of silicon, wherein each of the layers of silicon are formed in an ambient substantially devoid of oxygen so that no oxide layers are formed between the silicon layers; planarizing the dielectric layer to form a container comprising pillars of doped silicon painted with the layers of undoped amorphous silicon; removing selected portions of the insulative layer to expose exterior sidewalls of the containers; removing an oxide from the exterior sidewalls; seeding the first and second layers; and annealing the silicon layers to convert the first and second layers to HSG.
Claim 34
Independent Claim
160 words
A method for forming a capacitor in an insulative layer supported by a substrate, the method comprising the steps of: removing a first portion of the insulator layer to form an opening; forming a first layer of undoped amorphous silicon on the insulative layer; forming a layer of doped amorphous silicon on the first layer of silicon; forming a second layer of undoped amorphous silicon on the doped layer of silicon, wherein each of the layers of silicon are formed in an ambient substantially devoid of oxygen so that no oxide layers are formed between the silicon layers; planarizing the dielectric layer to form a container comprising pillars of doped silicon painted with the layers of undoped amorphous silicon; removing selected portions of the insulative layer to expose exterior sidewalls of the containers; removing an oxide from the exterior sidewalls; seeding the first and second layers; and annealing the silicon layers to convert the first and second layers to HSG.
Claim 35
Dependent Claim
17 words
The method of claim 28 , wherein the insulative layer comprises two layers having good etch selectivity.
Claim 36
Independent Claim
243 words
A method for forming a stacked capacitor in an insulative layer supported by a substrate, the method comprising the steps of: removing a first portion of the insulator layer to form an opening; forming a first layer of undoped amorphous silicon at a temperature between 450 and 525 degrees Celsius on the insulative layer, the first layer having a thickness between 40 and 200 angstroms; forming a layer of doped amorphous silicon on the first layer of silicon, the layer of doped amorphous silicon being formed at a temperature between 450 and 600 degrees Celsius with a doping level between 5×10 20 and 5×10 21 cm −3 ; forming a second layer of undoped amorphous silicon at a temperature between 450 and 525 degrees Celsius, the second layer having a thickness between 40 and 200 angstroms on the doped layer of silicon, wherein each of the layers of silicon are formed in an ambient substantially devoid of oxygen so that no oxide layers are formed between the silicon layers; planarizing the dielectric layer to form a container comprising pillars of doped silicon painted with the layers of undoped amorphous silicon; removing a second portion of the insulative layer to expose exterior sidewalls of the containers; removing an oxide from the exterior sidewalls; seeding the first and second layers with silane at a pressure of between 10 and 20 milliTorr; and annealing the silicon layers to convert the first and second layers to HSG.
Claim 37
Independent Claim
243 words
A method for forming a stacked capacitor in an insulative layer supported by a substrate, the method comprising the steps of: removing a first portion of the insulator layer to form an opening; forming a first layer of undoped amorphous silicon at a temperature between 450 and 525 degrees Celsius on the insulative layer, the first layer having a thickness between 40 and 200 angstroms; forming a layer of doped amorphous silicon on the first layer of silicon, the layer of doped amorphous silicon being formed at a temperature between 450 and 600 degrees Celsius with a doping level between 5×10 20 and 5×10 21 cm −3 ; forming a second layer of undoped amorphous silicon at a temperature between 450 and 525 degrees Celsius, the second layer having a thickness between 40 and 200 angstroms on the doped layer of silicon, wherein each of the layers of silicon are formed in an ambient substantially devoid of oxygen so that no oxide layers are formed between the silicon layers; planarizing the dielectric layer to form a container comprising pillars of doped silicon painted with the layers of undoped amorphous silicon; removing a second portion of the insulative layer to expose exterior sidewalls of the containers; removing an oxide from the exterior sidewalls; seeding the first and second layers with silane at a pressure of between 10 and 20 milliTorr; and annealing the silicon layers to convert the first and second layers to HSG.
Claim 38
Independent Claim
62 words
A method for forming at least a portion of a capacitor supported by a substrate, the method comprising the steps of: forming a bottom electrode container comprising pillars of heavily doped silicon sandwiched by layers of substantially undoped amorphous silicon with no oxide layers formed between the layers; and converting at least one selected layer of substantially undoped amorphous silicon to HSG.
Claim 39
Independent Claim
62 words
A method for forming at least a portion of a capacitor supported by a substrate, the method comprising the steps of: forming a bottom electrode container comprising pillars of heavily doped silicon sandwiched by layers of substantially undoped amorphous silicon with no oxide layers formed between the layers; and converting at least one selected layer of substantially undoped amorphous silicon to HSG.
Claim 40
Dependent Claim
21 words
The method of claim 31 wherein one selected layer of substantially undoped amorphous silicon and the pillars are converted to HSG.
Claim 41
Independent Claim
72 words
A method for forming at least a portion of a trench capacitor supported by a substrate, the method comprising the steps of: forming a trench in the substrate; forming a bottom electrode container in the trench comprising pillars of heavily doped silicon sandwiched by layers of substantially undoped amorphous silicon with no oxide layers formed between the layers; and converting at least one selected layer of substantially undoped amorphous silicon to HSG.
Claim 42
Independent Claim
72 words
A method for forming at least a portion of a trench capacitor supported by a substrate, the method comprising the steps of: forming a trench in the substrate; forming a bottom electrode container in the trench comprising pillars of heavily doped silicon sandwiched by layers of substantially undoped amorphous silicon with no oxide layers formed between the layers; and converting at least one selected layer of substantially undoped amorphous silicon to HSG.
Claim 43
Independent Claim
73 words
A method for forming a capacitor supported by a substrate, the method comprising the steps of: forming a bottom electrode container comprising pillars of heavily doped silicon sandwiched by layers of substantially undoped amorphous silicon with no oxide layers formed between the layers; converting selected layers of substantially undoped amorphous silicon to HSG; forming a dielectric layer on top of the HSG; and forming a top electrode on top of the dielectric layer.
Claim 44
Independent Claim
73 words
A method for forming a capacitor supported by a substrate, the method comprising the steps of: forming a bottom electrode container comprising pillars of heavily doped silicon sandwiched by layers of substantially undoped amorphous silicon with no oxide layers formed between the layers; converting selected layers of substantially undoped amorphous silicon to HSG; forming a dielectric layer on top of the HSG; and forming a top electrode on top of the dielectric layer.
Claim 45
Dependent Claim
26 words
The method of claim 34 wherein the dielectric layer comprises a dielectric selected from the group consisting of Ta 2 O 5 , BST and nitride.
Claim 46
Dependent Claim
23 words
The method of claim 34 wherein the top electrode comprises a conductor selected from the group consisting of refractory metal silicides and nitrides.
Claim 47
Dependent Claim
27 words
The method of claim 34 wherein the top electrode comprises a conductor selected from the group consisting of WN, TiN and conductive refractory metal silicides and nitrides.
Claim 48
Independent Claim
47 words
A method for forming a bottom electrode of a capacitor supported by a substrate, the method comprising the steps of: forming a bottom electrode container comprising a Si—Ge film; seeding the Si—Ge film with Ge; and annealing the bottom electrode to convert the Si—Ge film to HSG.
Claim 49
Independent Claim
47 words
A method for forming a bottom electrode of a capacitor supported by a substrate, the method comprising the steps of: forming a bottom electrode container comprising a Si—Ge film; seeding the Si—Ge film with Ge; and annealing the bottom electrode to convert the Si—Ge film to HSG.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 2004-07-02 | 2005-01-01 | 2005-07-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2008-07-02 | 2009-01-01 | 2009-07-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2012-07-02 | 2013-01-01 | 2013-07-03 | $7700.00 | Window Closed / Lapsed |