Patent US5753559A successfully refreshed from Google Patents.
US5753559A
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Method for growing hemispherical grain silicon
Assignee: United Microelectronics Corp
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Filing: 1996-10-09
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Granted: 1998-05-19
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Expires: 2016-10-09
Abstract
Abstract Hemispherical-grained silicon (HSG-Si) is grown on polysilicon by plasma deposition. A wider range of substrate deposition temperatures can be used in the plasma deposition of HSG-Si than can be maintained in the low pressure chemical vapor deposition (LPCVD) of HSG-Si. The plasma deposition of HSG-Si can be performed in an electron cyclotron resonance chemical vapor deposition (ECR-CVD) system at input power levels ranging from 100-1500 W, at total pressures between 5-60 mTorr, and at substrate temperatures ranging from 200°-500° C. A mixture of silane and hydrogen gases at a dilution ratio of silane within the silane and hydrogen gas mixture H 2 /(SiH 4 +H 2 ) between about 70-99% may be used in the ECR-CVD system. The polysilicon surface is cleaned of native oxides prior to plasma deposition of HSG-Si.
Inventors
- 👤 Tri-Rung Yew
- 👤 Water Lur
- 👤 Shih-Wei Sun
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 16:20
CPC Classifications
H; H10; H10D; H10D1/00; H10D1/60; H10D1/68; H10D1/692; H10D1/711; H10D1/712
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
81 words
A method of making a device comprising the steps of: providing to a deposition system a substrate having an exposed surface of a conductor primarily comprising silicon; generating a plasma region within the deposition system; providing at least one reactant gas comprising silicon to the deposition system so that ions comprising silicon are generated within the deposition system and are transported to the exposed surface; and depositing a layer of HSG-Si on the exposed surface of the conductor primarily comprising silicon.
Claim 2
Independent Claim
81 words
A method of making a device comprising the steps of: providing to a deposition system a substrate having an exposed surface of a conductor primarily comprising silicon; generating a plasma region within the deposition system; providing at least one reactant gas comprising silicon to the deposition system so that ions comprising silicon are generated within the deposition system and are transported to the exposed surface; and depositing a layer of HSG-Si on the exposed surface of the conductor primarily comprising silicon.
Claim 3
Dependent Claim
46 words
The method of claim 1, wherein the deposition system is an electron cyclotron resonance chemical vapor deposition system having a gas flow path extending from a first gas inlet through a reactant gas excitation region to a deposition system gas output coupled to a pumping system.
Claim 4
Dependent Claim
22 words
The method of claim 2, wherein the substrate is positioned downstream along the gas flow path from the reactant gas excitation region.
Claim 5
Dependent Claim
26 words
The method of claim 3, wherein the deposition system includes a second gas inlet along the gas flow path between the plasma region and the substrate.
Claim 6
Dependent Claim
27 words
The method of claim 4, wherein silane is introduced to the deposition system at the second gas inlet during the step of depositing a layer of HSG-Si.
Claim 7
Dependent Claim
33 words
The method of claim 5, further comprising the step of providing hydrogen gas to the deposition system at the first gas inlet so that the hydrogen gas is ionized within the plasma region.
Claim 8
Dependent Claim
39 words
The method of claim 6, wherein the hydrogen and silane gases are provided to the deposition system so that a dilution ratio of the silane and hydrogen gas mixture H 2 /(SiH 4 +H 2 ) is between 70-99%.
Claim 9
Dependent Claim
48 words
The method of claim 1, wherein the layer of HSG-Si is doped in situ by introducing a second reactant gas comprising a dopant species to the deposition system so that ions comprising the dopant species are generated within the deposition system and are transported to the exposed surface.
Claim 10
Dependent Claim
14 words
The method of claim 8, wherein the exposed surface is cleaned using hydrogen fluoride.
Claim 11
Independent Claim
113 words
A method of making a device comprising the steps of: depositing a layer of polysilicon on or above a silicon substrate; providing an exposed surface on the layer of polysilicon substantially free of native oxides; providing the silicon substrate to a deposition system; maintaining the silicon substrate at a temperature below about 590° C.; providing at least one reactant gas comprising silicon to the deposition system; generating a plasma within the deposition system so that the at least one reactant gas is excited to provide ions comprising silicon to the deposition system; and transporting the ions comprising silicon to the exposed surface of the layer of polysilicon and depositing a layer of HSG-Si.
Claim 12
Independent Claim
113 words
A method of making a device comprising the steps of: depositing a layer of polysilicon on or above a silicon substrate; providing an exposed surface on the layer of polysilicon substantially free of native oxides; providing the silicon substrate to a deposition system; maintaining the silicon substrate at a temperature below about 590° C.; providing at least one reactant gas comprising silicon to the deposition system; generating a plasma within the deposition system so that the at least one reactant gas is excited to provide ions comprising silicon to the deposition system; and transporting the ions comprising silicon to the exposed surface of the layer of polysilicon and depositing a layer of HSG-Si.
Claim 13
Dependent Claim
21 words
The method of claim 10, wherein the exposed surface is hydrogenated before the silicon substrate is provided to the deposition system.
Claim 14
Dependent Claim
18 words
The method of claim 10, wherein the silicon substrate is maintained at a temperature between about 200°-500° C.
Claim 15
Dependent Claim
20 words
The method of claim 10, wherein the deposition system is operated at a total pressure of between about 5-60 mTorr.
Claim 16
Dependent Claim
28 words
The method of claim 10, further comprising the step of forming a dielectric layer of less than eight nanometers in thickness on the surface of the HSG-Si layer.
Claim 17
Dependent Claim
23 words
The method of claim 10, further comprising the step of depositing a layer of silicon nitride over the surface of the HSG-Si layer.
Claim 18
Dependent Claim
31 words
The method of claim 15, further comprising the steps of forming an oxide on the silicon nitride layer and then forming a layer of a conductive material over the oxide layer.
Claim 19
Dependent Claim
26 words
The method of claim 16, wherein the layer of silicon nitride is deposited on a native oxide layer formed on the surface of the HSG-Si layer.
Claim 20
Dependent Claim
17 words
The method of claim 10, wherein the reactant gases in the deposition system comprise silane and hydrogen.
Claim 21
Dependent Claim
41 words
The method of claim 18, wherein the hydrogen and silane gases are provided to the deposition system so that a dilution ratio of silane within the silane and hydrogen gas mixture H 2 /(SiH 4 +H 2 ) is between 70-99%.
Claim 22
Dependent Claim
14 words
The method of claim 18, wherein the reactant gases further comprise a dopant gas.
Claim 23
Dependent Claim
11 words
The method of claim 16, wherein the conductive layer comprises polysilicon.
Claim 24
Independent Claim
102 words
A method of making a device comprising the steps of: depositing a layer of polysilicon on or above a silicon substrate; providing an exposed surface on the layer of polysilicon substantially free of native oxides; providing the silicon substrate to a deposition system; providing at least one reactant gas comprising silicon to the deposition system; generating a plasma within the deposition system so that the at least one reactant gas is excited to provide ions comprising silicon to the deposition system; and transporting the ions comprising silicon to the exposed surface of the layer of polysilicon and depositing a layer of HSG-Si.
Claim 25
Independent Claim
102 words
A method of making a device comprising the steps of: depositing a layer of polysilicon on or above a silicon substrate; providing an exposed surface on the layer of polysilicon substantially free of native oxides; providing the silicon substrate to a deposition system; providing at least one reactant gas comprising silicon to the deposition system; generating a plasma within the deposition system so that the at least one reactant gas is excited to provide ions comprising silicon to the deposition system; and transporting the ions comprising silicon to the exposed surface of the layer of polysilicon and depositing a layer of HSG-Si.
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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) | 2001-05-18 | 2001-11-17 | 2002-05-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-05-18 | 2005-11-17 | 2006-05-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-05-18 | 2009-11-17 | 2010-05-19 | $7700.00 | Window Closed / Lapsed |