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Patent US6020243A successfully refreshed from Google Patents.
US6020243A
Expired / Lapsed
US
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Zirconium and/or hafnium silicon-oxynitride gate dielectric
Assignee: Texas Instruments Inc
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Filing: 1998-07-15
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Granted: 2000-02-01
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Expires: 2018-07-15
Abstract
Abstract A field effect semiconductor device comprising a high permittivity zirconium (or hafnium) silicon-oxynitride gate dielectric and a method of forming the same are disclosed herein. The device comprises a silicon substrate 20 having a semiconducting channel region 24 formed therein. A zirconium silicon-oxynitride gate dielectric layer 36 is formed over this substrate, followed by a conductive gate 38. Zirconium silicon-oxynitride gate dielectric layer 36 has a dielectric constant is significantly higher than the dielectric constant of silicon dioxide. However, the zirconium silicon-oxynitride gate dielectric may also be designed to have the advantages of silicon dioxide, e.g. high breakdown, low interface state density, and high stability.
Inventors
- 👤 Robert M. Wallace
- 👤 Richard A. Stoltz
- 👤 Glen D. Wilk
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 23:52
CPC Classifications
H; H10; H10D; H10D64/00; H10D64/60; H10D64/66; H10D64/68; H10D64/691; H10D64/01; H10D64/013; H10D64/01302; H10D64/01332; H10D64/01336; H10D64/0134; H10D64/01342; H10D64/01344; H10D64/0135; H10D64/681; H10D64/685; H10D64/693; H10P; H10P14/00; H10P14/60; H10P14/63; H10P14/6302; H10P14/6318; H10P14/69; H10P14/692; H10P14/6921; H10P14/6922; H10P14/6927; H10P14/6938; H10P14/6939; H10P14/69392; H10P14/69395; H10P14/69397
Claims Analysis
Total Claims: 34
Claim 1
Independent Claim
54 words
A method of fabricating a field-effect device on an integrated circuit, the method comprising: providing a single-crystal silicon substrate; forming a metal silicon-oxynitride gate dielectric layer on the substrate, where the metal is selected from the group consisting of hafnium, zirconium, and mixtures thereof; and forming a conductive gate overlying the gate dielectric layer.
Claim 2
Independent Claim
54 words
A method of fabricating a field-effect device on an integrated circuit, the method comprising: providing a single-crystal silicon substrate; forming a metal silicon-oxynitride gate dielectric layer on the substrate, where the metal is selected from the group consisting of hafnium, zirconium, and mixtures thereof; and forming a conductive gate overlying the gate dielectric layer.
Claim 3
Dependent Claim
12 words
The method of claim 1, wherein the metal is substantially pure zirconium.
Claim 4
Dependent Claim
62 words
The method of claim 1, wherein the forming a metal silicon-oxynitride dielectric layer step comprises: forming a metal silicide on the substrate, where the metal silicide is selected from the group consisting of hafnium silicide, zirconium silicide, and mixtures thereof; and annealing the formed metal silicide in an atmosphere including oxygen and nitrogen, thereby forming a metal silicon-oxynitride layer on the substrate.
Claim 5
Dependent Claim
10 words
The method of claim 3, where the atmosphere includes NO.
Claim 6
Dependent Claim
19 words
The method of claim 3, where the atmosphere includes a nitrogen/oxygen plasma, the plasma generated remotely from the substrate.
Claim 7
Dependent Claim
40 words
The method of claim 3, where the annealing time is limited, such that the nitrogen to silicon ratio of the metal silicon-oxynitride layer is lower near the interface with the silicon substrate than near the interface with the conductive gate.
Claim 8
Dependent Claim
16 words
The method of claim 3, where the forming a metal silicide step comprises chemical vapor deposition.
Claim 9
Dependent Claim
56 words
The method of claim 3, wherein the forming a metal silicide step comprises: depositing a metal layer on the substrate in an inert atmosphere, where the metal is selected from the group consisting of hafnium, zirconium, and mixtures thereof; and annealing the substrate and metal layer in an inert atmosphere to form a metal silicide layer.
Claim 10
Dependent Claim
19 words
The method of claim 8, wherein the substrate comprises a clean Si surface immediately prior to the depositing step.
Claim 11
Dependent Claim
15 words
The method of claim 8, where the depositing a metal layer comprises chemical vapor deposition.
Claim 12
Dependent Claim
14 words
The method of claim 10, where the chemical vapor deposition uses a nitrogen-bearing precursor.
Claim 13
Dependent Claim
82 words
The method of claim 1, wherein the forming a metal silicon-oxynitride dielectric layer step comprises: forming a partially-reduced metal silicate on the substrate, where the metal silicate is selected from the group consisting of hafnium silicate, zirconium silicate, and mixtures thereof; annealing the formed metal silicate in a non-oxidizing atmosphere including nitrogen, thereby forming a reduced metal silicon-oxynitride layer on the substrate; and annealing the reduced metal silicon-oxynitride layer in an oxidizing ambient, thereby forming a metal silicon-oxynitride layer on the substrate.
Claim 14
Dependent Claim
14 words
The method of claim 12, wherein the non-oxidizing atmosphere is a remote nitrogen plasma.
Claim 15
Dependent Claim
63 words
The method of claim 12, wherein the forming a partially-reduced metal silicate step comprises: depositing a metal oxide layer on the substrate in an inert atmosphere, where the metal oxide is selected from the group consisting of hafnium oxide, zirconium oxide, and mixtures thereof; and annealing the substrate and metal oxide layer in an inert atmosphere to form a partially-reduced metal silicate layer.
Claim 16
Dependent Claim
79 words
The method of claim 1, wherein the forming a metal silicon-oxynitride dielectric layer step comprises: forming a metal silicide on the substrate, where the metal silicide is selected from the group consisting of hafnium silicide, zirconium silicide, and mixtures thereof; annealing the formed metal silicide in a non-oxidizing atmosphere including nitrogen, thereby forming a metal silicon-nitride layer on the substrate; and annealing the metal silicon-nitride layer in an oxidizing ambient, thereby forming a metal silicon-oxynitride layer on the substrate.
Claim 17
Dependent Claim
12 words
The method of claim 15, wherein the non-oxidizing atmosphere includes atomic nitrogen.
Claim 18
Dependent Claim
16 words
The method of claim 15, where the forming a metal silicide step comprises chemical vapor deposition.
Claim 19
Dependent Claim
56 words
The method of claim 15, wherein the forming a metal silicide step comprises: depositing a metal layer on the substrate in an inert atmosphere, where the metal is selected from the group consisting of hafnium, zirconium, and mixtures thereof; and annealing the substrate and metal layer in an inert atmosphere to form a metal silicide layer.
Claim 20
Dependent Claim
56 words
The method of claim 1, wherein the forming a metal silicon-oxynitride dielectric layer step comprises depositing a metal silicide on the substrate in an atmosphere including oxygen and nitrogen, thereby forming a metal silicon-oxynitride layer on the substrate; where the metal silicide is selected from the group consisting of hafnium silicide, zirconium silicide, and mixtures thereof.
Claim 21
Dependent Claim
24 words
The method of claim 19, where depositing a metal silicide comprises sputtering material from a target comprised of the metal silicide onto the substrate.
Claim 22
Dependent Claim
21 words
The method of claim 19, where depositing a metal silicide comprises evaporating a first metal and silicon from a common source.
Claim 23
Dependent Claim
20 words
The method of claim 19, where depositing a metal silicide comprises evaporating a first metal and silicon from separate sources.
Claim 24
Dependent Claim
37 words
The method of claim 22, wherein the evaporation rate of the separate sources are independently varied during the depositing step, thereby forming a metal silicon-oxynitride dielectric layer having a depth-varying ratio of the first metal to silicon.
Claim 25
Dependent Claim
29 words
The method of claim 23, where the metal to silicon ratio is lower near the interface with the silicon substrate than near the center of the metal silicon-oxynitride layer.
Claim 26
Dependent Claim
10 words
The method of claim 19, where the atmosphere includes NO.
Claim 27
Dependent Claim
12 words
The method of claim 19, where the atmosphere includes N 2 O.
Claim 28
Dependent Claim
12 words
The method of claim 19, further comprising annealing the metal silicon-oxynitride layer.
Claim 29
Dependent Claim
22 words
The method of claim 27, wherein the annealing step is carried out at a temperature sufficient to crystallize the metal silicon-oxynitride layer.
Claim 30
Dependent Claim
62 words
The method of claim 1, wherein the forming a metal silicon-oxynitride dielectric layer step comprises forming a silicon dioxide layer on the substrate; and simultaneously exposing the silicon dioxide layer to a nitrogen plasma and a metal plasma, where the metal is selected from the group consisting of hafnium, zirconium, and mixtures thereof; where the plasmas are generated remotely from the substrate.
Claim 31
Dependent Claim
10 words
An integrated circuit made by the method of claim 1.
Claim 32
Dependent Claim
10 words
An integrated circuit made by the method of claim 19.
Claim 33
Dependent Claim
10 words
An integrated circuit made by the method of claim 4.
Claim 34
Dependent Claim
10 words
An integrated circuit made by the method of claim 15.
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| 3.5 Years (Year 4) | 2003-01-31 | 2003-08-02 | 2004-02-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2007-01-31 | 2007-08-02 | 2008-02-01 | $3760.00 | Window Closed / Lapsed |
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