US6190963B1
Expired / Lapsed
US
⏱️ 0.0 years remaining
Composite iridium-metal-oxygen barrier structure with refractory metal companion barrier and method for same
Assignee: Sharp Corp
•
Filing: 1999-05-21
•
Granted: 2001-02-20
•
Expires: 2019-05-21
Abstract
Abstract An Ir—M—O composite film has been provided that is useful in forming an electrode of a ferroelectric capacitor, where M includes a variety of refractory metals. The Ir combination film is resistant to high temperature annealing in oxygen environments. When used with an underlying barrier layer made from the same variety of M transition metals, the resulting conductive barrier also suppresses to diffusion of Ir into any underlying Si substrates. As a result, Ir silicide products are not formed, which degrade the electrode interface characteristics. That is, the Ir combination film remains conductive, not peeling or forming hillocks, during high temperature annealing processes, even in oxygen. The Ir—M—O conductive electrode/barrier structures are useful in nonvolatile FeRAM devices, DRAMs, capacitors, pyroelectric infrared sensors, optical displays, optical switches, piezoelectric transducers, and surface acoustic wave devices. A method for forming an Ir—M—O composite film barrier layer and an Ir—M—O composite film ferroelectric electrode are also provided.
Inventors
- 👤 Fengyan Zhang
- 👤 Sheng Teng Hsu
- 👤 Jer-shen Maa
- 👤 Wei-Wei Zhuang
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 08:22
CPC Classifications
H; H10; H10D; H10D1/00; H10D1/60; H10D1/68; H10D1/692; H10D1/696; H10D84/00; H10D84/80; H10D1/682; H10P; H10P14/00; H10P14/40; H10P14/418
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
154 words
A method for forming a highly temperature stable conductive barrier overlying an integrated circuit substrate, the method comprising the steps of: forming a first barrier layer which serves to prevent the interdiffusion of Ir into the integrated circuit substrate, said first barrier layer being selected from the group consisting of Ta, Ti, Nb, Al, Hf, Zr, TaN, TiN, NbN, ZrN, AlN, and HfN overlying the substrate; forming a second barrier layer overlying said first barrier layer, said second barrier layer inhibiting the oxidation of said first barrier layer during subsequent annealing processes, said step of forming a second barrier layer including depositing a layer of material selected from the group consisting of Ir, Ru, IrO 2 , Pt, and RuO 2 ; and forming a first composite film including iridium, a refractory metal, and oxygen overlying the second barrier layer, whereby a multilayer structure is formed that is resistive to interaction with the substrate.
Claim 2
Independent Claim
154 words
A method for forming a highly temperature stable conductive barrier overlying an integrated circuit substrate, the method comprising the steps of: forming a first barrier layer which serves to prevent the interdiffusion of Ir into the integrated circuit substrate, said first barrier layer being selected from the group consisting of Ta, Ti, Nb, Al, Hf, Zr, TaN, TiN, NbN, ZrN, AlN, and HfN overlying the substrate; forming a second barrier layer overlying said first barrier layer, said second barrier layer inhibiting the oxidation of said first barrier layer during subsequent annealing processes, said step of forming a second barrier layer including depositing a layer of material selected from the group consisting of Ir, Ru, IrO 2 , Pt, and RuO 2 ; and forming a first composite film including iridium, a refractory metal, and oxygen overlying the second barrier layer, whereby a multilayer structure is formed that is resistive to interaction with the substrate.
Claim 3
Dependent Claim
35 words
A method as in claim 1 in which said step of forming a second barrier layer includes depositing the second barrier layer through deposition methods selected from the group consisting of CVD, PVD, and MOCVD.
Claim 4
Dependent Claim
26 words
A method as in claim 1 in which said step of forming a second barrier layer includes depositing the second barrier layer at approximately room temperature.
Claim 5
Dependent Claim
33 words
A method as in claim 1 in which said step of forming a second barrier layer includes depositing the second barrier layer having a thickness in the range of approximately 10-200 nanometers (nm).
Claim 6
Dependent Claim
63 words
A method as in claim 1 including the further steps, following said step of forming a first composite film, of: forming a third barrier layer selected from the group of materials consisting of IrO 2 , RuO 2 , Ir, Ru, and Pt overlying the first composite film, whereby the interface between the first composite film and a subsequently deposited material is improved.
Claim 7
Dependent Claim
41 words
A method as in claim 5 in which said step of forming a third barrier layer includes depositing the third barrier layer to a thickness in the range of approximately 10 to 200 nm using PVD, CVD, and MOCVD deposition methods.
Claim 8
Dependent Claim
26 words
A method as in claim 5 in which said step of forming a third barrier layer includes depositing the third barrier layer at approximately room temperature.
Claim 9
Dependent Claim
34 words
A method as in claim 1 in which said step of forming a first composite film includes depositing the first composite film to a thickness in the range of approximately 10 to 500 nm.
Claim 10
Dependent Claim
35 words
A method as in claim 1 in which said step of forming a first composite film includes depositing the first composite film by deposition methods selected from the group consisting of PVD, CVD, and MOCVD.
Claim 11
Dependent Claim
93 words
A method as in claim 9 in which said step of forming a first composite film includes dc cosputtering separate Ir and a metal targets with a power level in the range of approximately 2 to 20 kilowatts, in which the metal targets are selected from the group of metals consisting of Ta, Ti, Nb, Zr, Al, and Hf, in which the atmosphere is Ar—O 2 in a ratio in the range of approximately 1:5 to 5:1, and in which the atmosphere pressure is in the range of approximately 2 to 100 mT.
Claim 12
Dependent Claim
96 words
A method as in claim 9 in which said step of forming a first composite film includes RF cosputtering separate Ir and a metal oxide targets with a power level in the range of approximately 2 to 20 kilowatts, in which the metal oxide targets including metal selected from the group of metals consisting of Ta, Ti, Nb, Zr, Al, and Hf, in which the atmosphere is Ar—O 2 in a ratio in the range of approximately 1:5 to 5:1, and in which the atmosphere pressure is in the range of approximately 2 to 100 mT.
Claim 13
Dependent Claim
35 words
A method as in claim 9 in which said step of forming a first composite film includes depositing the first composite film through PVD deposition, sputtering with a single, composite source, in an oxygen environment.
Claim 14
Dependent Claim
51 words
A method as in claim 12 in which said step of forming a first composite film includes the single composite source being a target of Ir and a source material selected from the group of materials consisting of Ir, Ta, Ti, Nb, Zr, Al, Hf, and oxides of the above-mentioned materials.
Claim 15
Dependent Claim
37 words
A method as in claim 1 in which said step of forming a first composite film includes the first composite film being selected from the group of materials consisting of Ir—Ta—O, Ir—Ti—O, Ir—Nb—O, Ir—Al—O, Ir—Hf—O, and Ir—Zr—O.
Claim 16
Dependent Claim
26 words
A method as in claim 1 in which said step of forming a first composite film includes depositing the first composite film at approximately room temperature.
Claim 17
Dependent Claim
35 words
A method as in claim 1 in which said step of forming a first barrier layer includes depositing the first barrier layer through deposition methods selected from the group consisting of PVD, CVD, and MOCVD.
Claim 18
Dependent Claim
50 words
A method as in claim 16 in which said step of forming a first barrier layer includes depositing the first barrier material by sputtering at a power in the range of approximately 2 to 20 kilowatts, in an Ar atmosphere at a pressure of approximately 2 to 100 millitorr (mT).
Claim 19
Dependent Claim
39 words
A method as in claim 1 in which said step of forming a first barrier layer includes sputtering a metal selected from the group consisting of Ta, Ti, Nb, Al, Hf, and Zr in an Ar—N 2 ambient atmosphere.
Claim 20
Dependent Claim
26 words
A method as in claim 1 in which said step of forming a first barrier layer includes depositing the first barrier layer at approximately room temperature.
Claim 21
Dependent Claim
34 words
A method as in claim 1 in which said step of forming a first barrier layer includes depositing the first barrier layer to a thickness in the range of approximately 10 to 100 nm.
Claim 22
Dependent Claim
51 words
A method as in claim 1 , wherein a ferroelectric capacitor is formed, including further steps, following said step of forming a first composite film, of: forming a ferroelectric material overlying the first composite film; and forming a conductive top electrode overlying the ferroelectric material, whereby a ferroelectric capacitor is formed.
Claim 23
Dependent Claim
45 words
A method as in claim 1 including a further step, following said step of forming a first composite film, of: annealing the first composite film, whereby the conductivity of the first composite film is improved and the thickness of the first composite film is stabilized.
Claim 24
Dependent Claim
67 words
A method as in claim 22 in which said step of annealing the first composite film includes annealing in an atmosphere selected from the group of gases consisting of oxygen, N 2 , Ar, and a vacuum, and in which the annealing temperature is in the range of approximately 400 to 1000 degrees C., for a time duration in the range of approximately 1 to 120 minutes.
Claim 25
Dependent Claim
25 words
A method as in claim 1 wherein the substrate is selected from the group of materials consisting of silicon, polysilicon, silicon dioxide, and silicon-germanium compounds.
References Cited (Backward Citations)
US5008687A
Cited
US5793057A
Cited
US5834357A
Cited
US5573979A
Cited
US5668040A
Cited
US5708284A
Cited
US5861332A
Cited
US5854107A
Cited
US5807774A
Cited
US6121083A
Cited
US6048740A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2004-02-20 | 2004-08-21 | 2005-02-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2008-02-20 | 2008-08-21 | 2009-02-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2012-02-20 | 2012-08-21 | 2013-02-20 | $7700.00 | Window Closed / Lapsed |