US6297539B1
Expired / Lapsed
US
⏱️ 0.0 years remaining
Doped zirconia, or zirconia-like, dielectric film transistor structure and deposition method for same
Assignee: Sharp Corp
•
Filing: 2000-07-06
•
Granted: 2001-10-02
•
Expires: 2020-07-06
Abstract
Abstract A high-k dielectric films is provided, which is doped with divalent or trivalent metals to vary the electron affinity, and consequently the electron and hole barrier height. The high-k dielectric film is a metal oxide of either zirconium (Zr) or hafnium (Hf), doped with a divalent metal, such as calcium (Ca) or strontium (Sr), or a trivalent metal, such as aluminum (Al), scandium (Sc), lanthanum (La), or yttrium (Y). By selecting either a divalent or trivalent doping metal, the electron affinity of the dielectric material can be controlled, while also providing a higher dielectric constant material then silicon dioxide. Preferably, the dielectric material will also be amorphous to reduce leakage caused by grain boundaries. Also provided are sputtering, CVD, Atomic Layer CVD, and evaporation deposition methods for the above-mentioned, doped high dielectric films.
Inventors
- 👤 Yanjun Ma
- 👤 Yoshi Ono
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 14:07
CPC Classifications
H; H10; H10P; H10P14/00; H10P14/60; H10P14/69; H10P14/692; H10P14/6938; H10P14/6939; H10P14/69395; H10D; H10D30/00; H10D30/60; C; C23; C23C; C23C14/00; C23C14/06; C23C14/08; C23C14/083; C23C16/00; C23C16/22; C23C16/30; C23C16/40; C23C16/405; H10D64/00; H10D64/01; H10D64/013; H10D64/01302; H10D64/01332; H10D64/01336; H10D64/0134; H10D64/01342; H10D64/01346; H10D64/60; H10D64/66; H10D64/68; H10D64/681; H10D64/685; H10D64/691; H10P14/63; H10P14/6326; H10P14/6328; H10P14/6334; H10P14/66; H10P14/668; H10D1/00; H10D1/60; H10D1/68; H10D1/682; H10D1/684; H10P14/6329; H10P14/662; H10P14/6921; H10P14/6922; H10P14/6927; H10P14/69391; H10P14/69392; H10P14/69396; H10P14/69397; H10P14/694; H10P14/6943; H10P14/69433
Claims Analysis
Total Claims: 47
Claim 1
Independent Claim
42 words
A thin film having a high dielectric constant, with respect to silicon dioxide, comprising: a) a doping metal; b) a metal selected from the group consisting of zirconium (Zr) and hafnium (Hf); and c) oxygen, whereby a high dielectric film is formed.
Claim 2
Dependent Claim
42 words
A thin film having a high dielectric constant, with respect to silicon dioxide, comprising: a) a doping metal; b) a metal selected from the group consisting of zirconium (Zr) and hafnium (Hf); and c) oxygen, whereby a high dielectric film is formed.
Claim 3
Dependent Claim
31 words
The thin film as in claim 1 in which the doping metal is a trivalent metal selected from the group consisting of aluminum (Al), scandium (Sc), lanthanum (La), and yttrium (Y).
Claim 4
Dependent Claim
27 words
The thin film as in claim 1 in which the doping metal is a divalent metal selected from the group consisting of calcium (Ca), and strontium (Sr).
Claim 5
Dependent Claim
24 words
The thin film as in claim 1 in which the thin film has a thickness in the range of approximately 20 and 200 Å.
Claim 6
Dependent Claim
24 words
The thin film as in claim 1 in which the thin film has a dielectric constant in the range of approximately 10 to 25.
Claim 7
Dependent Claim
22 words
The thin film as in claim 1 in which the percentage of doping metal in the film does not exceed approximately 50%.
Claim 8
Dependent Claim
20 words
The thin film as in claim 6 in which the percentage of doping metal in the film is approximately 25%.
Claim 9
Dependent Claim
69 words
A MOSFET transistor comprising: a) a gate electrode; b) a channel region having a top surface underlying said gate electrode; and c) a gate dielectric film interposed between said gate electrode and said channel region top surface, having a high dielectric constant relative to silicon dioxide, including a metal selected from the group consisting of zirconium (Zr) and hafnium (Hf), and including oxygen, and further including a doping metal.
Claim 10
Dependent Claim
69 words
A MOSFET transistor comprising: a) a gate electrode; b) a channel region having a top surface underlying said gate electrode; and c) a gate dielectric film interposed between said gate electrode and said channel region top surface, having a high dielectric constant relative to silicon dioxide, including a metal selected from the group consisting of zirconium (Zr) and hafnium (Hf), and including oxygen, and further including a doping metal.
Claim 11
Dependent Claim
30 words
The transistor as in claim 8 in which the doping metal includes a trivalent metal selected from the group consisting of aluminum (Al), scandium (Sc), lanthanum (La), and yttrium (Y).
Claim 12
Dependent Claim
26 words
The transistor as in claim 8 in which the doping metal includes a divalent metal selected from the group consisting of calcium (Ca) and strontium (Sr).
Claim 13
Dependent Claim
25 words
The transistor as in claim 8 in which the percentage of doping metal in the film is in the range of approximately 0 to 50%.
Claim 14
Dependent Claim
19 words
The transistor as in claim 11 in which the percentage of doping metal in the film is approximately 25%.
Claim 15
Dependent Claim
24 words
The transistor as in claim 8 in which said gate dielectric film has a thickness in the range of approximately 20 and 200 Å.
Claim 16
Dependent Claim
24 words
The transistor as in claim 8 in which said gate dielectric film has a dielectric constant in the range of approximately 10 to 25.
Claim 17
Dependent Claim
65 words
The transistor as in claim 8 further comprising an interface barrier having a thickness in the range of approximately 2 to 5 Å, interposed between said channel region and said gate dielectric film, said interface barrier including materials selected from the group consisting of silicon nitride and silicon oxynitride, whereby said channel region top surface is smoother to increase the electron mobility of the MOSFET.
Claim 18
Dependent Claim
108 words
In the fabrication of an integrated circuit (IC) having a surface, a method of forming a doped metal oxide film on the IC surface comprising the steps of: a) establishing an atmosphere including oxygen; b) sputtering at least one target metal including a metal selected from the group consisting of Zr and Hf, and including a doping metal on the IC silicon surface; c) in response to Steps a) and b), forming the doped metal oxide film; and d) annealing at a temperature in the range of approximately 400 and 900 degrees C., whereby a thin film having a high dielectric constant and good barrier properties is formed.
Claim 19
Dependent Claim
108 words
In the fabrication of an integrated circuit (IC) having a surface, a method of forming a doped metal oxide film on the IC surface comprising the steps of: a) establishing an atmosphere including oxygen; b) sputtering at least one target metal including a metal selected from the group consisting of Zr and Hf, and including a doping metal on the IC silicon surface; c) in response to Steps a) and b), forming the doped metal oxide film; and d) annealing at a temperature in the range of approximately 400 and 900 degrees C., whereby a thin film having a high dielectric constant and good barrier properties is formed.
Claim 20
Dependent Claim
25 words
The method as in claim 16 wherein the IC surface is maintained in a temperature range of between approximately room temperature and 400 degrees C.
Claim 21
Dependent Claim
50 words
The method as in claim 16 in which Step a) includes the atmosphere including argon (Ar), in which the ratio of O 2 to Ar is in the range of approximately 5 to 25%, and in which the pressure is in the range of approximately 1 to 10 millitorr (mT).
Claim 22
Dependent Claim
47 words
The method as in claim 16 in which Step d) includes establishing an atmosphere including elements selected from the group consisting of Ar, N 2 , N 2 :H 2 forming gas, O 2 , H 2 O, N 2 O, NO, no gas, and oxygen plasma.
Claim 23
Dependent Claim
28 words
The method as in claim 16 , wherein the doping metal is a trivalent metal selected from the group consisting of aluminum (Al), scandium (Sc), and lanthanum (La).
Claim 24
Dependent Claim
26 words
The method as in claim 16 , wherein the doping metal is a divalent metal selected from the group consisting of calcium (Ca), and strontium (Sr).
Claim 25
Dependent Claim
40 words
The met hod as in claim 16 in which Step b) includes co-sputtering with separate targets including a first target of a metal selected from the group consisting of Zr and Hf, and a second target including a trivalent metal.
Claim 26
Dependent Claim
39 words
The method as in claim 16 in which Step b) includes co-sputtering with separate targets including a first target of a metal selected from the group consisting of Zr and Hf, and a second target including a divalent metal.
Claim 27
Dependent Claim
125 words
In the fabrication of an integrated circuit (IC) having a surface, a method of forming a doped metal oxide film comprising the steps of: a) preparing at least one precursor including a metal selected from the group consisting of Zr and Hf, and a doping metal; b) vaporizing the at least one precursor; c) establishing an atmosphere including oxygen; d) decomposing the precursor on the IC surface to deposit, by chemical vapor deposition (CVD), an alloy film including a metal selected from the group consisting of Zr and Hf, a doping metal, and oxygen; and e) annealing at a temperature in the range of approximately 400 to 900 degrees C., whereby a thin film having a high dielectric constant and good barrier properties is formed.
Claim 28
Dependent Claim
125 words
In the fabrication of an integrated circuit (IC) having a surface, a method of forming a doped metal oxide film comprising the steps of: a) preparing at least one precursor including a metal selected from the group consisting of Zr and Hf, and a doping metal; b) vaporizing the at least one precursor; c) establishing an atmosphere including oxygen; d) decomposing the precursor on the IC surface to deposit, by chemical vapor deposition (CVD), an alloy film including a metal selected from the group consisting of Zr and Hf, a doping metal, and oxygen; and e) annealing at a temperature in the range of approximately 400 to 900 degrees C., whereby a thin film having a high dielectric constant and good barrier properties is formed.
Claim 29
Dependent Claim
28 words
The method as in claim 24 further comprising establishing an IC surface temperature in the range of between approximately 300 and 500 degrees C. prior to step d).
Claim 30
Dependent Claim
50 words
The method as in claim 24 in which Step c) includes the atmosphere including argon (Ar), in which the ratio of O 2 to Ar is in the range of approximately 5 to 25%, and in which the pressure is in the range of approximately 1 to 10 torr (T).
Claim 31
Dependent Claim
47 words
The method as in claim 24 in which Step e) includes establishing an atmosphere including elements selected from the group consisting of Ar, N 2 , N 2 :H 2 forming gas, O 2 , H 2 O, N 2 O, NO, no gas, and oxygen plasma.
Claim 32
Dependent Claim
28 words
The method as in claim 24 in which the doping metal is a trivalent metal selected from the group consisting of aluminum (Al), scandium (Sc), and lanthanum (La).
Claim 33
Dependent Claim
26 words
The method as in claim 24 in which the doping metal is a divalent metal selected from the group consisting of calcium (Ca), and strontium (Sr).
Claim 34
Dependent Claim
197 words
In the fabrication of an integrated circuit (IC) having a surface, a method of forming a doped metal oxide film comprising the steps of: a) preparing a first precursor including a metal selected from the group consisting of Zr and Hf; b) vaporizing the first precursor and exposing the IC surface to the precursor, whereby a layer of the metal is chemically adsorbed to the surface to deposit, by ALCVD, the layer of metal; c) preparing an oxygen precursor; d) vaporizing the oxygen precursor and exposing the IC surface to the oxygen precursor, whereby a layer of oxygen is chemically adsorbed to the surface to deposit, by ALCVD, the layer of oxygen; e) preparing a doping metal precursor, which includes a doping metal; f) vaporizing the doping metal precursor and exposing the IC surface to the doping metal precursor, whereby a layer of the doping metal is chemically adsorbed to the surface to deposit, by ALCVD, the layer of doping metal; and g) annealing at a temperature in the range of approximately 300 to 900 degrees C. to condition the deposited layers, whereby a thin film having a high dielectric constant and good barrier properties is formed.
Claim 35
Dependent Claim
197 words
In the fabrication of an integrated circuit (IC) having a surface, a method of forming a doped metal oxide film comprising the steps of: a) preparing a first precursor including a metal selected from the group consisting of Zr and Hf; b) vaporizing the first precursor and exposing the IC surface to the precursor, whereby a layer of the metal is chemically adsorbed to the surface to deposit, by ALCVD, the layer of metal; c) preparing an oxygen precursor; d) vaporizing the oxygen precursor and exposing the IC surface to the oxygen precursor, whereby a layer of oxygen is chemically adsorbed to the surface to deposit, by ALCVD, the layer of oxygen; e) preparing a doping metal precursor, which includes a doping metal; f) vaporizing the doping metal precursor and exposing the IC surface to the doping metal precursor, whereby a layer of the doping metal is chemically adsorbed to the surface to deposit, by ALCVD, the layer of doping metal; and g) annealing at a temperature in the range of approximately 300 to 900 degrees C. to condition the deposited layers, whereby a thin film having a high dielectric constant and good barrier properties is formed.
Claim 36
Dependent Claim
27 words
The method as in claim 30 further comprising establishing an IC silicon surface temperature in the range of between approximately 100 and 700 degrees C. during processing.
Claim 37
Dependent Claim
28 words
The method as in claim 30 in which the doping metal is a trivalent metal selected from the group consisting of aluminum (Al), scandium (Sc), and lanthanum (La).
Claim 38
Dependent Claim
26 words
The method as in claim 30 in which the doping metal is a divalent metal selected from the group consisting of calcium (Ca), and strontium (Sr).
Claim 39
Dependent Claim
15 words
The method as in claim 30 in which the first precursor is ZrCl 4 .
Claim 40
Dependent Claim
15 words
The method as in claim 30 in which the oxygen precursor is H 2 O.
Claim 41
Dependent Claim
33 words
The method as in claim 30 in which the doping metal precursor is a precursor selected from the group consisting of AlCl 3 , Al(CH 3 ) 3 , and Al(acac) 3 .
Claim 42
Dependent Claim
167 words
In the fabrication of an integrated circuit (IC) having a silicon surface, a method of forming a doped metal oxide film comprising the steps of: a) preparing at least one crucible including a metal selected from the group consisting of Zr and Hf, and a doping metal; b) establishing a vacuum atmosphere; c) heating the at least one crucible to a crucible temperature in the range of approximately 1000 and 2000 degrees C., to evaporate the metals prepared in Step a); d) in response to Steps a) through c), depositing an alloy film including a metal selected from the group consisting of Zr and Hf, and the doping metal; and e) annealing in an atmosphere including oxygen at a temperature in the range of approximately 400 to 900 degrees C. to form an alloy film including the metal selected from the group consisting of Zr and Hf, the doping metal, and oxygen, whereby a thin film having a high dielectric constant and good barrier properties is formed.
Claim 43
Dependent Claim
167 words
In the fabrication of an integrated circuit (IC) having a silicon surface, a method of forming a doped metal oxide film comprising the steps of: a) preparing at least one crucible including a metal selected from the group consisting of Zr and Hf, and a doping metal; b) establishing a vacuum atmosphere; c) heating the at least one crucible to a crucible temperature in the range of approximately 1000 and 2000 degrees C., to evaporate the metals prepared in Step a); d) in response to Steps a) through c), depositing an alloy film including a metal selected from the group consisting of Zr and Hf, and the doping metal; and e) annealing in an atmosphere including oxygen at a temperature in the range of approximately 400 to 900 degrees C. to form an alloy film including the metal selected from the group consisting of Zr and Hf, the doping metal, and oxygen, whereby a thin film having a high dielectric constant and good barrier properties is formed.
Claim 44
Dependent Claim
74 words
The method as in claim 37 in which Step a) includes a first crucible for the metal selected from the group of Zr and Hf, and a second crucible for the doping metal, and in which Step c) includes heating the first crucible to a temperature in the range of approximately 1000 and 2000 degrees C., and heating the second crucible to a temperature in the range of approximately 1000 and 2000 degrees C.
Claim 45
Dependent Claim
28 words
The method as in claim 38 in which the doping metal is a trivalent metal selected from the group consisting of aluminum (Al), scandium (Sc), and lanthanum (La).
Claim 46
Dependent Claim
26 words
The method as in claim 38 in which the doping metal is a divalent metal selected from the group consisting of calcium (Ca), and strontium (Sr).
Claim 47
Dependent Claim
47 words
The method as in claim 37 in which Step e) includes establishing an atmosphere including elements selected from the group consisting of Ar, N 2 , N 2 :H 2 forming gas, O 2 , H 2 O, N 2 O, NO, no gas, and oxygen plasma.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2004-10-01 | 2005-04-02 | 2005-10-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2008-10-01 | 2009-04-02 | 2009-10-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2012-10-01 | 2013-04-02 | 2013-10-02 | $7700.00 | Window Closed / Lapsed |