US6730523B2
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Low temperature chemical vapor deposition process for forming bismuth-containing ceramic thin films useful in ferroelectric memory devices
Assignee: Infineon Technologies AG
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Filing: 2001-06-01
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Granted: 2004-05-04
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Expires: 2021-06-01
Abstract
Abstract A low temperature CVD process using a tris (beta-diketonate) bismuth precursor for deposition of bismuth ceramic thin films suitable for integration to fabricate ferroelectric memory devices. Films of amorphous SBT can be formed by CVD and then ferroannealed to produce films with Aurivillius phase composition having superior ferroelectric properties suitable for manufacturing high density FRAMs.
Inventors
- 👤 Frank S. Hintermaier
- 👤 Christine Dehm
- 👤 Wolfgang Hoenlein
- 👤 Peter C. Van Buskirk
- 👤 Jeffrey F. Roeder
- 👤 Bryan C. Hendrix
- 👤 Thomas H. Baum
- 👤 Debra A. Desrochers
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 01:01
CPC Classifications
C; C23; C23C; C23C16/00; H; H10; H10P; H10P14/00; H10P14/60; H10P14/69; H10P14/692; H10P14/6938; H10P14/69398; C23C16/22; C23C16/30; C23C16/40; C23C16/56; H10P14/66; H10P14/668; H10P14/63; H10P14/6326; H10P14/6328; H10P14/6334
Claims Analysis
Total Claims: 56
Claim 1
Independent Claim
54 words
A method of depositing bismuth or a bismuth-containing film on a substrate from a precursor therefor, comprising vaporizing a bismuth β-diketonate precursor to form a vaporized precursor, and contacting the vaporized precursor with the substrate to deposit bismuth or a bismuth-containing film thereon, wherein the bismuth β-diketonate precursor comprises an anhydrous mononuclear bismuth β-diketonate.
Claim 2
Independent Claim
54 words
A method of depositing bismuth or a bismuth-containing film on a substrate from a precursor therefor, comprising vaporizing a bismuth β-diketonate precursor to form a vaporized precursor, and contacting the vaporized precursor with the substrate to deposit bismuth or a bismuth-containing film thereon, wherein the bismuth β-diketonate precursor comprises an anhydrous mononuclear bismuth β-diketonate.
Claim 3
Dependent Claim
37 words
A CVD process for depositing bismuth on a substrate from a bismuth precursor, comprising using as said bismuth precursor anhydrous mononuclear tris (β-diketonate) bismuth, and carrying out said CVD process at a deposition temperature not exceeding 400°C.
Claim 4
Dependent Claim
37 words
A CVD process for depositing bismuth on a substrate from a bismuth precursor, comprising using as said bismuth precursor anhydrous mononuclear tris (β-diketonate) bismuth, and carrying out said CVD process at a deposition temperature not exceeding 400°C.
Claim 5
Dependent Claim
17 words
A CVD process according to ciaim 2 , wherein said bismuth precursor is anhydrous mononuclear tris(2,2,6,6-tetramethyl-3,5-heptanedionato) bismuth.
Claim 6
Dependent Claim
17 words
A CVD process according to ciaim 2 , wherein said bismuth precursor is anhydrous mononuclear tris(2,2,6,6-tetramethyl-3,5-heptanedionato) bismuth.
Claim 7
Dependent Claim
111 words
A CVD process according to claim 2 , for forming a film comprising bismuth which can be transformed into a ferroelectric film with a layered pseudo-perovskite structure (Aurivillius phase) having the general formula: (Bi 2 O 2 ) 2+ (A m−1 B m O 3m+1 ) 2+ , where A=Bi 3+ , L 3+ , L 2+ , Ca 2+ , Sr 2+ , Ba 2+ , Pb 2+ , Na + , B=Fe 3+ , Al 3+ , Sc 3+ , Y 3+ , L 3+ , L 4+ , Ti 4+ , Nb 5+ , Ta 5+ , W 6+ , Mo 6+ , L=a lanthanide metal, and m=1,2,3,4,5.
Claim 8
Dependent Claim
81 words
A CVD process according to claim 2 , for deposition of a bismuth phase selected from the group consisting of: Bi 2 WO 6 BiMO 3 (M=Fe, Mn) Ba 2 BiMO 6 (M=V, Nb, Ta) Pb 2 BiMO 6 (M=V, Nb, Ta) Ba 3 Bi 2 MO 9 (M=Mo, W) Pb 3 Bi 2 MO 9 (M=Mo, W) Ba 6 BiMO 18 (M=Mo, W) Pb 6 BiMO 18 (M=Mo, W) KBiTi 2 O 6 K 2 BiNb 5 O 15 .
Claim 9
Dependent Claim
29 words
A CVD process according to claim 2 , further comprising deposition of Sr from a precursor therefor selected from the group consisting of Sr(thd) 2 and Sr(thd) 2 adducts.
Claim 10
Dependent Claim
15 words
A CVD process according to claim 2 , comprising multiple precursors in a single solution.
Claim 11
Dependent Claim
28 words
A CVD process according to claim 2 , comprising combining multiple precursors together in a single solution as a precursor cocktail and delivering the precursors from said cocktail.
Claim 12
Dependent Claim
20 words
A CVD process according to claim 2 , using combinations of single, binary or ternary precursor solutions for precursors therein.
Claim 13
Dependent Claim
19 words
A CVD process according to claim 2 , wherein the precursor is vaporized at a temperature of 170-230° C.
Claim 14
Dependent Claim
102 words
A CVD process according to claim 2 , wherein a bismuth-containing film is deposited over a bottom electrode formed of a material selected from the group consisting of: metals Pt, Pd, Au, Ir, Rh, and alloys thereof, conducting metal oxides IrO x , RhO x , RuO x (0<x<2), and mixtures of thereof with one or more of said metals, conducting metal nitrides TiN x , ZrN x , (0<x<1.1), W x ,TaN x (0<x<1.7), and superconducting oxides selected from the group consisting of YBa 2 Cu 2 O 7-x and Bi 2 Sr 2 Ca 2 Cu 3 O 10 .
Claim 15
Dependent Claim
36 words
A CVD process according to claim 2 , using a substrate comprising at least one of the following: Si, n- or p-doped Si, SiO 2 , Si 3 N 4 , or a complex integrated circuit.
Claim 16
Dependent Claim
35 words
A CVD process according to claim 2 , using a substrate which comprises at least one of the following: GaAs, SiC, MgO, Al 2 O 3 , ZrO 2 and MTiO 3 (M=Sr, Ba, Pb).
Claim 17
Dependent Claim
17 words
A CVD process according to claim 2 , having a deposition pressure of 0.001 to 760 torr.
Claim 18
Dependent Claim
15 words
A CVD process according to claim 2 , having a deposition pressure of 0.1-10 torr.
Claim 19
Dependent Claim
19 words
A CVD process according to claim 2 , having a total gas flow during the deposition of 1-16,000 sccm.
Claim 20
Dependent Claim
21 words
A CVD process according to claim 2 , having Ar, He and/or N 2 as an inert gas for the precursor.
Claim 21
Dependent Claim
52 words
A CVD process according to claim 2 , wherein an oxidizer is mixed with the precursor vapor, and said oxidizer is selected from the group consisting of O 2 , singlet O 2 , ozone, NO x wherein x=1, 2, or 3, hydrogen peroxide, oxygen plasma, N 2 O, and mixtures thereof.
Claim 22
Dependent Claim
15 words
A CVD process according to claim 2 , enhanced by any physical or chemical techniques.
Claim 23
Dependent Claim
12 words
A CVD process according to claim 2 , for integration of SBT.
Claim 24
Dependent Claim
106 words
A CVD process according to claim 2 , for forming a bismuth containing film of a material selected from the group consisting of: SrBi 2 Ta 2 O 9 SrBi 2 Ta 2-x Nb x O 9 (0<x<2) SrBi 2 Nb 2 O 9 Sr 1-x Ba x Bi 2 Ta 2-y Nb y O 9 (0≦x≦1, 0≦y≦2) Sr 1-x Ca x Bi 2 Ta 2-y Nb y O 9 (0≦x≦1, 0≦y≦2) Sr 1-x Pb x Bi 2 Ta 2-y Nb y O 9 (0≦x≦1, 0≦y≦2) Sr 1-x-y-z Ba x Ca y Pb z Bi 2 Ta 2-p Nb p O 9 (0≦x≦1, 0≦y≦1, 0≦z≦1, 0≦p≦2).
Claim 25
Dependent Claim
215 words
A CVD process according to claim 2 , for deposition of a bismuth titanate material selected from the group consisting of: Bi 4 Ti 3 O 12 PrBi 3 Ti 3 O 12 HoBi 3 Ti 3 O 12 LaBi 3 Ti 3 O 12 Bi 3 TiTaO 9 Bi 3 TiNbO 9 SrBi 4 Ti 4 O 15 CaBiTi 4 O 15 BaBi 4 Ti 4 O 15 PbBi 4 Ti 4 O 15 Sr 1-x-y-z Ca x Ba y Pb z Bi 4 Ti 4 O 15 (0≦x≦1, 0≦y≦1, 0≦z≦1) Sr 2 Bi 4 Ti 5 O 18 Ca 2 Bi 4 Ti 5 O 18 Ba 2 Bi 4 Ti 5 O 18 Pb 2 Bi 4 Ti 5 O 18 Sr 2-x-y-z Ca x Ba y Pb z Bi 4 Ti 5 O 18 (0≦x≦2, 0≦y≦2, 0≦z≦2) SrBi 5 Ti 4 FeO 18 CaBi 5 Ti 4 FeO 18 BaBi 5 Ti 4 FeO 18 PbBi 5 Ti 4 FeO 18 Sr 1-x-y-z Ca x Ba y Pb z Bi 5 Ti 4 FeO 18 (0≦xφ1, 0≦y≦1, 0≦z≦1) Bi 5 Ti 3 FeO 15 LaBi 4 Ti 3 FeO 15 PrBi 4 Ti 3 FeO 15 Bi 6 Ti 3 FeO 18 Bi 9 Ti 3 Fe 5 O 27 .
Claim 26
Dependent Claim
88 words
A CVD process according to claim 2 , including the process steps of: inserting the substrate into a CVD reactor chamber, heating the substrate up to the deposition temperature, flushing the substrate with a mixture of an inert gas and an optionally an oxidizer, delivering precursor vapor mixed with an inert carrier gas, and optionally an oxidizer, exposing the substrate to the precursor vapor, discontinuing the flow of precursor vapor, flushing the substrate with a mixture of an inert gas and optionally an oxidizer, and cooling the substrate.
Claim 27
Dependent Claim
29 words
A CVD process according to claim 21 , wherein at least one of the elements of the film is substituted or doped by a metal of the lanthanide series.
Claim 28
Dependent Claim
29 words
A CVD process according to claim 22 , wherein at least one of the elements of the film is substituted or doped by a metal of the lanthanide series.
Claim 29
Dependent Claim
28 words
A CVD process according to claim 23 , comprising pretreating the substrate in the CVD reactor before deposition by (1) exposure to a predetermined atmosphere and/or (2) annealing.
Claim 30
Dependent Claim
41 words
A CVD process according to claim 23 , further comprising the post-processing steps of: annealing the film at 600-800° C., depositing a top electrode on the film, and further annealing the film at a temperature in the range of 600-800° C.
Claim 31
Dependent Claim
28 words
A CVD process according to claim 23 , further comprising the post-processing steps of: depositing a top electrode on the film, and annealing the film at 600-800° C.
Claim 32
Dependent Claim
14 words
A CVD process according to claim 23 , comprising a multiple step CVD process.
Claim 33
Dependent Claim
36 words
A CVD process according to claim 23 , including an intermediate removal of the substrate from the chamber, conducting other processes and reentering the substrate into the CVD chamber to continue CVD of the bismuth-containing film.
Claim 34
Dependent Claim
29 words
A CVD process according to claim 23 , comprising changing process parameters during the process selected from the group consisting of temperature, pressure, gas flows, and gas phase composition.
Claim 35
Dependent Claim
18 words
A CVD process according to claim 27 , comprising carrying out the annealing steps in an oxidizing atmosphere.
Claim 36
Dependent Claim
18 words
A CVD process according to claim 32 , comprising carrying out the annealing step in an oxidizing atmosphere.
Claim 37
Dependent Claim
20 words
A CVD process according to claim 2 , enhanced by an enhancement technique selected from plasma enhancement and photoactivation enhancement.
Claim 38
Dependent Claim
25 words
A CVD process according to claim 27 , comprising carrying out the annealing steps in an oxidizing atmosphere comprising O 2 or O 3 .
Claim 39
Dependent Claim
104 words
A CVD process for depositing bismuth on a substrate from a bismuth precursor, comprising using tris (β-diketonate) bismuth as said bismuth precursor, and carrying out said CVD process at a deposition temperature not exceeding 600° C., and further comprising deposition of Sr from a precursor therefor selected from the group consisting of Sr(thd) 2 and Sr(thd) 2 adducts where the Sr adduct is selected from the group consisting of tetraglyme (═MeO—(CH 2 CH 2 O) 4 —Me), triglyme (═MeO—(CH 2 CH 2 O) 3 —Me), N,N,N′,N″,N″-pentamethyldiethylenetriamine (═Me 2 N—(CH 2 CH 2 NMe) 2 —Me) and N,N,N′,N″,N′″,N′″-hexamethyltriethylenetetramine (═Me2N—(CH 2 CH 2 NMe) 3 —Me).
Claim 40
Dependent Claim
104 words
A CVD process for depositing bismuth on a substrate from a bismuth precursor, comprising using tris (β-diketonate) bismuth as said bismuth precursor, and carrying out said CVD process at a deposition temperature not exceeding 600° C., and further comprising deposition of Sr from a precursor therefor selected from the group consisting of Sr(thd) 2 and Sr(thd) 2 adducts where the Sr adduct is selected from the group consisting of tetraglyme (═MeO—(CH 2 CH 2 O) 4 —Me), triglyme (═MeO—(CH 2 CH 2 O) 3 —Me), N,N,N′,N″,N″-pentamethyldiethylenetriamine (═Me 2 N—(CH 2 CH 2 NMe) 2 —Me) and N,N,N′,N″,N′″,N′″-hexamethyltriethylenetetramine (═Me2N—(CH 2 CH 2 NMe) 3 —Me).
Claim 41
Dependent Claim
68 words
A CVD process for depositing bismuth on a substrate from a bismuth precursor, comprising using as said bismuth precursor tris (β-diketonate) bismuth, and carrying out said CVD process at a deposition temperature not exceeding 600° C., further comprising depositing tantalum from a Ta precursor of the general formula Ta(OR) 5-n (X) n wherein R=Me, Et, n-Pr, i-Pr, n-Bu, i-Bu, t-Bu, n-pentyl, or i-pentyl, X=β-diketonate, and n=1,2,3,4, or 5.
Claim 42
Dependent Claim
68 words
A CVD process for depositing bismuth on a substrate from a bismuth precursor, comprising using as said bismuth precursor tris (β-diketonate) bismuth, and carrying out said CVD process at a deposition temperature not exceeding 600° C., further comprising depositing tantalum from a Ta precursor of the general formula Ta(OR) 5-n (X) n wherein R=Me, Et, n-Pr, i-Pr, n-Bu, i-Bu, t-Bu, n-pentyl, or i-pentyl, X=β-diketonate, and n=1,2,3,4, or 5.
Claim 43
Dependent Claim
16 words
A CVD process according to claim 37 , employing Ta(OiPr) 4 (thd) as the Ta precursor.
Claim 44
Dependent Claim
54 words
A CVD process for depositing bismuth on a substrate from a bismuth precursor, comprising using as said bismuth precursor tris (β-diketonate) bismuth, and carrying out said CVD process at a deposition temperature not exceeding 600° C., wherein the precursor is provided in a solvent comprising an aliphatic, a cyclophatic or an aromatic hydrocarbon solvent.
Claim 45
Dependent Claim
54 words
A CVD process for depositing bismuth on a substrate from a bismuth precursor, comprising using as said bismuth precursor tris (β-diketonate) bismuth, and carrying out said CVD process at a deposition temperature not exceeding 600° C., wherein the precursor is provided in a solvent comprising an aliphatic, a cyclophatic or an aromatic hydrocarbon solvent.
Claim 46
Dependent Claim
20 words
A CVD process according to claim 39 , using a mixture of THF, iPrOH and tetraglyme as the precursor solvent.
Claim 47
Dependent Claim
21 words
A CVD process according to claim 39 , using a mixture of THF, iPrOH and a polyamine as the precursor solvent.
Claim 48
Dependent Claim
26 words
A CVD process according to claim 39 , using a hydrocarbon solvent comprising an alkane having a carbon number greater than 7 as the precursor solvent.
Claim 49
Dependent Claim
31 words
A CVD process according to claim 42 , wherein said alkane is selected from octane, nonane, decane, undecane, dodecane, tridecane, tetradecane, and mixtures comprising one or more of the foregoing species.
Claim 50
Dependent Claim
20 words
A CVD process according to claim 39 , using a mixture of octane, decane, and pentamethyldiethylenetriamine as the precursor solvent.
Claim 51
Dependent Claim
41 words
A CVD process for depositing a conformal bismuth film on a substrate from a bismuth precursor, comprising using as said bismuth precursor anhydrous mononuclear tris (β-diketonate) bismuth, and carrying out said CVD process at a deposition temperature not exceeding 400° C.
Claim 52
Dependent Claim
41 words
A CVD process for depositing a conformal bismuth film on a substrate from a bismuth precursor, comprising using as said bismuth precursor anhydrous mononuclear tris (β-diketonate) bismuth, and carrying out said CVD process at a deposition temperature not exceeding 400° C.
Claim 53
Dependent Claim
66 words
A CVD process for depositing bismuth on a substrate from a bismuth precursor, comprising using as said bismuth precursor tris (β-diketonate) bismuth, and carrying out said CVD process at a deposition temperature not exceeding 600° C., wherein the precursor is provided in a solvent comprising a substituted hydrocarbon solvent, wherein the substituted hydrocarbon includes a functional group selected from alcohols, ethers, esters, amines, ketones, and aldehydes.
Claim 54
Dependent Claim
66 words
A CVD process for depositing bismuth on a substrate from a bismuth precursor, comprising using as said bismuth precursor tris (β-diketonate) bismuth, and carrying out said CVD process at a deposition temperature not exceeding 600° C., wherein the precursor is provided in a solvent comprising a substituted hydrocarbon solvent, wherein the substituted hydrocarbon includes a functional group selected from alcohols, ethers, esters, amines, ketones, and aldehydes.
Claim 55
Independent Claim
100 words
A method of depositing bismuth or a bismuth-containing film on a substrate from a precursor therefor, comprising: (a) vaporizing a bismuth β-diketonate precursor to form a vaporized precursor, wherein the bismuth β-diketonate precursor comprises an anhydrous mononuclear bismuth β-diketonate; (b) contacting the vaporized precursor with the substrate to deposit bismuth or a bismuth-containing film thereon at temperatures not exceeding 600° C. to form a substantially amorphous bismuth or bismuth-containing film; and (c) annealing said amorphous film for a sufficient annealing time to convert said amorphous film to an Aurivillius phase film, wherein the annealing time is less than 15 minutes.
Claim 56
Independent Claim
100 words
A method of depositing bismuth or a bismuth-containing film on a substrate from a precursor therefor, comprising: (a) vaporizing a bismuth β-diketonate precursor to form a vaporized precursor, wherein the bismuth β-diketonate precursor comprises an anhydrous mononuclear bismuth β-diketonate; (b) contacting the vaporized precursor with the substrate to deposit bismuth or a bismuth-containing film thereon at temperatures not exceeding 600° C. to form a substantially amorphous bismuth or bismuth-containing film; and (c) annealing said amorphous film for a sufficient annealing time to convert said amorphous film to an Aurivillius phase film, wherein the annealing time is less than 15 minutes.
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