US5434102A — Process for fabricating layered superlattice mate…

Claim 1

Independent Claim 73 words

A method of fabricating a layered superlattice material comprising the steps of: providing a substrate, and a precursor containing metal moieties in effective amounts for yielding said layered superlattice material from said precursor: applying said precursor to said substrate; and rapid thermal processing by heating said precursor on said substrate to a target temperature greater than a crystallizing temperature of said layered superlattice material to form said layered superlattice material on said substrate.

Claim 2

Independent Claim 73 words

A method of fabricating a layered superlattice material comprising the steps of: providing a substrate, and a precursor containing metal moieties in effective amounts for yielding said layered superlattice material from said precursor: applying said precursor to said substrate; and rapid thermal processing by heating said precursor on said substrate to a target temperature greater than a crystallizing temperature of said layered superlattice material to form said layered superlattice material on said substrate.

Claim 3

Dependent Claim 28 words

A method as in claim 1 and further comprising the step of placing said substrate in an enclosure and introducing an atmosphere enriched in oxygen into said enclosure.

Claim 4

Dependent Claim 17 words

A method as in claim 1 wherein said target temperature ranges from 500° C. to 850° C.

Claim 5

Dependent Claim 17 words

A method as in claim 3 wherein said target temperature ranges from 675° C. to 750° C.

Claim 6

Dependent Claim 34 words

A method as in claim 1 wherein said step of rapid thermal processing comprises ramping a temperature of said precursor at a rate ranging from 1° C. per second to 200° C. per second.

Claim 7

Dependent Claim 32 words

A method as in claim 1 wherein said rapid thermal processing step comprises holding said precursor at said target temperature for a period of time ranging from 5 seconds to 300 seconds.

Claim 8

Dependent Claim 24 words

A method as in claim 1 and further comprising a step of furnace annealing said substrate subsequent to said step of rapid thermal processing.

Claim 9

Dependent Claim 22 words

A method as in claim 7 wherein said step of furnace annealing comprises heating said substrate in an atmosphere enriched in oxygen.

Claim 10

Dependent Claim 27 words

A method as in claim 7 wherein said step of furnace annealing comprises heating said substrate to a temperature of ranging from 700° C. to 850° C.

Claim 11

Dependent Claim 28 words

A method as set forth in claim 1, further comprising a step of fabricating an integrated circuit to form a plurality of interconnected electrical devices on said substrate.

Claim 12

Dependent Claim 39 words

A method as in claim 1, further comprising a step of prebaking said substrate to a prebake temperature above said target temperature of said rapid thermal process step prior to said step of applying said precursor to said substrate.

Claim 13

Dependent Claim 31 words

A method as in claim 1 wherein said precursor is a liquid precursor and further including a step of drying said liquid precursor prior to said step of rapid thermal processing.

Claim 14

Dependent Claim 65 words

A method as in claim 1 wherein said layered superlattice material comprises a material having a formula: SrBi 4-2x+ α {(Ta y ,Nb 1-y ) x ,(Ti z ,Zr 1-z ) 2-2x } 2 O 15-6x , wherein the subscripts x, y, z, and α denote limiting quantities used to calculate respective values of atomic elements in said formula, and 0≦x≦1.0, 0≦y≦1.0, 0≦z≦1.0, and x-2≦α≦1.6(2-x).

Claim 15

Dependent Claim 12 words

A method as in claim 13 wherein: 0.7≦x≦1.0, 0.8≦y≦1.0, 0.6≦z≦1.0, and 0≦α≦(2-x).

Claim 16

Independent Claim 68 words

A method of fabricating a layered superlattice material comprising the steps of: providing a substrate and a precursor containing a metal; thereafter prebaking said substrate at a target temperature; thereafter applying said precursor to said first substrate; and heating said precursor on said substrate up to an anneal temperature at most actual to said target temperature to form a layered superlattice material containing said metal on said substrate.

Claim 17

Independent Claim 68 words

A method of fabricating a layered superlattice material comprising the steps of: providing a substrate and a precursor containing a metal; thereafter prebaking said substrate at a target temperature; thereafter applying said precursor to said first substrate; and heating said precursor on said substrate up to an anneal temperature at most actual to said target temperature to form a layered superlattice material containing said metal on said substrate.

Claim 18

Dependent Claim 17 words

A method as in claim 15 wherein said target temperature ranges from 500° C. to 1000° C.

Claim 19

Independent Claim 82 words

A method of fabricating a layered superlattice material comprising the steps of: providing a precursor comprising a metal dissolved in a first solvent, said precursor having a first value of solvent parameter; diluting said precursor with a selected quantity of a second solvent to provide said precursor with a second value of said solvent parameter different than said first value; thereafter applying said precursor to a substrate; and rapid thermal processing said precursor to form a layered superlattice material on said substrate.

Claim 20

Independent Claim 82 words

A method of fabricating a layered superlattice material comprising the steps of: providing a precursor comprising a metal dissolved in a first solvent, said precursor having a first value of solvent parameter; diluting said precursor with a selected quantity of a second solvent to provide said precursor with a second value of said solvent parameter different than said first value; thereafter applying said precursor to a substrate; and rapid thermal processing said precursor to form a layered superlattice material on said substrate.

Claim 21

Dependent Claim 24 words

A method as in claim 17 wherein said solvent parameter comprises a parameter selected from the group consisting of solubility, viscosity, and boiling point.

Claim 22

Dependent Claim 20 words

A method as in claim 17 wherein said first solvent is a xylenes and said second solvent is n-butyl acetate.

Claim 23

Independent Claim 89 words

A method of fabricating a layered superlattice material comprising the steps of: providing a solution having a solvent and a precursor having metal moieties in an effective amount for yielding the layered superlattice material from said precursor, said precursor having a formula including a respective metal moiety bonded with an organic ligand having a first functional group, said solvent having a second functional group identical to said first functional group; applying said solution to a substrate; and treating said precursor to form said layered superlattice material on said substrate.

Claim 24

Independent Claim 89 words

A method of fabricating a layered superlattice material comprising the steps of: providing a solution having a solvent and a precursor having metal moieties in an effective amount for yielding the layered superlattice material from said precursor, said precursor having a formula including a respective metal moiety bonded with an organic ligand having a first functional group, said solvent having a second functional group identical to said first functional group; applying said solution to a substrate; and treating said precursor to form said layered superlattice material on said substrate.

Claim 25

Dependent Claim 18 words

A method as in claim 20 wherein said precursor comprises a strontium compound dissolved in said n-butyl acetate.

Claim 26

Dependent Claim 13 words

A method as in claim 20, wherein the functional group is an ester.

Claim 27

Dependent Claim 12 words

A method as in claim 22, wherein the ester is n-butyl acetate.

Claim 28

Independent Claim 76 words

A method of fabricating a layered superlattice material comprising bismuth and other metals, said method comprising the steps of: providing a substrate and a precursor including an amount of bismuth as compared to amounts of said other metals in excess of a proportional share of bismuth in a stoichiometric formula for the layered superlattice material comprising bismuth and said metals; applying said precursor to said substrate; and treating said substrate to produce the layered superlattice material.

Claim 29

Independent Claim 76 words

A method of fabricating a layered superlattice material comprising bismuth and other metals, said method comprising the steps of: providing a substrate and a precursor including an amount of bismuth as compared to amounts of said other metals in excess of a proportional share of bismuth in a stoichiometric formula for the layered superlattice material comprising bismuth and said metals; applying said precursor to said substrate; and treating said substrate to produce the layered superlattice material.

Claim 30

Dependent Claim 23 words

A method as in claim 24 wherein said amount of bismuth is between 105% and 140% of a normal stoichiometric amount of bismuth.

Claim 31

Dependent Claim 65 words

A method as in claim 24 wherein said layered superlattice material is a material having a formula SrBi 4-2x+ α {(Ta y ,Nb 1-y ) x ,(Ti z ,Zr 1-z ) 2-2x } 2 O 15-6x , wherein the subscripts x, y, z, and α denote limiting quantities used to calculate respective values of atomic elements in said formula, and 0≦x≦1.0, 0≦y≦1.0, 0≦z≦1.0, and 0≦α≦1.6(2-x).

Claim 32

Dependent Claim 12 words

A method as in claim 26 wherein 0.7≦x≦1.0, 0.8≦y≦1.0, 0.6≦z≦1.0, and 0≦α≦1.2(2-x).

Claim 33

Dependent Claim 18 words

A method as in claim 24 wherein said step of treating comprises heating said precursor on said substrate.

Claim 34

Independent Claim 165 words

A method of fabricating a layered superlattice thin film, said method comprising the steps of: providing a substrate; forming a first thin film by applying to said substrate a first precursor solution including a plurality of metal moieties in first molar portions effective for yielding a first layered superlattice material, said first molar portions being determined with respect to a mole of said first layered superlattice material capable of being formed from said first precursor solution; making a second thin film by depositing on said substrate a second precursor solution including said plurality of metal moieties in second molar portions effective for yielding a second layered superlattice material, at least one element of said second molar portions being different from said first molar portions, said second molar proportions being determined with respect to a mole of said second layered superlattice material capable of being formed from said second precursor solution; and heating said first and second thin films to form said layered superlattice thin film.

Claim 35

Independent Claim 165 words

A method of fabricating a layered superlattice thin film, said method comprising the steps of: providing a substrate; forming a first thin film by applying to said substrate a first precursor solution including a plurality of metal moieties in first molar portions effective for yielding a first layered superlattice material, said first molar portions being determined with respect to a mole of said first layered superlattice material capable of being formed from said first precursor solution; making a second thin film by depositing on said substrate a second precursor solution including said plurality of metal moieties in second molar portions effective for yielding a second layered superlattice material, at least one element of said second molar portions being different from said first molar portions, said second molar proportions being determined with respect to a mole of said second layered superlattice material capable of being formed from said second precursor solution; and heating said first and second thin films to form said layered superlattice thin film.

Claim 36

Dependent Claim 36 words

A method as in claim 29 wherein said first precursor solution comprises a stoichiometric solution and said second precursor solution comprises a solution having an excess amount of an element according to said first molar portion.

Claim 37

Dependent Claim 28 words

A method as in claim 30, wherein said element according to said first molar portion comprises an element selected from a group consisting of bismuth, thallium, and antimony.

Claim 38

Dependent Claim 31 words

A method as in claim 29 wherein a thickness of said second thin film is less than or equal to 50% of the total thickness of said layered superlattice thin film.

Claim 39

Dependent Claim 16 words

A method as in claim 29 wherein said step of heating comprises annealing in a furnace.

Claim 40

Dependent Claim 28 words

A method as in claim 33 wherein said step of heating is performed at a temperature ranging from 700° C. to 850° C. in an enriched oxygen atmosphere.

Claim 41

Dependent Claim 24 words

A method as in claim 29 wherein said heating step includes a step of rapid thermal processing of said first and second thin films.

Claim 42

Dependent Claim 37 words

A method as claim 35, wherein said step of rapid thermal processing comprises ramping the temperature of said first and second thin films at a rate ranging from 1° C. per second to 200° C. per second.

Claim 43

Dependent Claim 39 words

A method as in claim 35 wherein said step of rapid thermal processing comprises raising said first and second thin films to a target temperature and holding it at said target temperature for from 5 seconds to 300 seconds.

Claim 44

Dependent Claim 36 words

A method as in claim 29 wherein at least one of said steps of forming said first thin film and making said second thin film includes a step of rapid thermal processing the corresponding thin film.

Claim 45

Dependent Claim 35 words

A method as in claim 38 wherein said step of rapid thermal processing comprises ramping the temperature of said thin film at a rate of between 1° C. per second and 200° C. per second.

Claim 46

Dependent Claim 34 words

A method as in claim 38 wherein said step of rapid thermal processing comprises raising said thin film to a target temperature and holding it at said temperature from 5 seconds to 300 seconds.

Claim 47

Dependent Claim 58 words

A method as in claim 38 wherein at least one of said steps of forming said first thin film and making said second thin film comprises repeating at least one of said steps of applying and depositing to form multiple layers, and said step of rapid thermal processing comprises rapid thermal processing each layer of said multiple layers.

Claim 48

Dependent Claim 32 words

A method as in claim 38 wherein both said step of forming said first thin film and said step of making said second thin film comprise a step of rapid thermal processing.

Claim 49

Independent Claim 55 words

A method of fabricating a layered superlattice material comprising the steps of: providing a substrate and an essentially anhydrous liquid precursor containing a plurality of metals capable of forming a layered superlattice material; applying said precursor to said substrate; and rapid thermal processing said precursor on said substrate to form thereon a layered superlattice material.

Claim 50

Independent Claim 55 words

A method of fabricating a layered superlattice material comprising the steps of: providing a substrate and an essentially anhydrous liquid precursor containing a plurality of metals capable of forming a layered superlattice material; applying said precursor to said substrate; and rapid thermal processing said precursor on said substrate to form thereon a layered superlattice material.

Claim 51

Dependent Claim 60 words

The method as set forth in claim 43, wherein said rapid thermal processing step includes using an electromagnetic radiation heat source in an atmosphere having an oxygen ranging from 20% to 100% to obtain a thermal ramping rate from 1° C. per second to 200° C. per second up to a temperature plateau of from 500° C. to 850° C.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1998-07-17	1999-01-16	1999-07-18	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	2002-07-17	2003-01-16	2003-07-18	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2006-07-17	2007-01-16	2007-07-18	$7700.00	Window Closed / Lapsed

Process for fabricating layered superlattice materials and making electronic devices including same

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