JPH11511293A - Integrated circuit including a substrate and a wiring layer, and having a buffer layer between the substrate and the wiring layer - Google Patents

Abstract

Abstract: A thin film ferroelectric capacitor (20) includes a bottom electrode structure (26) having an adhesive metal layer (36) and a noble metal portion (38). An electrode (26) is deposited on the thin film buffer layer (24), the thin film buffer layer comprising a layered superlattice material. The buffer layer is sandwiched between the substrate (22) and the bottom electrode (26). The method includes depositing a liquid precursor on the substrate (22) prior to forming the bottom electrode (26).

Description

DETAILED DESCRIPTION OF THE INVENTION Integrated circuit including a substrate and a wiring layer, and having a buffer layer between the substrate and the wiring layer                                Background of the Invention 1. Field of the invention   The present invention compensates for the problem of interconnect layers in integrated circuit devices, and more particularly, interlayer mismatch. Electrodes containing buffer layers, and methods of making these buffer layers. You. More specifically, the buffer layer is preferably used for an electrode of a ferroelectric capacitor. It is. 2. Description of the prior art   Material mismatch issues can cause integrated circuit devices to fail or degrade. You. Surface unevenness problems can cause defects in continuously stacked layers You. Thin film layers can be contaminated by diffusion from adjacent layers. Add equipment during manufacturing The need to heat often arises, so different layers have different coefficients of thermal expansion or other growth. Due to cracking, peeling and surface irregularities problems can occur. Times These problems can be exacerbated due to the very thin nature of the track layers. Because that layer Without considering the substrate being formed, it is possible to predict the thermal properties of a given layer. Because you can't. Therefore, circuit designers must carefully select the material for forming each thin film layer. Must choose.   Common circuit defect mechanisms include shorts, which are weak bonds between adjacent layers Cracking caused by the Caused. In the case of equipment using silicon technology, a platinum wiring layer or The poles are silicon dioxide or titanium dioxide separating the platinum electrode from the silicon wafer. Can bond weakly with the tongue separation layer. Researchers before sputtering the platinum electrode By applying a titanium metal adhesive layer to the separation layer, the incidence of cracking can be reduced. Although it succeeded in lowering it, it turned out that there was a problem with the application of titanium metal I have. The added titanium has the effect of contaminating other layers by diffusion of titanium. Was. Diffusion titanium contamination is particularly problematic in integrated circuits. Because titanium The cations typically have different valence states (ie, +2, +3, and +4). As an attempt to separate the adhesive layer metal In addition, a metal nitride diffusion barrier layer is formed. For example, Larson U.S. Pat. Nos. 005, 102 and Garceau et al., "TiN As A Diffusion Barrier Layer In The Ti- Pt-Au Beam Less Metal System ", 60Thin Solid Films237-247, No. 2, (197 See 9). Both teach the use of a titanium nitride diffusion barrier layer. Nitriding Metal annealing causes short circuit in dielectric or ferroelectric capacitors Surface irregularities (eg, hillocks) can be caused.   The magnitude of polarization available from thin-film ferroelectric materials depends on the memory for a given voltage. It is the limiting factor that controls density. Larger polarization forms more dense memory Can be used to achieve Again, the ferroelectric may not adhere well to the substrate. Polarization reduction is necessary to promote diffusion between adjacent surfaces of two different layers. Can be obtained from the need to add a conductive material. Therefore, the collision of material selection affects adhesion. And the need for high polarization.   High adhesion, no surface irregularities causing short circuit, and high polarization There is still a need for an efficient bottom electrode structure.                              How to solve the problem   The present invention provides a wiring layer on a silicon substrate, and a buffer layer between the electrode and the substrate. Provided, the buffer layer allows the electrode to have substantially no surface irregularities, Overcome the problems outlined above. Optionally, the electrodes can contain an adhesive metal. Suitable In one embodiment, the wiring layer is a bottom electrode of the capacitor. Buffer layer Same processed ferroelectric capacitor without buffer layer due to addition In comparison with the polarization performance of ferroelectric capacitors, a substantial improvement of 100% or more Good is provided.   Generally, the electrode structure is formed between the substrate, the metal electrode or wiring layer, and the substrate and the wiring layer. And a layer continuum made of a material interposed between the integrated circuit devices. The layer continuum is Includes at least one buffer layer of layered superlattice material, essentially adding No wiring layer.   A particularly preferred form of electrode structure is a layer that is strontium bismuth tantalate. -Like superlattice material. Another suitable layered superlattice material is strontium bismuth Includes oblate and strontium bismuth niobium tantalate. The substrate is , Preferably the top silicon base layer adjacent to the layer sequence, i.e., the diacid Silicon nitride. Most preferred substrates include silicon wafers. Wiring layer is preferred Alternatively, it contains an adhesive metal component such as titanium or tantalum. This bonded metal is good Preferably, it is used in combination with a precious metal, which is most preferably platinum It is.   Ferroelectric capacitors are made by forming a ferroelectric layer on top of the electrode structure. Can be achieved. This ferroelectric layer is preferably made of strontium bismuth Layered strontium bismuth niobate or a combination thereof Including child material. The capacitor preferably forms a second electrode on the ferroelectric layer It is completed by doing.   Using a suitable method, an integrated circuit device having the above-described electrode structure is manufactured. This Providing a substrate having a non-metallic top surface, and providing a layered superlattice over the substrate. Forming a material and depositing an electrode on the layered superlattice material.   A particularly preferred method is that the forming step is performed by applying a liquid precursor on a substrate. Forming a precursor film. The precursor is preferably a heat treatment of the precursor Effective amount of polyoxyalkylated metal compound to produce a layered superlattice material during Including minutes. The precursor film is heat treated to produce a layered superlattice material. You.   This processing step is preferably performed at a temperature of at least 450 ° C., more preferably Annealing the precursor at a temperature of at least about 600 ° C. Further processing The process comprises removing substantially all of the precursor from the thin precursor film at a temperature up to about 450 ° C. It may include drying for a time sufficient to remove volatile organic components.   Using this method, a further step is to create a second layered superlattice material on top of the electrode. The process forms a capacitor device. Again, the liquid deposition technology Preferably, it is used for layer deposition. Layered superlattice material heats precursor solution At this time, it is spontaneously generated from the liquid precursor solution of the superlattice forming component.   As mentioned above, the ferroelectric material is preferably a perovskite-like layered superlattice. Material. The term "perovskite-like" includes trivalent metals such as bismuth , A lattice formed from oxygen octahedral layers separated by a superlattice generating layer. This While these materials are recognized as a broad class of ferroelectric materials, Historically, application to integrated circuit devices has not been successful due to device reliability issues . The perovskite-like portions of the layered superlattice material are separated by a bismuth oxide layer Formed as discrete layers. The perovskite-like layer has a large A at each apex. Ply with oxygen octahedra located in a cube defined by site metal Including maricell (primary cell). Oxygen atoms are located on the planar face of the cube. Occupy the center, small B-site elements occupy the center of the cube. No A-site element In some cases, the oxygen octahedral structure may be maintained.   The most preferred layered superlattice material is the average empirical formula SrBi_TwoTa_TwoO₉Straw with It is an Nb bismuth tantalate material. Most preferably, the superlattice generating layer comprises ( Bi_TwoO_Two)²⁺Formed from material, but may also contain thallium (III) as a metal You. Therefore, the most preferred oxygen octahedral structure layer is the average empirical formula (SrTa_TwoO₇)^2-To Have. When the annealing of the organometallic precursor solution is performed, each of the above layers spontaneously forms a layer. A superlattice. The oxygen octahedral layer is ferroelectric and has a balun of overall crystal charge. The average empirical formula for the ionic charge 1 offset by the superlattice generation layer I do. The buffer layer has a layered superstructure that has essentially no point defects that can reduce polarization. Works to keep child material.   Other features, objects, and advantages will be apparent to those skilled in the art from reading the following description and drawings. Will be apparent to those.                             BRIEF DESCRIPTION OF THE FIGURES   FIG. 1 shows a layer of layered superlattice material sandwiched between a bottom electrode and an underlying substrate. 2 shows a thin film ferroelectric capacitor device including a buffer layer.   FIG. 2 is a flow chart process used to make the capacitor of FIG. The figure is shown.   FIG. 3 is used to make a liquid precursor solution that can be used in the process of FIG. FIG.   FIG. 4 shows a defect bottom electrode structure having a large hillock structure on the top surface.   Figure 5 compares the average polarization values obtained from capacitors treated under different conditions FIG.                        Detailed Description of the Preferred Embodiment   FIG. 1 shows a substrate 22, a buffer layer 24, a bottom electrode 26, a metal oxide layer 28, 2 shows the capacitor 20 including the upper electrode 30. Preferably, the substrate 22 comprises the separation layer 3 4 with a conventional silicon layer 32 capped. Silicon layer 32 May be either single crystal or polycrystalline silicon, And are commercially available from various sources. Layer 32 is made of gallium arsenide, indium Ntimonide, magnesium oxide, strontium titanate, sapphire, water Formed from other known substrate materials, such as crystals and the above compounds, and other materials It may be. The separation layer 34 is formed by spinning the layer 32 in oxygen in a diffusion furnace. Layer 32 may be formed by known processes such as on-glass ("SOG") deposition or firing. Preferably, it is made of thick silicon dioxide formed thereon. In this specification The term "substrate" as used specifically provides support for any other layer. Layer. Substrate 22 serves to support all other layers, but in terms of All substrates can also refer to the substrate 22 in combination with other layers. Follow The combination of the substrate 22, the buffer layer 24, and the bottom electrode 26 is a metal oxide layer. The metal oxide layer 28 serves as a substrate or support for the upper electrode 30. It is very supportive.   The buffer layer 24 is on the substrate 22. Layer 24 is preferably a perovskite It is a layered superlattice material in the shape of. A particularly preferred layered superlattice material is strontium bi Sumastantalate, strontium bismuth niobate, and strontium Including mbismuth niobium tantalate. Most preferred strontium bismuthane Tarate is SrBi_TwoTa_TwoO₉Has an average empirical formula of Perovskite-like layer Many ferroelectric ferroelectrics are also high dielectrics.   The use of the buffer layer 24 allows for ferroelectric capacitors, particularly layered superlattice ferroelectrics. Significant polarization improvements are provided for body-based capacitors. Layered superlattice The material is at least a Smolenskii type ferroelectric layered superlattice material In other words, the average empirical formula is   (1) A_m-1S_TwoB_mO_{3m + 3},   (2) A_{m + 1}B_mO_{3m + 1},and   (3) A_mB_mO_{3m + 2}, All three types are included. Here, A is A in the perovskite-like superlattice. B is a B site metal in the perovskite-like superlattice. , S is a trivalent superlattice forming metal such as bismuth or thallium, and m is A sufficient number to balance body charge. In the whole equation, m is a fraction (Fractional), but typically this expression has multiple integer values. Providing different or mixed perovskite-like layers. A-site metal and The B-site metal may include a mixture of cations having similar ionic radii.   For the layered superlattice material of equation (1), the thermodynamics are m octahedral according to the following equation: It favors the formation of an oxygen octahedral structure of a plurality of layers having a thickness.   (4) (A_m-1B_mO_{3m + 1})^2- Where m is an integer greater than 1, and the other variables are as defined above. This These layers are separated by a bismuth oxide layer of the formula:   (5) (Bi_TwoO_Two)²⁺ Here, Bi is S in equation (1).   The superlattice generation layer S preferably contains an oxide of bismuth (III), Other similarly sized trivalent metal cations such as (III) may also be included. Layer of formula (1) Of bismuth in excess of the stoichiometrically required to produce a fibrous superlattice material Bismuth, when present, also acts as an A-site metal in the perovskite-like lattice. Works.   The bottom electrode 26 includes an adhesive metal part 36 and a noble metal part 38. Adhesive metal part 36 Preferably consists of sputtered titanium or tantalum, most preferably Is titanium. Portion 36 preferably has a height in the range of about 50 ° to 250 °. Sputtered to a suitable thickness, most preferably 200 °. First precious metal Portion 38 is preferably platinum, but may be gold, silver, palladium, iridium, rhenium. , Ruthenium, and osmium, and conductive oxides of these metals May be a noble metal. Preferably, the thickness of the adhesive metal part 36 is 3 to 15 times. Sputtering platinum on the top of the adhesive metal part 36 to make it thick Therefore, the first noble metal portion 38 is deposited. Adhesive metal part is 100Å to 200Å The most preferred thickness is about 2000 mm. Outside the above preferred range It is useful to use the thickness of the value, but when the first noble metal portion 38 becomes thin, The adhesive metal component that diffuses into the layer above 38 increases. When the part 38 becomes thicker, The amount of waste of metal materials increases.   Layer 28 is preferably a ferroelectric perovskite-like layered superlattice material. Special Suitable layered superlattice materials include strontium bismuth tantalate, strontium Um bismuth niobate and strontium bismuth niobium tantalate Including. The most preferred strontium bismuth tantalate is SrBi_TwoTa_TwoO₉ Has an average empirical formula of   The upper wiring layer or electrode 30 is preferably formed by sputtering on the metal oxide layer 30. Is a precious metal that is The thickness of the upper electrode 28 is typically from about 1000 ° Although it is in the range of about 2000 °, the thickness may be outside this range. Electrode 30 Consists most preferably of platinum.   FIG. 2 shows a flowchart of a process for manufacturing the capacitor 20. This Although the process is described with respect to the embodiment of FIG. 1, those skilled in the art will recognize other embodiments. Will be understood to be applicable.   In step P40, a substrate having a silicon layer 32 and a silicon dioxide layer 34 As 22, a silicon wafer is prepared. The silicon layer 32 is formed from about 500 ° C. to about 1 ° C. It can be fired in oxygen in a diffusion furnace at a temperature in the range of 100 ° C. This Firing removes impurities and water on the surface to form oxide coating 34. Is done. The wafer or layer 32 is also coated with a conventional spin-on-glass. And thereby form oxide layer 34. In general, step P40 comprises fabricating Depending on the nature of the device being sought, contactors for transistors or memory circuits Etching of the through hole (not shown) and doping of layer 32 (substrate 22 in a broad sense). Conventional procedures such as pinging may also be included.   In step P42, when the precursor solution is dried and annealed, the buffer layer 24 and the And / or has an effective amount of a plurality of metal components to produce ferroelectric layer 28 Including preparing one or more liquid precursor solutions. Further details on the preparation of precursor solutions Details are shown below.   In Step P44, the precursor solution in Step P42 is applied to the substrate in Step P42. . This creates an uppermost surface of the oxide layer 34 that receives the liquid precursor. Preferably At ambient temperature and pressure, the top surface of oxide layer 34 (substrate 22 in a broad sense) The liquid precursor solution is added dropwise, and then the excess solution is removed to leave a thin film liquid residue. Spin the substrate at about 1500-2000 RPM for about 30 seconds. By doing so, the above-described assignment is performed. The most preferred spin speed is 1500RP M. Alternately, a device such as the technology described in U.S. Patent No. 5,456,945. Applying liquid precursors by the misted deposition technique May be. The most preferred precursor solution is strontium bismuth tantalate or the like Can be produced.   Preferably, in step P46, the liquid precursor film of step P44 is dried on a heating plate. Dry at a temperature of about 200 ° C. to 500 ° C. in an air atmosphere. Drying time and drying The drying temperature removes substantially all organic materials from the liquid thin film and leaves dry metal oxides. Should be enough to leave a minute. Preferably, the drying time is from about 1 minute to about 30 minutes Is within the range. In the case of single-stage drying, in air, the drying temperature is 400 ° C for about 2 minutes. It is most preferable to carry out for 10 minutes. However, the liquid film is allowed to dry Drying is more preferred. For example, 5 minutes at 260 ° C. and 5 minutes at 400 ° C. It is possible to dry the membrane for minutes. Furthermore, it is short at a temperature exceeding 700 ° C. Preferably, the drying cycle is completed at rapid processing intervals. For example, tungsten Heating the substrate at 725 ° C. for 30 seconds using a nickel lamp; Drying process P4 6 are predictable or reproducible electronic features in the final metal oxide crystal composition. It is indispensable to get sex.   If it is desired to increase the thickness of the entire buffer layer 24, Step P44 And step P46 can be repeated, but usually with one coating of the precursor liquid. It is necessary or desirable to increase the thickness of layer 24 more than is possible to obtain. There is nothing wrong.   An optional step P48 is performed on top of the buffer layer 24, as is known in the art. According to a conventional protocol, the titanium adhesive metal layer 36 may be formed from about 50 ° to 250 °. Sputtering to a suitable thickness in the range of Sputter layer 36 Doing is preferably done for the purpose of providing higher adhesion to the layer 24. This sputtering may cause a short circuit in capacitor 20 While delamination and cracking are prevented, the bonding metal (preferably titanium) Diffusion can contaminate other layers. Step P50 is a process in which the noble metal part 3 8 to a suitable thickness in the range of about 1000 ° to 2000 ° including. Examples of suitable atomic sputtering protocols include RF sputtering And DC magnetron sputtering.   In step P52, the substrate 22 in step P50 is annealed to 24 metal oxides are formed. To distinguish it from other annealing steps, the process P52 Is referred to as “first annealing”, and other annealing steps are referred to as “first annealing”. It should be understood that this may be done before. In step P52, Preferably, in a diffusion furnace under an oxygen atmosphere, a temperature in the range of 450 ° C. to 1000 ° C. Include layers 36 and 38 for a time in the range of 30 minutes to 2 hours to temperature Heat the substrate. More preferably, at a temperature in the range of 600 ° C. to 800 ° C., the process P Perform 52. The most preferred annealing temperature is about 600 ° C. for 80 minutes. Suitably The first anneal of step P52 is to "push" into the furnace for 5 minutes and 5 minutes Push / pull process including "pull" from the furnace ). The annealing time stated is the thermal run time during furnace entry and removal. Includes the time used to form the thermal ramp. This annealing process The process is referred to as a first anneal to distinguish it from other anneal steps.   Step P54 deposits the layered superlattice precursor of Step P42 on the noble metal layer 38. Including Preferably, the precursor is a liquid precursor, but a solid target Sputtering is also possible. Preferably, the outside air temperature and the outside air The liquid precursor solution is dropped on the top surface of the bottom electrode 26 with pressure and then the excess solution Approximately 1500 RPM to 2000 RP to remove the liquid and leave a thin film liquid residue The application is performed by spinning the substrate at M for about 30 seconds. most A preferred spin speed is 1500 RPM. A preferred precursor solution is a layered superlattice material Including those having an effective amount of a metal component to produce a charge. Most suitable layered super case The child material is strontium bismuth tantalate.   Preferably, in step P56, the liquid precursor film of step P54 is dried on a heating plate. Dry at a temperature of about 200 ° C. to 500 ° C. in a dry air atmosphere. Drying time and The drying temperature is such that substantially all of the organic material is removed from the liquid film and the dried metal oxide residue is removed. Should be enough to leave a fraction. Preferably, the drying time is from about 1 minute to about 30 Within minutes. In the case of one-stage drying, in air, drying temperature 400 ° C, about 2 minutes It is most preferable to carry out for 10 minutes. However, the liquid film is Drying is more preferred. For example, at 260 ° C. for 5 minutes, and at 400 ° C. It is possible to dry the membrane for 5 minutes. Furthermore, at temperatures exceeding 700 ° C., Preferably, the drying cycle is completed at a slow heating interval. For example, tungsten-d The substrate is heated at 725 ° C. for 30 seconds using a hacker lamp. Drying process P56 Predictable or reproducible electronic properties in the final metal oxide crystal composition Indispensable to get.   In step P58, the dried film obtained in step P56 did not have the desired thickness. In this case, steps P54, P56 and P58 are repeated until a desired thickness is obtained. . Typically, to obtain a thickness of about 1800 ° to 2000 °, the disclosure disclosed herein Twice with 0.130M to 0.200M precursor solution using the parameters given Need to be coated.   In Step P60, the dried precursor residues in Steps P54 and P56 are annealed. Thus, a layered superlattice material of the layer 26 is formed. To distinguish it from other annealing processes For this reason, this annealing step is referred to as second annealing. Preferably, this second Neal is performed under the same conditions as those of the first annealing in step P52. .   In step P62, preferably, platinum is sputtered on the layered superlattice material layer 26. The upper electrode 28 is deposited by ringing. The capacitor 20 is preferably Can be optionally annealed at this time under the same conditions as in step P52.   Thereafter, a conventional photo-etching process (for example, ion etching in step P64) is performed. (Including applying photoresist after chinglitography) The apparatus is patterned. Preferably, the patterning is such that the third anneal is Generated by the patterning procedure by removing the patterning stress of the capacitor 20 Performed before the third anneal in step P66 to correct any defects You.   Preferably, the third anneal, step P66, comprises the first anneal in step P52. This is done in the same way as   Finally, in a process P68, the apparatus is completed and evaluated. Understood by those skilled in the art This complete process involves additional layer deposition, contact hole ion It may involve etching, and other procedures. The substrate or wafer 22 is By cutting into knits, multiple integrated circuit devices manufactured simultaneously on the substrate Can be separated.   Step P42: polyoxyalkylated metal precursor A suitable general process for preparing ursors is provided in U.S. Patent No. 5,514,822. I have. Preferably, the process involves converting the metal to an alkoxide (eg, 2-methoxy Ethanol) to form a metal alkoxide; Carboxylate (eg, 2-ethylhexanoate) ) And reacting with a metal alkoxycarboxylate (met al alkoxycarboxylate).   (6) (R'-COO-)_aM (-OR)_nOr   (7) (R'-CO-)_aM (-O-M '-(OCR-R ")_b-1)_n, Here, M is a metal cation having an outer valence of (a + n), and M ′ is an outer atom. A metal cation with a valency of b, M and M 'are preferably tantalum, calcium , Bismuth, lead, yttrium, scandium, lanthanum, antimony, black , Thallium, hafnium, tungsten, niobium, vanadium, zirconium , Manganese, iron, cobalt, nickel, magnesium, molybdenum, stront C Independently selected from the group consisting of R, barium, titanium, and zinc; And R 'are each preferably an alkyl group having 4 to 9 carbon atoms. R '' is preferably an alkyl group having 3 to 8 carbon atoms. Center The latter formula having the structure -O-M-O-M'-O- of the final solid metal oxide For in-solution production of at least 50% of the metal-oxygen bonds present in the product, Particularly preferred.   Preferably, the liquid precursor is a metal alkoxide or metal carboxylate. Most preferably diluted to the desired concentration with xylene or octane solvent. Metal alkoxycarboxylate. Metal alkoxide that is substantially anhydrous The use of cycarboxylates is critical for the longevity of solutions containing alkoxide ligands (sh elf life) can avoid water-induced polymerization or gelation. For this reason, it is particularly suitable. The presence of the hydrolysis-inducing component in the solution is preferably Avoided or minimized. Use of conventional hydrolysis precursors such as sol gel Although possible, increased solution viscosities are favored by suitable spin-on application processes (spin-on app lication process) tends to compromise the thickness uniformity and Solution quality tends to decrease rapidly over time. As a result, the prepared water Degraded gels increasingly produce unstable metal oxide films of poor quality over time . According to the preferred method, the precursor solution is provided well in advance of when it is needed. Can be prepared.   Understand that the formation of oxygen octahedral structures is thermodynamically advantageous where possible Thus, the precursor solution can be designed to produce a corresponding layered superlattice material. In general, either perovskite-like octahedral structure or perovskite octahedral structure Again, substantially similar ionic radii (ie, at each lattice site Equivalent displacement between metal cations having a radius of about 20% It is possible to be. These substitutions add another metal component to the precursor solution This is done by:   Suitable raw materials for the precursor solution are stoichiometrically balanced based on empirical formulas. Suitable metals of the desired layered superlattice material in the compound are included. A site department is good Suitably, Ba, Bi. Asa consisting of Sr, Pb, La, Ca, and a mixture thereof At least one A-site element selected from the group of It is formed by reacting with rubonic acid. The B site section is preferably Chole or a carboxylic acid, Zr, Ta. Mo, W, V, Nb, and mixtures thereof Reacts with at least one B-site element selected from the group of B-sites Induced by letting The use of titanium as an equivalent radius B site element is: Although possible, problems and problems arising from the diffusion of titanium into other integrated circuit components Practical advantages due to point charge defects caused by different valence states between tan ions Is not preferred. In the case of a layered superlattice material, a trivalent superlattice, preferably bismuth The resulting metal is also added. When heating, depending on its bismuth content, Although a bismuth oxide layer is spontaneously formed in the secondary material, excess bismuth Thus, the A-site element of the perovskite lattice can be provided.   FIG. 3 illustrates the present invention for providing a liquid precursor solution prepared in step P42. 2 shows a flowchart of a generalized process according to the invention. The word "precursor" Often used vaguely in the art. Final solution mixed with other materials Can mean a solution containing one metal to make In some cases, it may mean a solution containing several kinds of metals prepared as needed. In this paper In our preparation, unless the context clearly indicates otherwise This type of precursor is called a “precursor”. In the intermediate stage, we refer to the solution as " It may be referred to as "pre-precursor."   A liquid solution of metal alkoxide used to generate the initial metal precursor Preferred generalization of the production of ruboxylates and metal alkoxycarboxylates The chemical reactions performed are as follows.   (8) Alkoxide-M^{+ n}+ NR-OH → M (-OR)_n+ N / 2H_Two   (9) Carboxylate-M^{+ n}+ N (R-COOH) → M (-OOC-R)_n + N / 2H_Two   (10) alkoxycarboxylate-M (-O-R ')_n+ BR-COO H + heat → (R'-O-)_nbM (-OOC-R)_b+ BHOR Here, M is a metal cation having n charges, and b is in the range of 0 to n. Is the number of moles of carboxylic acid and R 'is preferably from 4 to 15 R is preferably an alkyl group having 3 to 9 carbon atoms. It is an alkyl group having a child.   In step P70, the first metal represented by the term M To form a metal alkoxycarboxylate pre-precursor. Form. Preferably, the process involves converting the metal to an alcohol (eg, 2-methoxy). Reacting with (ethanol) to form a metal alkoxide of formula (8) Reacting the metal alkoxide with a carboxylic acid (eg, 2-ethylhexanoic acid) , Forming a metal alkoxycarboxylate of formula (10). Unreasonable When the reactive metal is combined with the alcohol and carboxylic acid at the same time, Thus, the reaction of the formula (9) is also observed. The parallel reaction is preferably carried out by carboxylate Over a period of one to two days so that the alkoxide component is displaced by the ligand. A return heated by a hotplate having a temperature in the range of about 120 ° C to about 200 ° C It takes place in a reflux condenser. Preferably, an initial reaction period of 1-2 days At the end of the process, the reflux condenser is opened to the outside air and water and alcohol Fractional distillation plateau (fractional distillation plate) au), ie the solution temperature until a plateau at least above about 100 ° C. is observed Is monitored, and at this time, the solution is removed from the heat source. Distillation at ambient pressure is more preferred At a temperature of at least 115 ° C, most preferably from about 123 ° C to 127 ° C. At a temperature of   In the above formula, the metal is preferably tantalum, calcium, bismuth, lead, Yttrium, scandium, lanthanum, antimony, chromium, thallium, Huff , Tungsten, vanadium, niobium, zirconium, manganese, iron, iron Baltic, nickel, magnesium, molybdenum, strontium, barium, titanium It is selected from the group consisting of tan, vanadium, and zinc. Can be suitably used Alcohols include 2-methoxyethanol, 1-butanol, 1-pentanol , 2-pentanol, 1-hexanol, 2-hexanol, 3-hexanol , 2-ethyl-1-butanol, 2-ethoxyethanol, and 2-methyl- It contains 1-pentanol, preferably 2-methoxyethanol. Suitably The carboxylic acids that can be used include 2-ethylhexanoic acid, octanoic acid, and neoic acid. De Neodecanoic acid is included, preferably 2-ethylhexanoic acid.   Preferably, the reaction in step P70 and the subsequent steps is carried out in a compatible solvent (compa (ible solvent). Solvents that can be used include xylene, 2-methoxyethanol, n-butyl acetate, n-dimethylformamide, 2-methoxyethyl acetate, methyl isobutyl ketone, methyl isoamylke Ton, isoamyl alcohol, cyclohexanone, 2-ethoxyethanol, 2 -Methoxyethyl ether, methyl butyl ketone, hexyl alcohol, 2-pe Nthanol, ethyl butyrate, nitroethane, pyrimidine, 1,3,5 trioxa , Isobutyl isobutyrate, isobutyl propionate, propyl propionate Nate, ethyl lactate, n-butanol, n-pentanol, 3-pentano , Toluene, ethylbenzene, and octane, and many other solvents included. Preferably, these solvents distill the precursor and apply the precursor to the substrate. It has a boiling point above the boiling point of water for the purpose of removing water therefrom before Co-solvent Should be miscible with each other and the precursor materials must be completely soluble In some cases, especially in polar and non-polar solvents, different ratios are compatible (compatibl y) can be mixed. Xylene and octane are particularly preferred non-polar solvents, n- Butyl acetate is a particularly preferred polar co-solvent.   If intermediate metal reagents can be obtained in research grade purity, omit part of step P70 May be. For example, tantalum isobutoxide is available Preferably, the metal alkoxide is converted to 2-ethylhexa of formula (10) Isobutoxide component is acceptable by reacting with carboxylic acid such as acid Need only be replaced with a suitable carboxylate ligand.   In a typical second step, P72, a solid metal oxide of layer 26 is formed. Has a stoichiometrically balanced mixture of superlattice forming metal components that can be Metal carboxylate and metal alkoxide to form an intermediate precursor Either or both can be added to the metal alkoxycarboxylate. At this time, Suitably, the mixture may be used, if necessary, due to relative thermal instability. It does not contain bismuth compounds added later. All of the above metals are the above carboxylic acids To form a metal carboxylate by reacting with any of On the other hand, all of the above metals are reacted with any of the above alcohols to form alkoxides. Can be formed. The above reaction partially catalyzes the alkoxide ligand. In the presence of a slight excess of carboxylic acid for the purpose of displacing with a ruboxylate ligand It is particularly preferred to do so.   In step P74, metal alkoxycarboxylate, metal carboxylate The mixture of metal and / or metal alkoxide is optionally heated and stirred. To form a metal-oxygen-metal bond and remove all low-boiling organic matter produced by the reaction. Allow to evaporate. According to generalized reaction theory, metal alkoxides are converted to metal alkoxides. When added to the carboxylate and the solution is heated, the following reaction occurs .   (11) (R-COO-)_xM (-O-C-R ')_a+ M '(-O-C-R "" )_b→ (R-COO-)_xM-O-M '(-O-C-R ")_b-1)_a+ AR'-C -OC-R ""   (12) (R-COO-)_xM (-O-C-R ')_a+ XM '(-O-C-R' ’)_b→ (R'-CO-)_aM (-O-M '(-O-C-R ")_b-1)_x+ XR -COO-C-R "" Wherein M and M 'are metals, R and R' are as defined above, '' Is preferably an alkyl group having about 0 to 16 carbons, a, b and And x are the relative proportions of the corresponding substituents corresponding to the respective valence states of M and M '. It is an integer indicating the amount. In general, metal alkoxides are better than metal carboxylate Since it easily reacts, first, the reaction of the formula (11) occurs. Thus, in general, the boiling point Low ethers are produced. These ethers evaporate from the pre-precursor and are reduced The final product having an organic content of The genus-oxygen-metal bond is already partially formed. If heating is sufficient, Reaction (12) also occurs partially, forming a metal-oxygen-metal bond and ester. . Generally, esters have a relatively high boiling point and remain in solution. These high boiling organics The material inhibits the drying process after applying the final precursor to the substrate, Tend to reduce bugs and defects. Therefore, in each case, metal-oxygen- Metal bonds are formed to improve the properties of the final precursor.   Step P74 essentially consists of adding a solution as the reactions of formulas (11) and (12) progress. Is a distillation to remove volatile components from water. When volatile components are removed from the solution, Is completed, that is, the efficiency is increased. Removal of volatile components from solution requires membrane It also serves to prevent cracking and other defects. Cracking and And other defects, if not prevented, are associated with the presence of volatile components in the solution. Can be Therefore, the progress of the reaction (11) and the reaction (12) depends on the heating rate of the solution. And can be monitored by the volume of fluid present in the solution. Preferably at least Also 115 ° C, more preferably 120 ° C, and most preferably 123 ° C to 127 ° C. Heat the solution to a boiling point plateau of ° C.   Add the metal carboxylate to the metal alkoxycarboxylate and mix the mixture When heated, the following reactions occur.   (13) (R-COO-)_xM (-O-C-R ')_a+ XM '(-OOC-R ’))_b→ (R'-CO-)_aM (-O-M '(-OOC-R ")_b-1)_x+ X R-COOOC-R ' However, R-COOOC-R 'is an acid anhydride, and each item is as defined above. This reaction has significantly more than the above reactions (11) and (12). Requires heat and travels at a much slower rate.   In addition to the above reaction to produce a metal alkoxycarboxylate, the following A reaction occurs.   (14) M (-OR)_a+ AHO_TwoC₈H_Fifteen+ Heat → M (-O_TwoC₈H_Fifteen)_a+ AH OR However, each item is as defined above. For heating in the presence of excess carboxylic acid Thus, this reaction substitutes the alkoxide component of the intermediate metal alkoxycarboxylate. In turn, to form substantially complete carboxylate. But at the moment, In the parameters disclosed in the text, the alkoxide by carboxylate It is not believed that a complete substitution of Complete substitution of carboxylate To do so requires a significant, much higher amount of heating and still does not easily occur Maybe.   At the end of the process P74, the metal-oxygen bond of the metal oxide layer 26 is reduced in the solution. Preferably, at least 50% is formed. Monitor the solution temperature to determine if water, Alcohol, ether, and other reaction by-products are substantially all removed from the solution. Fractionation plateau, i.e., a plateau above at least 100 ° C Until heated by a hot plate having a temperature in the range of about 120 ° C to about 200 ° C. It is preferable that the above reaction be performed in a container which is heated and heated to the outside air pressure. . At this time, potentially undesirable due to extended refluxing Large amounts of ester or anhydride by-products may be formed, It is often difficult to remove from the solution. In the process P72, the metal Eliminates the need to add the carboxylate alone to reflux the solution By doing so, potential complications due to excessive anhydride concentrations can be completely avoided. You.   Step P76 is an optional solvent exchange step. General in various precursor solutions The use of a suitable solvent has a viscosity and an influence on the thickness of the liquid precursor film after being applied to the substrate. This is advantageous in terms of predictability of fluid parameters such as adhesion tension. These fluid parameters The quality and electrical properties of the corresponding metal oxide film after annealing the dried precursor residue. It also affects characteristics. In Step P76, preferably, xylene or n-octa is used. Standard solvent, and adjust the intermediate precursor to the desired superlattice raw material molarity. Add the appropriate amount to do so. Preferably, this molar concentration is For empirical formulas, it is in the range of about 0.100M to about 0.400M, most preferably Is about 0.130 M in moles of metal oxide material that can be formed from 1 liter of solution. 0.200M. After adding the standard solvent, distill off all non-standard solvents. Heat the solution to a temperature sufficient to leave the desired molarity of the solution.   Preferably, step P78 comprises applying a precursor to the layered superlattice material comprising bismuth. Only used. Bismuth (Bi)³⁺) Is the most preferred superlattice forming element and A suitable bismuth pre-precursor is bismuth tri-2-ethylhexanoate (bismuth  tri-2-ethylhexanoate). A process performed following the heating process of Step P74 The addition of a mass pre-precursor is advantageous in terms of the relative instability of these pre-precursors. Suitable. That is, significant heating can affect the ability of the solution to produce excellent thin film metal oxides. It can lead to disruption of coordination bonds, which can have adverse effects. Bismuth pre-precursor is often In the meaning that it can be added to any of the processes P70 and P74 without any problem. It should be understood that step P78 is optional.   In forming a layered superlattice material having a desired stoichiometric ratio, the precursor solution During heating and especially during high temperature annealing of the dried precursor residues, There is a special problem with regard to the potential for volatilization of smut. Therefore, in step P78 From about 5% to about 5% for the purpose of compensating the precursor solution for expected bismuth loss It is desirable to add 15% excess bismuth. About 600 ° C to about 850 ° C When treated at an annealing temperature within the range for about 1 hour, the excess vial in the precursor solution is obtained. Smuth components are typically required for stoichiometrically balanced layered superlattice products Between 5% and 15% of the desired amount. Excess bis during formation of metal oxide products If the mass did not volatilize completely, the remaining excess bismuth component would Can cause point defects in the resulting layered superlattice crystal.   In step P80, the solution is agitated to become substantially homogeneous and the final solution If the solution is not consumed within days or weeks, dry nitrogen or Preferably, it is stored under an inert atmosphere of Lugon. Precautions for this preservation include: Water-induced polymerization serves to ensure that the solution is kept substantially anhydrous , Viscous gelation, and precipitation of water-inducible metal components in alkoxide ligands Avoid the negative effects of Nevertheless, the precursor is preferably carbohydrate, as is the case. Mainly composed of metals bound to xylate ligands and alkoxycarboxylates If implemented, the above precautionary measures for dry inert storage are not strictly necessary.   The illustrative description of the reaction process as described above is generalized and therefore Is not limiting. The specific reaction that occurs depends on the metal used, the alcohol And the carboxylic acid, and the amount of heat applied. Detailed examples below Show.   The following non-limiting examples illustrate suitable materials and methods for practicing the present invention. Things.                                 Example 1                        Preparation of layered superlattice precursor solution   The precursor materials in Table 1 were obtained from the commercial sources listed, And the following components were obtained.   In Table 1, “FW” indicates formula weight, “g” indicates grams, and “mmole”. "s" indicates millimoles, and "Equiv." indicates the equivalent number of moles in the solution.   Place the tantalum in a 250 ml Erlenmeyer flask containing 40 ml of xylene. 252.85 mmol of lupentaboxide and 2-ethylhexanoic acid (Ie, about 50 ml of xylene for every 100 mmol of tantalum). Promotes reflux The flask to isolate the contents from atmospheric water. Was covered with a 50 ml beaker. On a heating plate at 160 ° C, use magnetic stirring for 48 hours. And reflux the mixture to remove butanol and tantalum 2-ethylhexanoate. A substantially homogeneous solution was formed. The butoxide component in the solution is almost completely Although replaced by 2-ethylhexanoic acid, the heating parameters in this example were It should be understood that no complete replacement took place. At the end of 48 hours Remove the 50 ml beaker with, then raise the temperature of the hot plate to 200 ° C, The fractions and water were distilled to remove them from solution. Butanol and water The solution reaches its maximum at 124 ° C as a temperature index indicating that all of it has left the solution. When the first was reached, the flask was removed from the hotplate. Place the flask and its contents at room temperature It has cooled down to   A cooled mixture of strontium and 50 ml of 2-methoxyethanol solvent And reacting it to produce strontium di-2-ethylhexanoate. To achieve. Add 100 ml of xylene to the strontium mixture and add And the contents were returned to the hot plate at 200 ° C. After refluxing for hours, the reaction is carried out to obtain an excellent tantalum-strontium alcohol of the formula (6). A xycarboxylate product was produced. Remove beaker and set solution temperature to 125 ° C To the 2-methoxyethanol solvent and all solvents in the solution. Ter, alcohol, or water were eliminated. After removing from the heat source, remove the flask Cooled to room temperature. Bismuthtri-2-ethylhexanoate to a cooled solution In addition, this is further diluted to 200 ml with xylene to eliminate the volatilization of bismuth In some cases, 0.200 moles of SrBi_2.18Ta_TwoO_9.27A precursor solution capable of producing Formed.   Therefore, in this embodiment, Step P70, that is, strontium metal, alcohol and And carboxylic acid react with tantalum pentaboxide and 2-ethylhexane Can occur in solutions containing tantalum alkoxycarboxylates derived from acids Which indicates that. Therefore, Step P70 and Step P72 are performed in a single solution, Further, it can be performed in the reverse order of FIG.   Bismuth volatilization in the process of producing solid metal oxides from liquid precursors The formulation of the precursor was designed to compensate. Specifically, Bi_2.18 The components contained about 9 percent excess (0.18) bismuth. Considering the expected volatilization of bismuth in the subsequent annealing process, The precursor solution is a stoichiometric material of m = 2 of formula (3), ie, 1 liter of solution. 0.2 mole of SrBi_TwoTa_TwoO₉, Was expected to produce.                                 Example 2                     Having a layered superlattice material buffer layer,               Formation of ferroelectric capacitor without adhesive metal layer   Numerous square ferroelectric capacitors having the schematic layered continuum shown in FIG. A wafer including a sensor was manufactured according to the method of FIG. Step P48 is not performed. As a result, the capacitor did not include the adhesive metal layer 36 (FIG. 1). Conventional diameter 4a The polycrystalline wafer or substrate 32 of FIG._TwoTa_TwoO₉Receiving solution Was prepared as follows. The preparation process produces a thick layer of silicon oxide 34. Including diffusion furnace firing in oxygen at 1100 ° C. according to conventional protocol ( (See FIG. 1).   0.2 M SrBi prepared according to Example 1_TwoTa_TwoO₉Precursor volume 2 ml The minute was adjusted to a concentration of 0.13M by adding 1.08 ml of n-butyl acetate. This was passed through a 0.2 μm filter. Use a dropper to add 2 ml of A precursor solution was applied, which was then applied using a conventional spin coating machine for 15 minutes. Spin at 00 rpm. The substrate coated with the precursor is placed on a hot plate and air Medium and dried at 400 ° C. for 30 minutes.   The substrate including the buffer layer 24 is cooled to room temperature, and a conventional DC magnetron sputtering is performed. It was placed in a vacuum chamber to perform the tarling. 130 volt discharge voltage and Using a current of 0.53 amps, 2,000 mm thick platinum on top of titanium metal Was sputtered. By this sputtering, any process P48 can be skipped. Thus, the step P50 of FIG. 2 is completed.   A substrate containing a liquid thin film is placed in a diffusion furnace in an oxygen atmosphere for 30 minutes at a temperature of 600 ° C. Annealed. The times included a 5 minute oven load and a 5 minute oven discharge. Profit The resulting structure included a buffer layer 24 as shown in FIG. For these tasks Therefore, the process up to step P52 of the process shown in FIG. 2 is completed.   0.2 M SrBi according to Example 2_TwoTa_TwoO₉Precursor volume of 2 ml for 1.0 The concentration was adjusted to 0.13 M by addition of 8 ml of n-butyl acetate, which was Passed through a 0.2 μm filter. Apply 2 ml of precursor solution to the substrate using a dropper And then, as before, 1500 rpm using a conventional spin coating machine. Spin at m. Spin coating machine for substrate coated with precursor And dried in air on a hot plate at 140 ° C. for 2 minutes. Second heating plate The substrate was dried at 260 ° C. for a further 4 minutes above. 1200W tungsten- Halogen lamp (visible spectrum; AG As using J208V bulb of Ushio of Japan) 3 more at 725 ° C in oxygen using Heatpulse 410) by Sociates, Inc. The substrate was dried for 0 seconds. Repeat spin coating and drying procedure Thus, the overall thickness of layer 28 was increased to about 1800 °.   Substrate 22 containing two coatings of the dried precursor residue is placed in an acid oven in a diffusion furnace. In a raw atmosphere, at a temperature of 800 ° C., including a 5-minute furnace insertion and a 5-minute furnace discharge, Annealed for minutes. By these operations, the process of FIG. 2 is completed up to step P58. did.   Sputtering platinum metal as the upper electrode 28, a 200 0% platinum was formed. Apply photoresist and follow it, including resist removal Ion etching was performed according to the following protocol. Patterning equipment In a diffusion furnace at 800 ° C. in an oxygen atmosphere for 5 minutes and out for 5 minutes Annealed for 30 minutes. By these operations, the process of FIG. Completed to step P68, having strontium bismuth tantalate as layer 26 A ferroelectric capacitor 20 of the type shown in FIG. 1 was provided. The buffer layer 24 A platinum layer 38 having a thickness of 500 ° and a thickness of 2000 ° was overlaid. .                                 Example 3             Having a layered superlattice material buffer layer and an adhesive metal layer                         Forming ferroelectric capacitors   Strontium bismuth tantalate conjugate having a layered continuum shown in FIG. A wafer including a denser was manufactured according to the method including the step P48 in FIG. This hand The order is the same as the procedure of Example 2 except that the process P50 was not performed. The capacitor included an adhesive metal layer 36. Sputter pressure 0.0081 Torr Buffer at 95 volts using a discharge voltage of 95 volts and a current of 0.53 amps. Sputtering titanium metal having a thickness of 200 ° as the bonding metal portion 36 on the layer 24 Was. The sputtering of the adhesive metal is performed by sputtering the platinum layer 38 in step P52. I went right before the ringing. The buffer layer 24 has a thickness of 500 ° and is made of titanium adhesive. A metal layer 36 (200 °) and a platinum layer 38 (2000 °) were overlaid.                                 Example 4           Has an adhesive metal layer and no layered superlattice material buffer layer                         Forming ferroelectric capacitors   A wafer containing a ferroelectric capacitor without the buffer layer 24 (FIG. 1) is shown in FIG. It was prepared according to the general method of the above. In this procedure, steps P44 and P46 are performed. Identical to the procedure of Example 3 except that it was not done. Resulting Capacitor 20 did not have layer 24, but had a 200 ° adhesion metal layer 36 and 2 000 ° of platinum layer 38. In this wafer, the bottom electrode 26 is And was not subjected to the first annealing in the step P52.                                 Example 5           With an adhesive metal layer, without a layered superlattice material buffer layer,                     Without bottom electrode annealing                         Forming ferroelectric capacitors   A wafer containing a ferroelectric capacitor without buffer layer 24 (FIG. 1) was implemented. Fabricated according to the method of Example 4, but Step 52 was not performed. The resulting con Although the denser 20 had the same layer continuum as the apparatus of Example 4, the process P54 was performed. Before being performed, the electrodes were not subjected to the first anneal in step P52. as a result The resulting capacitor 20 did not have layer 24, but had a 200 ° bond metal layer 36 And a 2000 ° platinum layer 38.                                 Example 6           With an adhesive metal layer, without a layered superlattice material buffer layer,        Formation of ferroelectric capacitor without bottom electrode annealing   Wafers containing ferroelectric capacitors without buffer layer 24 (FIG. 1) An adhesive metal having a thickness of 0 (not 200) is sputtered in step P48. Except for what was done, it was prepared according to the method of Example 5. as a result The resulting capacitor 20 did not have layer 24, but had a 200 ° bond metal layer. 36 and a 2000 ° platinum layer 38.                                 Example 7                Scanning electron microscope comparison of unevenness of bottom electrode surface   In the capacitor squares on the wafer of Example 4, Some short circuits were observed. Therefore, the second apparatus is used in the embodiment up to the step P52. 4 (that is, step P44 and step P46 were omitted). The electrode structure was observed using a scanning electron microscope at a magnification of about 40,000 ×. FIG. 4 shows the SEM observation. The electrode 24 includes a titanium bonding metal layer 36 and a platinum layer 38. And included. Electrodes 26 are sharp, irregularly spaced, upwardly facing hillocks. (E.g., hillocks 84 and 86). The hillock was raised from the surface 82 by about 900 °. Bottom electrode 26 and layer This is due to the different thermal shrinkage relative to the underlying substrate, including 32 and 34. These hillocks occurred. Each layer expanded upon heating. Silicone base for cooling The shrinkage of the metal layers 32 and 34 is greater than the shrinkage of the metallized layers 36 and 38. won. Layer 36 adheres to layer 34 and the resulting interlayer stress causes the formation of hillocks. Provoked.   On the surface 82, a thin film ferroelectric layer is intended to be liquid layer grown as layer 24. Have been. The thickness of these films is preferably in the range of 500 to 3000 Will be. Hillocks, such as hillocks 82 and 84, may be caused by a short circuit in layer 28. Lower process yields and, in addition, problems with long-term equipment reliability. Cause.   Until the first anneal in the step P52, the other anneals made according to the respective Examples 2 and 3 The same SEM observation was performed on the device sample. For other sample electrodes, No sharp hillocks were found. Some surface irregularities, i.e. small round shapes, It has been observed that these shapes rise from the surface 82 to less than about 50 to 80 degrees. It was presumed to be glue. These do not seriously threaten the performance of the Is relatively negligible. That is, the electrodes of Examples 2 and 3 There is no hillock qualitatively.                                 Example 8                         Comparative evaluation of capacitor devices   The wafers of Examples 2, 3, 4, 5, and 6 each had a thickness of about 1800 mm. Dielectric SrBi_TwoTa_TwoO₉Had the material. Hewlitt Packard 3314A Funk Function generator and Hewlitt Packard 54502A digital Uncompensated Sawye, including digitizing oscilloscope Using the r-Tower circuit, for each capacitor selected from each wafer, Extreme hysteresis measurements were performed. 10,000 Hz frequency and 0.25,0 . 5, 1.0, 1.5, 2.0, 2.5, 3.0, 4.0, 5.0, and 7. Measurements were taken at 20 ° C. using a sinusoidal function with a voltage amplitude of 0V.   FIG. 5 shows 2Pr polarization values (unit μC / cm) obtained from 3V switching measurement.^Two 3) shows a bar graph. Each bar is derived from a selected capacitor on a given wafer. 3 represents a three-point average of the obtained data. Each bar is labeled A, with descriptive information Labeled with the corresponding letters B, C, D, and E to identify the sample For easy reference.   The difference between the bar A and the bar B is as follows. The 2Pr polarization measured with respect to the bar line B is 5.6 by adding to the partial electrode 24. %. A non-short-circuited capacitor (bar Has no 30% increase in 2Pr polarization measured against bar B. Received a reduction. Therefore, the addition of the buffer layer 26 is performed by observing the polarization with respect to the bar C. Is the cause of the increase.   The addition of the titanium adhesion metal causes a corresponding reduction in polarization. Bar D And E indicate that the capacitor of bar D contains a 200 mm thick adhesive metal and that the capacitor of bar E Obtained from the same capacitor except that the capacitor contains 100mm thickness Represents polarization measurements. Add 100mm thickness of titanium bonded metal (bar D) Caused a 43% decrease in polarization measured for E. Buffer layer 2 The use of 6 (bars A and B) overcomes the negative effects of titanium.   Based on the above discussion, it is possible to provide relatively unfavorable modifications of the present invention. Noh. For example, adhesive metals include titanium oxide, tantalum, tantalum oxide, Alternatively, other known adhesive metals may be included. In practice, layer 26 may have a plurality of different Layers, and all such layers must be of the same type of layered superlattice material. No need. In addition, the geometric shapes and relative thicknesses shown in FIGS. It is shown for illustrative purposes only. These figures vary greatly in geometry and thickness. It is not intended to reflect the scale model of the actual material obtained.   Without departing from the true scope and spirit of the invention, the preferred It will be understood by those skilled in the art that obvious modifications can be made to the embodiments. Would. Accordingly, the inventors hereby expressly describe the purpose of protecting the complete right of the present invention. He states that he intends to rely on the doctrine of equivalents.

────────────────────────────────────────────────── ─── Continuation of front page    (72) Inventor Pas de Araujo, Carlos A.             United States Colorado 80919, Colorado             Rad Springs, W. samba             Dead Cliffs Lane 317 (72) Inventors Cutiaro, Joseph D.             United States Colorado 80919, Colorado             Rad Springs, Rossmare Street             G 2545

Claims (1)

[Claims] 1. Integrated circuit device (2) having a silicon substrate (22) and a metal wiring layer (26) 0), wherein the integrated circuit device comprises:   The layer continuum (24) is located directly on the silicon substrate; Being directly on the layer continuum, the layer continuum being a bag of layered superlattice material; And that the layer continuum does not have additional wiring layers. Integrated circuit device characterized by: 2. Wherein the layered superlattice material comprises strontium bismuth tantalate. Item 10. The apparatus according to Item 1. 3. The silicon substrate is an uppermost silicon base layer adjacent to the layer continuum ( An apparatus according to claim 2, comprising 34). 4. The method according to claim 1, wherein the wiring layer includes an adhesive metal (36) and a noble metal (38). On-board equipment. 5. A method of making an integrated circuit device (20), the method comprising: (P40) providing a silicon substrate (22) having 4);   The method comprises:   Depositing a layered superlattice material precursor (36) directly on the substrate (P44 and P4 6)   Heating the layered superlattice material precursor (P46), whereby the layered superlattice material Producing a residue of the charge precursor;   Depositing a metal wiring layer (38) directly on the residue (P50);   A method characterized by: 6. After the step of depositing the metal wiring layer on the integrated circuit device, at least Is further characterized by annealing at a temperature of 450 ° C. (P52). A method as claimed in claim 5. 7. The step of heating the layered superlattice material precursor comprises removing volatile organic compounds from the film. At a temperature up to about 450 ° C. for a time sufficient to remove substantially all of the precursor The method of claim 5, comprising drying. 8. 2. The integrated circuit according to claim 1, wherein a second layered superstructure is formed on top of the metal wiring layer. 6. The method of claim 5, wherein the method further comprises a second material on the wiring layer. Further comprising a step (P54) of forming a layered superlattice material (28) of The integrated circuit according to claim 1, or the method according to claim 5, characterized in that it is characterized.