CN102795853A - Method for preparing Bi2Ti2O7 dielectric ceramic film on surface of FTO (fluorine-doped tin oxide) substrate - Google Patents
Method for preparing Bi2Ti2O7 dielectric ceramic film on surface of FTO (fluorine-doped tin oxide) substrate Download PDFInfo
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- CN102795853A CN102795853A CN2012102357527A CN201210235752A CN102795853A CN 102795853 A CN102795853 A CN 102795853A CN 2012102357527 A CN2012102357527 A CN 2012102357527A CN 201210235752 A CN201210235752 A CN 201210235752A CN 102795853 A CN102795853 A CN 102795853A
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Abstract
The invention provides a method for preparing a Bi2Ti2O7 dielectric ceramic film on the surface of a FTO substrate. The method comprises the steps of: (1) preparing a single-layer OTS (octadecyltrichlorosilane) film on the FTO substrate; (2) preparing Bi2Ti2O7 precursor solution at a molar ratio of Bi to Ti being 1.0, adding proper amount of glacial acetic acid as the stabilizing agent, and keeping the total concentration of the solution between 0.02 to 0.04mol/L; (3) adding the FTO substrate with the single-layer OTS film in the precursor solution to obtain an amorphous film; (4) keeping the amorphous film at 560 DEG C for 10 to 60 minutes to obtain a crystallized Bi2Ti2O7 film; and (5) irradiating the crystallized Bi2Ti2O7 film with ultraviolet rays for 40 minutes, and repeating the steps (3) to (4) to obtain a multilayer film. The Bi2Ti2O7 film prepared by the method provided by the invention has the advantages of dense surface, uniform thickness and high dielectric constant.
Description
Technical field
The present invention relates to the functional materials preparation field, particularly a kind of bismuth titanates (Bi
2Ti
2O
7) preparation method of dielectric ceramic film.
Background technology
Bismuth titanates series has different components and structure, like Bi
4Ti
3O
12, Bi
2Ti
2O
7, Bi
20Ti
2O
20Deng.Bi wherein
2Ti
2O
7Belong to pyrochlore structure, can regard by Ti-O octahedron and the mixing of Bi-O tetrahedral structure and form that chemical general formula is A as
2B
2O
7, lattice parameter is a=b=c=2.068, belongs to isometric system, thereby Bi
2Ti
2O
7Film does not have piezoelectricity and ferroelectricity, but it has higher dielectric constant.
Along with gate insulation layer (SiO in the semiconducter device
2) continuous attenuate, occurred such as problems such as leakage current increase, device stability variation, one of approach that addresses these problems is to adopt the material of higher dielectric constant to replace SiO commonly used at present
2Gate insulation layer, therefore, people have carried out extensive studies to high dielectric constant material recently.Bi
2Ti
2O
7Film has higher relative dielectric constant (being about 150) and quite low leakage current, is in the high dielectric constant material of research at present, is hopeful to substitute to be used for senior MOS transistor traditional Si O
2One of material of gate insulation layer.Bi
2Ti
2O
7As the grid material of isolated gate FET, can improve the mutual conductance of isolated gate FET, reduce cut-in voltage, improve anti-breakdown characteristics, reduce device size.In addition, Bi
2Ti
2O
7Also at ferroelectric membranc PZT, PST and Bi
4Ti
3O
12Each process of system in, be used as impact plies, to improve the electrical properties of film.
At present, relevant Bi
2Ti
2O
7The report of film is less, and reported method only has chemical solution deposition and pulsed laser deposition.Though the chemical solution deposition process is simple, and is with low cost, the homogeneity of film and thickness are difficult to control.The advantage of pulsed laser deposition is that the quality of gained film is good, purity is high, good with the associativity of substrate, but processing unit comparatively complicated, need strict vacuum environment and process system, and cost is expensive.
Summary of the invention
The object of the present invention is to provide and a kind ofly prepare Bi at the FTO substrate surface
2Ti
2O
7The method of dielectric ceramic film, the Bi that this method is prepared
2Ti
2O
7Film surface is fine and close, thickness is even, and film has higher dielectric constant.
To achieve these goals, the technical scheme of the present invention's employing is following:
A kind ofly prepare Bi at the FTO substrate surface
2Ti
2O
7The method of dielectric ceramic film may further comprise the steps:
Step 1: the functionalization of substrate: the FTO substrate is cleaned up and after UV-light shines down, in the mixing solutions of OTS and toluene, deposit 30s ~ 20min to obtain the OTS unitary film; Toast subsequently to remove remained on surface solution, shine 40 ~ 60min down in UV-light again and realize the substrate surface functionalization;
Step 2: the preparation of precursor liquid: at first with Bi (NO
3)
35H
2O is dissolved in the EGME, in solution, adds Ti (OC then
4H
9)
4And Hydrocerol A, stir to clarify, add Glacial acetic acid min. 99.5 as stablizer, keep Bi in the solution
3+And Ti
4+Total concn be 0.02mol/L ~ 0.04mo l/L; Wherein Bi, Ti molar ratio are 1.0, and the amount of substance of Hydrocerol A is the amount sum of Bi and Ti;
Step 3: liquid phase method deposit film process: the FTO substrate that will adhere to the OTS unitary film places the precursor liquid for preparing, and obtains noncrystalline membrane at 50 ℃ ~ 70 ℃ deposit 10h ~ 20h;
Step 4: the crystallization of film is handled: dried noncrystalline membrane earlier through uviolizing, is put into retort furnace then, be incubated 10min ~ 60min to obtain crystalline state Bi at 560 ℃
2Ti
2O
7Film.
The present invention further improves and is: saidly prepare Bi at the FTO substrate surface
2Ti
2O
7The method of dielectric ceramic film also comprises: step 5: the deposition of multilayer film: with the Bi after step 4 crystallization
2Ti
2O
7Film places the precursor liquid of step 2 configuration once more after uviolizing, repeating step 3 ~ step 4 several times, thus obtain multilayer crystalline state Bi
2Ti
2O
7Film.
The present invention further improves and is: the method for cleaning in the step 1 is for successively using the FTO substrate respectively water-detergent solution, absolute ethyl alcohol and acetone ultrasonic washing 10 minutes.
The present invention further improves and is: the volume ratio of octadecyl trichlorosilane and toluene is 1:99
The present invention further improves and is: in the step 1 in 120 ℃ of bakings to remove remained on surface solution.
The present invention further improves and is: vacuumize processing after configuring precursor liquid in the step 2; The FTO substrate that will adhere to the OTS unitary film in the step 3 places the process for preparing to vacuumize the precursor liquid deposited amorphous attitude film of processing.
The present invention further improves and is: vacuumize processed steps and carry out vacuum-treat for the precursor liquid that configures is put into vacuum chamber together with beaker, open vacuum pump, vacuum pressure are adjusted to-0.2Kg/cm
2, the pumpdown time is 30-40mins.
With respect to prior art, beneficial effect of the present invention is: adopting liquid phase self-assembled monolayer membrane technique, is template with the OTS unitary film, induced growth Bi on functionalization FTO substrate
2Ti
2O
7Film is for Bi
2Ti
2O
7The preparation technology of film is a kind of brand-new trial, and this novel technology of preparing is a kind of innovation to technology itself not only, and gained Bi
2Ti
2O
7Film has higher dielectric constant.The present invention adopts liquid phase self-assembled monolayer membrane technique, utilizes Bi (NO
3)
35H
2O and Ti (OC
4H
9)
4Being raw material, is template with OTS, on the FTO substrate, has successfully prepared Bi
2Ti
2O
7Film.The advantage of this method be film in the spontaneous formation of substrate surface original position, defective is few, bonding force is strong, good crystallinity, film surface is fine and close, thickness is even, and film has higher dielectric constant.
Description of drawings
The Bi of Fig. 1 the present invention preparation
2Ti
2O
7The XRD figure spectrum of film.
The Bi of Fig. 2 the present invention preparation
2Ti
2O
7The FE-SEM photo of thin-membrane section.
The Bi of Fig. 3 the present invention preparation
2Ti
2O
7The graph of a relation of the specific inductivity of film and dissipation factor and frequency.
Embodiment
Embodiment 1
Step 1: the functionalization of substrate.The FTO substrate was successively used water-detergent solution, absolute ethyl alcohol and acetone ultrasonic washing respectively 10 minutes; Nitrogen dries up also and in the mixing solutions (volume ratio of OTS and toluene is 1:99) of OTS (octadecyl trichlorosilane) and toluene, deposits 20min to obtain the OTS unitary film behind the uv irradiating 10min; Toast 5 minutes down to remove remained on surface solution at 120 ℃ subsequently, shine 40min down in UV-light again and realize the substrate surface functionalization.
Step 2: the preparation of precursor liquid.At first with Bi (NO
3)
35H
2O is dissolved in the 20ml EGME, in solution, adds Ti (OC then
4H
9)
4And Hydrocerol A (wherein Bi, Ti molar ratio are 1.0, and the amount of substance of Hydrocerol A is the amount sum of Bi and Ti), stir to clarify, add the 2ml Glacial acetic acid min. 99.5 as stablizer, keep Bi in the solution
3+And Ti
4+Total concn be 0.02mol/L.The precursor liquid that configures is put into vacuum chamber together with beaker carry out vacuum-treat, open vacuum pump, vacuum pressure are adjusted to-0.2Kg/cm
2, the pumpdown time is 30-40mins.
Step 3: liquid phase method deposit film process.The FTO substrate that will adhere to the OTS unitary film places the precursor liquid for preparing, and obtains noncrystalline membrane at 50 ℃ of deposit 15h.
Step 4: the crystallization of film is handled.Dried noncrystalline membrane earlier through uviolizing 40min, is put into retort furnace then, be incubated 30min to obtain crystalline state Bi at 560 ℃
2Ti
2O
7Film.
Step 5: the deposition of multilayer film.With the Bi after the crystallization
2Ti
2O
7Film places the precursor liquid of step 2 configuration once more behind uviolizing 40min, repeating step 3 ~ step 4, multiplicity are 6 times, thereby realizes the preparation of multilayer film.
Embodiment 2
Step 1: the functionalization of substrate.The FTO substrate was successively used water-detergent solution, absolute ethyl alcohol and acetone ultrasonic washing respectively 10 minutes; Nitrogen dries up also and in the mixing solutions (volume ratio of OTS and toluene is 1:99) of OTS (octadecyl trichlorosilane) and toluene, deposits 20min to obtain the OTS unitary film behind the uv irradiating 10min; Toast 5 minutes down to remove remained on surface solution at 120 ℃ subsequently, shine 40min down in UV-light again and realize the substrate surface functionalization.
Step 2: the preparation of precursor liquid.At first with Bi (NO
3)
35H
2O is dissolved in the 20ml EGME, in solution, adds Ti (OC then
4H
9)
4And Hydrocerol A (wherein Bi, Ti molar ratio are 1.0, and the amount of substance of Hydrocerol A is the amount sum of Bi and Ti), stir to clarify, add the 2ml Glacial acetic acid min. 99.5 as stablizer, keep Bi in the solution
3+And Ti
4+Total concn be 0.03mol/L.The precursor liquid that configures is put into vacuum chamber together with beaker carry out vacuum-treat, open vacuum pump, vacuum pressure are adjusted to-0.2Kg/cm
2, the pumpdown time is 30-40mins.
Step 3: liquid phase method deposit film process.The FTO substrate that will adhere to the OTS unitary film places the precursor liquid for preparing, and obtains noncrystalline membrane at 70 ℃ of deposit 10h.
Step 4: the crystallization of film is handled.Dried noncrystalline membrane earlier through uviolizing 40min, is put into retort furnace then, be incubated 60min to obtain crystalline state Bi at 560 ℃
2Ti
2O
7Film.
Step 5: the deposition of multilayer film.With the Bi after the crystallization
2Ti
2O
7Film places the precursor liquid of step 2 configuration once more behind uviolizing 40min, repeating step 3 ~ step 4, multiplicity are 6 times, thereby realizes the preparation of multilayer film.
Embodiment 3
Step 1: the functionalization of substrate.The FTO substrate was successively used water-detergent solution, absolute ethyl alcohol and acetone ultrasonic washing respectively 10 minutes; Nitrogen dries up also and in the mixing solutions (volume ratio of OTS and toluene is 1:99) of OTS (octadecyl trichlorosilane) and toluene, deposits 20min to obtain the OTS unitary film behind the uv irradiating 10min; Toast 5 minutes down to remove remained on surface solution at 120 ℃ subsequently, shine 40min down in UV-light again and realize the substrate surface functionalization.
Step 2: the preparation of precursor liquid.At first with Bi (NO
3)
35H
2O is dissolved in the 20ml EGME, in solution, adds Ti (OC then
4H
9)
4And Hydrocerol A (wherein Bi, Ti molar ratio are 1.0, and the amount of substance of Hydrocerol A is the amount sum of Bi and Ti), stir to clarify, add the 2ml Glacial acetic acid min. 99.5 as stablizer, keep Bi in the solution
3+And Ti
4+Total concn be 0.04mol/L.The precursor liquid that configures is put into vacuum chamber together with beaker carry out vacuum-treat, open vacuum pump, vacuum pressure are adjusted to-0.2Kg/cm
2, the pumpdown time is 30-40mins.
Step 3: liquid phase method deposit film process.The FTO substrate that will adhere to the OTS unitary film places the precursor liquid for preparing, and obtains noncrystalline membrane at 60 ℃ of deposit 20h.
Step 4: the crystallization of film is handled.Dried noncrystalline membrane earlier through uviolizing 40min, is put into retort furnace then, be incubated 10min to obtain crystalline state Bi at 560 ℃
2Ti
2O
7Film.
Step 5: the deposition of multilayer film.With the Bi after the crystallization
2Ti
2O
7Film places the precursor liquid of step 2 configuration once more behind uviolizing 40min, repeating step 3 ~ step 4, multiplicity are 6 times, thereby realizes the preparation of multilayer film.
With the thing phase composite of XRD test case 1 gained film, and with the pattern of its section of SEM observation, the result is as depicted in figs. 1 and 2, utilizes the liquid phase self-assembling technique, is template with OTS, can successfully make Bi at the FTO substrate surface
2Ti
2O
7That film, film crystalline phase are grown is complete, surface compact, thickness are even; And technology is simple, and the experiment condition of requirement satisfies easily, and cost is lower.Fig. 3 is gained Bi
2Ti
2O
7The graph of a relation of the specific inductivity of film and dissipation factor and frequency, visible by figure, along with the increase of frequency, specific inductivity reduces gradually, and when frequency was 300kHz, specific inductivity was 118, and dissipation factor is 0.33.
The above is merely one embodiment of the present invention; It or not whole or unique embodiment; The conversion of any equivalence that those of ordinary skills take technical scheme of the present invention through reading specification sheets of the present invention is claim of the present invention and contains.
Claims (7)
1. one kind prepares Bi at the FTO substrate surface
2Ti
2O
7The method of dielectric ceramic film is characterized in that, may further comprise the steps:
Step 1: the functionalization of substrate: the FTO substrate is cleaned up and after UV-light shines down, in the mixing solutions of OTS and toluene, deposit 30s ~ 20min to obtain the OTS unitary film; Toast subsequently to remove remained on surface solution, shine 40 ~ 60min down in UV-light again and realize the substrate surface functionalization;
Step 2: the preparation of precursor liquid: at first with Bi (NO
3)
35H
2O is dissolved in the EGME, in solution, adds Ti (OC then
4H
9)
4And Hydrocerol A, stir to clarify, add Glacial acetic acid min. 99.5 as stablizer, keep Bi in the solution
3+And Ti
4+Total concn be 0.02mol/L ~ 0.04mo l/L; Wherein Bi, Ti molar ratio are 1.0, and the amount of substance of Hydrocerol A is the amount sum of Bi and Ti;
Step 3: liquid phase method deposit film process: the FTO substrate that will adhere to the OTS unitary film places the precursor liquid for preparing, and obtains noncrystalline membrane at 50 ℃ ~ 70 ℃ deposit 10h ~ 20h;
Step 4: the crystallization of film is handled: dried noncrystalline membrane earlier through uviolizing, is put into retort furnace then, be incubated 10min ~ 60min to obtain crystalline state Bi at 560 ℃
2Ti
2O
7Film.
2. according to claim 1ly a kind ofly prepare Bi at the FTO substrate surface
2Ti
2O
7The method of dielectric ceramic film is characterized in that, saidly prepares Bi at the FTO substrate surface
2Ti
2O
7The method of dielectric ceramic film also comprises:
Step 5: the deposition of multilayer film: with the Bi after step 4 crystallization
2Ti
2O
7Film places the precursor liquid of step 2 configuration once more after uviolizing, repeating step 3 ~ step 4 several times, thus obtain multilayer crystalline state Bi
2Ti
2O
7Film.
3. according to claim 1ly a kind ofly prepare Bi at the FTO substrate surface
2Ti
2O
7The method of dielectric ceramic film is characterized in that, the method for cleaning in the step 1 is for successively using the FTO substrate respectively water-detergent solution, absolute ethyl alcohol and acetone ultrasonic washing 10 minutes.
4. according to claim 1ly a kind ofly prepare Bi at the FTO substrate surface
2Ti
2O
7The method of dielectric ceramic film is characterized in that, the volume ratio of octadecyl trichlorosilane and toluene is 1:99
5. according to claim 1ly a kind ofly prepare Bi at the FTO substrate surface
2Ti
2O
7The method of dielectric ceramic film is characterized in that, in the step 1 in 120 ℃ of bakings to remove remained on surface solution.
6. according to claim 1ly a kind ofly prepare Bi at the FTO substrate surface
2Ti
2O
7The method of dielectric ceramic film is characterized in that, vacuumizes processing after configuring precursor liquid in the step 2; The FTO substrate that will adhere to the OTS unitary film in the step 3 places the process for preparing to vacuumize the precursor liquid deposited amorphous attitude film of processing.
7. according to claim 6ly a kind ofly prepare Bi at the FTO substrate surface
2Ti
2O
7The method of dielectric ceramic film is characterized in that, vacuumizes processed steps and carries out vacuum-treat for the precursor liquid that configures is put into vacuum chamber together with beaker, and open vacuum pump, vacuum pressure are adjusted to-0.2Kg/cm
2, the pumpdown time is 30-40mins.
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Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN103482691A (en) * | 2013-09-04 | 2014-01-01 | 陕西科技大学 | Doped Bi4Ti3O12 film and preparation method thereof |
CN105036183A (en) * | 2015-07-07 | 2015-11-11 | 陕西科技大学 | Preparation method for nanometer Bi2Ti2O7 powder |
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CN101659520A (en) * | 2009-09-17 | 2010-03-03 | 陕西科技大学 | Method for preparing bismuth iron functional film on glass substrate by utilizing liquid-phase self-assembly method |
CN102534610A (en) * | 2012-02-24 | 2012-07-04 | 陕西科技大学 | Method for depositing compact barium strontium titanate film on glass substrate |
-
2012
- 2012-07-09 CN CN2012102357527A patent/CN102795853A/en active Pending
Patent Citations (2)
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CN101659520A (en) * | 2009-09-17 | 2010-03-03 | 陕西科技大学 | Method for preparing bismuth iron functional film on glass substrate by utilizing liquid-phase self-assembly method |
CN102534610A (en) * | 2012-02-24 | 2012-07-04 | 陕西科技大学 | Method for depositing compact barium strontium titanate film on glass substrate |
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Title |
---|
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Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN103482691A (en) * | 2013-09-04 | 2014-01-01 | 陕西科技大学 | Doped Bi4Ti3O12 film and preparation method thereof |
CN105036183A (en) * | 2015-07-07 | 2015-11-11 | 陕西科技大学 | Preparation method for nanometer Bi2Ti2O7 powder |
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Application publication date: 20121128 |