JP2007119912A - Composite structure manufacturing method, structure manufacturing method, film forming apparatus, and composite structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a composite structure capable of easily peeling a film formed on a substrate by an AD method. <P>SOLUTION: The composite structure includes a substrate 11, and a structure 12 which is a polycrystalline structure formed directly or indirectly on a substrate by blowing a raw material powder formed of an inorganic material toward the substrate by using the aerosol deposition method, colliding the raw material powder with a lower layer, coupling particles having a newly generated active fresh surface by the breakage and/or crush of the raw material powder in the collision to deposit the raw material powder, and contains carbon over 150 ppm in weight as impurities to generate a gas when being heated. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention uses a method for manufacturing a composite structure using an aerosol deposition method in which raw material powder is deposited on a substrate by spraying the raw material powder toward the substrate, and a method for manufacturing such a composite structure. The present invention relates to a structure manufacturing method and a film forming apparatus, and a composite structure manufactured by such a composite structure manufacturing method.

  In recent years, in the field of micro electrical mechanical systems (MEMS), electrons that exhibit a predetermined function by applying voltage, such as dielectrics, piezoelectrics, magnetics, pyroelectrics, and semiconductors. Research for manufacturing elements including functional materials such as ceramics by using a film forming technique is actively underway.

  For example, in order to enable high-definition and high-quality printing in an inkjet printer, it is necessary to make the ink nozzles of the inkjet head fine and highly integrated. Therefore, miniaturization and high integration are also required for the piezoelectric actuator that drives each ink nozzle. In such a case, a film forming technique capable of forming a layer thinner than the bulk material and capable of forming a fine pattern is advantageous.

  Recently, an aerosol deposition method (hereinafter referred to as “AD method”), which is known as a film forming technique for ceramics and metals, has attracted attention as one of film forming techniques. The AD method is a film forming method in which a raw material powder (raw material powder) is dispersed in a gas (aerosolized) and sprayed from a nozzle toward the substrate to deposit the raw material on the substrate. Here, the aerosol refers to solid or liquid fine particles suspended in a gas. The AD method is also called a jet deposition method or a gas deposition method.

  As a related technique, in Patent Document 1, after performing a step of applying internal strain to brittle material fine particles, the brittle material fine particles to which the internal strain is applied are caused to collide with the surface of the substrate at high speed, and the impact of the collision. The fine particles of brittle material are deformed or crushed by re-bonding the fine particles to each other through the active new surface generated by the deformation or crushing, so that part of the fine particles bite into the substrate surface. A method for producing a composite structure is disclosed in which an anchor portion made of a crystalline brittle material is formed, and a structure made of a polycrystalline brittle material is subsequently formed on the anchor portion.

As disclosed in Patent Document 1, a film formation mechanism in which fine particles are bonded to each other on an active new surface generated in a collision is called a mechanochemical reaction. According to such an AD method, a dense and strong film can be formed. Therefore, it is expected to improve the performance of a device to which various functional films are applied.
JP 2002-235181 A (second page)

  However, the film produced by the AD method is firmly attached to the substrate due to the presence of the anchor portion. Therefore, the film can be used only as a composite structure integrated with the substrate.

  Therefore, in view of the above points, the present invention uses a method for manufacturing a composite structure that can easily peel off a film formed on a substrate by the AD method, and a method for manufacturing such a composite structure. It is a first object of the present invention to provide a method for manufacturing a structure and a film forming apparatus. Moreover, this invention sets it as the 2nd objective to provide the composite structure manufactured by the manufacturing method of such a composite structure.

  In order to solve the above-described problem, a method for manufacturing a composite structure according to one aspect of the present invention is a raw material powder formed of an inorganic material and containing an impurity that generates gas when heated. Step (a) in which an aerosol is dispersed by gas, and the activity newly generated by the deformation and / or crushing of the raw material powder at the time of collision by spraying the raw material powder in the aerosol state toward the substrate And (b) forming a polycrystalline structure containing impurities on the substrate by bonding the particles having faces to deposit raw material powder.

  A structure manufacturing method according to one aspect of the present invention includes a plurality of steps provided in the above-described composite structure manufacturing method, and heating the composite structure to at least a polycrystalline structure. And a step of peeling from the substrate.

  A film forming apparatus according to one aspect of the present invention is an aerosol generating means for making an aerosol state by dispersing raw material powder with gas, and an impurity added to the raw material powder, which generates gas when heated. Impurity supply means for supplying impurities to the aerosol generation means, and an injection nozzle for depositing the raw material powder on the substrate by spraying the raw material powder in the aerosol state by the aerosol generation means toward the substrate.

  The composite structure according to one aspect of the present invention uses a substrate and an aerosol deposition method to spray a raw material powder formed of an inorganic material toward the substrate to cause the raw material powder to collide with a lower layer. A polycrystalline structure formed directly or indirectly on the substrate by depositing raw material powder by bonding particles having active surfaces newly generated by deformation and / or crushing of raw material powder at the time of And a polycrystalline structure containing more than 150 ppm by weight of carbon as an impurity that generates gas when heated.

  According to the present invention, when forming a polycrystalline film (structure) of an inorganic material on a substrate by an aerosol deposition method, it is a raw material powder formed of an inorganic material and generates gas when heated. Therefore, the polycrystalline film can be easily peeled from the substrate by heat-treating the manufactured composite structure. Further, according to the present invention, for example, the polycrystalline film can be peeled off with a good yield and better than the conventional method of peeling off the film formed on the SUS substrate by etching. Accordingly, the peeled polycrystalline film can be used alone.

Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the drawings. The same constituent elements are denoted by the same reference numerals, and the description thereof is omitted.
FIG. 1 is a sectional view showing the structure of a composite structure according to the first embodiment of the present invention.
As shown in FIG. 1, the composite structure according to the present embodiment includes a substrate 11 and an impurity-containing AD layer 12.
The substrate 11 is a general film formation substrate formed of a material such as glass, ceramics, SUS, or YSZ (yttrium stabilized zirconia).

The impurity-containing AD layer 12 is an inorganic material layer formed by an AD method using an inorganic material including a brittle material such as ceramics or a semimetal, and contains a predetermined amount of impurities. This impurity is carbon (C) or a compound containing carbon. Such a substance generates carbon dioxide (CO ₂ ) gas or carbon monoxide (CO) gas when heated. Examples of the compound containing carbon include C ₁₈ H ₃₆ , C ₁₈ H ₃₈ , C ₂₀ H ₄₀ , C ₂₀ H ₄₂ , C ₂₂ H ₄₄ , C ₂₂ H ₄₆ , C ₂₄ H ₅₀ , and C ₂₆ H. ₅₂ , C ₂₈ H _{56 and} other alkyl compounds are included. Alkyl compounds can be either saturated or unsaturated. Further, the number of carbons contained in one molecule is not particularly limited.

  In this embodiment, the impurity-containing AD layer 12 is formed of PZT (lead zirconate titanate) which is a piezoelectric material, and contains carbon exceeding 150 ppm by weight as impurities. Here, the amount of carbon contained as an impurity is the amount of carbon (weight ppm) with respect to the entire components (inorganic material and impurities) of the impurity-containing AD layer 12. When the impurity is an alkyl compound, it indicates the amount of carbon in the alkyl compound.

  Such an impurity-containing AD layer 12 is formed by using the film forming apparatus shown in FIG. FIG. 2 is a schematic diagram showing a configuration of a film forming apparatus in which the method for manufacturing a composite structure according to the first embodiment of the present invention is used. This film forming apparatus has an aerosol generating unit and a film forming unit.

  As shown in FIG. 2, the aerosol generating unit includes an aerosol generating chamber 1, a vibration table 2, a hoisting gas nozzle 3, and a pressure adjusting gas nozzle 4. The film forming section includes a film forming chamber 7, an exhaust pipe 8, an injection nozzle 9, and a substrate stage 10. The film forming apparatus further includes an aerosol transport pipe 5 disposed between the aerosol generating unit and the film forming unit, and an impurity supply device 6 connected to the winding gas nozzle 3 of the aerosol generating unit.

  In the aerosol generation chamber 1, aerosol is generated. The aerosol generation chamber 1 is installed on a vibration table 2 that vibrates at a predetermined frequency in order to stir the raw material powder 13 disposed inside.

  A gas cylinder for supplying a carrier gas is connected to the winding gas nozzle 3. The winding gas nozzle 3 generates a cyclone flow by injecting the gas supplied from the gas cylinder into the aerosol generation chamber 1. Thereby, the raw material powder 13 disposed in the aerosol generation chamber 1 is rolled up and dispersed to generate an aerosol.

On the other hand, a gas cylinder that supplies a carrier gas for adjusting the gas pressure in the aerosol generation chamber 1 is connected to the pressure adjusting gas nozzle 4. By controlling the pressure in the aerosol generation chamber 1 by adjusting the flow rate of the pressure adjusting gas, the speed of the air flow (winding gas) generated in the aerosol generation chamber 1 is controlled.
Examples of the carrier gas supplied through the hoisting gas nozzle 3 and the pressure adjusting gas nozzle 4 include oxygen (O ₂ ), nitrogen (N ₂ ), helium (He), argon (Ar), or a mixed gas thereof, or Dry air or the like is used.

The aerosol transport pipe 5 transports the aerosol generated in the aerosol generation chamber 1 to the nozzle 9 disposed in the film forming chamber 7.
The impurity supply device 6 supplies impurities added to the raw material powder into the aerosol generation chamber 1. The impurity supply device 6 rolls up impurities such as carbon powder or an alkyl compound and supplies them into the gas nozzle 3. Thereby, impurities are supplied into the aerosol generation chamber 1 together with the carrier gas and mixed into the raw material powder.

The inside of the film forming chamber 7 is evacuated by an evacuation pump connected to an evacuation pipe 8, thereby maintaining a predetermined degree of vacuum.
The injection nozzle 9 has an opening having a predetermined shape and size, and injects the aerosol supplied from the aerosol generation chamber 1 via the aerosol transport pipe 5 toward the substrate 11 at a high speed.

  The substrate stage 10 to which the substrate 11 is fixed is a three-dimensionally movable stage for controlling the relative position and relative speed between the substrate 11 and the nozzle 9. By adjusting this relative speed, the thickness of the film formed per reciprocation is controlled.

  In such a film forming apparatus, the raw material powder 13 is placed in the aerosol generation chamber 1 and the substrate 11 is set on the substrate stage 10 and kept at a predetermined film forming temperature. For example, when forming a PZT film on a YSZ substrate, the substrate temperature is set to about 400.degree. Then, the substrate 11 is moved at a predetermined speed while driving the film forming apparatus to spray aerosol from the spray nozzle 9. As a result, the raw material powder collides with the substrate 11 or the structure previously deposited on the substrate, and the particles are bonded to each other on the active new surface generated by the deformation or crushing of the raw material powder. Is deposited on the substrate. In addition, depending on the material of the substrate 11 (for example, in the case of a metal material such as SUS), the raw material powder colliding with the substrate 11 bites into the substrate, and an anchor portion is formed. By such a film formation mechanism, a composite structure (FIG. 1) including the substrate 11 and the impurity-containing AD layer 12 in close contact therewith is obtained.

In order to peel off the AD film from such a composite structure, the composite structure is heat-treated at a predetermined temperature. The heat treatment temperature at this time is set to, for example, about 600 ° C. to about 800 ° C., preferably about 650 ° C. in consideration of the heat resistance of the substrate 11. Since the impurity-containing AD layer 12 contains impurities, gas is generated from the impurity-containing AD layer 12 by heat treatment, and as a result, the impurity-containing AD layer 12 is peeled from the substrate 11. The atmosphere of the heat treatment is selected according to the impurity component. For example, when the impurity is carbon, a gas containing oxygen (O ₂ ) is used. In this stripping step, for the purpose of stripping only, heat treatment may be performed at a lower temperature (eg, 600 ° C.) at which gas can be generated from the impurities, and post-annealing can also be tolerated by the substrate 11. Heat treatment may be performed at a higher temperature (for example, 800 ° C.).

  The single AD film obtained as a result has high density and hardness due to the mechanochemical reaction. Further, this AD film may be subjected to post-annealing at a high temperature (for example, 800 ° C. or higher). Thereby, the crystallinity of the AD film can be further improved.

Next, in the manufacturing method of the composite structure according to the first embodiment of the present invention, the reason for adding impurities to the raw material powder will be described in detail.
The method for manufacturing a composite structure according to the present embodiment is characterized in that the ceramic film is peeled off from the substrate by using impurities added to the raw material powder and a special film forming mechanism in the AD method. Therefore, a difference in film forming mechanism between a general solid phase sintering method as a method for manufacturing a ceramic structure and an AD method used in the present embodiment will be described.

  In the solid-phase sintering method, first, a green body, that is, a green compact is produced by pressing and solidifying raw material powder. In that case, an organic binder is usually used in order to improve the moldability of the green compact. FIG. 3A shows an enlarged view of such a green compact. As shown in FIG. 3A, pores exist between the pressed raw material powders inside the green compact. These holes are open pores communicating with the inside and outside of the green compact.

Next, such a green compact is heat-treated at about 500 ° C to 800 ° C. As a result, organic substances present in the green compact are thermally decomposed and evaporated, and escape to the outside of the green compact through the open pores. This is called a degreasing process.
Further, the green compact is heat-treated (fired) at a higher temperature. Thereby, as shown to (b) of FIG. 3, sintering of raw material powder advances. In the case of normal PZT, sintering starts from around 800 ° C. and is completed at around 1200 ° C.
As described above, when the solid phase sintering method is used, most of the oily components such as organic contamination components and binders in the raw material powder become carbon dioxide (CO ₂ ) gas in the degreasing process and escape to the outside of the sample. To go. Therefore, organic contamination that cannot escape during the production process of the ceramic raw material powder does not have a great influence in the solid-phase sintering method.

On the other hand, in the AD method, a film is formed by a normal temperature impact solidification phenomenon in which particles are bonded to each other on a new surface generated by collision of raw material powder with a lower layer. Therefore, the properties of the membrane are very dense, and it is considered that there are almost no air holes (open pores) leading from the inside of the membrane to the outside. Therefore, by heat-treating (post-annealing) the AD film, even if the organic matter remaining in the AD film burns and a gas such as CO ₂ is generated, the gas cannot escape to the outside of the AD film. Therefore, pores (closed pores) are formed inside the AD film.

As shown in FIG. 4A, the gas (bubbles 102) generated near the interface between the AD film 100 and the substrate 101 diffuses and accumulates at the interface of the substrate 101. Furthermore, the bubbles 102 expand in volume as the temperature rises. When the internal pressure of the bubble 102 exceeds the adhesion force between the AD film 100 and the substrate 101, the AD film 100 is peeled off from the substrate 101 at that time, and the pressure in the bubble 102 increases. As a result, as shown in FIG. 4B, the AD film 100 is peeled from the substrate 101 so as to be lifted by a gas such as CO ₂ .

  Thus, the inventor of the present application has found that by using the AD method, the film can be easily peeled from the substrate by heat treatment. However, depending on the amount of impurities added to the raw material powder, heat treatment conditions, etc., the film may not be peeled off from the substrate, or conversely, hillocks (abnormal volume expansion that occurs in part of the film) may occur in the film, resulting in deterioration of film quality. May invite. Therefore, the inventor of the present application conducted an experiment for extracting appropriate conditions for peeling off the AD film from the substrate.

First, this inventor analyzed the gas which generate | occur | produces by heating commercially available PZT raw material powder by TPD-MS method. That is, the PZT raw material powder is placed on a Pt boat installed in the chamber, and heated to about 1000 ° C. at 20 ° C./min while flowing high purity helium (He) gas at 40 cc / min. After holding for about 5 minutes, it was cooled to room temperature, and the gas generated during that time was continuously measured using a mass spectrometer. As the mass spectrometer, AGS-7000 type manufactured by Anerva Co., Ltd. was used. FIG. 5 shows the resulting CO ₂ gas generation pattern. In FIG. 5, the horizontal axis indicates the temperature change during the TPD-MS analysis, and the vertical axis indicates the intensity (arbitrary unit: au). From this experiment, it was confirmed that the amount of carbon was predominantly carbon dioxide.

Next, the inventor of the present invention uses a GC-MS (gas chromatograph mass) for substances adhering to the surface of a commercially available PZT raw material powder in order to clarify the components that cause CO ₂ gas. I decided to investigate by analysis. Here, the GC-MS is an apparatus in which a gas chromatograph and a mass spectrometer are combined, and is an analysis apparatus that has both the separability of a mixture by the gas chromatograph and the constant performance of the mass spectrometer. That is, a mixture sample is separated into a plurality of types of substances by gas chromatography, and these types of substances are directly guided to a mass spectrometer to identify the types of substances. In this experiment, a mass spectrometer JMS-700Mstation manufactured by JEOL Ltd. was used.

  The analysis was performed as follows. That is, first, commercially available raw material powder (PZT powder) not subjected to special treatment was washed away with hexane, and the hexane was concentrated and applied to a GC-MS apparatus. In addition, when the amount of carbon contained in the raw material powder was separately measured by TPD-MS analysis, it was about 150 ppm by weight. The method of TPD-MS analysis and the apparatus used are the same as those described above.

FIG. 6 shows the analysis result. As shown in FIG. 6, it is clear that alkyl compounds such as C ₂₀ H ₄₂ , C ₂₀ H ₄₀ , C ₂₂ H ₄₆ , and C ₂₄ H ₅₀ were attached to the surface of the raw material powder (sample A). became. Here, it is not clear why such impurities (alkyl compounds) adhere to the raw material powder. However, since the raw material powder is produced at a temperature of about 800 ° C., almost no impurities should be attached to the raw material powder immediately after production. Therefore, after producing the raw material powder, it is considered that the oil mist floating in the air adheres to the raw material powder, or impurities are mixed from the vinyl container used when storing or transporting the raw material powder. . In FIG. 6, two C ₂₀ H ₄₀ peaks are shown, which may be due to the presence of isomers having different double bond positions or isomers having different branch structures. .

Next, the inventor of the present application examined the relationship between the amount of carbon adhering to the raw material powder and the amount of CO ₂ gas generated by heat-treating the raw material powder by TPD-MS analysis. The method of TPD-MS analysis and the apparatus used are the same as those described above. The result is shown in FIG.

In this experiment, a commercially available PZT powder was used as a sample. In order to temporarily reduce the amount of carbon, the PZT powder was baked in an electric furnace, and the PZT powder was exposed to an organic vapor atmosphere as an impurity addition treatment for increasing carbon. did. Here, the organic vapor atmosphere is an atmosphere in which vaporized organic substances are dispersed. Normally, PZT powder not subjected to special treatment contains some carbon due to adsorption of organic substances in the air. The amount of carbon was controlled by adjusting the baking time in an electric furnace, the time of exposure to organic vapor, or the concentration of organic vapor. The amount of carbon was calculated based on the measured value obtained by measuring the amount of CO ₂ gas generated when PZT powder was burned in a high-frequency induction heating furnace by the non-dispersive infrared absorption method.

Here, the amount of carbon adhering to the raw material powder or the amount of carbon contained in the raw material powder is the amount of carbon (weight ppm) with respect to the total amount of the raw material powder and impurities, and when the impurities are simple carbon. Indicates the amount of carbon alone, and when the impurity is an alkyl compound, indicates the amount of carbon in the alkyl compound.
As shown in FIG. 7, it can be said that the amount of carbon adhering to the raw material powder, the amount of CO ₂ gas generated by heating the raw material powder is generally proportional.

Furthermore, when the kind of impurities adhering to the raw material powder was examined by performing GC-MS analysis on the above-mentioned raw material powder subjected to the impurity addition treatment, the result shown in FIG. 8 was obtained. In this measurement, the powder in which the amount of carbon contained in the raw material powder (by TPD-MS analysis) is 200 ppm or more was targeted. As shown in the analysis result of FIG. 8, C ₁₈ H ₃₆ , C ₁₈ H ₃₈ , C ₂₀ H ₄₀ , C ₂₀ H ₄₂ , C ₂₂ H ₄₄ , C _{22 H 46, C 24 H 50} , many of alkyl compounds, such as _{C 26 H 52, C 28 H} 56 has been detected.

From the results shown in FIGS. 6 to 8, the impurities that cause the generation of CO ² gas by heating are mainly alkyl compounds, and the amount of such impurities is obtained by subjecting the raw material powder to an impurity addition treatment. It became clear that it can be adjusted.

Further, the inventors of the present application conducted an experiment in which a film was formed by AD method using PZT raw material powders having different carbon contents (adhesion amount), and the film was heat-treated (post-annealed). The experimental results are shown in FIG.
In FIG. 9, as the annealing conditions (1) to (5), an annealing temperature (° C.) and an annealing time (h) are shown. The numerical values of the AD films (a) to (e) indicate the carbon content (weight ppm) in the AD film. Furthermore, the x mark in the table indicates that neither peeling nor hillock occurred. Here, the hillock is a phenomenon in which a part of the film expands, and is formed when gas is generated from impurities taken into the film.

Note that the carbon content in each AD film shown in FIG. 9 represents the amount of carbon alone or the amount of carbon in the alkyl compound. Therefore, the amount of the alkyl compound contained in the AD film is larger than the amount shown in FIG. Further, the carbon content shown in FIG. 9 is calculated based on the measured value obtained by measuring the amount of CO ₂ gas generated when the PZT raw material powder is burned in the high frequency induction heating furnace by the non-dispersive infrared absorption method. It was.

  As shown in FIG. 9, the more the carbon content contained in the raw material powder, the easier it is for the AD film to peel from the substrate. This supports the peeling principle that carbon dioxide is generated due to carbon incorporated in the AD film. It was also found that when the raw material powder is the same as in the AD films (b) and (c), hillocks are more likely to occur as the annealing temperature is higher. This is presumably because the higher the temperature, the more active the reaction between carbon and oxygen in the PZT composition increases the amount of carbon dioxide and moisture generated and the volume expands. Furthermore, as in the annealing conditions (3) to (5), it was found that hillocks were first generated as the carbon content increased, and peeling occurred when the carbon content was further increased.

  From the above, the following conclusion could be obtained. That is, if the AD film contains more than about 150 ppm of carbon, the AD film can be easily peeled from the substrate by heat treatment at 800 ° C. or higher. If the AD film contains about 222 ppm or more of carbon, the AD film can be peeled off from the substrate by heat treatment at 600 ° C. or more. Here, the normal post-annealing for the AD film is performed at a temperature higher than the film forming temperature (for example, 400 ° C.), so it is considered sufficient if the conditions in the temperature region of 600 ° C. or higher can be secured.

  In general, as the number of carbon atoms contained in one molecule is smaller (for example, the carbon number is less than 18), the alkyl compound is more easily separated from the raw material powder, and as the carbon number is larger (for example, the number of carbons is 18 or more), the alkyl compound is less likely to leave. . Therefore, it is desirable to control the heat treatment temperature in accordance with the impurity composition. An alkyl compound in which 18 or more carbon atoms are linked in a chain in a molecule is sometimes called a long-chain alkyl compound.

Next, a composite structure according to a second embodiment of the present invention will be described with reference to FIG.
As shown in FIG. 10, the composite structure according to this embodiment includes a substrate 21 and an impurity-containing AD layer 22. Note that the substrate material, the inorganic material forming the AD layer, and the impurity components in this embodiment are the same as those in the first embodiment.

  The impurity-containing AD layer 22 is formed so that the concentration of impurities in the layer changes in an inclined manner according to the distance from the substrate 21. For example, in the impurity-containing AD layer 22, when the impurity concentration on the substrate side is high and the impurity concentration is low as the distance from the substrate increases, the amount of impurities supplied per unit time is gradually increased in the film forming apparatus shown in FIG. The film can be formed by controlling the impurity supply device 6 so as to reduce the film thickness.

  Such a composite structure has an advantage that a region to be preferentially peeled can be controlled when the impurity-containing AD layer 22 is peeled from the substrate by heat treatment. For example, when the impurity concentration on the substrate side is increased in the layer of the impurity-containing AD layer 22 (for example, when the impurity is carbon, it exceeds 150 ppm or 222 ppm by weight), the impurity-containing AD layer 22 and the substrate It is possible to surely cause peeling in the interface region with 21.

  In addition, after the impurity-containing AD layer 22 is peeled off from the substrate 21 by heat treatment, a region having a high impurity concentration in the impurity-containing AD layer 22 (region close to the substrate 21) is removed by polishing or the like. Then, the remaining region, that is, a region with a low impurity concentration in the impurity-containing AD layer 22 (region away from the substrate 21) is further subjected to heat treatment. Thereby, the growth of crystal grains can be promoted while suppressing the generation of gas (that is, without generating hillocks).

Next, a composite structure according to a third embodiment of the present invention will be described with reference to FIG.
As shown in FIG. 11, the composite structure according to this embodiment includes a substrate 31, an impurity-containing AD layer 32, and an AD layer 33. Note that the substrate material, the inorganic material forming the AD layer, and the impurity components in this embodiment are the same as those in the first embodiment.

  The impurity-containing AD layer 32 is a peeling sacrificial layer mainly made of an inorganic material, and contains a predetermined amount of impurities (for example, carbon exceeding 150 ppm or 222 ppm by weight). The AD layer 33 is an inorganic material layer to which no impurity is added. The composition of the inorganic material forming the impurity-containing AD layer 32 and AD layer 33 may be the same or different from each other. Note that even an inorganic material layer to which no impurities are added may contain some carbon (for example, about 50 ppm) due to adsorption of organic substances in the air.

  In such a composite structure, in the film forming apparatus shown in FIG. 2, first, the impurity-containing AD layer 32 is formed on the substrate 31 while the impurity supply apparatus 6 is operated, and then the operation of the impurity supply apparatus 6 is performed. It can be produced by forming the AD layer 33 on the impurity-containing AD layer 32 in a stopped state.

  By heat-treating the composite structure shown in FIG. 11, gas is generated from the impurity-containing AD layer 32, and the impurity-containing AD layer 32 is peeled from the substrate 31. As a result, a single structure (AD layer) can be obtained. The impurity-containing AD layer 32 adhering to the AD layer 33 may be used as a part of the structure as it is, or may be removed by polishing or the like as necessary. Further, after peeling off the AD layer 33 from the substrate 31, annealing may be performed at a higher temperature (for example, 850 ° C. or higher). Thereby, the crystallinity of the AD layer 33 can be increased, and the function of the structure (for example, piezoelectric performance in the case of a piezoelectric body) can be improved.

  Also in the impurity-containing AD layer 32, as in the second embodiment, the impurity concentration may be changed in an inclined manner. For example, by increasing the impurity concentration on the substrate 31 side, peeling can be preferentially caused at the interface between the impurity-containing AD layer 32 and the substrate 31. On the other hand, by increasing the impurity concentration on the AD layer 33 side, separation can be preferentially caused at the interface between the impurity-containing AD layer 32 and the AD layer 33.

Next, a composite structure according to a fourth embodiment of the present invention will be described with reference to FIG.
As shown in FIG. 12, the composite structure according to the present embodiment includes a substrate 41, a first peeling sacrificial layer 42, a second peeling sacrificial layer 43, and an AD layer 44. Note that the substrate material, the inorganic material forming the AD layer, and the impurity components in this embodiment are the same as those in the first embodiment.

The first peeling sacrificial layer 42 has an inorganic material as a main composition and contains a predetermined amount of impurities (for example, carbon exceeding 150 ppm or 222 ppm by weight), and is formed by an AD method.
In addition, the second peeling sacrificial layer 43 is formed of a metal material having a melting point higher than the film formation temperature (for example, 400 ° C.) by the AD method and the heat treatment temperature (for example, 600 ° C. or more). It is formed using a known film forming method such as a plating method. As the second exfoliation sacrificial layer 43, for example, it is desirable to use a stable material such as platinum (Pt) that has little interaction with the composition of the adjacent AD layer (eg, PZT).

In order to improve the adhesion between the AD layer and the platinum layer, previously titanium oxide from the platinum layer may be formed (TiO ₂₎ layer. Furthermore, the thickness of the second peeling sacrificial layer 43 takes into account the depth of anchoring (for example, about 10 nm to 100 nm) that occurs when the AD layer 44 is formed when a metal material that can cause anchoring is used. For example, it is desirable to set it to 200 nm or more.
Furthermore, the AD layer 44 is an inorganic material layer to which no impurity is added.

  By heat-treating such a composite structure, gas is generated from the first exfoliation sacrificial layer 42, the interface between the substrate 41 and the first exfoliation sacrificial layer 42, and the first exfoliation sacrificial layer 42 and the second exfoliation sacrifice. Peeling occurs at the interface with the layer 43. Thereby, the structure (AD layer 44) can be obtained without damaging the peeled surface.

In general, the adhesion force between the second peeling sacrificial layer 43 and the AD layer 44 is greater than the adhesion force between the second peeling sacrificial layer 43 and the first peeling sacrificial layer. The layer 43 remains on the AD layer 44 side. This is because the anchor ring generated in the AD method is superior in base adhesion as compared with a general vacuum film forming method. The second peeling sacrificial layer 43 remaining on the AD layer 44 may be removed by polishing or the like, or may be used as an electrode while being attached to the AD layer 44.
According to the present embodiment, it is possible to use the structure (AD layer) without the trouble of removing the peeling sacrificial layer by polishing or the like.

Next, modified examples of the composite structure according to the first to fourth embodiments of the present invention will be described with reference to FIG.
The composite structure shown in FIG. 13 includes a substrate 51, a metal layer 52, and an impurity-containing AD layer 53. This composite structure is obtained by inserting a metal layer between a substrate and an impurity-containing AD layer with respect to the composite structure shown in FIG. The composition and formation method of the substrate 51 and the impurity-containing AD layer 53 shown in FIG. 13 are the same as those of the substrate 11 and the impurity-containing AD layer 12 shown in FIG.

The metal layer 52 is formed of a metal material having a melting point higher than the film formation temperature by the AD method and the heat treatment temperature, using a known film formation method such as an evaporation method. As the metal layer 52, it is desirable to use a stable material that has little interaction with the composition of the adjacent AD layer (for example, PZT), such as platinum (Pt). In that case, a titanium oxide (TiO ₂ ) layer may be further provided under the platinum layer as the adhesion layer.

  In the first to fourth embodiments described above, the impurity-containing AD layer is directly formed on the substrate (see FIGS. 1 and 10 to 12). Therefore, when a ceramic substrate is used, it is conceivable that the AD layer may be damaged particularly when a part of the impurity-containing AD layer remains on the substrate during the heat treatment. Therefore, in this modification, the metal layer 52 is provided so that the impurity-containing AD layer 53 is easily peeled off from the substrate 51. That is, in general, since the metal material allows gas to pass therethrough, the composite structure shown in FIG. 13 is heat-treated to generate gas from the impurity-containing AD layer 53, whereby the substrate 51 and the impurity-containing AD layer 53 are brought into contact with the metal layer. 52 can be smoothly peeled off at the boundary.

The metal layer 52 remaining in the impurity-containing AD layer 53 may be used as an electrode as it is, or an electrode may be formed by applying a metal paste or the like on the remaining metal layer. Alternatively, the metal layer 52 remaining in the impurity-containing AD layer 53 may be removed by polishing, or an electrode may be separately formed on the polished surface.
For the composite structures according to the second to fourth embodiments, by inserting a metal layer between the substrate and the impurity-containing AD layer, the damage on the peeling surface and its periphery is minimized, and peeling is performed. It becomes possible to proceed more smoothly.

  When a piezoelectric material such as PZT is used as the inorganic material of the composite structure according to the first to fourth embodiments of the present invention, an electrode is provided on a single piezoelectric film obtained by heat-treating the composite structure. By forming the piezoelectric element, a piezoelectric element can be manufactured. Such a film-like piezoelectric element can be used as a small piezoelectric actuator, a piezoelectric element for driving an inkjet head, or a transducer (ultrasonic transducer) for transmitting and receiving ultrasonic waves in an ultrasonic probe. Here, in the piezoelectric body, it is known that the single body peeled from the substrate exhibits higher piezoelectric performance than the state of being fixed to the substrate. Therefore, by separating and using the dense and strong piezoelectric film formed by the AD method from the substrate, it is possible to improve the performance of the piezoelectric element and the entire device including the piezoelectric element.

Next, a modification of the film forming apparatus shown in FIG. 2 will be described.
In this modification, instead of supplying the powder containing carbon in the impurity supply device 6 shown in FIG. 2, organic vapor is generated and supplied. Specifically, in the impurity supply device 6, for example, organic vapor such as hydrocarbon is heated to generate organic vapor, which is then fed into the gas nozzle 3. Thereby, the raw material powder arrange | positioned in the aerosol production | generation chamber 1 is exposed to the atmosphere of organic vapor | steam, and an impurity adheres to the surface of the raw material powder used as the aerosol state.

  In the above description, as shown in FIG. 2, the aerosol was generated by adding impurities while dispersing the raw material powder with gas. However, the raw material powder may be in an aerosol state by dispersing the raw material powder in advance, and impurities may be added to such raw material powder, or the raw material powder to which the impurities have been added in advance may be dispersed by gas. It is good also as a state.

  In the former case, for example, in the aerosol generation chamber 1 shown in FIG. 2, after the raw material powder is sufficiently dispersed, impurities (organic compound, carbon powder, organic vapor, etc.) are introduced from the impurity addition processing device 6. What is necessary is just to make it supply. In the latter case, for example, the raw material powder is dipped in an organic solvent and then dried, or the raw material powder is exposed to an organic vapor atmosphere for a predetermined period to produce a raw material powder having impurities attached to the surface. be able to.

  Alternatively, carbon powder or powder of a compound containing carbon may be mixed in the raw material powder in advance. Furthermore, the raw material powder may be coated by attaching a carbon powder having a particle size smaller than that of the raw material powder or a powder of a compound containing carbon to the surface of the raw material powder.

In the above description, PZT is used as the inorganic material, but PLZT (lanthanum-doped lead zirconate titanate), TiBaO ₃ (barium titanate), or Al ₂ O ₃ (aluminum oxide) is also used. ) Or the like can be used. For example, the PLZT film can be applied to an optical member, and the TiBaO ₃ film can be applied to a ceramic capacitor.

  The present invention uses a method for manufacturing a composite structure using an aerosol deposition method in which raw material powder is deposited on a substrate by spraying the raw material powder toward the substrate, and a method for manufacturing such a composite structure. The present invention can be used in a structure manufacturing method and a film forming apparatus, and a composite structure manufactured by such a composite structure manufacturing method.

It is sectional drawing which shows the structure of the composite structure which concerns on the 1st Embodiment of this invention. It is a schematic diagram which shows the structure of the film-forming apparatus with which the manufacturing method of the composite structure which concerns on the 1st-4th embodiment of this invention is used. It is a schematic diagram which shows the structure of the sample in the case of producing ceramics by a solid phase sintering method. It is a figure for demonstrating the principle which peeling of a film | membrane produces at the time of heat processing. It is a figure which shows the GC-MS analysis result with respect to commercially available raw material powder. Is a diagram illustrating the generation patterns of CO ₂ gas generated by heat-treating the PZT powder. And the amount of carbon adhering to the raw material powder is a diagram showing the relationship between the amount of CO ₂ gas generated by heat-treating the raw material powder. It is a figure which shows the GC-MS analysis result with respect to the raw material powder after the impurity addition process. It is a figure which shows the result of the experiment which heat-processes AD film produced with the PZT raw material powder from which carbon content differs. It is sectional drawing which shows the structure of the composite structure which concerns on the 2nd Embodiment of this invention. It is sectional drawing which shows the structure of the composite structure which concerns on the 3rd Embodiment of this invention. It is sectional drawing which shows the structure of the composite structure which concerns on the 4th Embodiment of this invention. It is sectional drawing which shows the structure of the modification of the composite structure which concerns on the 1st Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Aerosol production chamber 2 Shaking table 3 Hoisting gas nozzle 4 Pressure adjustment gas nozzle 5 Aerosol conveyance pipe 6 Impurity addition processing apparatus 7 Deposition chamber 8 Exhaust pipe 9 Injection nozzle 10 Substrate stage 11, 21, 31, 41, 51, 101 Substrate 12, 22, 32, 53 Impurity-containing AD layer 13 Raw material powder 33, 34 AD layer 42 First peeling sacrificial layer 43 Second peeling sacrificial layer 52 Metal layer 100 AD film 102 Bubble

Claims (38)

A raw material powder formed of an inorganic material, wherein the raw material powder containing impurities that generate gas by being heated is dispersed in a gas to form an aerosol state (a);
By spraying the raw material powder in an aerosol state toward the substrate, the raw material powder is newly deformed and / or crushed in the event of a collision so that particles having active surfaces newly generated are bonded together to deposit the raw material powder, Forming a polycrystalline structure containing impurities thereon (b);
A method for producing a composite structure comprising:   The method for producing a composite structure according to claim 1, wherein the impurities include carbon or a compound containing carbon.   The method for producing a composite structure according to claim 2, wherein the compound containing carbon includes an alkyl compound. The alkyl compound is C ₁₈ H ₃₆ , C ₁₈ H ₃₈ , C ₂₀ H ₄₀ , C ₂₀ H ₄₂ , C ₂₂ H ₄₄ , C ₂₂ H ₄₆ , C ₂₄ H ₅₀ , and C ₂₆ H. _The method for producing a composite structure according to claim 3, comprising at least one of ₅₂ and C ₂₈ H ₅₆ .   The method for producing a composite structure according to any one of claims 2 to 4, wherein the amount of carbon in the raw material powder is more than 150 ppm by weight.   The method for producing a composite structure according to any one of claims 1 to 5, further comprising a step (a ') of adding the impurities to the raw material powder before the step (a).   The manufacturing method of the composite structure of any one of Claims 1-5 including adding the said impurity to the said raw material powder, when a process (a) makes the said raw material powder into an aerosol state.   The manufacturing method of the composite structure of any one of Claims 1-5 in which a process (a) includes adding the said impurity with respect to the said raw material powder of an aerosol state.   The method for producing a composite structure according to any one of claims 1 to 8, wherein the step (a) or (a ') includes changing the content or addition amount of the impurities with time.   The method for producing a composite structure according to claim 9, wherein the step (a) or (a ′) includes reducing the content or addition amount of the impurities with time.   11. The composite structure according to claim 10, wherein the impurity includes carbon or a compound containing carbon, and the amount of carbon in the raw material powder is more than 150 ppm by weight at the start of formation of the polycrystalline structure. Production method.   The composite according to any one of claims 1 to 11, wherein the step (a) or (a ') includes mixing a powder of carbon or a powder of a compound containing carbon into the raw material powder as an impurity. Manufacturing method of structure.   The process (a) or (a ') includes attaching carbon powder or carbon-containing compound powder as impurities to the surface of the raw material powder. A method for manufacturing a composite structure.   The manufacturing of the composite structure according to any one of claims 1 to 11, wherein the step (a) or (a ') includes adding impurities by disposing the raw material powder in an atmosphere of organic vapor. Method.   The method for producing a composite structure according to claim 14, wherein step (a) or (a ′) includes generating organic vapor by heating the organic substance.   The method for producing a composite structure according to any one of claims 1 to 11, wherein the step (a) or (a ') includes adding impurities by immersing the raw material powder in an organic solvent.   The method of manufacturing a composite structure according to any one of claims 1 to 16, further comprising a step of forming a film of a metal material on the substrate before the step (b).   18. The method according to claim 1, further comprising a step (c) of directly or indirectly forming a second polycrystalline structure formed of an inorganic material on the polycrystalline structure. The manufacturing method of the composite structure of description.   19. The method of manufacturing a composite structure according to claim 18, further comprising a step of forming a metal material film on the first polycrystalline structure prior to the step (c). A plurality of steps included in the method for producing a composite structure according to any one of claims 1 to 19,
Peeling the at least the polycrystalline structure from the substrate by heating the composite structure;
The manufacturing method of the structure which comprises this.   21. The structure manufacturing method according to claim 20, further comprising a step of heat-treating at least the polycrystalline structure peeled from the substrate. A plurality of steps included in the method for producing a composite structure according to any one of claims 1 to 19,
Peeling the substrate from the substrate while heat-treating at least the polycrystalline structure by heating the composite structure;
The manufacturing method of the structure which comprises this. Aerosol generating means for making an aerosol state by dispersing raw material powder with gas,
Impurity supply means for supplying impurities to the aerosol generation means, which are impurities added to the raw material powder and generate gas when heated.
An injection nozzle for depositing the raw material powder on the substrate by spraying the raw material powder in the aerosol state by the aerosol generating means toward the substrate;
A film forming apparatus comprising:   The film forming apparatus according to claim 23, wherein the impurity includes carbon or a compound containing carbon.   The film forming apparatus according to claim 24, wherein the compound containing carbon includes an alkyl compound. The alkyl compound is C ₁₈ H ₃₆ , C ₁₈ H ₃₈ , C ₂₀ H ₄₀ , C ₂₀ H ₄₂ , C ₂₂ H ₄₄ , C ₂₂ H ₄₆ , C ₂₄ H ₅₀ , and C ₂₆ H. The film forming apparatus according to claim 25, comprising at least one of ₅₂ and C ₂₈ H ₅₆ .   27. The film forming apparatus according to claim 23, further comprising control means for changing the amount of impurities supplied by the impurity supply means over time. A substrate,
Using the aerosol deposition method, the raw material powder formed of an inorganic material is sprayed toward the substrate to cause the raw material powder to collide with the lower layer, so that the raw material powder is deformed and / or crushed at the time of collision. A polycrystalline structure formed directly or indirectly on the substrate by bonding particles having active surfaces generated in the substrate and depositing raw material powder, which generates gas when heated. The polycrystalline structure containing more than 150 ppm carbon by weight as impurities; and
A composite structure comprising: A substrate,
Using the aerosol deposition method, the raw material powder formed of an inorganic material is sprayed toward the substrate to cause the raw material powder to collide with the lower layer, so that the raw material powder is deformed and / or crushed at the time of collision. A polycrystalline structure formed directly or indirectly on the substrate by bonding particles having active surfaces generated in the substrate and depositing raw material powder, which generates gas when heated. The polycrystalline structure containing impurities and formed such that the concentration of the impurities varies according to the distance from the substrate;
A composite structure comprising:   30. The composite structure according to claim 28 or 29, wherein the impurities include carbon or a compound containing carbon.   The composite structure according to claim 30, wherein the compound containing carbon includes an alkyl compound. The alkyl compound is C ₁₈ H ₃₆ , C ₁₈ H ₃₈ , C ₂₀ H ₄₀ , C ₂₀ H ₄₂ , C ₂₂ H ₄₄ , C ₂₂ H ₄₆ , C ₂₄ H ₅₀ , and C ₂₆ H. and _52, including at least one of the _C 28 _{H 56,} claim 31 composite structure according.   33. The composite according to claim 29, wherein, in the polycrystalline structure, the concentration of the impurity at the interface on the substrate side is higher than the concentration of the impurity at the interface on the side opposite to the substrate. Structure.   34. The composite structure according to claim 33, wherein the amount of carbon in the polycrystalline structure is greater than 150 ppm by weight at the interface on the substrate side. A substrate,
Using the aerosol deposition method, the raw material powder formed of an inorganic material is sprayed toward the substrate to cause the raw material powder to collide with the lower layer, so that the raw material powder is deformed and / or crushed at the time of collision. The first polycrystalline structure formed directly or indirectly on the substrate by bonding the particles having active surfaces generated in the substrate and depositing the raw material powder, and the gas is generated by heating. The first polycrystalline structure containing more than 150 ppm by weight of carbon as impurities that generate
Using the aerosol deposition method, the raw material powder formed of an inorganic material is sprayed toward the first polycrystalline structure to cause the raw material powder to collide with the lower layer, whereby the first polycrystalline structure A second polycrystalline structure formed directly or indirectly thereon;
A composite structure comprising:   36. The composite structure according to claim 35, further comprising a film of a metal material formed between the polycrystalline structure and the second polycrystalline structure.   37. The composite structure according to any one of claims 28 to 36, further comprising a film of a metal material formed between the substrate and the polycrystal. The inorganic material is PZT (lead zirconate titanate), PLZT (lead lanthanum zirconate titanate), TiBaO ₃ (barium titanate), or Al ₂ O ₃ (aluminum oxide). 37. The composite structure according to any one of 37.