JP3140221B2 - Gold single crystal thin film, its production method and application - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device or an element useful for various electronic technologies, in particular, a surface acoustic wave element, a polycrystalline type curved crystal for X-ray spectroscopy which disperses X-rays and simultaneously collects or forms an image. The present invention relates to an electrode of a liquid crystal optical panel and an adhesive element for performing adhesion by an adhesive action using a hyperplane of a gold thin film, and also relates to a thin film composed of a gold single crystal or a group of gold single crystals used therein and a method of manufacturing the same.

[0002]

2. Description of the Related Art First, a prior art relating to the first invention, a surface acoustic wave device, will be described.

A surface acoustic wave element that generates and receives a surface acoustic wave by using at least one comb-shaped electrode (IDT) provided on a piezoelectric substrate has been actively studied in recent years, and has been widely applied to filters, resonators, convolvers, and the like. Have been. When a high-frequency electric signal is input to a comb-shaped electrode (IDT) provided on a piezoelectric substrate, electro-mechanical conversion occurs due to a piezoelectric effect of the piezoelectric substrate, and a surface acoustic wave is generated and propagates on the piezoelectric substrate. It has been known. These comb-shaped electrodes (IDT) are made of a conductive material such as Al or Au, and are usually formed using a photolithography technique.

FIGS. 19A and 19B are schematic views showing such a conventional surface acoustic wave device, wherein FIG. 19A is a plan view and FIG. 19B is a cross-sectional view taken along line AA 'in FIG. In the figure, 1 is lithium niobate (LiNb ₃ ), lithium tantalate (Li
A piezoelectric substrate such as TaO ₃ ) or quartz (SiO ₂ ), and 6 is a comb-shaped electrode formed on the surface of the piezoelectric substrate 1.

However, in the surface acoustic wave device of the above example, the comb-shaped electrodes are mainly formed of polycrystalline Al formed by a vapor deposition method, a sputtering method, or the like. There has been a problem of electrode deterioration such as migration occurring and disconnection of the comb-shaped electrode fingers.

It is considered that the mechanical migration is caused by polycrystalline metal atoms diffusing at grain boundaries due to surface acoustic wave stress.

[0007] The surface acoustic wave stress applied to the comb-shaped electrode increases as the power and frequency increase. Therefore, in a surface acoustic wave filter for communication or a surface acoustic wave resonator that requires high-frequency high-power transmission, the electrode deteriorates. Is even more problematic.

In particular, for a surface acoustic wave device for a mobile phone that requires 1 to 5 W of electric power in the 800 MHz band, it is essential to improve the comb-shaped electrode.

In order to suppress electrode deterioration due to such mechanical migration, for example, Cu or Ni is used for Al.
Is being studied to suppress the diffusion of metal atoms at the grain boundary, but further high durability is required, and there are problems such as variations and variations in electrode film composition and an increase in electrode film resistance. .

Next, a description will be given of a second invention, a prior art relating to a curved crystal for polycrystalline X-ray spectroscopy.

X having a relatively short wavelength of about 1 to 10 °
The wire is widely used for crystal structure evaluation, composition analysis, and the like.

For these measurements, it is often necessary to extract only the desired wavelength. In this wavelength range, a filter, a spectral crystal, a total reflection mirror, and the like have a spectral action. Among these, the filter and the total reflection mirror have a wide wavelength band, and the band is greatly restricted. Therefore, when a narrow wavelength band is required, a spectral crystal is used. Further, in the X-ray optical system, there is a case where an action of condensing the X-rays or forming an X-ray image at the same time as dispersing the X-rays is required. When these are performed in the narrow wavelength band, a curved crystal that has a spectral function and a condensing function by bending the crystal into a desired shape is often used.

In the case where X-rays are focused or focused only in one-dimensional direction, a cylindrical curved crystal is used. In contrast, when X-rays are condensed or imaged two-dimensionally, a three-dimensionally curved crystal such as an elliptical surface or a spherical surface is used.

The curved dispersive crystal utilizes a plastic deformation or an elastic deformation of the crystal material.
When the diameter is reduced to about cm, the crystal is cracked due to strain during processing. For this reason, the light-collecting performance and the spectral performance deteriorate, and when used for imaging, a uniform X-ray image cannot be obtained. Therefore, it is difficult to produce such a crystal having a small radius of curvature, and there is a problem that the apparatus becomes large. Also, it was difficult to deal with three-dimensional curved surfaces such as elliptical surfaces and spherical surfaces.

In order to solve these problems, a method of cutting a crystal thinly and attaching it to a desired curved surface has been devised. However, cracking and dislocation of the crystal cannot be prevented, and the resolution is reduced by stress. I will.

Furthermore, a method has been attempted in which a crystal is cut at a fine pitch and the crystal is joined on a curved substrate having a desired shape. However, this processing has a problem that processing is very difficult because the pitch of the cut is fine and the cut must be deep.

In addition, there has been proposed a method of growing a single crystal thin film on a desired curved substrate by using a technique of graphoepitaxy or selective nucleation. Graphoepitaxy forms a fine structure on the substrate surface, generates polycrystalline nuclei having a uniform crystal orientation by utilizing the property that the orientation of the crystal nuclei is influenced by the substrate structure, and grows them to continuously produce single crystals. It is about to crystallize. In the selective nucleation growth method, when a region having a high nucleation density is minutely provided on the surface of a substrate having a low nucleation density and a film-forming substance is deposited, a single nucleus is formed on the material having a high nucleation density. Then, the polycrystalline thin film is grown on the substrate surface having a low nucleation density to form a polycrystalline thin film.

In a curved dispersive crystal, the crystal lattice plane to be diffracted by X-rays must be curved into a desired shape. For this reason, in the above method, the crystal is grown by controlling the orientation of the crystal so as to have a crystal lattice plane in parallel on a curved substrate having a desired shape,
This is for forming a polycrystalline or single-crystal thin film having a crystal plane along the curved surface of the substrate. At present, a perfect single crystal cannot be obtained even by the graphoepitaxy method, and it is a mosaic-like polycrystal. Therefore, in practice, a polycrystalline thin film in which individual crystals are oriented perpendicular to the substrate surface.

When a polycrystalline thin film is formed on a curved substrate to form a spectral crystal, the most important thing is the parallelism between each crystal plane and the substrate surface. This tolerance depends on the focal length, image resolution,
Determined by energy resolution and the like. For example, a magnification of 20
In order to obtain an image resolution of 10 μm in an imaging system having a distance of 10 cm between the crystal plane and the image, the shift angle of the crystal must be 10 ⁻³ rad or less. Generally, when the diffraction intensity curve of a single crystal is measured by the X-ray diffraction method, the spread is 10 ⁻⁴ ra.
Although it is about d, the crystallinity of the polycrystalline thin film obtained by the graphoepitaxy has a considerable variation in both the vertical direction and the horizontal direction with respect to the substrate, and the vertical There may be a variation of about 2.5 × 10 ^-2 rad or more. In selective nucleus growth, the shift angle of the crystal is even larger. For this reason, there is a problem that the spectral performance, the light-collecting performance, and the imaging performance cannot be sufficiently obtained with the polycrystalline spectral crystals produced by these methods.

In the selective nucleus growth method and the like, since a crystal thin film is formed by a CVD method and the substrate temperature is raised to several hundred degrees or more, the substrate previously formed into a desired shape by polishing or the like is greatly deformed. Was also a problem.

Next, a third invention, a conventional technique relating to an electrode of a liquid crystal optical panel, will be described.

With the advance of electronics technology, especially semiconductor technology, the amount of information that can be handled is increasing at an accelerating rate. Correspondingly, the majority of information exchanges between electronic devices and humans are done through vision, making them more and more dependent on displays.

In order to make the conventional liquid crystal optical panel higher in gradation, higher in contrast and higher in brightness, or in order to realize a high image quality on a large screen, a large panel and a large number of pixels have been actively researched and developed. . In order to simultaneously satisfy the demand for larger panels and higher performances, there is an increasing demand for technical contents that have not been regarded as a problem in conventional liquid crystal panel manufacturing techniques.

Conventionally, a liquid crystal optical panel is, for example, a TFT-LCD.
There is an example in which amorphous Si is used in an LCD, and FIG. 27 shows a general configuration thereof. In the same figure, 213 is amorphous Si, 214 is a gate electrode, 215 is a gate insulating film, 216 is a pixel electrode, 217 is a protective film, 218 is a drain electrode (V _D ), 219 is a source electrode (V _COM ), 2
Reference numeral 20 denotes a black matrix, and 221 denotes a color filter. 203 is an alignment film, 204 is a glass substrate, 2
07 denotes a common electrode (V _COM ), and 209 denotes a liquid crystal. The common electrode 207 for the pixel electrode 216 is generally formed as a solid film on one surface of the panel as shown in FIG. Normally, ITO or the like is used as an electrode having high transmittance, and has good conductivity and good transmittance.
A sputtering method is used as a film forming method for satisfying the two conditions.

However, in the conventional configuration, since the common electrode is solidly formed by sputtering or the like, there is a problem that the glass substrate is distorted by stress. Therefore, when forming a liquid crystal panel having a size of 3 inches to 5 inches or more, it is very difficult to form a constant gap between the liquid crystal layers at the center and the end of the panel. As a result, the image quality deteriorates at the edges and the reliability of the panel deteriorates. Further, there is a serious problem in performing gradation display using ferroelectric liquid crystal or the like.

In particular, in the case of a ferroelectric liquid crystal which has a characteristic of having a high-speed response as compared with a TN (twisted nematic) liquid crystal conventionally used as a display element, generally, it is generally required to control the alignment. Gap is 1-2
It is extremely thin as μm. On the other hand, larger LCD panels
It is inevitable that the uniformity of the gap is more and more strictly required as the gradation becomes higher.

Further, a fourth invention, a prior art relating to an adhesive element, will be described.

Conventionally, the Journal of the Japan Institute of Metals (Vol. 46, No. 9,
As described in 1982, pp. 935-943), room temperature pressure bonding (adhesion) is to remove the surface film by ion sputtering in an ultra-high vacuum, and then to reduce the bonding surface gap to a distance on the order of atoms. It required plastic deformation to produce a slip line. That is, an external load was required at the time of bonding in order to cause plastic deformation.

However, in the above-mentioned conventional example, the metal is mainly joined by melting and diffusing at a high temperature, such as welding, diffusion or normal temperature welding, or while being plastically deformed by applying a load at normal temperature. Each of them has the following drawbacks, since it must be performed by the action of making the bonding surface gap close to the atomic order distance. (1) Since it is performed at a high temperature, it is difficult to bond materials having a large difference between melting points. (2) Since the bonding is carried out by high-temperature diffusion, the bonding time is prolonged, so that an intermetallic compound is easily generated at the bonding interface. (3) In the case of bonding at room temperature, application of an external load causes plastic deformation of the bonding material, so that a large external load needs to be applied during bonding.

[0030]

SUMMARY OF THE INVENTION An object of the present invention is to provide a gold single crystal thin film which can solve the above-mentioned problems. The present invention also provides various uses of the gold single crystal thin film.

[0031]

Means for Solving the Problems The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, decompose the gold complex in the gold complex solution to shift the gold in the solution to a supersaturated state. As a result, a single crystal and a gold crystal thin film composed of a single crystal group can be formed on the substrate surface, and the present invention has been completed.

[0032]

In order to facilitate the understanding of the present invention, the gold complex in the gold complex solution is decomposed to shift the gold in the solution to a supersaturated state, thereby forming a gold thin film comprising a group of gold single crystals on the substrate surface. The formation process will be described.

As an example, a case where a thin film is formed on a LiNbO ₃ substrate by [AuI ₄ ] ⁻ as a gold complex and volatilization as a decomposition treatment means will be described.

First, potassium iodide and iodine are added to distilled water to prepare an aqueous iodine solution, and then gold is added to prepare a gold complex solution containing [AuI ₄ ] ^- . At this time, it is considered that I ₃ ⁻ and K ⁺ exist in the solution in addition to [AuI ₄ ] ⁻ .

Next, after the surface of the LiNbO ₃ substrate is brought into contact with the above solution, the temperature of the solution is raised to 30 to 100 ° C. to promote the volatilization of the iodine component. For maintenance of equilibrium due to volatilization of iodine component which is present in the state, ^- I ₃ are in a solution system
It is considered that decomposition due to dissociation of the iodine component from [AuI ₄ ] ⁻ or decomposition due to direct volatilization of the iodine component in the complex existing in the form of [AuI ₄ ] ⁻ progresses, and as a result, the gold becomes supersaturated. .

Although the type of gold complex and the method of decomposition are different, gold powder for a conductive gold paste is deposited in a floating state in the system by utilizing the gold supersaturation phenomenon in the solution due to such decomposition of the gold complex. The technique for this is disclosed in JP-A-56-38406 and JP-A-55-54509. The present inventors have found that the supersaturated gold in the solution is randomly deposited as nuclei on the substrate surface, and thereafter the nucleation continues for a while, but when a certain number of nuclei are formed. Then, it was found that the growth of nuclei stopped, the nuclei grew in a single crystal in a self-aligned manner, and the growth was continued, whereby grain boundaries were formed by collision between the single crystals.

The gold complex used in the present invention includes [A
uI ₄ ] ^- , [AuCl ₄ ] ^- , [Au (CN) ₂ ] ^- , [A
u (CN) ₃ ] ^{— and the} like.

The means for decomposing the gold complex in the present invention include a method of volatilizing a readily volatile component such as an iodine component in the complex by heating to shift gold to a supersaturated state,
A method such as reduction to a gold atom by adding a reducing agent may be used.

The heating temperature is preferably about 30 to 100 ° C.

As the reducing agent, for example, hydroquinone,
Pyrogallol, pyrocaquiten, guxin, methol hydroquinone, amidole, methol, sodium sulfite,
In addition to sodium thiosulfate, substances having a reducing action in a solution are used.

In the present invention, a substrate on which a gold single crystal thin film is to be formed is brought into contact with or dipped in a solution containing the above-described gold complex, and heating or addition of a reducing agent is started so that the gold single crystal is formed on the substrate. A crystalline thin film is formed.
FIG. 1 shows a process of forming the gold single crystal thin film. First, a nucleus is generated on the surface 2 of the substrate 1 (FIG. 1A), and a single crystal grows in a self-aligned manner in the plane direction of the substrate around the nucleus (FIG. 1B). The crystals collide with each other to form grain boundaries 4 and stop crystal growth (FIG. 1C). In the obtained thin film of the gold single crystal group, as shown in FIG. 2, the gold single crystals 3 grown at random form grain boundaries 4.

The gold crystal thin film formed by the above method is a single crystal having no defect, and has a 111 direction perpendicular to the substrate. Further, the crystal surface is extremely smooth.

The crystal orientation, which is important when used as a spectral crystal, is extremely high, and is slightly inferior to that of a Si single crystal. When the diffraction intensity curve is measured by the X-ray diffraction method, the angular spread of the diffraction peak is almost 10 ⁻³ ra.
d or less and does not exceed 10 ^-2 rad. Therefore,
By forming the above-described gold crystal thin film as an X-ray diffraction layer on a curved substrate having a desired shape and forming a curved crystal for X-ray spectroscopy, it is possible to create a curved crystal having a small radius of curvature. Compared to the case where the X-ray diffraction layer is formed by the selective nucleus growth method, the spectral performance and the light collecting performance are higher, and when used for imaging, a high image resolution and a uniform image can be obtained. Further, since the surface is extremely smooth, not only the secondary processing of the surface is not required, but also the scattered light can be extremely reduced.

Further, the present method is characterized in that since a crystal thin film can be formed almost at normal temperature and normal pressure, deformation of the substrate after film formation is extremely small, and the shape of the substrate can be maintained.

[0045]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

Example 1 A surface made of a material having a high nucleation density was obtained by using Ti, a surface having a low nucleation density was LiNbO ₃ , [AuI ₄ ] ⁻ was used as a gold complex, and volatile was used as a decomposition treatment means. An example of producing a comb-shaped electrode for a surface acoustic wave device will be described.

First, Ti is vapor-deposited on the entire surface of the LiNbO ₃ wafer 1 and then etched by using a resist.
As shown in FIGS. 3 (a) and 3 (b), _{3 is formed} on the LiNbO ₃ wafer.
A substrate in which a × 3 μm square Ti thin film 2 was formed substantially at the center of the comb-shaped electrode forming region was obtained.

In the present invention, nucleation of only a single nucleus can be performed by making the surface made of a material having a high nucleation density a sufficiently small area. 10 μm or less, more preferably 5 μm
It is as follows.

Next, potassium iodide and iodine are added to distilled water to form an aqueous iodine solution, and then gold is added and stirred and dissolved to prepare a gold complex solution containing [AuI ₄ ] ^- . At this time, in addition to the gold complex [AuI ₄ ] ⁻ ,
It is considered that ₃ ^- and K ⁺ exist.

The aqueous iodine solution can also be prepared by dissolving an iodide compound other than potassium iodide, for example, ammonium iodide. Further, an iodine alcohol solution using an alcohol as a solvent or an iodine alcohol aqueous solution using a mixture of alcohol and water as a solvent can also be used in the present invention. The concentration of iodine or iodide compound in the solution defines the amount of gold that can be dissolved.

Next, after the surface of the substrate is brought into contact with the solution, the temperature of the solution is raised to 30 to 100 ° C. to promote the volatilization of the iodine component.

[0052] In the solution-based, I ₃ ^- for the maintenance of the equilibrium state of the solution system caused by volatilization of iodine component which is present in the state,
It is considered that decomposition due to dissociation of the iodine component from [AuI ₄ ] ⁻ or decomposition due to direct volatilization of the iodine component in the complex existing in the form of [AuI ₄ ] ⁻ progresses, and as a result, the gold becomes supersaturated. . The supersaturated gold 3 in the solution precipitates as a single nucleus only on the surface of the Ti thin film 2 having a high nucleation density. At this time, LiNbO having a low nucleation density is used.
_{3 No} nuclei were found on the wafer surface 5 (see FIG. 4).
(A), (b)).

As a result of the analysis, the formed crystal was a single crystal having no defect and had 111 orientations. Further, as a result of observing the growth rate, the ratio of the vertical direction to the horizontal direction was 1: 1.
It was found that the growth was at a rate of 00 to 200.

When the growth is further continued, the particle size becomes about 100
A gold crystal thin film composed of a single crystal of 0 μm was formed (FIG. 5).
(A), (b)).

As described above, the gold single crystal thin film according to the present invention
The formation position (crystal position and grain boundary position) can be determined in design.

This embodiment shows an effect that a gold single crystal having an extremely smooth surface can be formed. This is considered to be because the iodide ions present in the solution suppress further generation of new nuclei on the growing gold crystal due to the gold dissolving action.

Thereafter, the same resist pattern 7 as the desired comb-shaped electrode pattern is formed on the single-crystal gold thin film by using a usual photolithography technique (FIGS. 6A and 6B), and then etched. Then, the comb-shaped electrode 6 was formed by removing the gold in the portion where the resist pattern was not formed (FIGS. 7A and 7B).

Embodiment 2 Next, an example in which a comb-shaped electrode is manufactured using a reducing agent as a decomposition processing means will be described.

In the same manner as in Example 1, a substrate was obtained in which a 3 × 3 μm square Ti thin film was formed on the LiNbO ₃ wafer at almost the center of the comb-shaped electrode forming region. Next, the substrate was brought into contact with the same gold complex solution as in Example 1. Next, an aqueous hydroquinone solution as a reducing agent was slowly dropped into the gold complex solution to cause crystal growth. Further grow, average particle size 100μ
m single crystals could be selectively formed.

After that, the same resist pattern as the desired comb-shaped electrode pattern is formed on the gold single crystal thin film by using the usual photolithography technique, and then the gold in the portion where the resist pattern is not formed is removed by etching. By removing, a comb-shaped electrode was formed.

Example 3 As in Example 1, Ti was vapor-deposited on a LiNbO ₃ wafer and then etched using a resist to form a film on the LiNbO ₃ wafer 1 as shown in FIGS. 8A and 8B. 3
A substrate in which a × 3 μm square Ti thin film 2 was formed in a matrix with a feeling of 100 μm was obtained.

The distance between the nucleation planes is a range in which nuclei are not formed by long-range order in order to suppress nucleation on a material having a low nucleation density, that is, the average grain size when a thin film is formed over the entire surface under the same conditions. The following ranges are preferred.

Next, a gold crystal was deposited in the same manner as in Example 1. The supersaturated gold in the solution precipitates as a single nucleus only on the surface of the Ti thin film 2 having a high nucleation density, and no nucleus is observed on the surface 5 made of a material having a low nucleation density. (FIGS. 9A and 9B).

When the crystal growth is further continued, the crystals collide with each other, and a grain boundary is formed almost in the middle of each surface made of a material having a high nucleation density, and there are many surfaces made of a material having a low nucleation density. As shown in FIGS. 10A and 10B, a gold crystal thin film 3 composed of a single crystal group having a particle size of about 50 μm was formed in the comb electrode forming region.

Thus, the formation position (crystal position and grain boundary position) of the gold single crystal of the present invention can be known in design.

Thereafter, as shown in FIGS. 11A and 11B, the same resist pattern as the desired comb-shaped electrode pattern is formed on the gold single crystal thin film by using the ordinary photolithography technique, and then the etching method is performed. As a result, a comb-shaped electrode was formed by removing gold in a portion where a resist pattern was not formed (FIGS. 12A and 12B).

Example 4 First, a negative resist pattern of a comb-shaped electrode was formed on a LiNbO ₃ wafer by using a usual photolithography technique (FIGS. 13A and 13B). Next, potassium iodide and iodine are charged into distilled water to form an aqueous iodine solution, and then gold is charged and stirred and dissolved to prepare a gold complex solution containing [AuI ₄ ] ^- . Next, after the surface of the substrate is brought into contact with the solution, the temperature of the solution is raised to 30 to 100 ° C. to promote the volatilization of the iodine component. The supersaturated gold in the solution precipitates as random nuclei on the LiNbO ₃ substrate and the resist. At this time, the nuclei grow in a self-aligned manner while maintaining a low nucleation density.

As the growth continues, the crystals collide with each other,
Grain boundaries are formed. On the LiNbO ₃ substrate, the crystals that collided with the resist stopped growing, covered the surface of the comb-shaped electrode pattern region on the substrate, and formed a gold crystal thin film pattern composed of a group of single crystals with a particle size of about 50 μm (FIG. 14 (a),
(B)). Thereafter, the resist and the gold thin film on the resist were removed to obtain a comb-shaped electrode (FIGS. 15A and 15B).

Example 5 As a fifth embodiment, an example in which a comb-shaped electrode is formed using a resist as a surface made of a material having a high nucleation density and a resist as a surface made of a material having a low nucleation density is used. Will be described.

After the Cr surface 2 was deposited on the comb electrode forming region on the LiNbO ₃ wafer, a negative resist pattern 7 for the comb electrode was formed (FIGS. 16A and 16B).

Next, by depositing a gold crystal in the same manner as in Example 1, as shown in FIG.
The region where the resist pattern was not formed on the bO ₃ substrate was buried. Thereafter, the resist and Cr were removed to obtain a comb-shaped electrode 6 (FIGS. 18A and 18B).

As described above, by forming Cr between the gold thin film and the LiNbO ₃ substrate, the adhesion of the gold thin film can be improved.

In the present invention, the surface made of a material having a low nucleation density and the surface made of a material having a high nucleation density are not limited. It is sufficient that the material having a high formation density is a surface that is sufficiently fine to form a single nucleus.

The maximum distance between a surface made of a material having a low nucleation density and a surface made of a material having a high nucleation density is the same as that of a surface formed of a material having a low nucleation density under the same conditions. It is preferable that the average particle diameter is within the range.
In other words, in order to increase the maximum spacing, LiNbO ₃ , LiTa having a particularly low nucleation density are required.
It is preferable to use an insulating material such as O ₃ , SiO ₂ , and Al ₂ O ₃ .

Materials having a high nucleation density include Au,
Ti, Cr, Cu, W, WSi, MoSi, Fe, S
Conductive and semiconductor materials such as i and Ge can be used.

In the above embodiment, a surface acoustic wave filter is shown as an example of a surface acoustic wave element.
A similar effect can be obtained with an element using a comb electrode, such as a surface acoustic wave resonator and a surface acoustic wave convolver.

The substrate 1 is not limited to a piezoelectric single crystal such as lithium niobate, but may have a structure in which a piezoelectric film is added on a semiconductor or glass substrate, for example.

Further, by making the comb-shaped input electrode in the above embodiment a double electrode (split electrode), it is possible to suppress the reflection of surface acoustic waves at the input electrode, and to further improve the characteristics of the element. Can be.

In the above embodiment, the surface acoustic wave excited from the comb-shaped electrode can be applied not only to a Rayleigh wave but also to a surface acoustic wave that can be transmitted and received by a comb-shaped electrode such as a Love wave or a Sezawa wave.

Embodiment 6 Next, a polycrystalline curved crystal for X-ray spectroscopy will be described.

FIG. 20 is a typical view showing the structure of a curved crystal 103 for polycrystalline X-ray spectroscopy according to the present invention. In FIG. 1, reference numeral 101 denotes a substrate processed into a curved shape,
Numeral 02 is an X-ray diffraction layer of a crystal thin film composed of a group of gold single crystals formed by the present method.

An embodiment in which the curved crystal for X-ray spectroscopy of the present invention is used in an imaging optical system will be described below.

A silicon carbide substrate polished to form a part of a spheroid having a major axis of 300 mm and a minor axis of 50 mm and having a concave surface polished into a substrate 10
Used as 1. After 30 ml of hydrochloric acid and 10 ml of nitric acid are mixed to prepare aqua regia, 2 g of gold is added to this solution and dissolved by stirring. After dissolution, a 10 ml aliquot is taken from this solution and placed in a reaction vessel, to which 100 ml of distilled water is further added and stirred.
Next, sodium hydroxide (NaOH) was added to this solution for 1 hour.
An aqueous solution in which 0 g is dissolved is gradually added.

The surface of the substrate is brought into contact with this solution, and the solution is kept at 40 ° C. After about one hour, a gold crystal thin film composed of a group of gold single crystals having a particle size of about 100 μm is formed on the substrate. Using this gold crystal thin film as the X-ray diffraction layer 102,
The curved crystal 103 for X-ray spectroscopy is formed.

FIG. 21 shows a configuration of an X-ray imaging optical system using the curved crystal 103 for spectrum. 104 is an X-ray source, 103 is a curved crystal for spectroscopy, 105 is an X-ray, 106 is a detector, 107 is an object (sample) to be measured, 108 is an object image formed on the detector 106, 109 is An incident light cutting aperture 110 is a diffracted light cutting aperture. The sample 107 is illuminated by using an X-ray tube of a copper target as the X-ray source 104. Sample 107 and detector 10
Numeral 6 is arranged on the focal point of the spheroid of the curved crystal for spectroscopy 103. At this time, the incidence / emission angle of the X-rays to / from the curved crystal for spectroscopy 103 is 19.09 °. Therefore, the X-rays 105 transmitted and scattered from the sample 107 are reflected and diffracted by the curved crystal for spectroscopy 103 to form an object image 108 on the detector 106. At this time, X-rays having different wavelengths are emitted from the curved bending crystal 103.
Since the diffraction angles at the light source are different from each other, an object image can be obtained only by X-rays of a desired wavelength by the diffracted light cutting aperture. As a sample 107, a 3 μm mesh pattern formed of gold on a silicon nitride membrane was used.
When an X-ray film is used as the detector 106, a mesh pattern of the sample 107, which is enlarged about 14 times, is clearly observed on the X-ray film. From this, the Kβ line and continuous line of copper are separated by the curved crystal for spectroscopy, and the K
It can be seen that a uniform image is formed only by α rays.

Conventionally, a curved crystal having a radius of curvature of about 50 mm is
Although it was difficult to produce single crystals by elastic or plastic deformation, selective nucleus growth and graphoepitaxy could not provide sufficient spectral performance and imaging.However, the method of the present invention required a small spectral radius with a small radius of curvature. It was shown that crystals could also be made.

Embodiment 7 Next, an embodiment in which the curved crystal for X-ray spectroscopy of the present invention is used for spectroscopy and focusing will be described.

The curved crystal used in this embodiment is prepared as follows.

The quartz is polished so as to form a concave spherical surface having a radius of 80 mm to obtain a substrate 101. Potassium iodide and iodine are added to distilled water to prepare an aqueous iodine solution, and then gold is added and stirred and dissolved to prepare a gold complex solution containing [AuI ₄ ] ^- . Next, after the surface of the substrate 101 is brought into contact with the solution, the temperature of the solution is raised to 70 ° C. to promote volatilization of the iodine component. The supersaturated gold in the solution precipitates on the substrate,
A gold crystal thin film 102 composed of a group of gold single crystals having a particle size of about 400 μm is formed. Each gold single crystal of this gold crystal thin film is oriented 111 with respect to the substrate. The thickness of the gold crystal thin film is about 3 μm. The gold crystal thin film is used as an X-ray diffraction layer.

FIG. 22 shows a structure in which the curved crystal for spectrum 103 is applied to an electron beam excited X-ray composition analysis method.

An electron gun 111 irradiates a sample 113 with an electron beam 112 generated thereby. As a result, fluorescent X-rays 114 corresponding to the composition are generated from the sample.
Since the fluorescent X-rays are generated in a wider direction than the sample surface, the fluorescent X-rays are condensed using the curved crystal for spectroscopy 103, and the X-rays are separated at the same time. For this purpose, the sample 113 and the diffracted X-ray cutting aperture 115 are arranged on a Roland circle having a radius of 40 mm such that the X-ray incidence / emission angle θ to the curved bending crystal becomes the Bragg angle of the X-ray wavelength to be separated. . The curved curved crystal 103 is arranged so as to be in contact with the top of the Rowland circle. The wavelength of the X-ray to be detected can be changed by moving the arrangement of the curved crystal 103 for spectroscopy, the aperture 115 and the detector 116 behind the same along a Rowland circle, and changing the incident / emission angle θ of the X-ray. it can.

When a metal plate containing titanium and vanadium was used as the sample 113 and the X-ray incident angle θ was changed and the X-ray spectrum was measured, the titanium and vanadium were clearly separated at θ = 35.7 ° and 32.1 °, respectively. It has been observed.
This indicates that the curved crystal for X-ray spectroscopy according to the present invention has an appropriate spectral performance. Further, the Roland circle can be reduced to a radius of 40 mm, and the size of the entire apparatus can be reduced.

Embodiment 9 Next, an embodiment of an electrode for a liquid crystal optical panel according to the third invention of the present application will be described. FIG. 23 is a drawing that best illustrates the features of the present invention.
Is a transparent electrode made of ITO or the like, 202 is an electrode part having no stress (or extremely small), and 203 is a liquid crystal alignment film.

The electrode 203 shown in FIG.
4 can be formed. That is, first, the liquid crystal panel driving wiring 2
A resist pattern 210 is formed in a region which is the same as or narrower than a portion which is shielded by light 05 (the same applies to both a simple matrix and an active matrix TFT) by using a normal photolithography technique. At this time, a resist such as photosensitive PI (positive type) or OMR-83 (negative type) is preferably used so that the resist can be easily removed in a later step. Exposure can be performed using ultraviolet light or far ultraviolet light. As described above, the gold single crystal thin film 202 ′ is formed on the substrate surface on which the resist pattern has been formed.

As a method of forming a gold single crystal thin film, the gold complex in the above-described embodiment is decomposed to change the gold in the solution to a supersaturated state, and the gold crystal composed of a single crystal group is formed on the substrate surface. A method for forming a thin film can be appropriately selected and used.

The supersaturated gold in the solution precipitates randomly as nuclei on the substrate surface. Thereafter, the nucleus formation continues for a while, but when a certain number of nuclei are formed, the increase of the nuclei stops, and the nuclei grow in a self-aligned single crystal. Thereafter, by continuing growth, each single crystal collides with each other to form a grain boundary. When the growth is further continued, the crystals collide with each other, and a grain boundary is formed almost in the middle of each surface made of a material having a high nucleation density, thereby covering the substrate surface and forming a gold crystal thin film. This film is defect-free, has low stress, has perfect orientation, and has extremely excellent conductivity and thermal conductivity.

After a gold single crystal thin film having a desired film thickness is formed on a portion where a resist pattern is not formed as described above, the resist pattern and the gold single crystal formed on the resist are removed with a normal resist remover. The thin film is simultaneously removed.

Conventionally, IT used as a transparent electrode
O has a thickness of 1000 to 1000 for ensuring sufficient conductivity.
Approximately 3000 $ is required. For example, if the gold single crystal film is formed to have a thickness substantially equal to the thickness of ITO, a resist covering the gold single crystal pattern is formed as follows by utilizing a sufficient shielding of ultraviolet light and far ultraviolet light. That is, FIG.
As shown in FIGS. 4 (e) and 4 (f), a resist is applied to the surface on which the gold pattern is formed, and the resist is exposed by irradiating ultraviolet light or far ultraviolet light from the glass substrate side, and then developed. The resist can be formed only on the gold pattern.

When ITO having a desired film thickness is formed by sputtering (FIG. 9G) and the resist is removed, an electrode surface which is a partially gold single crystal film as shown in FIG. it can.

By using this process, it is possible to form an electrode plate as shown in FIG. 25 such that the gold single crystal pattern 202 is accommodated in the portion 208 that is shielded from the liquid crystal drive wiring portion. Here, reference numeral 212 denotes an opening (non-light-shielding portion).

The electrode fabricated as described above is made of ITO
The problem that the substrate is distorted by the stress caused by the above and the gap of the liquid crystal panel is different between the center portion and the end portion of the panel is solved. As a result, the orientation of the liquid crystal is uniform over the entire panel, and high-definition display is possible. Also,
Since a desired value can be uniformly maintained in the gap of each pixel, a liquid crystal panel with excellent gradation can be provided by making maximum use of power supplied by transistors and the like.

Further, according to the above-described method for producing a gold single crystal film, since the film is formed in a solution at about 30 to 100 ° C.,
Compared to other film formation, there is an advantage that a film can be formed in a large area at the same time as a low-temperature process.

It is not necessary to provide a low-stress part in all the parts shielded from light by the drive wiring part. A necessary and sufficient amount depends on the stress generated by the characteristics of the process when forming the transparent electrode film, the direction and the size. The low stress portion may be provided, and for example, it may be formed in a pattern as shown in FIG. As a result, the gap between the center portion and the end portion of the relatively large liquid crystal panel such as 3 to 5 inches is made uniform, and high-definition display can be performed.

Embodiment 10 FIG. 28 shows an example in which a gold single crystal thin film according to the present invention is used for an adhesive element. In the figure, 301, 302, and 303 are S
An i-substrate, 304 is a weight portion made of a Si substrate, 305 is a Si substrate that mechanically connects the weight portion 304 and the Si substrate 303 by adhesion, and 306 is a surface formed by plating on the Si substrate 301. 2 μm thick and 500 μm in size with a smoothness of about 20 angstroms
307 is a gold single crystal thin film similar to the gold single crystal thin film 306 formed on the Si substrate 302, and 308 and 309 are gold single crystal thin films formed on both surfaces of the Si substrate 303 This is a gold single crystal thin film similar to the thin films 306 and 307.

Next, in the above configuration, the Si substrates 301, 302 and 303 can be integrated with each other by pushing the Si substrates 301 and 302 from both sides of the Si substrate 303 with a load F. 303 and the gap between the Si substrates 302 and 303 can be controlled to the thickness of the gold single crystal thin films 306 to 309. Note that the load F was extremely small, and the Si substrates 301, 302, and 303 adhered to each other only by being gently placed.

Si using the bonding elements 306 to 309
Bonding of the substrates 301 to 303 was performed at normal temperature and in the air, and by using the present bonding element, a structure of an acceleration sensor as shown in FIG. 28 could be easily manufactured.

The gold single crystal thin film as the adhesive element was formed as follows.

4 g of potassium iodide and 6 g of iodine were added to 500 ml of distilled water, and dissolved by stirring.
Was added and stirred and dissolved, 100 ml of the solution was taken, put into a reactor, further added with 500 ml of distilled water and stirred, and then hydroquinone 100 m was added to the obtained solution.
50 ml of an aqueous solution in which g was dissolved was gradually added, and then a film was formed by immersing the Si substrate in this solution for 3 hours at room temperature.

Embodiment 11 FIGS. 29 to 31 illustrate a second embodiment of the adhesive element.
Reference numerals 06 and 307 denote the same components as those in FIG.
The glass rod 311 that is mechanically connected to the substrate 301 by anodic bonding prevents a large load from being generated when the bonding elements 306 and 307 are bonded, that is, a spring (plate) having a small elastic coefficient for generating a minute load. Reference numeral 312 denotes a micrometer capable of freely moving the bonding element 306 in the XYZ directions.
Denotes a stage, 314 denotes a heat resistant glass (product name: Pyrex) for anodic bonding with the Si substrate 302, and 315 denotes a heater.

Next, in the above configuration, the micrometer 3
When the adhesive element 306 and the adhesive element 307 come into light contact with each other by operating No. 12, the adhesive element 306 is pulled upward (FIG. 3).
0). That is, the Si substrate 302 is simultaneously pulled up. At the next stage, the above-described Si is placed on the heat-resistant glass 314 on the heater 315 by operating the micrometer 312.
The substrate 302 is placed, and the heat-resistant glass 314 is placed on the Si substrate 30.
After anodic bonding to No. 2, the adhesive element 306 is slowly moved in the direction of the arrow (FIG. 31). This method makes it possible to prevent particles and the like from being contaminated by the conventional tweezers. The Si substrate 302 and the heat-resistant glass 3 in a particle-free or dust-free state between the bonding surfaces can be prevented.
14 became possible.

The gold single crystal thin film as the adhesive element used in this embodiment was also formed on a Si substrate in the same manner as in the tenth embodiment.

[0112]

As described above, the present invention shifts gold in a solution containing a gold complex to a supersaturated state, thereby eliminating the need for any special device and at a temperature close to normal pressure and normal temperature. Thus, a thin film composed of a gold single crystal and a group of gold single crystals can be selectively formed. The gold single crystal thin film obtained by the present invention has a crystal plane oriented in 111 with high precision in a direction perpendicular to the substrate, and can form an extremely smooth plane.

Using the gold single crystal and the thin film composed of the gold single crystal group, a surface acoustic wave device having a comb-shaped electrode having excellent resistance to mechanical migration and oxidation and having low electric resistance can be manufactured. . In addition, by forming a thin film composed of a group of gold single crystals on a curved substrate having a desired shape, a polycrystalline type having a small radius of curvature, high wavelength resolution, light-collecting performance, and a more uniform image can be obtained. A curved crystal for X-ray spectroscopy is obtained.

By providing the gold thin film of the present invention as a portion for alleviating the stress of the entire surface electrode in a portion shielded by the drive wiring portion of the liquid crystal optical panel, the uniformity of the gap between the end portion and the center portion of the panel can be improved. By improving the gap and making the gap uniform, the orientation of the injected liquid crystal is improved, and high-definition liquid crystal display can be performed even on a relatively large liquid crystal panel such as 3 to 5 inches.

Further, by forming an adhesive element made of the gold single crystal thin film of the present invention on a Si substrate, a small and complex structure made of a Si substrate such as a micromachine can be manufactured at room temperature and under a small load. Only by applying
It is possible to connect the i-substrates together, and at the time of handling the Si substrate, there is an effect as particle-free and dust-free tweezers.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing a manufacturing process of a gold single crystal thin film of the present invention.

FIG. 2 is a schematic plan view of the obtained gold single crystal thin film.

3 (a) is a plan view and FIG. 3 (b) is a cross-sectional view taken along the line AA 'of FIG. 3 (a). ).

FIG. 4 is a diagram showing a state where gold nuclei are formed on the substrate of FIG. 3;

FIG. 5 is a view showing a state in which a gold single crystal thin film is formed around the gold nucleus in FIG. 4;

FIG. 6 is a view showing a state in which a resist pattern is formed on the formed gold single crystal thin film of FIG. 5;

FIG. 7 is a view showing the obtained comb-shaped electrode.

FIG. 8 is a diagram showing a substrate on which a Ti film used in Example 3 of the present invention is formed in a matrix.

FIG. 9 is a diagram showing a state in which gold nuclei are formed on the substrate of FIG. 8;

FIG. 10 is a view showing a state in which a gold single crystal thin film is formed around the gold nucleus in FIG. 9;

FIG. 11 is a view showing a state in which a resist pattern is formed on the formed gold single crystal thin film of FIG.

FIG. 12 is a view showing an obtained comb-shaped electrode.

FIG. 13 is a diagram showing a state in which a negative resist pattern is formed on a substrate in Example 4 of the present invention.

FIG. 14 is a view showing a state in which a gold single crystal thin film is formed on a portion of the substrate of FIG. 13 where a resist is not formed.

FIG. 15 is a view showing the obtained comb-shaped electrode.

FIG. 16 is a view showing a state in which a negative resist pattern is formed on a Cr film in Example 5 of the present invention.

FIG. 17 is a view showing a state in which a gold single crystal thin film is formed on a portion of the substrate of FIG. 16 where a resist is not formed.

FIG. 18 is a view showing the obtained comb electrode.

FIG. 19 is a view showing a comb electrode.

FIG. 20 is a schematic diagram of a polycrystalline curved crystal for X-ray spectroscopy according to the present invention.

FIG. 21 is a schematic sectional view of the optical system described in the sixth embodiment.

FIG. 22 is a schematic diagram of the system described in the seventh embodiment.

FIG. 23 is a sectional view of a liquid crystal panel embodying the present invention.

24 is a diagram illustrating a step of manufacturing a common electrode of the liquid crystal panel illustrated in FIG.

FIG. 25 is a plan view showing an example of a common electrode plate of the liquid crystal panel.

FIG. 26 is a plan view showing another example of the common electrode plate of the liquid crystal panel.

FIG. 27 is a cross-sectional view showing a general configuration of a conventional TFT-LCD.

FIG. 28 is a schematic cross-sectional view showing a structure of an acceleration sensor using an adhesive element made of a gold single crystal thin film of the present invention.

FIG. 29 is a schematic diagram showing a configuration of another example using an adhesive element made of a gold single crystal thin film of the present invention.

30. In FIG. 29, S
It is a schematic diagram which shows the state which pulled up the i board.

FIG. 31 is a schematic view showing a state in which heat-resistant glass is anodically bonded to the pulled-up substrate in FIG. 29 and the adhesive element is separated.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 2 Nucleation surface 3 Gold single crystal film 4 Grain boundary 6 Comb electrode 7 Resist 101 Substrate 102 Gold single crystal thin film 103 Curved crystal 201 ITO transparent electrode 202 Low stress electrode part (gold single crystal thin film) 207 Common electrode 301, 302, 303 Si substrate 306-309 Adhesive element (gold single crystal thin film)

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI H03H 9/145 H03H 9/145 Z (72) Inventor Tomoko Maruyama 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (72) Inventor Masami Hayashida 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Yoshiaki Fukuda 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (56) References JP-A-6-107493 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C23C 18/00-18/54 G02F 1/1343 G21K 1/06 H03H 9/08, 9/145

Claims (28)

(57) [Claims] 1. A gold complex in a gold complex solution is decomposed to cause the gold in the solution to transition to a supersaturated state, and a gold thin film composed of a gold single crystal or a group of gold single crystals is grown on a substrate surface. Gold single crystal thin film. 2. The gold single crystal thin film according to claim 1, wherein the single crystal is a single crystal having a high 111 orientation. 3. The gold single crystal thin film according to claim 1, wherein the gold complex contains [AuI ₄ ] ⁻ . 4. The gold single crystal thin film according to claim 1, wherein the gold complex contains [AuCl ₄ ] ⁻ . 5. The monolithic metal according to claim 1, wherein the decomposition treatment is performed by volatilizing a component constituting the gold complex from a solution system. Crystal thin film. 6. The method according to claim 1, wherein the decomposition treatment is performed by adding a reducing agent to a solution system.
5. The gold single-crystal thin film according to any one of items 4 to 4. 7. A method of decomposing a gold complex in a gold complex solution to shift gold in the solution to a supersaturated state and grow a gold thin film composed of a gold single crystal or a group of gold single crystals on a substrate surface. A method for producing a gold single crystal thin film. 8. The method according to claim 7, wherein the single crystal is a single crystal having a high 111 orientation. 9. The method for producing a gold single crystal thin film according to claim 7, wherein the gold complex contains [AuI ₄ ] ⁻ . 10. The method according to claim 7, wherein the gold complex contains [AuCl ₄ ] ⁻ . 11. The monometal according to claim 7, wherein the decomposition treatment is performed by volatilizing components constituting the gold complex from a solution system. Manufacturing method of crystalline thin film. 12. The method for producing a gold single-crystal thin film according to claim 7, wherein the decomposition treatment is performed by adding a reducing agent to a solution system. . 13. A surface acoustic wave element that generates and receives a surface acoustic wave by at least one comb-shaped electrode provided on a piezoelectric substrate.
A surface acoustic wave device formed of a thin film comprising a group of gold single crystals. 14. The surface acoustic wave device according to claim 13, wherein the thin film made of the gold single crystal or the group of gold single crystals is the thin film according to claim 1. 15. A thin film comprising a group of gold single crystals is provided on a substrate in which a surface made of a material having a high nucleation density and a surface made of a material having a low nucleation density are disposed adjacent to each other. By decomposing the gold complex, gold in the solution is shifted to a supersaturated state, and a gold crystal thin film composed of a single crystal group is formed only on the surface of the material having a high nucleation density. The surface acoustic wave device according to claim 13. 16. The surface acoustic wave device according to claim 15, wherein the surface made of a material having a high nucleation density is a surface fine enough to form a single nucleus. 17. The surface acoustic wave device according to claim 15, wherein the material having a high nucleation density is a semiconductor material. 18. The surface acoustic wave device according to claim 15, wherein the material having a high nucleation density is a conductive material. 19. The surface acoustic wave device according to claim 15, wherein the material having a low nucleation density is an insulating material. 20. A curved crystal for X-ray spectroscopy, wherein an X-ray diffraction layer comprising a group of gold single crystals oriented in 111 directions perpendicular to the substrate surface is formed on a curved substrate surface having a desired shape. Curved crystal for polycrystalline X-ray spectroscopy. 21. The polycrystalline curved crystal for X-ray spectroscopy according to claim 20, wherein the single crystal group is the gold single crystal thin film according to claim 1. 22. In the orientation of the gold single crystal group with respect to the substrate surface, a half width of a peak is 10 ⁻² rad or less in a diffraction intensity curve by X-ray diffraction of the gold single crystal group. 20 curved crystals for polycrystalline X-ray spectroscopy. 23. An electrode of a liquid crystal optical panel, wherein an electrode portion is provided in a part different from that of an electrode of a part which is not shielded from light by a drive wiring. 24. The electrode according to claim 23, wherein the portion of the electrode shielded by the drive wiring is the gold single crystal thin film according to claim 1. 25. The electrode according to claim 23, which is used for a liquid crystal optical panel using a ferroelectric liquid crystal. 26. The semiconductor device according to claim 1, having a hyperplane on the Si substrate.
An adhesive element comprising the gold single crystal thin film, wherein the gold single crystal thin film is provided, and the super planes of the single crystal thin film are overlapped with each other, and then the bonding can be performed by applying an extremely small load. 27. The adhesive element according to claim 26, wherein the application of the load is performed at a normal temperature. 28. The adhesive element according to claim 26, wherein the adhesive element has a flat plate shape.