JP3253716B2 - Applied product of noble metal single crystal group and manufacturing method thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of forming a noble metal single crystal group suitably used for a sample substrate for a scanning tunneling microscope, an X-ray mask structure, a diffraction grating element, a bump bonding bump, and the like. The present invention relates to the obtained applied product and a method for producing the same.

[0002]

2. Description of the Related Art Regarding the first aspect of the present invention, a scanning tunneling microscope (hereinafter, referred to as STM) capable of directly observing an electronic structure on a material surface and in the vicinity of the surface has recently been developed [G. Binn
inget al. , Helvetica Physi
ca acta, 55, 726 (1982)], which makes it possible to observe a real-space image at a high resolution regardless of whether it is a single crystal or non-crystal, and that the measurement can be performed with low power without damaging the sample substance by an electric current. Furthermore, since it operates not only in ultra-high vacuum but also in air and in solution, and can be applied to various materials, it is expected to be widely applied.

[0003] In particular, in the measurement in the atmosphere and in a solution, observation of an organic / biopolymer thin film is possible at a molecular / atomic level resolution, and thus observation is being actively conducted. When observing such a sample, it is necessary to fix a thin film on a flat substrate. However, since such a substrate conventionally requires atomic level flatness, HOPG (High)
y ordered pyrographic graph
item; highly oriented pyrolytic graphite) and a gold thin film formed on a cleaved mica (mica) by a vacuum evaporation method or a CVD method.

Regarding the second aspect of the present invention, the pattern line width of an integrated circuit tends to be reduced by 70% in about three years as the density and speed of a semiconductor integrated circuit increase in recent years. With the further integration of large-capacity memory elements, the printing apparatus is required to have higher performance.
A high performance of 3 μm or less has been demanded. Therefore, a stepper utilizing light in the X-ray region (0.2 to 2 nm) as an exposure wavelength is being developed. The X-ray mask used in the X-ray exposure apparatus has a structure as shown in FIGS. 10 (e), 11 (d) and 12 (d) which has conventionally been manufactured by the manufacturing steps as shown in FIGS. Was something. X
In this structure, nothing remains on the non-pattern forming portion of the X-ray absorber on the radiation transmitting film. Although details will be described, FIG. 10 shows a case where an electrolytic plating method is used as the X-ray absorber forming method. B51 is a substrate serving as a holding frame, and a Si wafer is often used. As the X-ray transmitting film B52, a thin film having a good X-ray transmitting property and a thickness of about 2 μm, such as silicon nitride or silicon carbide, is used.

[0005] When chromium (5 nm) and gold (50 nm), which become the plating electrode B55 for X-ray absorber film formation, are continuously deposited by EB evaporation, the result is as shown in FIG. On top of that, the desired fine resist pattern B
54 are formed, as shown in FIG. The resist used may be a single layer or a multilayer. Next, gold to be the X-ray absorber B53 is formed by electrolytic gold plating. When the resist pattern B54 is peeled off, it becomes as shown in FIG. Further, a portion of the metal thin film B5 where there is no X-ray absorber
5 is peeled off, and is sputter-etched using an argon gas or etched using a reactive gas (chlorine-based gas), resulting in the state shown in FIG. Finally, the Si wafer is back-etched to form a holding frame B51.
0 (e).

FIG. 11 shows a case where a vacuum evaporation method or an electroless plating method and etching are used. B61 is a substrate serving as a holding frame, and a Si wafer is often used. X
As the light transmitting film B62, a thin film having a good X-ray transparency and a thickness of about 2 μm, such as silicon nitride or silicon carbide, is used. next,
Gold thin film B63 using vacuum evaporation or electroless plating
Is formed as shown in FIG. A desired fine resist pattern B64 is formed thereon by an electron beam lithography apparatus, as shown in FIG. The resist used may be a single layer or a multilayer. Further, the gold thin film is etched using a sputter etch using an argon gas or a reactive gas (a chlorine-based gas) as shown in FIG. Finally, the Si wafer is back-etched to form a holding frame B61, as shown in FIG.

Next, FIG. 12 shows a case where a vacuum deposition method or an electroless plating method and lift-off are used. Similarly,
B71 is a substrate serving as a holding frame, a Si wafer, and as the X-ray transmitting film B72, a thin film having a good X-ray transmitting property, such as silicon nitride or silicon carbide, having a thickness of about 2 μm is used. FIG.
As shown in FIG. A desired fine resist pattern B74 is formed thereon by an electron beam lithography apparatus, and FIG.
(B). The resist used may be a single layer or a multilayer.

Next, gold to be the X-ray absorber B73 is formed by a vacuum evaporation method or an electroless plating method. The resist pattern B74 is removed, lift-off is performed, and FIG.
(C). Finally, the Si wafer is back-etched to form a holding frame B71, as shown in FIG.

According to the third aspect of the present invention, a diffraction grating having a step-like structure has a continuous grating structure such as a Fresnel lens or a blazed grating, and is similar to a multi-step shape. Diffraction gratings manufactured using semiconductor manufacturing techniques such as, are known, for example,
It is disclosed in U.S. Pat. No. 4,895,790. FIG. 15 shows a manufacturing process of the diffraction grating element disclosed in the U.S. Pat. No. 4,895,790.

[0010] A Cr layer 102 is deposited on a transparent substrate 101 such as SiO ₂ , and a photoresist layer 103 is further coated. The substrate having such a layer configuration is E
The lattice pattern is subjected to UV exposure using a mask 104 manufactured by a B drawing apparatus or the like. Thereafter, the photoresist layer 103 and the Cr layer 102 are removed by wet etching, the mask pattern is transferred to the Cr layer 102, and the substrate 101 is etched by reactive ion etching (RIE) to remove the remaining Cr layer 102. Remove.

In this case, the etching depth of the substrate 101 to be etched by the RIE method is given by the following equation: d = λ / 2 (n−1)
Where λ is the wavelength of light used when using the diffraction grating,
n is the refractive index of the substrate 101. The etching rate of this reactive ion etch is 10 nm to 20 n per minute.
m, the wavelength of light used is λ = 632.8 nm, and if quartz is used as the substrate, an etching depth of 703 nm is required, and an etching time of about 1.5 hours is required. It is.

By the above process, a two-stage phase grating can be manufactured. When manufacturing a multi-stage grating, the grating is manufactured by repeatedly performing the same process as described above. In this case, assuming that the phase level (the number of stages) is K and the number of masks is N, K = ^2N , and the etching depth by the reactive ion etching in each step is expressed by the formula d = λ / 2 ^N ( It is necessary to satisfy n-1). Here, λ is the wavelength of the used light, and n is the refractive index of the substrate.
For example, with a four-level grid, using two masks,
In a first step, etching is performed to a depth of d = λ / 2 (n−1), and in a second step, d = λ / 4 (n−
Etching is performed to a depth of 1). Conventionally, a multi-stage grating is manufactured by the above-described method.

Regarding the fourth aspect of the present invention, the number of extraction electrodes of an LSI chip has increased and the dimensions of the electrodes have also decreased with the recent increase in functions and capacity of LSIs. As a semiconductor mounting technology for electrically connecting an LSI chip to a circuit board or an IC package, a wire bonding method, a TAB
(Tape Automated Bonding) method, flip chip method using solder bumps, solderless mounting method that does not use solder by conductive paste or conductive plating resin balls, etc., but solderless mounting method is relatively compared to the temperature required during solder reflow. Electrical connection can be performed at low temperature, and research and development for practical use as a next-generation component mounting technology corresponding to miniaturization (fine pitch) of electrodes has been actively performed. Among them, conductive plating resin ball connection method and microbump bonding method (Hata, IEICE, CPM88-64, 198
8) is a mechanical contact type, so that it selects a combination which is essentially free of thermal expansion, does not cause thermal damage to an LSI chip or a circuit board, and does not cause a difference in thermal expansion coefficient between the board and the component. be able to.

FIG. 20 shows a process of micro-bump bonding. The substrate D for bump formation shown in FIG.
A bump-forming substrate in which an Au bump D43 is formed by electroplating on 41 is pressed and heated on an aluminum electrode D45 on an LSI chip D44 to form a gold-aluminum alloy and transferred. obtain. The transfer rate depends on the heat transfer temperature. Next, the photocurable insulating resin D46 is
The wiring electrode D48 on the circuit board D47 dropped like 0 (c) is aligned with the LSI chip D44, pressurized and irradiated with ultraviolet light, and the LSI chip D4 is placed on the circuit board D47.
4 is completed (see FIG. 20D).

[0015]

The first aspect of the present invention relates to a sample fixing substrate for performing a scanning tunneling microscope observation for observing a material surface with high accuracy in a non-contact manner. The second aspect of the present invention relates to an X-ray mask structure having a pattern to be transferred and used in an X-ray exposure apparatus for manufacturing a semiconductor, and a method for manufacturing the same, which relates to a sample fixing substrate comprising a group of noble metal single crystals obtained. The third aspect of the present invention relates to a diffraction grating element, and particularly relates to a reflection type diffraction grating element having a stepped structure and a method of manufacturing the same. Further, the fourth aspect of the present invention relates to a technology for mounting components on an IC substrate, a printed board, or the like. In particular, the present invention relates to a method of forming a bump and a bump.

When a cleaved surface of a layered crystal material such as HOPG is used as a sample fixing substrate for observation by a scanning tunneling microscope, the cleaved surface is very flat.
It is not covered with the same uniform cleavage surface, and steps along the many different cleavage surfaces, flakes where the cleavage surface peels off, and the like are generated on the way.

Such a surface defect has an STM on it.
This makes it difficult to observe an organic polymer film or a biological polymer film deposited as an observation target. In addition, recently, in observation of DNA molecules on HOPG, a report has been made indicating that there is a risk that a defect such as a step on HOPG may be mistaken as if it were a DNA molecule (C).
arol R. Clemmer et al. Science, VO
L. 251, 640, 1991). As described above,
There was a problem that HOPG was not very suitable as a substrate for STM.

On the other hand, it has been reported by Mizutani et al. Of the Institute of Electrical and Electronics Engineers that a flat surface can be obtained at the atomic level as in the case of HOPG for the gold thin film on mica (Symposium of "STM Application to Chemistry and Biotechnology", 1996.1.1
4). However, in the case of such a gold thin film, gold is vacuum-deposited while maintaining the substrate temperature at 473K, and is further deposited at 723K.
As a method for obtaining a substrate for STM, there is a drawback that the equipment is large and the process takes too much time such as temperature control.
Further, there is a disadvantage that the substrate of the gold thin film is limited to mica.

As described above, in the conventional manufacturing process of the X-ray mask, the method using the vacuum deposition method or the electroless plating method and the etching shown in FIG. X-ray absorber with high aspect ratio (line width of 0.3 μm or less, thickness of 0.7 μm
Is difficult to manufacture.

As shown in FIG. 12, when the vacuum evaporation method or the electroless plating method and the lift-off are used, in order to form an X-ray absorber having a high aspect ratio, the resist pattern B75 is considerably thicker than the absorber ( (About twice as large as the absorber), which is disadvantageous in terms of fine workability as compared with the manufacturing method using the electrolytic plating method shown in FIG.

Therefore, among the conventional methods, the electroplating method shown in FIG. 10 is mainly used for forming the gold absorber. However, in the electrolytic plating method, a metal thin film B5 serving as a plating electrode is used.
There is a process in which the resist is peeled off to peel off the metal thin film 4, and the metal thin film itself is also peeled off. When the metal thin film remains, there is no major problem in terms of the ratio of the X-ray absorptivity in the portion with and without the absorber, but when the X-ray mask is used in the exposure apparatus, the wafer to be exposed and the mask are exposed. In this case, since visible light or infrared light is usually used, the mask must transmit the light to be used. Therefore, it is necessary to peel off the metal thin film B54.

In addition to the complexity of the process, a fine absorber pattern having a high aspect ratio is present on the X-ray permeable film without being supported. In the case of X-ray exposure, the distance between the wafer and the mask is usually kept at 10 to several tens of μm for proximity exposure. Since a 6 to 8 inch wafer is moved at such a distance, the mask is liable to be damaged or defective by the wafer.

Further, it has been difficult to form a thin film having a small stress and a small surface roughness even if a metal film is formed by any of electrolysis, electroless plating and vacuum evaporation. The gold thin film of the X-ray mask absorber is required to have a small surface roughness so that the X-ray absorptivity is constant and a small stress so as to reduce the displacement of the absorber. However, in the above-described film forming method, the surface roughness is small, and a film having a fine particle size has a large stress, and a film having a small stress has a large surface roughness.

As described above, the conventional diffraction grating has a large number of steps, and in order to further improve the reflectance particularly in a reflection type diffraction grating, a higher reflection factor is formed on a multi-stage diffraction grating manufactured by the above method. There was a problem that a film had to be deposited. Further, as an optical element for an optical integrated circuit in recent years, it is desired that these optical elements be formed simply and accurately on the same semiconductor substrate on which a light emitting element, a light receiving element, and the like are formed.

As described above, in the conventional mechanical contact system, it is necessary to crush the contact portion stably, and the pressure must be controlled with high accuracy. It depends on the restoring force of a certain resin ball or Au bump and the compressive stress of the resin around the chip. For this reason, it is necessary to adjust the pressing force with high precision and control the conditions for solidifying the resin around the chip, and the above-mentioned bonding conditions also affect the contact resistance value and the fluctuation range of the resistance value.

Furthermore, in the micro-bump bonding method, heating at 340 ° C. or more is required for 100% transfer by the bump transfer process, and the substrate for bump formation suffers from a problem of durability deterioration due to pressurization and heating. Was. With respect to an LSI chip, the above-mentioned heating temperature is not a problem in an IC using a conventional MOS or the like. However, when a functional material other than Si, such as zinc oxide having a relatively high dielectric constant, is formed in a thin film in the chip, 300. If the temperature is higher than ℃, the characteristics change and the device reliability is reduced, which is a problem.

[0027]

As described above, the first aspect of the present invention relates to a substrate for fixing a sample when performing a scanning tunneling microscope observation for observing a material surface with high accuracy without contact. In particular, the present invention relates to an X-ray mask structure on which a pattern to be transferred is formed, which is used in a semiconductor manufacturing X-ray exposure apparatus or the like, and particularly relates to a sample fixing substrate comprising a group of noble metal single crystals obtained by a specific forming method. The third aspect of the present invention relates to a diffraction grating element and particularly relates to a reflection type diffraction grating element having a stepped structure and a method of manufacturing the same, and the fourth aspect of the present invention relates to an IC substrate and a printed circuit board In particular, the present invention relates to a method of mounting bumps and bumps.

The first aspect of the present invention is to use a sample substrate for STM composed of an arbitrary base substrate and a group of noble metal single crystals deposited thereon, and the noble metal single crystal is deposited from a solution in which the noble metal is dissolved. By using a single crystal with excellent crystallinity and excellent surface flatness, there is no defect such as a step or flake caused by a cleaved surface as seen in a conventional HOPG substrate, and the preparation method is a conventional gold thin film. An object of the present invention is to provide a sample substrate for STM which is extremely simple, does not require a vacuum or high temperature, is easy to prepare, and has high performance.

The above-mentioned problem relating to the second aspect of the present invention is solved by the present invention described below. That is, in a method for forming an X-ray mask having an X-ray absorber having a desired pattern, an X-ray transmitting film supporting the absorber, and a holding frame for holding the X-ray absorber, a nucleus is provided at a desired position on the X-ray absorber. A surface made of a material having a high formation density is provided, a surface made of a material having a low nucleation density is arranged adjacent to an undesired position, and the gold complex in the gold complex solution is subjected to a decomposition treatment, whereby gold in the solution is dissolved. To an oversaturated state, an X-ray mask structure having an X-ray absorber formed by selective deposition of a gold crystal thin film composed of a single crystal group having a high 111 orientation only on the substrate surface having a high nucleation density, and The problem is solved by an X-ray mask manufacturing method.

In the manufacturing process of the absorber formed by selective deposition of a gold crystal thin film from a gold complex solution, a complicated metal thin film is not required because a metal thin film serving as a plating electrode is not required unlike electrolytic plating. The peeling may not be performed. The absorber can be protected by the permeable film by also using the material having a low nucleation density and the X-ray permeable film. If a gold crystal thin film formed by decomposing a gold complex in a gold complex solution and shifting the gold in the solution to a supersaturated state is used, the absorber having a line width of about several tens μm is a single crystal. Therefore, a stress-free absorber having a very small surface roughness can be manufactured.

The third aspect of the present invention is to form a reflection type diffraction grating by selectively forming a gold single crystal on a ceramic or semiconductor substrate. By repeating the forming process several times, the sawtooth shape of the micro Fresnel lens or the blazed diffraction grating is approximated by a step-like structure to constitute the diffraction grating element.

In the method for selectively forming a single gold crystal used in the present invention, the method comprises the steps of: providing a surface made of a material having a high nucleation density and a surface made of a material having a low nucleation density on a substrate; By decomposing the gold complex in the gold complex solution,
A method for selectively forming a gold thin film, comprising: shifting gold in a solution to a supersaturated state, and forming a gold crystal thin film composed of a single crystal group only on the surface of the substrate having a high nucleation density.

In a fourth aspect of the present invention, in the bump bonding, the bump is formed of a gold crystal thin film composed of a single crystal group, and the bump is formed on the first and second substrates. The electrical connection is made by pressing and pressing the bump surface of the substrate.

As a method of forming a group of single crystals of gold in the present invention, a gold complex in a gold complex solution is decomposed to shift the gold in the solution to a supersaturated state, and only on a substrate surface having a large nucleation density. It is characterized in that a bump composed of a single crystal group is formed. The gold complex is [AuI ₄ ] ⁻ or [AuCl ₄ ] ⁻ , and the decomposition treatment is performed by volatilizing a substance constituting the gold complex from a solution system or adding a reducing agent.

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

The maximum distance between the surface made of a material having a low nucleation density and the surface made of a material having a high nucleation density is the same as that of a material made of a material having a low nucleation density when the entire surface is formed under the same conditions. It is desirable that the average particle size is within the range. In other words, in order to increase the maximum spacing, the nucleation density of SiO ₂ , Si ₃ N ₄ , or Si is particularly low.
It is preferable to use a ceramics material such as C or Al ₂ O ₃ . Materials having a high nucleation density include Au, Ti,
Cu, W, WSi, MoSi, Fe, Si, Ge and the like can be used.

The gold complex solution is, for example, a solution in which potassium iodide and iodine are charged into distilled water to obtain an aqueous iodine solution, and then gold is charged and stirred and dissolved to contain [AuI ₄ ] ^- . In the solution, the gold complex [AuI ₄ ] ^-
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 and iodide compound in the solution determines the amount of gold that can be dissolved. The gold complex is [Au
I _4] ^- as the other ^{_{[AuCl 4] -, [Au}} (C
^{_{N) 4] -, [Au}} (CN) 3] - can be used complex such.

As the decomposition treatment means, a volatilization or reduction treatment operation is used. In the volatilization treatment, after the surface of the substrate is brought into contact with the solution in the gold complex solution, the temperature of the solution is raised to 30 to 100 ° C. to volatilize the complex component such as iodine. As the reducing agent, for example, hydroquinone, pyrogallol, pyrocatechin, guxin, methol hydroquinone, amidol, methol (trade name), sodium sulfite, sodium thiosulfate, and other substances having a reducing action in a solution are used.

[0040]

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

Example 1 FIG. 1 is a sectional view showing a sample substrate for a scanning tunneling microscope according to the present invention, which best illustrates one feature of the present invention. A1 is a base substrate, and A2 is a noble metal single crystal group. In the above configuration, Si is used as a base substrate of A1 and A2 is used as a base substrate.
A specific example using Au as a noble metal single crystal will be described in detail below.

In an iodine solution obtained by stirring and dissolving 40 g of potassium iodide (KI) and 6 g of iodine (I ₂ ) in 500 ml of pure water, 3 g of gold (Au) was stirred and dissolved. Using the obtained gold-iodine complex solution as a stock solution, 100 ml of the stock solution was taken and placed in a reaction beaker, and 500 ml of distilled water was further added thereto, followed by stirring to obtain a mother liquid for crystal growth. A silicon substrate whose natural oxide film has been etched with hydrofluoric acid is immersed in the mother liquor,
Heat to ° C. When iodine sublimates and the solution becomes transparent light yellow, a plate-like group of gold crystals is formed on the entire surface of the Si surface.
It was produced at a density of about pieces / mm ² .

FIG. 2 shows a photograph of one crystal in this crystal group observed by a scanning electron microscope. The diameter is slightly more than 15 μm, which is equivalent to a substantially average particle size of a crystal group. The shape is a characteristic regular hexagonal shape formed by growing the flat surface in 111 directions. FIG. 3 shows an X-ray diffraction pattern of the gold crystal group, which is oriented in 111 directions, and has a small dispersion angle of 0.924 ° and high crystallinity.

Further, the STM of the plane surface of the 111 direction
The image is shown in FIG. Scanning range is 500nm x 500nm
The surface showed a very good smoothness with a roughness PV value of 0.77 nm. The base S thus obtained
FIG. 5 shows an example of use of a sample substrate for STM comprising an Au single crystal group on i. A3 is underlying Si, A4 is Au single crystal, A
5 is a polymer film, for example, behenic acid: CH ₃ (CH ₂ ) ₂₀ CO by the LB method (Langmuir blow jet method).
One kind of fatty acid such as OH was observed. A6 is S
It is a probe for TM, which is machined from Pt-Ir.

As the base substrate, any material can be used as long as it does not cause significant corrosion by the gold complex solution used in the present method. That is, various metals and their compounds can be used as appropriate. In addition, as the noble metal single crystal of the present method, a material using gold as a material has been exemplified, but other noble metal materials capable of forming a halogenated complex, for example,
Application to Pt, Pd, Rh, Ir, etc. is also possible.

Embodiment 2 FIG. 6 is a cross-sectional view of an X-ray mask manufacturing process of Embodiment 2.
As the substrate B11 serving as a holding frame, a Si wafer is often used. This time, the one having a diameter of 3 inches and a thickness of 2 mm was used. The substrate is set in a plasma CVD (PCVD) apparatus. First, after suctioning the back pressure to 2 × 10 ^-6 Torr,
5 sccm of silane gas and 20 sccm of ammonia gas diluted to 10% with hydrogen were supplied from a hole formed in the lower electrode. The temperature of the substrate B11 was heated to 250 ° C., and the pressure was 5 × 1.
By applying a high frequency power of 20 W at 0 ^-3 Torr and forming a silicon nitride film to a thickness of 1 μm, an X-ray transmission film B12 shown in FIG.
(A). Electron beam resist PM on it
MA (OEBR-1000: trade name, manufactured by Tokyo Ohka) is applied, and a desired fine resist pattern B14 is formed by an electron beam lithography apparatus, as shown in FIG. 6B.

The patterning of the X-ray permeable film B12 is performed by RI
This is performed with the E device. After suctioning the back pressure to 1 × 10 ⁻⁵ Torr, CF ₄ + O ₂ = 50 + 5 sccm is flowed and 5 × 10 ⁻² Torr.
200 W is applied for etching. At this time, the resist pattern B14 is also etched at the same time, and FIG.
become that way. In order to prevent the resist pattern B14 from remaining, it is preferable that after the etching of the X-ray permeable film B12 is completed, the etching be performed using only oxygen gas.

[0048] The surface of Si is holding frame B11 as a surface consisting of a material having a large nucleation density, SiN is X-ray transparent film B12 as small sides of nucleation density as gold complex [AuI _4] ^- to, By using volatilization as the decomposition means, gold is selectively grown to 0.8 μm to produce an X-ray absorber B13, as shown in FIG. 6D. Gold complexes include [AuI ₄ ] ⁻ , [AuCl ₄ ] ⁻ ,
[Au (CN) ₂ ] ⁻ , [Au (CN) ₃ ] ^{− and the} like can be used. The details are described below.

In 500 ml of distilled water, 40 g of potassium iodide
And 6 g of iodine were charged and dissolved by stirring. 3 g of gold was added to this solution and dissolved by stirring. After dissolution, 100 ml of this solution was taken and placed in a reaction vessel, and 500 ml of distilled water was further added thereto, followed by stirring to obtain a solution for crystal growth.
At this time, in the solution, the gold complex [AuI ₄ ] ⁻ , other I ₃ ⁻ , K
⁺ Is considered to 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 / water solution using a mixture of alcohol and water as a solvent can also be used in the present invention. The concentration of iodine and iodide compound in the solution determines the amount of gold that can be dissolved.

Next, after the surface of the substrate was immersed in dilute hydrofluoric acid to remove the surface oxide film on Si, the substrate was brought into contact with a crystal growth solution, and the solution was heated to 80 ° C. and allowed to stand. Since the heating is to promote the volatilization of the iodine component, the temperature is selected between 30 and 100 ° C. to adjust the nucleation density. In the solution system, I
₃ ^- due to volatilization of iodine component which is present in the state, for the maintenance of the equilibrium in the solution system [AuI _4] ^- degradation by dissociation of I component from, or [AuI _4] ^- complex present in the form of It is considered that the decomposition by direct volatilization of the iodine component therein proceeds, and as a result, the gold becomes oversaturated.

The supersaturated gold in the solution precipitates as random nuclei only on the surface of the Si substrate having a high nucleation density. A feature of the method of the present invention is that nuclei grow in a self-aligned manner while maintaining a low nucleation density.
As a result of the analysis, the formed crystal was a single crystal having no defect and had 111 orientations.

When the growth is continued for about one hour, the crystals collide with each other to form a grain boundary, and a material (Si) having a high nucleation density is formed.
Thus, a gold crystal thin film composed of a single crystal group was selectively formed. No nucleation was observed on the surface made of a material having a low nucleation density (SiN). In this embodiment, there is an effect that a gold single crystal having an extremely smooth surface can be formed. This is considered to be because iodine existing in the solution system suppresses generation of new nuclei on the growing gold crystal due to its gold dissolving action.

First, the substrate on which the X-ray absorber B13 has been formed is set again in the plasma CVD apparatus. An X-ray permeable film B12 ′ is formed to a thickness of 1 μm under the same conditions as when the X-ray permeable film B12 was produced, and as shown in FIG. Finally,
30 wt% potassium hydroxide (110 ° C) for Si wafer
6 to form a holding frame B11.
As shown in (f), it is completed as an X-ray mask. Since the X-ray absorber produced by the above method has a very small surface roughness and is stress-free, a mask having a constant X-ray transmittance and high positional accuracy can be produced, and the probability of occurrence of defects and breakage Can be reduced, so X
It is possible to supply a mask used for line exposure.

Third Embodiment FIG. 7 is a sectional view of an X-ray mask manufacturing process according to a third embodiment.
As the substrate B21 serving as a holding frame, a Si wafer is used. This time, the one having a diameter of 3 inches and a thickness of 1 mm was used.
The substrate is set in a thermal decomposition CVD device. First, after suctioning the back pressure to 2 × 10 ⁻⁶ Torr, silane gas diluted to 10% with hydrogen was flowed at 50 sccm to raise the pressure to 0.3 to 0.1 Torr.
The pressure was set to 5 Torr, and the substrate was heated to a temperature of 600 to 650 ° C. to form polysilicon (1 μm), thereby forming an X-ray transmitting film B22. Next, in the plasma CVD apparatus, the back pressure was set to 1 × 1
After sucking to 0 ^-6 Torr, 10 sccm of silane gas and 10 sccm of methane gas diluted to 10% with hydrogen were supplied from a hole formed in the lower electrode. The temperature of the substrate B21 is set to 650
℃, pressure 5 × 10 ^-3 Torr and high frequency power 50W
Is applied to form a silicon carbide film having a thickness of 1 μm to form an X-ray transmission film B22 ′ as shown in FIG. 7A.

The PIQ on which a two-layer resist is formed as a lower layer is formed.
(Trade name, manufactured by Hitachi Chemical), Si-containing resist to be the upper layer
SNR (trade name, Toyo Soda) is applied and an electron beam writer
7 to form a desired fine resist pattern B24.
(B). Next, the X-ray transmitting film B22 '
Is performed by an RIE apparatus. Back pressure 1 × 10
^-FiveAfter suctioning to Torr, SF_Four Flow 20 sccm of gas and
× 10^-2Apply 200 W at Torr and etch SiC
You. At this time, the resist pattern B24 is simultaneously etched.
FIG. 7 (c). Resist pattern B
In order to prevent the remaining of 24, the etching of X-ray permeable membrane B22 '
After etching, change the gas to oxygen gas and etch.
And good.

The surface made of polysilicon (P-Si), which is the X-ray transmission film B22, is used as the surface made of a material having a high nucleation density, and the X-ray transmission film B2 is used as the surface made of a material having a low nucleation density.
By using SiC 2 ′ as [AuI ₄ ] ⁻ as a gold complex and a reducing agent as a decomposition treatment means, gold was reduced to 0.1.
An X-ray absorber B23 was produced by selective growth of 8 μm, and FIG.
(D) As shown. The details are described below.

40 g of potassium iodide in 500 ml of distilled water
And 6 g of iodine were charged and dissolved by stirring. 3 g of gold was added to this solution and dissolved by stirring. After dissolution, 100 ml of this solution is taken, put into a reaction vessel, and further distilled water is added.
00 ml was added and stirred to obtain a crystal growth solution. After immersing the prepared substrate in dilute hydrofluoric acid to remove the surface oxide film on p-Si (poly Si), the substrate surface is brought into contact with a solution for crystal growth, and 30 ml of an aqueous solution in which 100 mg of hydroquinone is dissolved in the solution is slowly added. It was left unattended. After 3 hours, the substrate was taken out and observed. As a result, a single crystal group having 111 directions was formed on p-Si. Examples of the reducing agent used in the present invention include substances having a reducing action in a solution such as pyrogallol, pyrocatechin, guxin, methol hydroquinone, amitol, methol, sodium sulfite, and sodium thiosulfate, in addition to hydroquinone.

Further, the substrate is set in the plasma CVD apparatus again, and silicon carbide is formed to a thickness of 1 μm by the same film forming method as that of the X-ray transmission film B22 ', and the X-ray transmission film B22 "is formed as shown in FIG. As shown in the figure, 30 Si wafers were used.
Back etching is performed with wt% potassium hydroxide (110 ° C.) to form a holding frame B21, as shown in FIG. 7F. Since the X-ray absorber produced by the above method has a very small surface roughness and is stress-free, a mask having a constant X-ray transmittance and high positional accuracy can be produced, and the probability of occurrence of defects and breakage Therefore, it is possible to supply a mask used for X-ray exposure requiring high precision.

Fourth Embodiment FIG. 8 is a cross-sectional view of an X-ray mask manufacturing process according to a fourth embodiment.
You. The substrate B31 serving as a holding frame is a Si wafer having a diameter of
One having a thickness of 3 inches and a thickness of 2 mm was used. Pyrolyze the substrate
Set in a CVD device. First, set the back pressure to 2 × 10^-6Torr
Silane gas diluted to 10% with hydrogen
Flow at 50 sccm, pressure 0.3-0.5 Torr, substrate temperature
Heat to 600-650 degrees Celsius, polysilicon (1μm)
To form an X-ray permeable film B32. Next, plasma C
In a VD device, the back pressure is 1 × 10 ^-6Aspirated to Torr
Then, 5 sccm of silane gas diluted to 10% with hydrogen and
Monia gas was supplied at a flow rate of 20 sccm through the hole formed in the lower electrode.
Paid.

The temperature of the substrate B31 is increased to 250 ° C.
Power 5 × 10^-3Nitriding by applying high frequency power of 20 W at Torr
Silicon is deposited to a thickness of 1 μm to form an X-ray transparent film B32 ′,
The configuration is as shown in FIG. Electron beam resist on it
PMMA (OEBR-1000: trade name, manufactured by Tokyo Ohka)
And apply the desired fine resist pattern with an electron beam lithography system.
A pattern B34 is formed as shown in FIG. X-ray
The permeable film B32 'is patterned by an RIE apparatus.
U. Back pressure 1 × 10^-FiveAfter suctioning to Torr, CF _Four + O
_Two = 50 + 5sccm and 5 × 10^-2200W mark at Torr
And etch. At this time, the resist pattern B3
4 is also etched at the same time, as shown in FIG.
To prevent the resist pattern B34 from remaining, an X-ray transparent film
After the etching of B32, the gas is changed to only oxygen gas.
It is good to etch.

As a surface made of a material having a high nucleation density, a surface made of polysilicon which is an X-ray transmission film B32, and as a surface made of a material having a low nucleation density, Si which is an X-ray transmission film B32 '.
Using [AuI ₄ ] ⁻ as the N and gold complex and volatilization as the decomposition treatment means, 0.8 μm of gold is selectively grown to produce an X-ray absorber B33, as shown in FIG. 8D. The details are described below.

After 60 ml of hydrochloric acid and 20 ml of nitric acid were mixed to prepare aqua regia, 4 g of gold was added to this solution and dissolved by stirring. After dissolution, 30 ml of this solution was taken and placed in a reaction vessel, and 300 ml of distilled water was further added thereto and stirred to obtain a solution for crystal growth. After the prepared substrate is immersed in dilute hydrofluoric acid to remove the surface oxide film, the substrate surface is brought into contact with a solution for crystal growth, and then the solution is heated to 40 ° C., and then an aqueous solution in which 30 g of potassium hydroxide is dissolved is gradually added. In addition, it was left alone. After 1.5 hours, the substrate was taken out and observed.
A single crystal group having a 111 orientation was formed on -Si.

The Si wafer is back-etched with 30 wt% potassium hydroxide (110 ° C.) to form a holding frame B31, as shown in FIG. Since the X-ray absorber produced by the above method has a very small surface roughness and is stress-free, a mask having a constant X-ray transmittance and high positional accuracy can be produced, and the probability of occurrence of defects and breakage Therefore, it is possible to supply a mask used for X-ray exposure that requires high precision.

Fifth Embodiment FIG. 9 is a sectional view showing an X-ray mask manufacturing process according to a fifth embodiment of the present invention. As the substrate B41 serving as a holding frame, a Si wafer is used. In the present example, the one having a diameter of 3 inches and a thickness of 1 mm was used. The substrate was set in a plasma CVD apparatus, and the back pressure was suctioned to 1 × 10 ⁻⁶ Torr. Then, 10 sccm of silane gas and 10 sccm of methane gas diluted to 10% with hydrogen were added thereto.
It was supplied from a hole drilled in the lower electrode. The temperature of the substrate B41 was heated to 650 ° C., a high frequency power of 50 W was applied at a pressure of 5 × 10 ⁻³ Torr, and silicon carbide was deposited to a thickness of 1 μm.
The X-ray transmitting film B42 is used as shown in FIG.

The PIQ on which a two-layer resist is formed as a lower layer
(Trade name, manufactured by Hitachi Chemical Co., Ltd.), an upper layer Si-containing resist SNR (trade name, Toyo Soda) is applied, and a desired fine resist pattern B44 is formed by an electron beam lithography apparatus.
(B). Next, the X-ray transmission film B42 is etched by the RIE device. Back pressure of 1 × 10 ^-5 Torr
After that, SF ₄ gas of 20 sccm was flowed and 5 × 10
Etch SiC by applying 200 W at ^-2 Torr.
At this time, the resist pattern B44 is also etched at the same time, as shown in FIG. Resist pattern B44
After the etching of the X-ray permeable film B42 is completed, it is preferable to use oxygen gas as the etching gas in order to prevent the remaining of the gas.

[0067] The surface of Si is holding frame B41 as a surface consisting of a material having a large nucleation density, the SiC is X-ray transparent film B42 as small sides of nucleation density as gold complex [AuI _4] ^- to Also, by using a reducing agent as a decomposition treatment means, gold is selectively grown to 0.8 μm to produce an X-ray absorber B43, as shown in FIG. 9D. The details are described below.

In 500 ml of distilled water, 40 g of potassium iodide
And 6 g of iodine were charged and dissolved by stirring. 3 g of gold was added to this solution and dissolved by stirring. After dissolution, 100 ml of this solution was taken and placed in a reaction vessel, and 500 ml of distilled water was further added thereto and stirred to obtain a solution for crystal growth.
After the prepared substrate was immersed in dilute hydrofluoric acid to remove the surface oxide film on Si, the substrate surface was brought into contact with a solution for crystal growth, and 30 ml of an aqueous solution in which 10 mg of sodium sulfite was dissolved was slowly added and left. After 3 hours, the substrate was taken out and observed. As a result, a single crystal group having a 111 orientation was formed on Si.

The Si wafer is back-etched with 30 wt% potassium hydroxide (110 ° C.) to form a holding frame B41, as shown in FIG. Since the X-ray absorber produced by the above method has a very small surface roughness and is stress-free, a mask having a constant X-ray transmittance and high positional accuracy can be produced, and the probability of occurrence of defects and breakage Therefore, it is possible to supply a mask used for X-ray exposure that requires high precision.

Embodiment 6 This embodiment will be described with reference to FIG. The Si wafer is annealed, to form a thermal oxide film C5 of SiO ₂ on the surface, after depositing Ti to (C2) on the entire surface by etching using a resist, SiO ₂ film as shown in FIG. 13 (a) C5 Ti thin film C with minimum grating pitch of 6 μm
2 was obtained in a ring shape.

Potassium iodide and iodine are charged into distilled water to obtain an aqueous iodine solution, and then gold is charged and dissolved by stirring.
A gold complex solution containing [AuI ₄ ] ⁻ was prepared. Next, after the surface of the substrate was brought into contact with the solution, the solution was heated to 80 ° C.
To promote the volatilization of the iodine component. The supersaturated gold C3 in the solution was deposited as random nuclei only on the surface of the Ti substrate C2 having a high nucleation density (FIG. 13).
(B)). When the growth is further continued, as shown in FIG. 13C, the crystals collide with each other to form a grain boundary C4, which covers the surface made of the material having a high nucleation density, and has an average grain size of about 2 μm.
A gold crystal thin film composed of a single crystal group having a maximum particle size of about 5 μm was selectively formed. No nucleation was observed on the surface made of a material having a low nucleation density.

In this way, a one-step step diffraction grating was obtained. Next, after performing alignment with the first annular pattern using a second photomask having a minimum grating pitch of 3 μm, a second annular resist pattern C6 is formed as shown in FIG. 13D. . Here, the gold single crystal C3 was further formed on the first annular gold single crystal C3 by using the gold single crystal selective formation method (see FIG. 13E). In the case of this process, the material having a high nucleation density is the first annular gold single crystal C3.
The resist C6 is used as a material having a low nucleation density. By repeating such a process several times, a multistage stepped diffraction grating element made of a single crystal of gold was obtained.

Embodiment 7 An example of a step-like diffraction grating element of the present invention will be described with reference to FIG. This is an example in which a diffraction grating element is formed using gold as a material having a high nucleation density and resist as a material having a low nucleation density. A gold thin film C2 is formed on the Si wafer C1 by using a conventional vacuum deposition method, CVD method, electrolytic plating method, electroless plating method, or the like. A resist C6 is applied to the Si wafer C1 on which the gold thin film is formed, and after exposing a first annular photomask, an annular resist pattern is obtained as shown in FIG.

On the substrate, [AuI ₄ ] ⁻
Further, a crystal was grown using a volatilization treatment as a decomposition treatment means in the same manner as in Example 6 to form a one-step step-like diffraction grating element (see FIG. 14B). Furthermore, resist 6
Is applied, a second annular resist pattern is formed using a second annular photomask (see FIG. 14C).
After that, a single crystal of gold was selectively grown by the method described above (C3 ') to obtain a two-step step-like diffraction grating element (FIG. 14).
(D)).

As described above, in the present embodiment, an example of the case of a two-stage diffraction grating element has been described, but a multi-stage diffraction grating element can be manufactured by repeating the same process several times. In the present embodiment, an example of an annular micro Fresnel lens or the like is used. However, the same method can be applied to a case of a blazed diffraction grating. In this case, a photomask used for forming a resist pattern is used. It can be easily handled by changing.

Embodiment 8 FIG. 16 is a schematic view showing a process for forming a bump according to the present invention. [AuI ₄ ] ⁻ is used as a gold complex and a bump is formed by volatilization processing as a separation processing means on a substrate D1 in which a Ti film D2 serving as a bump formation nucleus is formed on a first substrate D1 made of Al ₂ O _3. This is an example.

As shown in FIG. 16A, a Ti film D2 was formed to a thickness of 50 nm by vacuum electron beam evaporation.
A resist layer was applied on the Ti film D2, exposed, developed, and patterned. The resist layer as a mask, reactive ion etching using CF ₄ gas (R
IE) was performed to pattern Ti, and the resist layer was peeled off to form a bump forming nucleus D3 shown in FIG. 16B.
The pattern of the nucleus D3 for bump formation is 3 μm square and 200 μm.
They were arranged in rows at μm intervals.

First, potassium iodide 4 was added to 500 ml of distilled water.
After charging 0 g and iodine 6 g to obtain an iodine aqueous solution,
3 g of gold was charged and dissolved by stirring to prepare an aqueous solution of a gold complex containing [AuI ₄ ] ⁻ . After dissolution, 10
0 ml was placed in a container, and distilled water was further added to the container.
0 ml was added and stirred to obtain a bump growth solution. Then T
After the surface of the Al ₂ O ₃ substrate 1 on which i was formed was brought into contact with the solution, the temperature of the solution was raised to 80 ° C. to promote the volatilization of the iodine component.

[0079] In the solution-based, I ₃ ^- [AuI _4] for the maintenance of the equilibrium state of the solution due to volatilization of iodine component which is present in the state ^- separation by dissociation of the I component from, or,
Decomposition by direct volatilization of the iodine component in the complex existing in the form of [AuI ₄ ] ⁻ proceeds, resulting in supersaturation of gold. The supersaturated gold in the solution is shown in FIG.
As shown in (c), single nuclei were deposited only on the Ti surface, but no gold was deposited on the Al ₂ O ₃ substrate surface. The Al ₂ O ₃ substrate was in contact with the bump growth solution for 50 minutes. The deposited gold single crystal has a thickness of 1 μm and a grain size of 100
μm. The gold single crystal thus formed is used as the bump D4.

FIG. 17 is a top view of FIG. As a result of analyzing the gold crystal which becomes the bump D4 on the formed Ti surface, it was a single crystal having no defect and had 111 orientations, that is, a hexagon as shown in FIG. Further, when the surface of the single crystal surface within an arbitrary 1 μm square was observed by a tunnel current microscope (STM), the unevenness of the single crystal surface was 0.5 nm. The bump according to the invention consists of a single gold crystal with a very smooth surface.

Next, a second substrate for making an electrical connection with the first substrate is formed.
A process for forming a bump on a substrate will be described with reference to FIG.
8). As a second substrate, a thermal oxide film SiO ₂ (D
Using the Si substrate D5 coated in 6), a bump forming nucleus D3 'was formed on the thermal oxide film D6 in the same manner as in the first substrate. As the bump forming nucleus D3 ', tungsten W often used in an IC process was used. The tungsten film was formed by sputtering a tungsten target by a sputtering method to a thickness of 200 nm. The bump forming nucleus was formed into a pattern having a size of 3 μm square using the same patterning process as that of Ti. The second substrate was placed in a bump growth solution similar to that used in the process shown in FIG.
The bump D4 'was formed by indirectly bonding at 0 ° C. for 50 minutes.

Using the bumps formed by the above method, the bump bonding of the present invention will be described. After the alignment of the bumps on the first substrate and the bumps on the second substrate,
As shown in FIG. 18, the second substrate is pressed against the first substrate. The bump of the present invention is a single crystal of gold and has an extremely smooth surface in the atomic order as described above, and is adsorbed by intermolecular attraction between the smooth surfaces. As a final form, the bumps D4 and D4 'are made of metal. It becomes a combined state. The load at the time of pressing and pressing is basically the same as the weight of the second substrate,
When a difference occurs in the thickness of each bump or when the first or second substrate is warped, a load of about several g per bump is applied.

When the resistance between the bumps of the thus formed bump bonding of the present invention was measured,
It is clear from this resistance value that the bumps are metal-bonded. This value is extremely small as compared with the conventional microbump bonding.

Embodiment 9 A method for forming bumps and forming bumps according to the present invention will be described below with reference to FIG. In 500 ml of distilled water, 40 g of ammonium iodide and 10 g of iodine were charged and dissolved by stirring. 3 g of gold was added to this solution and dissolved by stirring. After dissolution, 100 ml of this solution was taken and placed in a reaction vessel, and 500 ml of distilled water was further added thereto and stirred to obtain a solution for crystal growth. Ti is formed to a thickness of 0.1 μm by electron beam evaporation on a Si substrate D36 on which a thermal oxide film (thickness 0.5 μm) is formed as a first substrate, and a pattern made of Ti is formed by the same method as in the eighth embodiment. A 5 μm square bump forming core D33 was formed. Core D for bump formation
The intervals of 33 were 20 μm in a 3 × 3 matrix (see FIG. 19).

The thus prepared first substrate was brought into contact with the crystal growth solution, and then the solution was heated to 80 ° C. and left for 1 hour. A bump D34 consisting of the single crystal group shown in FIG. 19 was obtained. FIG. 19A is a side view, and FIG.
(B) is a top view. The single crystal had 111 orientations and the diameter was about 20 μm. No nuclei were found on the thermal oxide film. As a result of observation by STM, the unevenness of the surface of each single crystal was 0.5 nm within 1 μm square.

Next, bumps were formed on the second substrate. As a substrate, an S substrate having a thermal oxide film formed to a thickness of 0.5 μm was used.
Poly-Si (p
-Si) A film having a thickness of 50 nm was used. A resist was applied on the p-Si film, exposed and developed to form a resist pattern. Using the resist pattern as a mask, p-Si was patterned by RIE using SF ₆ gas, and the resist layer was peeled off. The pattern is 5μm
Is the diameter. The second substrate thus produced was immersed in dilute hydrofluoric acid to remove the surface oxide film on the p-Si surface, and the same gold complex solution (crystal) comprising potassium iodide and iodine as used in Example 8 was used. Growth solution). A bump having a diameter of 50 μm made of a single crystal was formed on the second substrate.

The first substrate having the gold single crystal group bumps formed as described above and the second substrate having the single crystal bumps are aligned so that the bumps overlap, and pressed. Bump bonding was performed by pressure contact. It was 15 when the resistance between bumps was measured.
It was 0 μΩ.

Embodiment 10 Another embodiment of the bump forming method of the present invention will be described. The solution for crystal growth used was 60 ml of hydrochloric acid and 20 m of nitric acid.
1 g was mixed to prepare aqua regia, 4 g of gold was added to this solution, and the mixture was stirred and dissolved. Further, 30 ml of this solution was dispensed, placed in a reaction vessel, added with 300 ml of distilled water, and stirred. As the substrate, a substrate in which a silicon nitride (Si ₃ N ₄ ) film was formed to 0.3 μm on a Si substrate by a low pressure CVD method was used. The above-mentioned Si ₃ N _{4 is} used as a core for bump formation.
The Si surface exposed by patterning the film was used. The pattern on the Si surface had a diameter of 3 μm.

Next, after bringing the substrate into contact with a solution for crystal growth, an aqueous solution in which 30 g of sodium hydroxide was dissolved was gradually added, and the solution was left at 40 ° C. One hour later, the substrate was taken out and observed. As a result, a single crystal of 111 orientation was formed within the Si diameter. No nuclei were found on the surface of the silicon nitride film having a low nucleation density.

[0090]

As described above, a high-performance STM sample observation substrate having high crystallinity and extremely good smoothness can be obtained very simply by using a noble metal deposition method from a liquid phase.

An X-ray absorber having a desired pattern;
In a method for forming an X-ray mask comprising an X-ray transmission film supporting the absorber and a holding frame for holding the X-ray transmission film,
A surface made of a material having a high nucleation density is provided at a desired position of the line absorber, and a surface made of a material having a low nucleation density is arranged adjacent to an undesired position to decompose the gold complex in the gold complex solution. By treating, the gold in the solution is shifted to a supersaturated state, and the X-ray absorber formed by selective deposition of a gold crystal thin film composed of a single crystal group having a high 111 orientation is formed only on the substrate surface having a high nucleation density. The X-ray mask structure and the manufacturing method of the X-ray mask do not require a metal thin film serving as a plating electrode as in the case of electrolytic plating, thereby eliminating the need for complicated stripping of the metal thin film. In addition, a material having a low nucleation density and X
By also using the line permeable film, the absorber can be protected by the permeable film, and defects and breakage of the absorber can be reduced.

Also, since the absorber having a line width of about several tens of μm is formed of a single crystal, the surface roughness can be made very small and a stress-free absorber can be manufactured. Is constant and the mask has high positional accuracy. Therefore, the above mask can be suitably used for high-precision X-ray exposure.

The present invention controls the solubility of a solution in which gold is dissolved, so that no special apparatus is required, and a gold crystal thin film can be selectively formed at normal pressure and at a temperature close to normal temperature. After the resist pattern is processed by using the photolithography technique, the process of selectively forming gold according to the present invention is repeated several times, whereby a multi-stage step-like diffraction grating element can be formed. In addition, the crystal grain size can be controlled by the surface material and the complex species, and in particular, by selecting the solution type of the growth system, a gold crystal thin film composed of a single crystal group having an extremely smooth surface can be obtained. In addition, a high-quality optical element with less scattering and loss can be configured as a diffraction grating element.

Further, as described above, the bump bonding and bump forming method according to the present invention does not require any special device and does not use a bump forming substrate.
The first substrate and the second substrate having extremely low contact resistance values can be easily electrically connected only by pressure contact at a temperature close to normal temperature and low pressure. Further, the method for forming a bump of the present invention makes it possible to form a single crystal having an extremely smooth surface on substrates of various materials by selecting a solution type of a growth system. Further, since the bump of the present invention is composed of a single crystal group, it is excellent in corrosion resistance, low resistance, melt resistance and the like.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a sample substrate for a scanning tunnel microscope according to the present invention.

FIG. 2 shows SE showing the morphology of a flat gold single crystal according to the present invention.
M image.

FIG. 3 is an X-ray diffraction result showing the crystallinity of a gold single crystal group.

FIG. 4 is an SEM image showing the flatness of the gold single crystal of FIG.

FIG. 5 is a schematic view showing an example used as a substrate for a scanning tunneling microscope.

FIG. 6 is a process sectional view of the X-ray mask structure according to the present invention.

FIG. 7 is a process sectional view of another example of the X-ray mask structure according to the present invention.

FIG. 8 is a process sectional view of another example of the X-ray mask structure according to the present invention.

FIG. 9 is a process sectional view of another example of the X-ray mask structure according to the present invention.

FIG. 10 is a process sectional view of a conventional X-ray mask structure.

FIG. 11 is a process sectional view of a conventional X-ray mask structure.

FIG. 12 is a process sectional view of a conventional X-ray mask structure.

FIG. 13 is a forming process diagram showing a manufacturing process of a step-like diffraction grating element according to the present invention.

FIG. 14 is another formation step view.

FIG. 15 is a process chart for forming a conventional step-like diffraction grating element.

FIG. 16 is a process flow chart of a bump forming method according to an eighth embodiment.

FIG. 17 is a front view of a bump according to an eighth embodiment.

FIG. 18 is an overall configuration diagram of bump bonding according to an eighth embodiment.

FIG. 19 is a configuration diagram of a bump made of a single crystal group in Example 9.

FIG. 20 is a process flowchart of a conventional bump bonding process.

[Explanation of symbols]

A1 Base substrate A2 Noble metal single crystal group A3 Si base substrate A4 Au single crystal A5 Polymer film A6 Probe B11, B21, B31, B41, B51, B61, B
71 holding frame (substrate) B12, B12 ', B22, B22', B22 ", B3
2, B32 ', B42, B52, B62, B72 X-ray permeable films B13, B23, B33, B43, B53, B63, B
73 X-ray absorber B14, B24, B34, B44, B54, B64, B
74 resist B55 plating electrode C1 substrate C2 larger surface C3 Gold C4 grain boundary C5 nucleation density smaller surface C6 resist D1 Al ₂ O ₃ substrate D2 Ti film nucleation density D3, D3 ', nuclear D4, D4 for D33 bumping ', D34 bumps D5, D31 Si substrate D6, D36 SiO ₂ film D41 bump forming substrate D43 Au bumps D44 LSI chip D45 Al electrode D46 photocurable insulating resin D47 circuit board D48 wiring electrode 101 substrate 102 Cr layer 103 photoresist layer 104 mask

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Takasato Taniguchi 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Takayuki Yagi 3-30-2 Shimomaruko, Ota-ku, Tokyo (56) References JP-A-6-136551 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C23C 18/08 C22B 11/00 C23C 14/14 G21K 1 / 06

Claims (27)

(57) [Claims] 1. A sample substrate for a scanning tunneling microscope, wherein the substrate is composed of a base substrate and a noble metal single crystal group deposited on the base substrate, and the noble metal single crystal group has a property of dissolving the noble metal.
Using a noble metal complex solution in which the noble metal is dissolved in a solution,
By decomposing the noble metal complex, the noble metal in the solution
It is formed by a method of shifting to a supersaturated state and precipitating a noble metal single crystal , and has a maximum surface irregularity of 500 nm square in a flat plate shape having a maximum diameter of 10 μm or more and an aspect ratio of 10 or more. A sample substrate for a scanning tunneling microscope characterized by being within 0.8 nm. 2. The method according to claim 1, wherein the decomposition treatment is carried out by promoting the volatilization of the components constituting the noble metal complex from the solution system by raising the temperature of the solution system to 100 ° C. or lower. Sample base for scanning tunneling microscope
Board . 3. The scanning method according to claim 1, wherein the decomposition treatment is performed by adding a reducing agent to a solution system.
Substrate for scanning tunnel microscope . 4. The flat plate orientation of the noble metal single crystal is 11
2. The sample substrate for a scanning tunneling microscope according to claim 1 , wherein the sample substrate has one direction (X-ray diffraction). 5. The base substrate constituting the sample substrate, a ceramic material, semiconductor material and scanning tunneling microscope sample substrate according to claim 1, characterized in that those selected from the group consisting of noble metal material. 6. A method for dissolving gold in a method for forming an X-ray mask structure comprising an X-ray absorber having a desired pattern, an X-ray transparent film supporting the absorber, and a holding frame for holding the X-ray absorber. Using a gold complex solution in which gold is dissolved in a solution having the following, a surface made of a material having a high nucleation density is provided at a desired position of the X-ray absorber, and a surface made of a material having a low nucleation density is provided at an undesired position. By disposing the gold complex in the gold complex solution in a supersaturated state by disposing the gold complex in the gold complex solution by disposing the surfaces adjacent to each other, gold consisting of a single crystal group is formed only on the surface of the substrate having a high nucleation density. A method for manufacturing an X-ray mask, wherein an X-ray absorber is produced by selectively forming a crystalline thin film. 7. The gold complex in the gold complex solution is [AuI
_4] ^- A method for fabricating an X-ray mask according to claim 6, characterized in that the. 8. The gold complex in the gold complex solution is [AuC
l ₄ ] ^- , and the method for manufacturing an X-ray mask according to claim 6 . 9. decomposition treatment of the gold complex of the gold complex solution is, according to any one of claims 6 to 8, characterized in that is carried out by evaporation of a solution-based material constituting the gold complex A method for manufacturing an X-ray mask. 10. A decomposition treatment of the gold complex of the gold complex solution is, any one of claims 6 to 8, characterized in that is carried out by the addition of a reducing agent to a solution-based substance constituting the gold complex 3. The method for manufacturing an X-ray mask according to 1. 11. An X-ray absorber having a desired pattern,
An X-ray mask structure comprising an X-ray transmission film supporting the absorber and a holding frame for holding the X-ray absorber, wherein the X-ray absorber is manufactured by the method according to any one of claims 6 to 10 , and An X-ray mask structure characterized in that a gold thin film comprising a group of gold single crystals having a high 111 orientation is formed by selective deposition. 12. An X-ray absorber having a desired pattern,
An X-ray mask structure comprising an X-ray transmission film supporting the absorber and a holding frame holding the X-ray mask, wherein the X-ray mask structure is formed by the method according to any one of claims 7 to 11. An X-ray mask structure. 13. Use of a gold complex solution in which gold is dissolved in a solution having the property of dissolving gold to manufacture a diffraction grating element for a reflection type optical element in which a gold single crystal is selectively formed from the gold complex solution. In the method, the gold complex in the gold complex solution is decomposed on a substrate having a surface made of a material having a high nucleation density and a surface made of a material having a low nucleation density disposed adjacent to each other. To shift the gold inside to supersaturation,
A method for manufacturing a diffraction grating element, wherein a gold crystal thin film composed of a single crystal group is selectively formed only on a substrate surface having a high nucleation density. 14. The gold complex in the gold complex solution is [Au
I _4] ^- the production method of a diffraction grating element according to claim 13, wherein the a. 15. The gold complex in the gold complex solution is [Au
14. The method of manufacturing a diffraction grating element according to claim 13 , wherein Cl ₄ ] ^- . 16. decomposition treatment of the gold complex of the gold complex solution is, according to any of claims 13 to 15, characterized in that is carried out by evaporation of a solution-based material constituting the gold complex Manufacturing method of diffraction grating element. 17. decomposition treatment of the gold complex of the gold complex solution is 13 to claim characterized in that it is carried out by the addition of a reducing agent to a solution based material constituting the該記gold complex
15. The method for manufacturing a diffraction grating element according to any one of items 15 . 18. The diffraction grating element of reflection type optical element, on a substrate of ceramic and semiconductors, etc., of claims 13 to 17 using the gold complex solution prepared by dissolving gold in a solution having a property of dissolving gold A diffraction grating element for a reflective optical element, wherein a gold single crystal is selectively formed by any one of the methods described above. Is 19. The shape of the gold single crystal for the selectively formed, characterized by having a step-like structure according to claim 1
8. The diffraction grating element according to 8 . 20. The diffraction grating device according to claim 18, wherein the step-like structure is formed by repeating a process of selectively forming the gold single crystal at least twice or more. . 21. A method for forming a bump for bump bonding, comprising: using a gold complex solution obtained by dissolving gold in a solution having the property of dissolving gold, and decomposing the gold complex in the gold complex solution. A gold thin film bump, comprising: shifting gold in the solution to a supersaturated state, and selectively forming a gold single crystal thin film composed of a gold single crystal group only on a substrate surface having a high gold nucleation density. Formation method. 22. The gold complex in the gold complex solution is [Au
22. The method of forming a bump according to claim 21 , wherein I ₄ ] ^- . 23. The gold complex in the gold complex solution is [Au
22. The method for forming a bump according to claim 21 , wherein Cl ₄ ] ^- . 24. decomposition treatment of the gold complex of the gold complex solution is, according to any one of claims 21 to 23, characterized by being performed by volatilization from a solution-based material constituting the gold complex The method of forming the bump. 25. decomposition treatment of the gold complex of the gold complex solution is, claim 2 1 to 23, characterized in that it is carried out by addition of the reducing agent to the solution based material constituting the gold complex
The method for forming a bump according to any one of the above. 26. A bump bonding using a bump formed of a gold crystal thin film composed of the gold single crystal group, the bumps made of gold thin film formed by the bump forming method according to any one of claims 21 to 25 bumps Bump bonding, characterized in that: 27. By pressing and pressing each of the bumps of the first and second substrates having the bumps,
27. The bump bonding according to claim 26, wherein the first substrate and the second substrate are electrically connected.