JP3191066B2 - Gold thin film and method of forming patterned gold thin film - 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 for forming a gold thin film, and more particularly to electrodes and wirings of electronic and optical elements such as semiconductor integrated circuits, optical integrated circuits and magnetic circuits, or piezoelectric elements, electron-emitting elements, and recording devices. The present invention relates to a gold thin film used for a medium or the like and a method for forming a patterned gold thin film.

[0002]

2. Description of the Related Art Conventionally, gold thin films have been used for lead frames and H
It has been widely used for wiring and electrodes in the field of thick films such as ICs and thin-film wiring of GaAs semiconductors. Recently, the electromigration of Al wiring has become a serious problem due to the increase in the density of Si semiconductor devices, and gold, which is a noble metal, is regarded as a promising wiring material.

[0003] Such a gold thin film is desired to be a gold crystal thin film comprising a group of single crystals having a large grain size, which is particularly excellent in electromigration, corrosion resistance, low resistance, melt resistance and the like.

Under such circumstances, as a method of forming a gold crystal thin film on a substrate, a vacuum deposition method, a CVD method, an electrolytic plating method, an electroless plating method and the like are conventionally known. For example, in a vacuum deposition method, a substrate of Si, SiO ₂ , SiN, GaAs, sapphire, Cr, Ti, Cu, mica, etc.
After heating to about 00 to 700 ° C., gold is transferred on a substrate in a vapor phase in a vacuum of 10 ⁻⁶ torr or less to perform deposition. As a specific example, gold having a diameter of several tens μm There is a report that a gold single crystal was formed (Dennis
J. Trevor et al., Physical Review
w Letters Magazine, Vol. 162, No. 8, 1989).
There is also an example in which a gold polycrystalline thin film is formed on Si by thermal CVD or PECVD (N. Misawa et al., The 37th Symposium on Semiconductors and Integrated Circuits, December 1989).
March 7). Further, a technique of depositing a gold powder for a conductive gold paste in a floating state in a system by utilizing a gold saturation phenomenon in a solution due to decomposition of a gold complex is disclosed in Japanese Patent Application Laid-Open No. 56-38406.
It is disclosed in JP-A-55-54509.

[0005]

However, these conventional methods have the following problems.

When a gold thin film is formed on a substrate by a vacuum deposition method or a CVD method, a gold crystal thin film composed of a group of single crystals having a large grain size is formed by using a single crystal inert substrate such as mica or highly oriented graphite. Other than these, for example, on a semiconductor material such as Si or GaAs, or on SiO ₂ ,
On an insulating material such as SiN or Al ₂ O _3, a single crystal group or a polycrystalline film having a submicron diameter is formed. Also, in the former case, strict control is required, such as the deposition temperature and the firing conditions of the substrate. Even if these controls are sufficiently performed, a polycrystalline film is often formed, and a single-crystal film is often formed. It is relatively difficult to provide a group of gold thin films with good reproducibility.

Furthermore, since there is a demand for maintaining the substrate temperature at a relatively high temperature, it is extremely difficult to use the device for a device that cannot be maintained at a high temperature. We must also pay attention. For example,
In the case of forming a gold thin film on Si, the eutectic temperature is 363 ° C.
If the substrate is heated beyond the limit, an Au-Si alloy is formed.

In addition, the electrolytic plating method or the electroless plating method results in a polycrystalline film, and it is impossible to form a single crystal in the first place.

[0009] In addition to these, there is a problem that occurs when patterning such a gold thin film. Using a conventionally known photolithography technology as a method of making a pattern,
For example, if a gold thin film composed of the above-mentioned single crystal group is to be patterned, a lift-off method (first, a patterned photoresist film is formed on a substrate, and then a gold thin film is deposited on the entire surface of the substrate, It is extremely difficult to use the above-mentioned method of stripping the photoresist and patterning the gold thin film). The reason is that the heat resistance of the photoresist is usually equal to or less than the above-described vapor deposition conditions.

Therefore, after forming a gold thin film on a substrate,
A method is employed in which this is partially etched away to form a pattern. In this case, first, a patterned mask is closely formed on the gold thin film, and then etching is performed.
The last remaining mask is peeled off, but depending on the etching conditions, the portion of the gold thin film covered with the mask may be damaged. Further, if such a mask is made sufficiently strong, there is a possibility that the surface of the gold thin film may be damaged when the mask is peeled off.

As a method of patterning a gold thin film, in addition to the above-described photolithography, for example, by irradiating a part of the gold thin film with an energy beam such as an ion beam and scanning the same, the gold is scanned. It is also conceivable to use a direct writing method for partially removing by the electric field evaporation or the sputtering effect. In this case, however, the energy distribution of the energy ray source used is a Gaussian distribution with respect to the line width. Over time, there is a risk that the surface of the irradiated object may be gradually modified.

In view of the above-mentioned problems of the prior art, an object of the present invention is to provide a single crystal having a large grain size which is excellent in electromigration resistance, corrosion resistance, low resistance, melt resistance and the like. It is an object of the present invention to provide a method for stably forming a gold crystal thin film comprising a group, and further, the gold crystal thin film patterned into a desired pattern on various substrates under conditions close to normal temperature and normal pressure.

[0013]

According to the present invention, by decomposing a gold complex in a gold complex solution, the gold in the solution is shifted to a saturated state, and the gold is converted into a relatively simple solution. By depositing and growing on a surface-treated substrate, a gold thin film composed of a single crystal group having a large grain size can be formed with good reproducibility.

That is, the present invention is a method for decomposing a gold complex in a gold complex solution, shifting the gold in the solution to a saturated state, and forming a gold thin film on the substrate in the solution. The substrate has a layer of organic molecules having a substituent containing sulfur on the surface, and deposits gold on the layer of organic molecules.
A method of forming a gold thin film, characterized by growing the organic thin film, further comprising the organic molecule having a substituent containing sulfur is an organic silane molecule, and a step of patterning a layer of the organic silane molecule, This is a method for forming a patterned gold thin film, wherein gold is deposited and grown on a layer of organosilane molecules patterned by a patterning step.

The present inventors have found that gold in the saturated solution selectively and stably deposits and grows on the organic molecule layer having a substituent containing sulfur.
A gold crystal thin film consisting of a group of single crystals with a large grain size, which is excellent in electro-migration resistance, corrosion resistance, low resistance, melt resistance, etc., is stably applied on various substrates under conditions close to normal temperature and normal pressure. This has led to the present invention which can be formed.

Since the gold crystal thin film according to the present invention is characterized by being composed of a group of single crystals of gold having a (111) orientation, for example, a piezoelectric material or the like is deposited on the gold crystal thin film of the present invention. At this time, the azimuth can be inherited.

The substrate used in the present invention is capable of depositing a layer comprising an organic molecule having a substituent containing sulfur (hereinafter referred to as an organic sulfur compound) on its surface, and has a resistance to a gold deposition step described later. If so, in principle, the material and shape are not limited.

Examples of the sulfur-containing substituent in the above-mentioned organic sulfur compound include a thiocarboxy group (—CSO
H), dithiocarboxy group (-CSSH), a sulfo group (-SO ₃ H), sulfino group (-SO ₂ H), sulfeno group (-SOH), thiocyanato group (-SCN), thioxo group (= S), A mercapto group (-SH), a sulfide group (-S-), a disulfide group (-SS-) and the like can be mentioned, and a mercapto group is preferable.

The organic sulfur compound containing the above substituent is deposited on the surface of the target substrate. In the subsequent gold deposition process, the interaction between gold and sulfur plays an important role. Therefore, it is desirable that the sulfur site be located on the surface as much as possible. Since the interaction between the deposited layer of the organic sulfur compound and gold is mainly performed between the outermost portion of the deposited layer and the deposited layer, the thickness of the deposited layer does not need to be particularly large. Rather, if the film thickness is locally greatly different, has a large defect, or the distribution of the substituents containing sulfur is not uniform, the deposition of gold may be non-uniform. Attention should be paid to the points.

On the other hand, if the adhesion between the organic sulfur compound and the substrate is poor, the adhesion between the finally formed gold thin film and the substrate is reduced, and the organic sulfur compound and the substrate are chemically adsorbed. Is preferred. From such a demand, it is preferable to introduce a special substituent, for example, a silane, an amino group, a carboxyl group, or the like into the organic sulfur compound according to the substrate material to be used. , There is no obstacle to gold deposition by these substituents. Specifically, for example, the organic sulfur compound is a silane compound (hereinafter, referred to as an organic sulfur silane compound)
In the case of (1), by forming a siloxane (Si-O bond) between the organic sulfur silane compound and the substrate, the adhesion between them can be enhanced. From such demands, it is preferable that the substrate has Si, O, or OH groups exposed on the surface. For example, silicon, silicon oxide, silicon nitride, metal oxide, mica, or a layer composed of these Various substrates deposited on the surface can be mentioned.

The organic sulfur silane compound suitable for the present invention is
The following general formula (1)

[0022]

Embedded image Indicated by Here, with respect to R2, R3 and R4, R2
= R3 = R4 = C1 or R2 = R3 = R4 = OCH ₃ or _{R2 = R3 = R4 = OCH 2} H 5 or R2 = C1, R
3 = R4 = OCH ₃ or R2 = C1, R3 = R4 = OC
H ₂ H ₅ or R2 = C1, R3 = R4 = CH 3 or R2
= R3 = C1, R4 = OCH ₃ or R2 = R3 = C1,
R4 = OCH ₂ H ₅ or R2 = R3 = C1, R4 = CH
Of _3, selected from any combination, with respect to R1, thiocarboxy group (-CSOH), dithiocarboxy group (-CSSH), a sulfo group (-SO ₃ H), sulfino group (-SO ₂ H), sulfeno Substitution containing sulfur such as a group (-SOH), a thiocyanato group (-SCN), a thioxo group (= S), a mercapto group (-SH), a sulfide group (-S-), a disulfide group (-SS-). It is a hydrocarbon group having 1 to 24 carbon atoms having a group. Most preferred of these R1s are those having a terminal substituted by a mercapto group. Further, some or all of the hydrogen atoms of the hydrocarbon group constituting R1 may be substituted with fluorine. Furthermore,
A polymer (polysiloxane) of the above organic sulfur silane compound may be used.

From this point of view, it is desirable that the deposited layer of the organic sulfur compound or the organic sulfur silane compound is composed of a monomolecular film or a cumulative film thereof. As the formation method, a vapor deposition method may be used, but a conventionally known Langmuir-Blodgett method, a liquid phase adsorption method, a gas phase adsorption method and the like are preferable. According to these methods, although a slight restriction is imposed on the molecular structure, a uniform deposited layer can be easily formed irrespective of the shape of the substrate, and the position of the sulfur-containing substituent in the deposited layer can be easily determined. (The thickness direction) can be made uniform (orientation control).

Furthermore, it is extremely preferable that the deposited layer of the organic sulfur compound or the organic sulfur silane compound is made of a polymer, because the mechanical and thermal strength of the formed gold crystal thin film further increases.

Next, the method for forming a gold thin film of the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram showing an example of the process of the present invention. First, the step of depositing an organic sulfur compound layer on a substrate will be described.

If silicon or silicon oxide (glass) is used as the substrate 1, the organic sulfur compound may be, for example, mercaptomethyltrimethoxysilane or 3
-Use of an organic sulfur silane compound containing a silane and a mercapto group such as mercaptopropyltrichlorosilane is preferred.

Next, the substrate is allowed to be adsorbed in a vapor phase by leaving the substrate in a vapor atmosphere of the organic sulfur compound, or the substrate is immersed in a solution in which the organic sulfur compound is dissolved to be adsorbed in the liquid phase. Then, an organic sulfur compound is deposited on the substrate 1 to form an organic sulfur compound layer 2 (see FIG. 1B). After that, the substrate may be washed with an appropriate solvent to remove an excessively physically adsorbed organic sulfur compound to obtain a monomolecular film. In addition, by appropriately adjusting the treatment time required for the adsorption step and the concentration of the solution used in the case of the liquid phase adsorption method, it is possible to form the uniform organic sulfur compound layer 2 without particularly performing the washing step. Is also possible. Alternatively, an organic sulfur compound layer composed of a monolayer or a monolayer accumulation film may be formed by the Langmuir-Blodgett method. In the case where the substrate itself is made of, for example, an organic polymer material and has a suitable substituent containing sulfur, the step of depositing the organic sulfur compound may be omitted.

Next, the gold deposition / growth step will be described assuming that [AuI ₄ ] ⁻ is used as the gold complex and volatilization processing is used as the decomposition processing means of the gold complex.

First, potassium iodide and iodine are charged into distilled water to prepare an iodine aqueous solution, and then gold is charged and stirred and dissolved to prepare a gold complex solution 3 containing [AuI ₄ ] ^- . At this time, in addition to the gold complex [AuI ₄ ] ⁻ ,
It is considered that ₃ ^- and K ⁺ exist. Next, the substrate 1 is immersed in the gold complex solution 3 (see FIG. 1C), and the solution temperature is raised (30 to 100 ° C.) to promote the volatilization of iodine. At this time, the decomposition of [AuI ₄ ] ⁻ proceeds in order to maintain the chemical equilibrium, and as a result, the gold becomes supersaturated. The supersaturated gold reacts with the mercapto group in the organic sulfur compound layer on the substrate, and precipitates on the organic sulfur compound to form crystal nuclei 4
Becomes Thereafter, new crystal nucleus generation and crystal nucleus growth proceed in parallel. At this time, the crystal nucleus grows in a single crystal in a self-aligned manner (see FIG. 1E). Thereafter, a gold crystal thin film 5 composed of a single crystal group is formed by collision between the single crystals (see FIG. 1 (f)).

The aqueous iodine solution may dissolve an iodide compound other than potassium iodide, such as ammonium iodide.
The method is not limited. Instead of an aqueous solution, an alcohol solution or a mixed solution of alcohol and water may be used. Also, instead of dissolving gold, a suitable gold compound,
For example, AuI, AuI ₃ or the like may be used. In short, it is sufficient that the gold complex [AuI ₄ ] ⁻ is sufficiently present in the solution. Furthermore, the gold complex is not limited to [AuI ₄ ] ^- ,
[AuCl ₄ ] ⁻ , [Au (CN) ₂ ] ⁻ , [Au (C
N) ₃ ] ^- . The means for decomposing these gold complexes is not limited to volatilization by heating, and may use a reducing agent. Specific examples of the reducing agent include, for example, hydroquinone, pyroganol, pyrocaquitene, guccin, metholhydroquinone, amidol, methol,
In addition to sodium sulfite, sodium thiosulfate, etc., materials having a reducing action in a solution can be widely used.

Next, a method for forming a patterned gold thin film of the present invention, in which an organic sulfur silane compound layer is patterned and gold is deposited and grown on the patterned organic sulfur silane compound layer, will be described.

First, the step of forming a patterned layer of an organic sulfur silane compound on a substrate will be described with reference to FIG.

First, an organic sulfur silane compound is deposited on the substrate 11 in the same manner as described above with reference to FIG.
An organic sulfur silane compound layer 12 is formed (see FIG. 2B).

The organic sulfur silane compound layer 12 thus formed is partially and selectively irradiated with an energy beam 13 such as an electron beam, X-ray, ultraviolet ray, far ultraviolet ray or ion beam according to a desired pattern. (See FIG. 2 (c)),
The organic sulfur silane compound in the irradiated portion 14 is removed or a portion containing sulfur (generally, R1 in the above formula (1)
The patterning layer 15 of the organic sulfur silane compound (see FIG. 2D) is obtained by removing the base group. In FIG. 2C, a mask 16 is used to selectively irradiate the organic sulfur silane compound layer 12 with the energy rays 13. However, even if the energy rays 13 are directly scanned and drawn. good. In this case, it is possible to form a fine pattern (on the order of submicrons) having a line width of the energy beam to be irradiated.

In the present invention, at the time of patterning the organic sulfur silane compound layer, the above-mentioned energy ray is irradiated to remove or alter the organic sulfur silane compound in the irradiated portion, or at the same time, after the addition of water, steam or The second organosulfur silane compound as shown in the general formula (1) is caused to act on the irradiated portion, and these active substances are selectively reacted or adsorbed on the irradiated portion to form the organic sulfur silane compound. A patterned layer can also be obtained.

Next, the step of depositing and growing gold will be described with reference to FIG. 3 assuming that [AuI ₄ ] ⁻ is used as the gold complex and volatilization is used as the decomposition treatment means of the gold complex.

First, potassium iodide and iodine are charged into distilled water to prepare an aqueous iodine solution, and then gold is charged and stirred and dissolved to prepare a gold complex solution 17 containing [AuI ₄ ] ^- . At this time, in addition to the gold complex [AuI ₄ ] ⁻ ,
It is considered that ₃ ^- and K ⁺ exist. Next, the substrate 11 having the patterning layer 15 is immersed in the gold complex solution 17 (see FIG. 3B), and the solution temperature is increased (30).
１００100 ° C.) Promotes iodine volatilization. At this time, the decomposition of [AuI ₄ ] ⁻ proceeds in order to maintain the chemical equilibrium, and as a result, the gold becomes supersaturated. The supersaturated gold reacts with the mercapto group of the patterning layer 15 on the substrate, and precipitates on the organic sulfur silane compound constituting the patterning layer 15 to form a crystal nucleus 18 (see FIG. 3C). Thereafter, new crystal nucleus generation and crystal nucleus growth proceed in parallel. At this time, the nuclear crystal grows in a single crystal in a self-aligned manner (see FIG. 3D). Thereafter, a patterned gold crystal thin film 19 composed of a single crystal group is formed by collision between the single crystals (see FIG. 3E).

The gold crystal thin film or the patterned gold crystal thin film obtained by the present invention is composed of a single crystal gold group having an extremely smooth surface, which is formed of a halogen such as iodine or the like existing in the gold complex solution. Has a gold dissolving effect, and it is considered that the generation of new crystal nuclei on the growing gold crystal is suppressed. In addition, since the patterned gold crystal thin film is patterned at the same time as the formation, there is no need to pattern the gold crystal thin film again after the formation, and therefore there is no damage to the surface due to the patterning.

[0039]

Embodiments of the present invention will be described below.

Embodiment 1 This embodiment will be described with reference to FIG.

An Si wafer was used as the substrate 1,
After washing with a 0% aqueous hydrofluoric acid solution, the substrate is left in a container filled with saturated vapor of 3-mercaptopropyltrimethoxysilane for 6 hours to adsorb 3-mercaptopropyltrimethoxysilane in gaseous phase, and onto the substrate 1. Then, an organic sulfur compound layer 2 was formed.

Next, potassium iodide 4 was added to 500 ml of distilled water.
0 g and 6 g of iodine are dissolved to prepare an aqueous iodine solution,
Further, 3 g of gold was stirred and dissolved therein. 10 from such solution
0 ml was dispensed into the reaction vessel and distilled water 500m
stirred with l, [AuI _4] ^- gold complex solution 3 containing
It was created. The substrate 1 was immersed in the solution, and the solution temperature was further increased to 80 ° C. to evaporate iodine. After being left in this state for 50 minutes, the substrate was taken out, and a gold crystal thin film 5 composed of a single crystal group having a particle size of 50 to 500 μm was formed. The thickness was 200 nm.

When the surface of this gold crystal thin film was observed with a scanning tunneling microscope, the surface was extremely smooth, and the unevenness of the surface of each single crystal was within 5 ° within a 1 μm square.

Example 2 In Example 1, as a method of forming the organic sulfur compound layer 2, a hydrofluoric acid-treated Si wafer was immersed in a 1% toluene solution of 6-mercaptohexyltrichlorosilane for 20 minutes, and then cleaned. Except that the substrate was sufficiently washed with toluene, further dried at 90 ° C. for 15 minutes, and the solvent was removed by evaporation to change the monomolecular film of 6-mercaptohexyltrichlorosilane to one formed on a Si substrate. In the same manner as in Example 1, a gold crystal thin film was formed.

The obtained gold crystal thin film has a particle size of 50 to 500.
It was composed of a group of single crystals of μm, and had a thickness of 200 nm. Observation of the surface of this gold crystal thin film with a scanning tunneling microscope revealed that the surface was extremely smooth, and the irregularities on the surface of each single crystal were within 5 ° within a 1 μm square.

Example 3 In Example 1, the substrate 1 was replaced with a Si wafer.
A gold crystal thin film was prepared in exactly the same manner as in Example 1 except that a glass substrate (Corning Co., # 7059) was used. still,
The glass substrate was immersed in an ethanol solution saturated with KOH, subjected to ultrasonic cleaning for 10 minutes, then sufficiently washed with pure water, and dried by heating at 90 ° C. for 15 minutes.

The obtained gold crystal thin film has a particle size of 50 to 500.
It was composed of a group of single crystals of μm, and had a thickness of 200 nm. Observation of the surface of this gold crystal thin film with a scanning tunneling microscope revealed that the surface was extremely smooth, and the irregularities on the surface of each single crystal were within 5 ° within a 1 μm square.

Embodiment 4 This embodiment will be described with reference to FIG.

An Si wafer was used as the substrate 1,
After washing with a 0% aqueous hydrofluoric acid solution, a container filled with saturated vapor of mercaptomethyltrimethoxysilane is charged with 6%.
After standing for a while, mercaptomethyltrimethoxysilane was adsorbed in the gas phase to form an organic sulfur compound layer 2 on the substrate 1.

Next, potassium iodide 4 was added to 500 ml of distilled water.
0 g and 6 g of iodine are dissolved to prepare an aqueous iodine solution,
Further, 3 g of gold was stirred and dissolved therein. 10 from such solution
0 ml was dispensed into the reaction vessel and distilled water 500m
stirred with l, [AuI _4] ^- gold complex solution 3 containing
It was created. The substrate 1 was immersed in the solution, 30 ml of an aqueous solution in which 100 mg of hydroquinone was dissolved was slowly added to the solution, and the solution was allowed to stand. After leaving the substrate for 4 hours in this state, the substrate is taken out.
A gold crystal thin film 5 composed of a group of single crystals of μm was formed. The thickness was 150 nm.

When the surface of the gold crystal thin film was observed with a scanning tunneling microscope, the surface was extremely smooth, and the unevenness of the surface of each single crystal was within 5 ° within a 1 μm square.

Embodiment 5 This embodiment will be described with reference to FIGS.

A Si wafer was used as the substrate 11, washed with a 10% aqueous hydrofluoric acid solution, and then left for 6 hours in a container filled with saturated vapor of 3-mercaptopropyltrimethoxysilane to obtain 3-mercaptopropyl. Trimethoxysilane was adsorbed in the gas phase to form an organic sulfur silane compound layer 12 on the substrate 11.

Next, the organic sulfur silane compound layer 12
Through a 1 μm line / space mask 16 on the surface,
The patterning layer 15 was formed by irradiating an Ar-F excimer laser (wavelength: 193 nm) (dose amount: 500 J / cm ² ).

Next, potassium iodide 4 was added to 500 ml of distilled water.
0 g and 6 g of iodine are dissolved to prepare an aqueous iodine solution,
Further, 3 g of gold was stirred and dissolved therein. 10 from such solution
0 ml was dispensed into the reaction vessel and distilled water 500m
stirred with l, [AuI _4] ^- gold complex solution 1 containing
7 was created. The substrate 11 was immersed in the solution, and the solution temperature was further increased to 80 ° C. to evaporate iodine. After being left in this state for 50 minutes, the substrate was taken out, and a 1 μm-pitch patterned gold crystal thin film 19 composed of a single crystal group having a particle size of 50 to 500 μm was formed. The thickness was 200 nm.

When the gold surface of the patterned gold crystal thin film was observed with a scanning tunneling microscope, the surface was extremely smooth, and the unevenness of each single crystal surface was 5 μm within 1 μm square.
Within Å.

Example 6 In Example 5, as a method of forming the organic sulfur silane compound layer 12, a hydrofluoric acid-treated Si wafer was placed in a 1% toluene solution of 3-mercaptopropyltrichlorosilane.
After immersion for 0 minutes, the substrate was thoroughly washed with clean toluene, and further dried at 90 ° C. for 15 minutes to evaporate the solvent, thereby removing a 3-mercaptopropyltrichlorosilane monolayer from a Si substrate. A patterned gold crystal thin film was formed in exactly the same manner as in Example 5 except that the above-mentioned one was changed.

The obtained gold crystal thin film has a particle size of 50 to 500.
It was composed of a group of single crystals of μm, and had a thickness of 200 nm. When the gold surface of the patterned gold crystal thin film was observed with a scanning tunneling microscope, the surface was extremely smooth, and the irregularities on the surface of each single crystal were within 5 ° within a 1 μm square.

Example 7 A patterned gold crystal thin film was obtained in the same manner as in Example 5 except that a glass substrate (# 7059 manufactured by Corning Incorporated) was used instead of the Si wafer as the substrate 11. Created. In addition, the glass substrate was immersed in an ethanol solution saturated with KOH, subjected to ultrasonic cleaning for 10 minutes, then sufficiently washed with pure water, and dried by heating at 90 ° C. for 15 minutes. .

The resulting patterned gold crystal thin film is
It was composed of a single crystal group having a particle size of 50 to 500 μm, and had a thickness of 200 nm. When the gold surface of the patterned gold crystal thin film was observed with a scanning tunneling microscope, the surface was extremely smooth, and the unevenness of each single crystal surface was
The angle was within 5 ° within a 1 μm square.

Embodiment 8 This embodiment will be described with reference to FIGS.

A Si wafer was used as the substrate 11, which was washed with a 10% aqueous hydrofluoric acid solution, and then left in a container filled with saturated vapor of mercaptomethyltrimethoxysilane for 6 hours to remove mercaptomethyltrimethoxysilane. The organic sulfur silane compound layer 12 was formed on the substrate 11 by gas phase adsorption.

Next, the organic sulfur silane compound layer 12
Through a 1 μm line / space mask 16 on the surface,
The patterning layer 15 was formed by irradiating an Ar-F excimer laser (wavelength: 193 nm) (dose amount: 500 J / cm ² ).

Next, potassium iodide 4 was added to 500 ml of distilled water.
0 g and 6 g of iodine are dissolved to prepare an aqueous iodine solution,
Further, 3 g of gold was stirred and dissolved therein. 10 from such solution
0 ml was dispensed into the reaction vessel and distilled water 500m
stirred with l, [AuI _4] ^- gold complex solution 1 containing
7 was created. The substrate 11 having undergone the above-described steps was immersed in the solution, and 30 ml of an aqueous solution in which 100 mg of hydroquinone was dissolved was slowly added to the solution and allowed to stand.
After standing for 4 hours in this state, the substrate was taken out, and a patterned gold crystal thin film 19 composed of a single crystal group having a particle size of 50 to 300 μm was formed. The thickness is 150 nm
Met.

When the gold surface of the patterned gold crystal thin film was observed with a scanning tunneling microscope, the surface was extremely smooth, and the unevenness of the surface of each single crystal was 5 μm within 1 μm square.
Within Å.

Embodiment 9 This embodiment will be described with reference to FIGS.

A Si wafer was used as the substrate 11, washed with a 10% aqueous hydrofluoric acid solution, and then left in a vessel filled with saturated vapor of 3-mercaptopropyltrimethoxysilane for 6 hours to obtain 3-mercaptopropyl. After the trimethoxysilane was adsorbed in the gas phase, the substrate was sufficiently washed with clean ethanol to form an organic sulfur silane compound layer 12 on the substrate 11.

Next, the organic sulfur silane compound layer 12
EB direct drawing (acceleration: 5 keV, dose: 1 μC / cm ² ) was performed on the surface at a line / space of 0.25 μm to form a patterning layer 15.

Next, potassium iodide 4 was added to 500 ml of distilled water.
0 g and 6 g of iodine are dissolved to prepare an aqueous iodine solution,
Further, 3 g of gold was stirred and dissolved therein. From such a solution
A 100 ml aliquot is placed in a reaction vessel, and 500 ml of distilled water is further added.
Then, the mixture was added and stirred to prepare a gold complex solution 17 containing [AuI ₄ ] ^- . Immersing the substrate 11 in such a solution,
The solution temperature was further increased to 80 ° C. to evaporate iodine. After being left in this state for 25 minutes, the substrate was taken out, and a single crystal group consisting of a single crystal group having a particle size of 50 to 500 μm was obtained.
A patterned gold crystal thin film 19 having a pitch of μm was formed. The film thickness was 60 nm.

When the gold surface of this patterned gold crystal thin film was observed with a scanning tunneling microscope, the surface was extremely smooth, and the unevenness of each single crystal surface was 5 μm within 1 μm square.
Within Å.

[0071]

As described above, according to the present invention,
It has the following effects. (1) The deposition and growth of gold is performed by controlling the chemical equilibrium state of the gold complex solution. No special equipment is required, and the organic sulfur compound layer or the organic sulfur compound layer is formed under conditions close to normal temperature and normal pressure. A gold crystal thin film or a patterned gold crystal thin film can be formed on various substrates on which an organic sulfur silane compound layer is deposited. (2) The amount of the organic sulfur compound or the organic sulfur silane compound to be deposited on the substrate is very small, and the deposition method can be a conventionally known, very simple method. (3) The orientation of each gold single crystal constituting the gold crystal thin film is (11)
The gold crystal thin film having the orientation controlled in 1) and having an extremely smooth surface can be stably formed.

[Brief description of the drawings]

FIG. 1 is a schematic view showing an example of a production process of a gold crystal thin film of the present invention.

FIG. 2 is a schematic view showing an example of a step of forming a patterned organic sulfur silane compound layer on a substrate in the present invention.

FIG. 3 is a schematic view showing an example of a step of depositing and growing gold on a patterned organic sulfur silane compound layer in the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 2 Organic sulfur compound layer 3 Gold complex solution 4 Gold crystal nucleus 5 Gold crystal thin film 11 Substrate 12 Organic sulfur silane compound layer 13 Energy ray 14 Irradiated part 15 Patterning layer 16 Mask 17 Gold complex solution 18 Gold crystal nucleus 19 Patterning Gold crystal thin film

Continued on the front page (72) Inventor Toshihiko Takeda 3- 30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (72) Inventor Haruki Kawasaki 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (72) Inventor Kiyoshi Takimoto 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (56) References JP-A-54-28233 (JP, A) JP-A-56-38406 (JP, A) JP-A-55-54509 (JP, A) JP-A-4-80373 (JP, A) JP-A-5-201793 (JP, A) Goss, Charles A. et al. , "Application of 3-mercaptopropyl trimethyoxylane as a molecular ad hesive in the fabrication of vapor-deposited reviews. Chem. , Vol. 63, No. 1, 1991, p. 85-88 (58) Field surveyed (Int. Cl. ⁷ , DB name) C30B 1/00-35/00 CA (STN) EPAT (QUESTEL) WPI (DIALOG)

Claims (16)

(57) [Claims] 1. A method for decomposing a gold complex in a gold complex solution to shift the gold in the solution to a saturated state and forming a gold thin film on the substrate in the solution, Is a method of forming a gold thin film, comprising: a layer of an organic molecule having a substituent containing sulfur on a surface thereof; and depositing and growing gold on the layer of the organic molecule. 2. The method according to claim 1, wherein the gold thin film is composed of a group of single crystals of gold having a (111) orientation. 3. The method for forming a gold thin film according to claim 1, wherein the gold complex is [AuI ₄ ] ⁻ . 4. The method for forming a gold thin film according to claim 1, wherein the gold complex is [AuCl ₄ ] ⁻ . 5. The method for forming a gold thin film according to claim 1, wherein the decomposition treatment is performed by volatilizing a substance constituting the gold complex from a solution system. 6. The method for forming a gold thin film according to claim 1, wherein the decomposition treatment is performed by adding a reducing agent to a solution system of a substance constituting the gold complex. 7. The method for forming a gold thin film according to claim 1, wherein the substituent containing sulfur is a mercapto group. 8. The method according to claim 1, wherein the organic molecule having a substituent containing sulfur is chemically adsorbed to the substrate. 9. The organic molecule layer having a substituent containing sulfur is a monomolecular film or a monomolecular cumulative film formed on the substrate. Of forming a thin gold film. 10. The substrate according to claim 1, wherein the substrate is made of any one of silicon, silicon oxide, and silicon nitride, or a substrate having a layer made of these on the surface. The method for forming a gold thin film according to any one of the above. 11. The method for forming a gold thin film according to claim 1, wherein the substrate itself is formed of an organic molecule having a substituent containing sulfur. 12. The organic molecule having a substituent containing sulfur is an organic silane molecule.
11. The method for forming a gold thin film according to any one of claims 10 to 10. 13. The method according to claim 12, wherein the organosilane molecule having a substituent containing sulfur is polysiloxane. 14. The method for forming a gold thin film according to claim 12, further comprising a step of patterning a layer of the organic silane molecule having a substituent containing sulfur, wherein the patterning is performed by the patterning step. A method for forming a patterned gold thin film, comprising depositing and growing gold on a layer of organosilane molecules. 15. The step of patterning the layer of the organosilane molecule having a substituent containing sulfur includes partially selectively applying energy to the organic silane molecule layer having a substituent containing sulfur deposited on a substrate. 2. Irradiating a line to remove or alter an organic silane compound having a sulfur-containing substituent in a portion to be irradiated.
5. The method for forming a patterned gold thin film according to 4. 16. The step of patterning the layer of the organosilane molecule having a substituent containing sulfur includes partially selectively applying energy to the organic silane molecule layer having a substituent containing sulfur deposited on a substrate. Irradiating a line to remove or alter the organic silane compound having a sulfur-containing substituent in the irradiated portion, or at the same time, or thereafter, cause water, water vapor, or a second organic silane compound to act on the irradiated portion. The method for forming a patterned gold thin film according to claim 14, wherein these active substances are selectively reacted or adsorbed to the irradiated portion.