JP2018168005A - Control method for decomposition and storage of gold oxide - Google Patents

Abstract

Disclosed is a method for controlling decomposition and storage of gold oxide capable of controlling the reduction reaction from gold oxide to gold, such as storing gold oxide for a long period of time or promoting decomposition. The decomposition and storage of gold oxide are controlled by adjusting the irradiation state of the ultraviolet ray UV to the gold oxide thin film 2 and adjusting the state of moisture around the gold oxide thin film 2. The gold oxide thin film 2 is blocked by irradiating the ultraviolet ray UV and the gold oxide thin film 2 is stored, or moisture is removed from the periphery of the gold oxide thin film 2 to store the gold oxide thin film 2. Alternatively, the gold oxide may be decomposed by irradiating at least a part of the gold oxide thin film 2 with ultraviolet light and applying moisture to the portion of the gold oxide thin film 2 irradiated with the ultraviolet light UV. [Selection] Figure 4

Description

  The present invention relates to a method for controlling decomposition and storage of gold oxide.

  Conventionally, various gold surface treatment methods have been proposed (see, for example, Patent Document 1). Gold is not oxidized in the air or oxygen, but a gold oxide thin film is formed on the surface by oxygen glow discharge or the like. The gold oxide thin film may play an important role in the surface treatment of gold because gold oxide is hydrophobic while the gold oxide produced is hydrophilic.

JP 2011-109117 A

  However, since the reaction from gold to gold oxide is an endothermic reaction, if left in a room, the gold oxide decomposes and returns to the original gold after a few days. There is no knowledge about the decomposition of gold oxide and its suppression, and long-term storage of gold oxide and its industrial use are difficult.

  The present invention has been made in view of the above circumstances, and it is possible to control the reduction reaction from gold oxide to gold, such as storing gold oxide for a long period of time or accelerating its decomposition. And to provide a storage control method.

In order to achieve the above object, the method for controlling decomposition and storage of gold oxide of the present invention comprises:
The decomposition and storage of the gold oxide are controlled by adjusting the irradiation state of the light having a wavelength equal to or less than the ultraviolet region to the gold oxide or adjusting the state of moisture around the gold oxide.

In this case, the gold oxide is stored by preventing the light from being irradiated to the gold oxide.
It is good as well.

Further, the light is prevented from being irradiated to the gold oxide by the substance that blocks the light.
It is good as well.

Remove moisture from the surroundings of gold oxide to preserve the gold oxide,
It is good as well.

Store gold oxide in a moisture-free vacuum, gas, liquid or solid,
It is good as well.

Irradiating at least a part of the gold oxide with the light, and decomposing the gold oxide by applying moisture to a portion of the gold oxide that is irradiated with the light,
It is good as well.

A mask in which the first portion where the light is blocked or moisture is removed and the second portion where the light is irradiated and the moisture is attached to the thin film of gold oxide formed on the gold surface are patterned. Form the
Supplying moisture to the gold oxide thin film through the mask and irradiating the light;
It is good as well.

The second part is
An opening that exposes the gold oxide thin film,
It is good as well.

Control the decomposition and storage of gold oxide by adjusting the wavelength of the light or adjusting the amount of water around the gold oxide.
It is good as well.

  According to this invention, while adjusting the irradiation state to the gold oxide of the light whose wavelength is below the ultraviolet region, the state of moisture around the gold oxide is adjusted. This makes it possible to store gold oxide for a long period of time, promote decomposition, etc. by utilizing the property that water is decomposed into radicals by irradiation with light whose wavelength is below the ultraviolet region and gold oxide is reduced to gold. The reduction reaction from gold oxide to gold can be controlled.

It is a flowchart of the production | generation and usage method of the gold oxide thin film which concerns on Embodiment 1 of this invention. It is sectional drawing of a gold thin film. It is sectional drawing of the gold oxide thin film formed on the gold thin film. It is an example of the structure which interrupts | blocks an ultraviolet-ray from a gold oxide thin film. It is a graph which shows the light transmittance characteristic of common glass and a laminated glass. It is a graph which shows the light transmittance characteristic of borosilicate glass and soda-lime glass. It is a graph which shows the light transmittance characteristic of quartz glass. It is sectional drawing at the time of providing a waterproof film on a gold oxide thin film. It is sectional drawing which shows a mode that the circumference | surroundings of the gold oxide thin film were filled with the gas without a water | moisture content. It is sectional drawing which shows a mode that the circumference | surroundings of the gold oxide thin film were made into the vacuum. FIG. 11A and FIG. 11B are diagrams showing a method for forming a gold oxide thin film pattern using a mask. It is a figure which shows the Au 4f spectrum and O 1s spectrum of untreated gold, and the Au 4f spectrum and O 1s spectrum of gold oxide. It is a schematic diagram which shows the lamination | stacking model of the gold oxide thin film and oxygen on a gold thin film. FIGS. 14A and 14B are diagrams showing the peak positions and half-width setting values of the spectrum to be measured. It is a figure which compares and shows the Au4f spectrum and O1s spectrum of gold oxide in the taking-out angle where photoelectrons differ. It is a figure which shows the relationship between the elapsed time of oxygen glow discharge, Au4f spectrum, and O1s spectrum. It is the figure which compared the change of Au4f spectrum and O1s spectrum in the dark place and bright place of a gold oxide thin film. It is a figure which shows Au4f spectrum and O1s spectrum at the time of irradiating a gold-oxide thin film in the air | atmosphere with a different wavelength. It is a figure which compares and shows the decomposition | disassembly state of the gold oxide which irradiated the ultraviolet-ray of wavelength 302nm for 24 hours in a dark place, a high vacuum, and atmospheric pressure. It is a figure which compares and shows the decomposition | disassembly state of gold oxide at the time of irradiating the ultraviolet-ray with a wavelength of 302 nm for 6 hours in nitrogen, oxygen, and water vapor | steam. It is a figure which shows the comparison result of Au4f and O1s spectrum (photoelectron taking-out angle (theta) = 90 degrees) of gold oxide which irradiated the ultraviolet-ray of a different wavelength in water vapor | steam for 3 hours. It is a figure which shows the comparison result of Au4f and O1s spectrum (photoelectron taking-out angle (theta) = 10 degrees) of the gold oxide which irradiated the ultraviolet-ray of a different wavelength in water vapor | steam for 3 hours. It is a figure which shows the comparison result of the decomposition | disassembly state of a gold oxide thin film in the case where it preserve | saved for 24 hours in a dark place, and the case where an incandescent bulb is irradiated for 24 hours. It is a figure which shows the result of the decomposition | disassembly state of a gold oxide thin film at the time of preserve | saving for a long time in nitrogen. FIG. 25A, FIG. 25B, FIG. 25C, and FIG. 25D are tables that summarize the results of irradiating a gold oxide thin film with ultraviolet light under various conditions. It is a figure which shows the absorption spectrum of water vapor | steam. It is a figure which shows the comparison result when the gold thin film which performed 300 second oxygen glow discharge was heated in air | atmosphere at each temperature for 3 hours. FIG. 28 (A) is a diagram showing a state immediately after dropping a 1 wt% polyvinyl alcohol aqueous solution onto a gold thin film. FIG. 28 (B) is a diagram showing a state after the water droplets of the 1 wt% polyvinyl alcohol aqueous solution dropped on the gold thin film are dried. FIG. 28 (C) is a diagram showing a state immediately after dropping a 1 wt% polyvinyl alcohol aqueous solution onto the gold oxide thin film. FIG. 28 (D) is a diagram showing a state after the water droplets of the 1 wt% polyvinyl alcohol aqueous solution dropped on the gold oxide thin film are dried.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. In the present embodiment, a control method for controlling decomposition and storage of gold oxide (thin film) formed on the surface of gold (thin film) will be described.

  The present inventor has revealed that ultraviolet rays and water are involved in the decomposition of gold oxide, and has found that the decomposition of gold oxide can be suppressed by blocking the ultraviolet rays and water from the gold oxide. Therefore, in the method for controlling decomposition and storage of gold oxide according to the present embodiment, the decomposition of gold oxide is adjusted by adjusting the state of irradiation of gold oxide with ultraviolet light and adjusting the state of moisture around the gold oxide. And control saving.

A method for producing and using a gold oxide thin film to be controlled will be described. As shown in FIG. 1, first, a gold thin film 1 is generated (step S1). For example, a vacuum vapor deposition method is used to produce the gold thin film 1. In the vacuum deposition method, for example, gold having a purity of 99.99% is deposited on a mica substrate at a thickness of 50 nm in a high vacuum of 10 ⁻⁴ Pa. Thereby, the gold thin film 1 is formed as shown in FIG.

  Subsequently, a gold oxide thin film 2 is generated from the generated gold thin film 1 (step S2). For example, oxygen glow discharge is used to generate the gold oxide thin film 2. For example, oxygen glow discharge (10 Pa, 5 mA, 10 seconds to 30 minutes) is performed using an aluminum discharge ring while flowing high-purity oxygen (99.999%) through the produced gold thin film 1. As a result, a gold oxide thin film 2 is generated on the gold thin film 1 as shown in FIG.

  Subsequently, the environmental condition around the generated gold oxide thin film 2 is adjusted (step S3). In this step, specifically, the irradiation state of the ultraviolet ray UV onto the gold oxide thin film 2 is adjusted, and the state of moisture around the gold oxide thin film 2 is adjusted. Here, for example, when the gold oxide thin film 2 is stored, at least one of the treatment of blocking the irradiation of the ultraviolet rays UV on the gold oxide thin film 2 or removing the moisture from the periphery of the gold oxide thin film 2 is performed. Is done.

In order to prevent the ultraviolet ray UV from being irradiated to the gold oxide thin film 2 in step S3, for example, the ultraviolet ray UV is irradiated to the gold oxide thin film 2 by a material that blocks the ultraviolet UV, that is, a material member. Prevent it. For example, as shown in FIG. 4, the gold thin film 1 and the gold oxide thin film 2 are installed in a metal or resin container 3 that blocks ultraviolet rays UV. Although the container 3 is provided with glass (excluding quartz glass) 4, the glass 4 also blocks ultraviolet rays UV. In the container 3, the presence of water vapor (H ₂ O) is allowed as shown in FIG. Even if the water vapor enters, the ultraviolet ray UV is not irradiated to the gold oxide thin film 2, so that the decomposition of gold oxide into gold can be suppressed.

  5 and 6 show the relationship between the wavelength of light and the transmittance in glass. FIG. 5 shows light transmittance characteristics of a general glass having a thickness of 3 mm and a laminated glass formed by bonding a glass having a thickness of 3 mm. As shown in FIG. 5, the glass having a thickness of 3 mm blocks ultraviolet UV of 300 nm or less, and the laminated glass blocks ultraviolet UV of 380 nm or less.

  FIG. 6 shows the light transmittance characteristics of borosilicate glass and soda lime glass having a thickness of 3 mm. As shown in FIG. 6, the borosilicate glass with a thickness of 3 mm blocks ultraviolet rays UV of 270 nm or less, and the soda-lime glass with a thickness of 3 mm blocks ultraviolet rays UV of about 290 nm or less. As the glass 4, those shown in FIGS. 5 and 6 can be used.

  On the other hand, FIG. 7 shows the light transmittance characteristics of quartz glass. As shown in FIG. 7, quartz glass is not suitable for use as the glass 4 in FIG.

  On the other hand, in step S3, in order to remove moisture from the periphery of the gold oxide thin film 2, the periphery of the gold oxide thin film 2 may be filled with a vacuum, gas, liquid, or solid without moisture. As such a gas, for example, dry air, nitrogen gas, or oxygen gas can be used. As the liquid, for example, hexane or chloroform can be used.

  For example, as shown in FIG. 8, a waterproof film 5 as a solid may be provided on the gold oxide thin film 2, and as shown in FIG. 9, a gas 6 such as dry air, nitrogen gas or oxygen gas is used. You may make it fill. Further, as shown in FIG. 10, the inside of the container 3 may be evacuated and the gold oxide thin film 2 may be placed therein. When the gas 6 is filled or evacuated, the glass 4 ′ may be quartz glass that passes ultraviolet UV. In this way, since moisture has been removed from the periphery of the gold oxide thin film 2, the decomposition of the gold oxide can be suppressed even if the ultraviolet ray UV is incident on the gold oxide thin film 2.

  Further, in step S3, at least a part of the gold oxide thin film 2 is irradiated with ultraviolet UV, and moisture is applied to a portion of the gold oxide thin film 2 irradiated with the ultraviolet UV, so that the gold oxide is decomposed. Also good.

For example, as shown in FIG. 11A, a region A (first portion) in which the ultraviolet ray UV is blocked or moisture is removed from the gold oxide thin film 2 generated on the surface of the gold thin film 1 and the ultraviolet ray UV. Is applied to the region B (second portion) to which moisture adheres, and a mask (7) is formed. Through the mask 7, moisture (H ₂ O) is supplied to the gold oxide thin film 2 and ultraviolet rays UV are supplied. May be irradiated. In this way, as shown in FIG. 11B, in region B, the decomposition of gold oxide to gold proceeds and the surface returns to gold, but gold oxide is stored in region A. Thereby, a desired pattern of the gold oxide thin film 2 can be formed on the surface of the gold thin film 1.

  In addition, although the area | region B (2nd part) is an opening part which exposes the gold oxide thin film 2, you may make it arrange | position the member which permeate | transmits ultraviolet-ray UV in the area | region B. FIG.

  In the case of decomposing gold oxide into gold, the shorter the wavelength of the ultraviolet ray UV to be irradiated, the faster the decomposition of gold oxide, and the greater the amount of water around the gold oxide, the faster the decomposition of gold oxide. For this reason, the decomposition and storage of the gold oxide may be controlled by adjusting the wavelength of the ultraviolet ray UV irradiated to the gold oxide or adjusting the amount of water around the gold oxide. For example, in order to accelerate the decomposition time of gold oxide, the wavelength of ultraviolet light UV to be irradiated may be shortened to increase the amount of water around the gold oxide.

  As a premise, the gold oxide thin film 2 is kept at 75 ° C. or less, and a strong base (sodium hydroxide, potassium hydroxide), hydrohalic acid (hydrochloric acid, hydrobromic acid), aldehyde (formaldehyde, acetaldehyde) ) Is also adjusted so that it does not touch.

<Experimental result>
Various experiments were conducted to clarify the usefulness of the control method of the gold oxide thin film 2 according to the present embodiment. Measurement of these experimental results was performed by X-ray photoelectron spectroscopy using one of the following two XPS (X-ray photoelectron spectroscopy) apparatuses. X-ray photoelectron spectroscopy is a method for acquiring a spectrum by irradiating soft X-rays on a sample surface placed in an ultra-high vacuum and dispersing the kinetic energy of core electrons emitted by the external photoelectric effect. . In X-ray photoelectron spectroscopy, the binding energy between electrons before being emitted and nuclei is calculated. The binding energy shows a value peculiar to the element, and the amount of photoelectron emission increases or decreases depending on the element concentration in the measurement region. Therefore, the element can be identified and quantitatively analyzed based on the calculation result.

The specifications of the two XPS devices are as follows.
(1) XPS equipment: Shimadzu Axis-ULTRA DLD
Excitation light source: Monochromatic AlKα (1486.6 eV)
Resolution: about 0.6eV
Analysis area: 0.7 × 0.3 mm ²
Energy step: 0.1 eV
Energy correction: Au 4f _7/2 84.0 eV
(2) XPS equipment: Shimadzu ESCA-1000
Excitation light source: MgKα (1253.6 eV)
Resolution: 1.1 eV
Analysis area 3 × 10mm ²
Energy step: 0.1 eV
Energy correction: Au 4f _7/2 84.0 eV

  In this experiment, Au 4f spectrum and O 1s spectrum in gold oxide were measured. The Au 4f spectrum and the O 1s spectrum are represented by count numbers where the horizontal axis represents the binding energy and the vertical axis represents the photoelectron intensity.

  In FIG. 12, the Au 4f spectrum and O 1s spectrum of untreated gold are shown on the upper side, and the Au 4f spectrum and O 1s spectrum of gold oxide are shown on the lower side. These spectra are measured by the apparatus of (1) above. As shown in FIG. 12, in the XPS spectrum, in gold oxide, a component chemically shifted due to the electronegativity of oxygen and an O 1s peak appear on the high energy side of the Au 4f peak, and its existence can be clearly confirmed. . In addition, in the O 1s spectrum, the oxygen component spectrum does not appear in the untreated gold spectrum, but the O 1s spectrum of gold oxide shows three components: I component, II component, and III component. can do. As shown in FIG. 13, the I component is a component located in the upper layer of the two layers of oxygen present on the gold oxide, the II component is a component located in the lower layer, and the III component is composed of gold and It is a component that is bound.

That is, in the case of gold oxide, the XPS spectrum shows four peaks for Au: Au 4f _7/2 (Metal), Au 4f _5/2 (Metal), Au 4f _7/2 (Oxide), and Au 4f _5/2. Four peaks (Oxide) were observed. Regarding O, three peaks, O 1s (I component), O 1s (II component), and O 1s (III component) were observed. Therefore, in this experiment, changes in each spectrum were measured, and conditions for controlling the decomposition and storage of gold oxide were searched.

Each measured spectrum is obtained by dividing the spectrum into peaks by a least square method using a Gauss-Lorentz function and forming a curve for each peak. In peak splitting, the Shirley method was used to determine the background. The area intensity ratio was set to Au 4f _7/2 : Au 4f _5/2 = 4: 3. Further, for the device of (1) above, the peak positions and half-value widths of Au 4f and O 1s are set as shown in FIG. 14 (A), and for the device of (2) shown in FIG. 14 (B). Measurements were made with the settings shown.

  Further, in the above-described XPS apparatus, the state of the outermost surface can be analyzed as the sample is rotated toward the detector and the photoelectron extraction angle θ from the sample surface is reduced. Therefore, first, the Au 4f spectrum in the product after 300 seconds of oxygen glow discharge is obtained by changing the photoelectron extraction angle θ from gold oxide to 90 °, 30 °, and 10 ° using the apparatus of (1) above. And O 1s spectrum were measured. As a result, as shown in FIG. 15, in the Au 4f spectrum, the peak derived from gold oxide increases as the angle decreases, whereas in the O 1s spectrum, the extraction angle θ decreases. The longer the peak of the I component, the lower the peak of the III component. From this result, it is presumed that the gold oxide thin film 2 is formed on the gold surface, and oxygen-derived components are distributed from the surface in the order of I component → II component → III component.

(Relationship between glow discharge time and product spectrum)
FIG. 16 shows the relationship between the glow discharge time and the product spectrum. The Au 4f spectrum and O 1s spectrum shown in FIG. 16 are measured by the apparatus (1). As shown in FIG. 16, generation of an oxide-derived peak was confirmed after 60 seconds. Regarding the O 1s spectrum, I and II components first appeared, and after 60 seconds, a III component appeared. Thus, the production process of gold oxide was clarified by changing the oxygen glow discharge time.

  From this experimental result, it became clear that the I component and the II component were generated first, and then the III component was generated. Further, as shown in FIG. 15, the depth distribution of gold oxide, I component, II component, III component, etc. can be clarified based on the angular dependence of the gold oxide thin film 2 after 300 seconds of oxygen glow discharge. did it.

(Storage in the dark)
Then, the preservation | save state of the dark place and the bright place of the gold oxide thin film 2 produced | generated by performing oxygen glow discharge for 30 minutes at 1.0 * 10 < ⁵ > Pa in air | atmosphere was compared. FIG. 17 shows a comparison result of spectra when the gold oxide thin film 2 is stored in a dark place and when stored in a bright place near a window where natural light enters. Note that the data shown in FIG. 17 was measured by the apparatus (2).

  As shown in FIG. 17, when the gold oxide thin film 2 was stored in a dark place, the Au 4f spectrum and the O 1s spectrum hardly changed even after 10 days. On the other hand, when the gold oxide thin film 2 was stored in a bright place, the Au 4f spectrum and the O 1s spectrum changed with the passage of time, and returned to the state of untreated gold after 7 days. As described above, it has been clarified that gold oxide is not decomposed when ultraviolet light UV is not incident, and gold oxide is decomposed and reduced to gold when ultraviolet light UV is incident.

(UV wavelength dependence)
Subsequently, the decomposition state of gold oxide with respect to the wavelength of ultraviolet UV was measured. FIG. 18 shows the measurement results of the Au 4f spectrum and the O 1s spectrum when the gold oxide thin film 2 is irradiated with ultraviolet rays UV of 365 nm, 302 nm, and 254 nm for 6 hours at 1.0 × 10 ⁵ Pa in the atmosphere. ing. In this measurement, the apparatus (1) was used. As shown in FIG. 18, gold oxide was well decomposed in the order of 365 nm, 302 nm, and 254 nm. Therefore, it became clear that decomposition | disassembly of gold oxide is accelerated | stimulated, so that the wavelength of ultraviolet-ray UV becomes short.

(Comparison of decomposition state of gold oxide in dark place, high vacuum and atmospheric pressure)
Subsequently, the decomposition state of gold oxide irradiated with ultraviolet rays with a wavelength of 302 nm for 24 hours in a dark place, high vacuum, and atmospheric pressure was compared. FIG. 19 shows an Au 4f spectrum and an O 1s spectrum when irradiated with ultraviolet rays having a wavelength of 302 nm for 24 hours in a dark place, in a high vacuum (10 ⁻⁴ Pa), and at atmospheric pressure. For this measurement, the apparatus (1) was used. As shown in FIG. 19, the gold oxide was decomposed at atmospheric pressure, but the spectrum did not change in the dark or high vacuum, and the decomposition of gold oxide was suppressed. From the above results, it was revealed that the decomposition of gold oxide is suppressed in a state where ultraviolet rays UV is not irradiated and in a state where moisture is removed.

(Comparison in nitrogen, oxygen, and water vapor)
Next, the decomposition state of gold oxide was compared when irradiated with ultraviolet UV having a wavelength of 302 nm in nitrogen, oxygen, and water vapor for 6 hours. In FIG. 20, ultraviolet rays with a wavelength of 302 nm are irradiated for 6 hours in nitrogen (6.0 × 10 ⁴ Pa), oxygen (6.0 × 10 ⁴ Pa), and water vapor (1.5 × 10 ³ Pa). In this case, Au 4f spectrum and O 1s spectrum are shown. This measurement was performed using the apparatus (1). As shown in FIG. 20, it was revealed that the decomposition of gold oxide was suppressed in nitrogen and oxygen, and the gold oxide was decomposed in water vapor.

(UV irradiation in water vapor: Photoelectron extraction angle = 90 °)
Subsequently, the measurement was performed when the gold oxide thin film 2 was placed in water vapor and irradiated with ultraviolet rays UV having different wavelengths for 3 hours. FIG. 21 shows Au 4f and O 1s spectra of gold oxide (photoelectron extraction angle θ = 3) irradiated with ultraviolet rays UV of each wavelength (365 nm, 302 nm, 254 nm) in water vapor (1.5 × 10 ³ Pa) for 3 hours. 90 °). For this measurement, the apparatus (1) was used. As shown in FIG. 21, when the ultraviolet ray having a wavelength of 254 nm was irradiated, the Au ₂ O ₃ component decreased in the Au 4f spectrum. It was confirmed that the shorter the wavelength of ultraviolet light, the faster the decomposition of gold oxide.

(UV irradiation in water vapor: Photoelectron take-off angle = 10 °)
Similarly, measurement was performed when the gold oxide thin film 2 was placed in water vapor and irradiated with ultraviolet rays UV having different wavelengths for 3 hours. Again, the apparatus of (1) above was used. FIG. 22 shows Au 4f and O 1s spectra (photoelectron extraction angle θ = 10 °) of gold oxide irradiated with ultraviolet rays of each wavelength for 3 hours in water vapor (1.5 × 10 ³ Pa). . As shown in FIG. 22, when θ = 10 °, the analysis depth of the spectrum is about 1/6 compared to when θ = 90 °, but even at the outermost surface of the gold oxide thin film 2. It was confirmed that the shorter the wavelength of the ultraviolet UV, the faster the decomposition of gold oxide.

(Comparison between UV and visible light)
A comparison was made of the manner in which gold oxide was decomposed between irradiation with ultraviolet UV and irradiation with visible light. In this experiment, the Au 4f spectrum and O 1s spectrum of the gold oxide thin film 2 were measured when stored in the dark at 1.0 × 10 ⁵ Pa in the atmosphere for 24 hours and when irradiated with visible light from an incandescent bulb for 24 hours. did. This measurement was performed using the apparatus (1). FIG. 23 shows a comparison result of the decomposition state of gold oxide when stored in a dark place and when irradiated with an incandescent bulb. As shown in FIG. 23, it was confirmed that gold oxide was decomposed by ultraviolet rays UV and not decomposed by visible light.

(Long-term storage)
Subsequently, the gold oxide thin film 2 was stored in a dark place without water for about 30 days, and the state of decomposition was confirmed. In this measurement, the apparatus (1) was used. FIG. 24 shows the result of the decomposition state of gold oxide when stored for a long time in nitrogen (6.0 × 10 ⁴ Pa). As shown in FIG. 24, there is no change in the Au 4f spectrum and the O 1s spectrum of the gold oxide thin film 2 stored in nitrogen in the dark, and the gold oxide thin film 2 remains in the dark for a long period (30 days or more). It was confirmed that it could be stored.

(Summary of experimental results)
The experimental results so far are summarized in the tables of FIGS. 25 (A) to 25 (D). In each table, a double circle indicates that the decomposition of gold oxide has been completed, a circle indicates that gold oxide is being decomposed, and a triangle indicates the start of decomposition of gold oxide. X indicates that the gold oxide was not decomposed.

  As shown in FIG. 25A, as a result of irradiating the gold oxide thin film 2 with ultraviolet rays UV having wavelengths of 365 nm, 302 nm, and 254 nm in the atmosphere, it is clear that ultraviolet rays UV having a short wavelength of 302 nm and 254 nm decompose gold oxide. It became. This indicates that the decomposition and storage of gold oxide can be controlled by adjusting the wavelength of ultraviolet rays.

  As shown in FIG. 25B, it was confirmed that the decomposition of gold oxide was delayed as a result of irradiating the gold oxide thin film 2 with ultraviolet light UV having a wavelength of 365 nm in atmospheric pressure and water vapor. Further, the time required for decomposition was shorter in water vapor. Thereby, it became clear that the one where there is much water promotes decomposition | disassembly of a gold oxide. This indicates that the decomposition and storage of gold oxide can be controlled by adjusting the amount of water around the gold oxide.

  As shown in FIG. 25C, when the gold oxide thin film 2 is irradiated with ultraviolet rays UV having a wavelength of 302 nm in various atmospheres such as atmospheric pressure, the atmospheric pressure, the low vacuum, the high vacuum, and the water vapor. Gold oxide was decomposed, and gold oxide was not decomposed in oxygen and nitrogen. Decomposition was the fastest in steam. Further, when the ultraviolet ray UV was not irradiated in the water vapor, the gold oxide was not decomposed. As a result, it has been clarified that gold oxide is not decomposed when either ultraviolet rays or moisture does not exist.

  As shown in FIG. 25D, as a result of irradiating the gold oxide thin film 2 with ultraviolet light UV having a wavelength of 254 nm in atmospheric pressure and water vapor, the gold oxide was completely decomposed. The time required for the decomposition was shorter in the water vapor, and the decomposition time was shorter than that in the case of irradiating the ultraviolet ray UV having a wavelength of 365 nm shown in FIG.

(About the wavelength range of light)
In addition, the light which decomposes | disassembles gold oxide is not restricted to ultraviolet-ray UV. As is apparent from the absorption spectrum of water vapor in FIG. 26, light having a wavelength shorter than the ultraviolet region (far ultraviolet light, vacuum ultraviolet light) also radicalizes water vapor in the same way as ultraviolet UV, so that gold oxide is not decomposed. it is obvious. Therefore, in order to suppress decomposition of gold oxide, it is necessary to block not only ultraviolet rays UV but also light having a wavelength shorter than the ultraviolet region.

  In the present embodiment, the temperature of the gold oxide thin film 2 needs to be kept below 80 ° C. in order to preserve it. FIG. 27 shows a comparison result when the gold thin film 1 subjected to the oxygen glow discharge for 300 seconds was heated in the atmosphere at each temperature for 3 hours. The compared temperatures are 75 ° C, 80 ° C, 85 ° C, 256 ° C. As shown in FIG. 27, two peaks of Au 4f (Oxide) and a peak of III component of O 1s appear in the gold thin film 1 subjected to oxygen glow discharge for 300 seconds before heating. However, two peaks of Au 4f (Oxide) and the peak of the III component of O 1s began to decrease from 80 ° C., and these peaks disappeared at 85 ° C., and it was confirmed that gold oxide was completely decomposed.

<Gold surface hydrophobicity and hydrophilicity>
A state when a 1% by weight polyvinyl alcohol aqueous solution is dropped onto the gold oxide thin film 2 or the like to form a polyvinyl alcohol thin film will be described. FIG. 28A shows a state immediately after the water droplet of this aqueous solution is dropped on the gold thin film 1. As shown in FIG. 28 (A), the contact angle of water droplets of the polyvinyl alcohol aqueous solution was increased, and it was confirmed that the gold thin film 1 was hydrophobic. FIG. 28B shows the state of the polyvinyl alcohol thin film obtained by drying the water droplets. As shown in FIG. 28B, the hydrophilic polyvinyl alcohol thin film became non-uniform on the gold thin film 1.

  On the other hand, FIG. 28C shows a state immediately after a water droplet of the aqueous solution is dropped on the gold oxide thin film 2. As shown in FIG. 28C, the contact angle of water droplets was extremely small, and it was confirmed that the gold oxide thin film 2 was hydrophilic. FIG. 28D shows the state of the polyvinyl alcohol thin film obtained by drying the water droplets. As shown in FIG. 28 (D), the polyvinyl alcohol thin film remained on the gold oxide thin film 2 in a uniform state.

  Such a property of the gold oxide thin film 2 is useful as a surface of a gold thin film on which a reagent is mounted, for example, in a surface plasmon resonance apparatus. Even if the measurement target is hydrophilic, it is possible to make the measurement target uniform by modifying the gold surface to gold oxide, so that good measurement is possible.

  As described in detail above, according to the present embodiment, the state of irradiation of the gold oxide thin film 2 with light having a wavelength equal to or less than the ultraviolet range (for example, ultraviolet UV) is adjusted, and the surroundings of the gold oxide thin film 2 are adjusted. Adjust the moisture condition. This makes it possible to store the gold oxide thin film 2 for a long period of time or to promote decomposition by utilizing the property that water is decomposed into radicals by irradiation with light having a wavelength of ultraviolet or shorter and the gold oxide is reduced to gold. The reduction reaction from gold oxide to gold can be controlled.

  Various embodiments and modifications can be made to the present invention without departing from the broad spirit and scope of the present invention. The above-described embodiments are for explaining the present invention and do not limit the scope of the present invention. In other words, the scope of the present invention is shown not by the embodiments but by the claims. Various modifications within the scope of the claims and within the scope of the equivalent invention are considered to be within the scope of the present invention.

  The present invention can greatly contribute to science and technology as a surface treatment technique for a gold thin film. In particular, it can be applied as a new gold surface treatment technology in the electronics industry and semiconductor business using gold thin films and gold bonding wires. In addition, the present invention can be applied to various chemical fields such as a surface plasmon measuring device that performs measurement by placing a hydrophilic sample on a gold thin film.

  1 Gold thin film, 2 Gold oxide thin film, 3 Container, 4, 4 'glass, 5 Waterproof film, 6 Gas, 7 Mask, A, B region, UV UV

Claims (9)

Control the decomposition and storage of gold oxide by adjusting the irradiation state of light with a wavelength below the ultraviolet region to the gold oxide or by adjusting the state of moisture around the gold oxide.
Control method for decomposition and storage of gold oxide. Preventing the light from being irradiated to the gold oxide and storing the gold oxide;
The method for controlling decomposition and storage of gold oxide according to claim 1. Preventing the light from being irradiated to the gold oxide by the substance that blocks the light;
The method for controlling decomposition and storage of gold oxide according to claim 2. Remove moisture from the surroundings of gold oxide to preserve the gold oxide,
The method for controlling decomposition and storage of gold oxide according to any one of claims 1 to 3. Store gold oxide in a moisture-free vacuum, gas, liquid or solid,
The method for controlling decomposition and storage of gold oxide according to claim 4. Irradiating at least a part of the gold oxide with the light, and decomposing the gold oxide by applying moisture to a portion of the gold oxide that is irradiated with the light,
The method for controlling decomposition and storage of gold oxide according to claim 1. A mask in which the first portion where the light is blocked or moisture is removed and the second portion where the light is irradiated and the moisture is attached to the thin film of gold oxide formed on the gold surface are patterned. Form the
Supplying moisture to the gold oxide thin film through the mask and irradiating the light;
The method for controlling decomposition and storage of gold oxide according to claim 6. The second part is
An opening that exposes the gold oxide thin film,
The method for controlling decomposition and storage of gold oxide according to claim 7. Control the decomposition and storage of gold oxide by adjusting the wavelength of the light or adjusting the amount of water around the gold oxide.
The method for controlling decomposition and storage of gold oxide according to claim 1.

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