Photochemical deposition method of copper and method for conformally depositing copper patterns on inner wall of device

Abstract

The present invention relates to the field of functional materials and micro-nano devices, and discloses a method for photochemical deposition of copper and a method for conformally depositing a copper pattern on the inner wall of a device. The method includes: (I-1) contacting a copper salt, a photoreductant, a neutral multidentate ligand with a first deionized water, respectively, to prepare a copper salt mother liquor, a photoreductant mother liquor, and a neutral multidentate ligand mother liquor; (I-2) mixing the copper salt mother liquor, the photoreductant mother liquor, the neutral multidentate ligand mother liquor, and a second deionized water to prepare a precursor solution; (I-3) adding the precursor solution dropwise onto the surface of a substrate, performing a photochemical reaction using ultraviolet light illumination, and depositing a copper film on the surface of the substrate. The present invention utilizes a photochemical reaction rather than a conventional catalytic reaction to carry out liquid-phase metal deposition. The method of the present invention is simple, can efficiently complete patterned deposition and conformal deposition, and is applicable to complex-shaped substrates and / or the inner wall of a device.

Description

Technical Field

[0001] The present invention relates to the field of functional materials and micro-nano devices, and in particular to a method for photochemical deposition of copper and a method for conformally depositing a copper pattern on the inner wall of a device. Background Art

[0002] Metals not only possess excellent toughness and strength, but also possess superior electrical and thermal conductivity and corrosion resistance. Patterning and depositing metals onto substrates of other materials can create a variety of functional components, finding widespread application in high-end manufacturing applications such as electronic chips, energy conversion, information communications, sensors, and wearable devices.

[0003] Currently popular metal deposition methods include physical vapor deposition (PVD), chemical vapor deposition (CVD), and electrochemical deposition (ECD). Although these methods can deposit metals onto substrate materials, they suffer from harsh working conditions, complex process operations, high dependence on templates, and a limited range of applicable substrate materials, making them unable to meet the needs of modern manufacturing.

[0004] In recent years, electroless deposition (ELD) technology has gradually gained attention. ELD reduces and deposits metal ions based on liquid-phase chemical reactions, and generally includes the following key steps. First, a catalytically active substance is added to the substrate surface through physical adsorption or chemical modification, and then a metal salt solution and a reducing agent are added to induce an in-situ metal reduction reaction. After one metal is completely deposited, if another metal needs to be deposited, the above operation is repeated. The ELD reaction conditions are mild and can occur on a variety of substrate surfaces, effectively improving many of the shortcomings of traditional metal deposition methods. However, ELD still has several technical limitations. First, to achieve metal patterning in ELD, the substrate must first be patterned and modified, so that different areas of the substrate have different catalytic activities, that is, metal deposition and patterning cannot be completed in one step. Secondly, ELD's patterning modification of the substrate still relies on a template, and the process flow is relatively cumbersome. Finally, due to the geometric size of the template itself, substrate modification in complex or narrow spaces is difficult to complete, which restricts the application of ELD in some important devices, such as optical fibers containing narrow and long pipes, microfluidic channels, and other products. Summary of the Invention

[0005] The present invention aims to overcome the problems of harsh working conditions in existing metal deposition methods such as physical vapor deposition (PVD), chemical vapor deposition (CVD), and electrochemical deposition (ECD), as well as the defect that metal deposition and patterning cannot be completed in one step in the electroless deposition (ELD) method. A method for photochemical deposition of copper and a method for conformally depositing a copper pattern on the inner wall of a device are provided. The present invention utilizes a photochemical reaction rather than a conventional catalytic reaction to perform liquid-phase metal deposition. The method of the present invention is simple, can deposit in one step, and is applicable to complex substrates and / or the inner walls of complex devices.

[0006] In order to achieve the above object, the first aspect of the present invention provides a method for photochemically depositing copper on a substrate surface, wherein the method comprises:

[0007] (I-1) separately contacting a copper salt, a photoreducing agent, and a neutral multidentate ligand with first deionized water to prepare a copper salt mother solution, a photoreducing agent mother solution, and a neutral multidentate ligand mother solution;

[0008] (I-2) mixing the copper salt mother solution, the photoreducing agent mother solution, the neutral multidentate ligand mother solution, and a second deionized water to prepare a precursor solution;

[0009] (I-3) dropping the precursor solution onto the surface of a substrate, irradiating the substrate with ultraviolet light to carry out a photochemical reaction, and depositing a copper film on the surface of the substrate.

[0010] A second aspect of the present invention provides a method for conformal photochemical copper deposition patterning on the inner wall of a device, wherein the method comprises:

[0011] (II-1) separately contacting a copper salt, a photoreducing agent, and a neutral multidentate ligand with first deionized water to prepare a copper salt mother solution, a photoreducing agent mother solution, and a neutral multidentate ligand mother solution;

[0012] (II-2) mixing the copper salt mother solution, the photoreducing agent mother solution, the neutral multidentate ligand mother solution, and a second deionized water to prepare a precursor solution;

[0013] (II-3) pouring the precursor solution into the interior of the device so that it fills the inner wall of the device;

[0014] (II-4) focusing the patterned light field onto the inner wall of the device, performing a photochemical reaction by irradiating the device with ultraviolet light, and depositing a patterned copper film conformally on the inner wall of the device.

[0015] A third aspect of the present invention provides an application of the aforementioned method in one or more of the fields of sensors, wearable devices, chips, microfluidic devices containing narrow and long pipes, and optical fibers.

[0016] Through the above technical solution, the method of the present invention is universal and can be used to deposit copper patterns on different substrate surfaces and / or inside devices. It has the advantages of mild experimental conditions, simple process flow, one-step deposition, and applicability to complex substrate shapes and / or inside devices. It can be further applied in the fields of sensors, wearable devices, chips, microfluidics, and optical fibers containing narrow and long pipes. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a schematic diagram of the principle of photochemical deposition of metallic copper provided by the present invention;

[0018] Figure 2 These are photos and microscopic images of photochemically deposited copper in Examples 1-2 and Comparative Examples 3-15 of the present invention, wherein: Figure 2 A is a photograph of the precursor solution containing copper chloride and sodium ascorbate of Comparative Example 3-10 after irradiation for 12 seconds; Figure 2 Figure B shows photographs and microscopic images of precursor solutions containing copper chloride, sodium ascorbate, and PEHA of Comparative Examples 11-14, Examples 1-2, and Comparative Example 15 after 10 minutes of illumination. The scale bar in the microscopic image is 10 μm.

[0019] Figure 3 This is an image of photochemically deposited copper metal according to Example 3 of the present invention, wherein: Figure 3 A in the middle is a photo of a checkerboard pattern of copper deposited on a flat glass surface; Figure 3 Middle B is the SEM image of the checkerboard pattern; Figure 3 C is the EDX element analysis corresponding to the pattern in B; Figure 3 D and E in the middle are photos of other copper patterns deposited on the flat glass surface;

[0020] Figure 4 is an image of a conformally deposited patterned copper film on the inner wall of the device of Example 4 of the present invention, wherein: Figure 4 A in the middle shows the working principle of depositing copper patterns on the inner wall of hollow silica optical fiber; Figure 4 B and C in the middle are photos of copper patterns deposited on the inner wall of hollow silica optical fiber;

[0021] Figure 5 This is an image of the precursor solution containing copper chloride, sodium citrate and PEHA in Comparative Example 1 after irradiation for 3 minutes;

[0022] Figure 6 This is an image of the precursor solution containing copper chloride, sodium ascorbate, and acrylamide in Comparative Example 2 after irradiation for 3 minutes;

[0023] Figure 7 This is an image of the precursor solution containing copper chloride, sodium ascorbate and allylamine in Comparative Example 3 after irradiation for 3 minutes. DETAILED DESCRIPTION

[0024] The endpoints of the ranges and any values ​​disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoints of each range, the endpoints of each range and individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered to be specifically disclosed herein.

[0025] As mentioned above, the first aspect of the present invention provides a method for photochemically depositing copper on a substrate surface, wherein the method comprises:

[0026] (I-1) separately contacting a copper salt, a photoreducing agent, and a neutral multidentate ligand with first deionized water to prepare a copper salt mother solution, a photoreducing agent mother solution, and a neutral multidentate ligand mother solution;

[0027] (I-2) mixing the copper salt mother solution, the photoreducing agent mother solution, the neutral multidentate ligand mother solution, and a second deionized water to prepare a precursor solution;

[0028] (I-3) dropping the precursor solution onto the surface of a substrate, irradiating the substrate with ultraviolet light to carry out a photochemical reaction, and depositing a copper film on the surface of the substrate.

[0029] A second aspect of the present invention provides a method for conformal photochemical copper deposition patterning on the inner wall of a device, wherein the method comprises:

[0030] (II-1) separately contacting a copper salt, a photoreducing agent, and a neutral multidentate ligand with first deionized water to prepare a copper salt mother solution, a photoreducing agent mother solution, and a neutral multidentate ligand mother solution;

[0031] (II-2) mixing the copper salt mother solution, the photoreducing agent mother solution, the neutral multidentate ligand mother solution, and a second deionized water to prepare a precursor solution;

[0032] (II-3) pouring the precursor solution into the interior of the device so that it fills the inner wall of the device;

[0033] (II-4) focusing the patterned light field onto the inner wall of the device, performing a photochemical reaction by irradiating the device with ultraviolet light, and depositing a patterned copper film conformally on the inner wall of the device.

[0034] The inventors of the present invention have found that: a precursor solution containing a copper salt, a photoreducing agent and a neutral multidentate ligand is used, and the precursor solution is then dropped onto the surface of the substrate. Figure 1 As shown, Figure 1This is a schematic diagram of the principle behind the photochemical deposition of metallic copper provided by the present invention. Under illumination, a photoreducing agent first reduces metal ions, such as copper ions, into independent copper nanoparticles. A neutral multidentate ligand then partially replaces the photoreducing agent on the surface of the copper nanoparticles. Simultaneously, the multiple functional groups on the neutral multidentate ligand can connect to multiple nanoparticles, anchoring them together. The neutral multidentate ligand itself also possesses a certain degree of reducing properties. Under continuous illumination, the neutral multidentate ligand and the photoreducing agent work together to cause adjacent nanoparticles to grow and connect, forming a continuous, patterned copper film.

[0035] Furthermore, based on the above principles, the present invention also proposes a method for conformal patterned copper deposition on the inner wall of a device. The precursor solution is poured into the inner wall of a complex device until it fills the inner wall, and a focus-adjusted multiple exposure method is used to deposit a maskless conformal copper pattern on the inner wall of the device.

[0036] Furthermore, this method has the advantages of mild experimental conditions, simple process flow, one-step deposition, and applicability to complex substrate shapes. It is expected to be further applied in fields such as sensors, wearable devices, chips, microfluidics, and optical fibers containing narrow and long tubes.

[0037] According to the present invention, the copper salt is selected from one or more of copper chloride, copper sulfate and copper nitrate, preferably copper chloride.

[0038] According to the present invention, the photoreducing agent includes one or more of sodium ascorbate, sodium tartrate and sodium oxalate, preferably sodium ascorbate.

[0039] According to the present invention, the neutral multidentate ligand includes one or more of ethylenediamine (EDA), diethylenetriamine (DETA), pentaethylenehexamine (PEHA), pentamethyldiethylenetriamine (PMDETA) and 1,1,4,7,10,10-hexamethyltriethylenetetramine (HMTETA), preferably pentaethylenehexamine (PEHA).

[0040] According to the present invention, first, a mother liquor needs to be prepared; wherein the concentration of the copper salt mother liquor is 0.1-10 mol / L, preferably 1-2 mol / L; the concentration of the photoreducing agent mother liquor is 0.1-10 mol / L, preferably 1-2 mol / L; the concentration of the neutral multidentate ligand mother liquor is 0.01-10 mol / L, preferably 0.167-1 mol / L.

[0041] According to the present invention, secondly, a precursor solution is prepared, and copper salt, photoreducing agent, and neutral multidentate ligand mother liquor are mixed in a certain proportion to prepare a precursor solution. The proportion of each component can be adjusted according to the deposition parameter requirements. Wherein, in step (I-2) and / or step (II-2), relative to the total amount of 1000 μL of the copper salt mother liquor, the photoreducing agent mother liquor, and the neutral multidentate ligand mother liquor, the amount of the second deionized water is 100-1000 μL, preferably 780-870 μL.

[0042] According to the present invention, in the precursor solution, the concentration of the copper ions is 1-100 mM, preferably 20-30 mM.

[0043] According to the present invention, in the precursor solution, the concentration ratio of the copper ions to the photoreducing agent is (0.1-2):1, preferably (0.2-0.25):1.

[0044] According to the present invention, in the precursor solution, the concentration ratio of the copper ions to the neutral multidentate ligand is (0.2-10):1, preferably (0.25-0.33):1.

[0045] According to the present invention, the copper film is deposited by light irradiation: a precursor solution is added dropwise to a substrate and exposed to ultraviolet light for a predetermined period of time to obtain a copper film. Preferably, the exposure time is 1-15 minutes, more preferably 2-10 minutes.

[0046] According to the present invention, the method further comprises chemically modifying the substrate and / or the inner wall of the device. In the present invention, the substrate and / or the inner wall of the device are chemically modified to enhance their hydrophilicity and affinity for copper ions.

[0047] According to the present invention, the chemical modification comprises:

[0048] (1) using solvents and / or plasma to clean and / or hydroxylate the substrate and / or the inner wall of the device;

[0049] (2) Then, the substrate and / or the inner wall of the device are soaked in a terminal amino-containing silicone solution.

[0050] According to the present invention, the modification process includes cleaning and surface hydroxylating the substrate using a solvent, plasma, or the like, followed by soaking the substrate in a terminally amino-terminated siloxane solution. The solvent cleaning step involves alternating deionized water and anhydrous isopropyl alcohol cleaning. The solvent cleaning step lasts for 1-10 minutes, while the plasma cleaning step lasts for 1-10 minutes. Preferably, the solvent cleaning step lasts for 2-5 minutes, while the plasma cleaning step lasts for 1-3 minutes.

[0051] According to the present invention, the terminal amino-modified siloxane solution is an ethanol solution of 3-amino-propyl-trimethoxysilane (APTMS); preferably, the concentration of the ethanol solution of 3-amino-propyl-trimethoxysilane is 0.1-10 wt%, preferably 1-2 wt%.

[0052] According to the present invention, the soaking time is 10-24 hours, preferably 12-14 hours.

[0053] According to the present invention, the substrate includes one or more of glass, ceramic, silicon dioxide, polydimethylsiloxane (PDMS), silicon nitride, polyimide, polyethylene terephthalate (PET), iron, zinc and aluminum.

[0054] According to the present invention, conformal copper film deposition on the inner surface of a device is achieved by affixing the modified device to a mechanical stage. A dynamic light processing (DLP) projector then focuses a patterned light field onto the desired portion of the device's inner surface to deposit the patterned copper film. For non-planar substrates, the mechanical stage adjusts the relative position of the instrument's focal plane to the substrate, allowing for multiple exposures to achieve conformal metal deposition. A single exposure typically lasts 1-15 minutes.

[0055] A third aspect of the present invention provides an application of the aforementioned method in one or more of the fields of sensors, wearable devices, chips, microfluidic devices containing narrow and long pipes, and optical fibers.

[0056] The present invention will be described in detail below through examples.

[0057] In the following examples and comparative examples:

[0058] The SEM used was a Nova Nano SEM200 electron microscope scanner purchased from FEI Company of the Netherlands;

[0059] EDX elemental analysis was performed using the EDAX 9100 energy dispersive spectrometer attached to the SEM;

[0060] The copper salt, photoreducing agent, neutral multidentate ligand, neutral monodentate ligand, and non-neutral multidentate ligand raw materials are all commercially available.

[0061] Example 1-2

[0062] This embodiment is intended to illustrate the use of the method of the present invention to deposit a copper film on a substrate.

[0063] First, the glass substrate was surface modified: the glass substrate was cleaned alternately with deionized water and anhydrous isopropyl alcohol three times, dried with cold air, and placed in a plasma cleaner for 3 minutes. After being taken out, it was placed in a 1wt% APTMS-ethanol solution, soaked for 14 hours, taken out, washed with anhydrous ethanol, dried, and stored for later use.

[0064] Subsequently, copper chloride and sodium ascorbate were dissolved in deionized water to prepare copper chloride mother solution with a concentration of 1 mol / L and sodium ascorbate mother solution with a concentration of 1 mol / L, respectively, and PEHA was dissolved in deionized water to prepare PEHA mother solution with a concentration of 0.167 mol / L.

[0065] Secondly, 100 μL of sodium ascorbate mother solution was added to 20 μL of copper chloride mother solution, and then 60 μL and 80 μL of PEHA mother solution and 820 μL and 800 μL of H2O corresponding to the PEHA mother solution were added respectively, and mixed evenly to prepare a precursor solution;

[0066] In addition, 200 μL of the precursor solution was dropped onto the surface of a flat glass substrate, and the precursor solution was vertically irradiated with a UV lamp with a wavelength of 365 nm for 10 min.

[0067] That is, a sample with a metal copper pattern deposited on the surface of a glass substrate is obtained (eg Figure 2 (B) When the PEHA concentration is 10 mM and 13.33 mM, observation under an optical microscope found that the brightness of the sample in bright field mode was significantly higher than that in dark field mode, and the number of particles in dark field mode was greatly reduced, proving that a continuous membrane structure was formed.

[0068] Example 3

[0069] This embodiment is intended to illustrate the patterned deposition of copper using the method of the present invention.

[0070] First, the glass substrate was surface modified: the glass substrate was cleaned alternately with deionized water and anhydrous isopropyl alcohol three times, dried with cold air, and placed in a plasma cleaner for 3 minutes. After being taken out, it was placed in a 1wt% APTMS-ethanol solution, soaked for 14 hours, taken out, washed with anhydrous ethanol, dried, and stored for later use.

[0071] Subsequently, copper chloride and sodium ascorbate were dissolved in deionized water to prepare copper chloride mother solution with a concentration of 1 mol / L and sodium ascorbate mother solution with a concentration of 1 mol / L, respectively, and PEHA was dissolved in deionized water to prepare PEHA mother solution with a concentration of 0.167 mol / L.

[0072] Secondly, 20 μL of copper chloride mother solution, 80 μL of PEHA mother solution and 100 μL of sodium ascorbate mother solution were added to 800 μL of H2O in sequence and mixed well to prepare precursor solution A;

[0073] In addition, a glass substrate cover glass was fixed on the mechanical platform of the DLP projector, 200 μL of the prepared precursor solution A was dropped on the surface of the glass substrate cover glass, and the patterned light field was focused on the surface of the glass substrate cover glass. The illumination was carried out for 10 minutes at a wavelength of 365 nm. Immediately after illumination, the deposition area on the surface of the glass substrate cover glass was rinsed with deionized water to remove the remaining precursor solution and dried. Figure 3 As shown, a sample with a metal copper pattern deposited on a flat glass surface was obtained ( Figure 3 A), SEM observation of the sample shows that the pattern area is a continuous and densely packed nanoparticles ( Figure 3 B), EDX analysis of the region shows that the element in the region is copper ( Figure 3 C). Other patterns can be deposited on the glass surface by changing the light field pattern ( Figure 3 DE).

[0074] Example 4

[0075] This embodiment is intended to illustrate the use of the method of the present invention to deposit a copper film on the inner wall of a device.

[0076] First, the inner surface of the silica fiber was surface-modified. The inner surface of the silica fiber (1.5 mm inner diameter) was cleaned alternately with deionized water and anhydrous isopropyl alcohol. After drying with cold air, it was placed in a plasma cleaner for 10 minutes. After removal, it was placed in a 1wt% APTMS-ethanol solution and soaked for 18 hours. After removal, it was washed with anhydrous ethanol, dried, and stored for future use.

[0077] Subsequently, copper chloride and sodium ascorbate were dissolved in deionized water to prepare copper chloride mother solution with a concentration of 1 mol / L and sodium ascorbate mother solution with a concentration of 1 mol / L, respectively, and PEHA was dissolved in deionized water to prepare PEHA mother solution with a concentration of 0.167 mol / L.

[0078] Secondly, 20 μL of copper chloride mother solution, 80 μL of PEHA mother solution and 100 μL of sodium ascorbate mother solution were added to 800 μL of H2O in sequence and mixed well to prepare precursor solution A;

[0079] In addition, a silica fiber was fixed on the printing platform of a DLP 3D printer, and the precursor solution A was poured into the silica fiber to fill the inner wall. The patterned light field was focused on a specific position on the inner wall of the fiber and illuminated for 10 minutes to deposit a copper pattern. The focus position was then adjusted and multiple exposures were performed to conformally deposit copper patterns in different areas, such as Figure 4 As shown, the target pattern is finally obtained ( Figure 4 A), the wavelength of light is 365nm. Immediately after light exposure, the inner wall of the silica fiber is rinsed with deionized water to remove the residual precursor solution and dried to obtain a sample with a copper pattern deposited on the inner wall of the silica fiber in one step ( Figure 4 BC).

[0080] Comparative Example 1

[0081] First, copper chloride and sodium citrate were dissolved in deionized water to prepare 1 mol / L copper chloride mother solution and 1 mol / L sodium citrate mother solution, respectively. PEHA was dissolved in deionized water to prepare 0.167 mol / L PEHA mother solution.

[0082] Secondly, 100 μL of sodium citrate mother liquor was added to 20 μL of copper chloride solution, and then 10 μL (1.67 mM), 20 μL (3.34 mM), 40 μL (6.67 mM), 60 μL (10 mM), 80 μL (13.33 mM), and 100 μL (16.7 mM) of PEHA mother liquor and 870 μL, 860 μL, 840 μL, 820 μL, 800 μL, and 780 μL of H2O corresponding to the PEHA mother liquor were added, and the mixture was evenly mixed to prepare a precursor solution.

[0083] 300 μL of the precursor solution was dropped onto the surface of the ceramic substrate, and the precursor solution was vertically irradiated with a UV lamp with a wavelength of 365 nm for 3 minutes.

[0084] like Figure 5 As shown, there is no significant change in each precursor solution after illumination, and no copper nanoparticles or copper films are generated ( Figure 5 ). This is caused by replacing sodium ascorbate with sodium citrate, which has insufficient reducing properties.

[0085] Comparative Example 2

[0086] First, copper chloride, sodium ascorbate, and acrylamide (AM) were dissolved in deionized water to prepare 1 mol / L copper chloride mother solution, 1 mol / L sodium ascorbate mother solution, and 1 mol / L acrylamide (AM) mother solution, respectively.

[0087] Next, 100 μL of sodium ascorbate mother solution was added to 20 μL of copper chloride solution, and 10 μL (10 mM), 20 μL (20 mM), 40 μL (40 mM), 60 μL (60 mM), 80 μL (80 mM), and 100 μL (100 mM) of AM mother solution and 870 μL, 860 μL, 840 μL, 820 μL, 800 μL, and 780 μL of HO corresponding to the AM mother solution were added, and the mixture was evenly mixed to prepare a precursor solution.

[0088] Next, 300 μL of the precursor solution was dropped onto the surface of the ceramic substrate, and a UV lamp with a wavelength of 365 nm was used to vertically irradiate the precursor solution for 3 min.

[0089] like Figure 6 As shown, copper nanoparticles were generated after light irradiation, but no copper film was generated ( Figure 6 ). This is caused by replacing PEHA with a non-polydentate neutral ligand.

[0090] Comparative Examples 3-10

[0091] First, copper chloride and sodium ascorbate were dissolved in deionized water to prepare copper chloride mother solution with a concentration of 1 mol / L and sodium ascorbate mother solution with a concentration of 1 mol / L, respectively. PEHA was dissolved in deionized water to prepare PEHA mother solution with a concentration of 0.167 mol / L.

[0092] First, to 5 μL of copper chloride mother solution, 2.5 μL, 5 μL, 10 μL, 15 μL, 20 μL, 25 μL, 50 μL, and 100 μL of sodium ascorbate mother solution and 992.5 μL, 990 μL, 985 μL, 980 μL, 975 μL, 970 μL, 945 μL, and 895 μL of H O were added and mixed evenly to prepare a precursor solution;

[0093] Secondly, 300 μL of the precursor solution was dropped onto the surface of the ceramic substrate and the precursor solution was vertically irradiated with a UV lamp with a wavelength of 365 nm for 12 s; Figure 2 A is the image of the precursor solution containing copper chloride and sodium ascorbate of comparative example 3-10 after 12 seconds of illumination. Figure 2 As shown in A, copper nanoparticles appeared after light exposure.

[0094] Comparative Examples 11-15

[0095] First, the glass substrate was surface modified: the cover glass was cleaned alternately with deionized water and anhydrous isopropyl alcohol three times, dried with cold air, and placed in a plasma cleaner for 3 minutes. After being taken out, it was placed in a 1wt% APTMS-ethanol solution, soaked for 14 hours, taken out, cleaned with anhydrous ethanol, dried, and stored for later use.

[0096] Subsequently, copper chloride and sodium ascorbate were dissolved in deionized water to prepare copper chloride mother solution with a concentration of 1 mol / L and sodium ascorbate mother solution with a concentration of 1 mol / L, respectively, and PEHA was dissolved in deionized water to prepare PEHA mother solution with a concentration of 0.167 mol / L.

[0097] First, 100 μL of sodium ascorbate mother solution, 10 μL, 20 μL, 40 μL, and 100 μL of PEHA mother solution, and 870 μL, 860 μL, 840 μL, and 780 μL of H O were added to 20 μL of copper chloride mother solution and mixed well to prepare a precursor solution.

[0098] Next, 200 μL of the precursor solution was dropped onto the surface of the glass substrate, and a UV lamp with a wavelength of 365 nm was used to vertically irradiate the precursor solution for 10 min.

[0099] In addition, if Figure 2 The images of the precursor solutions containing copper chloride, sodium ascorbate and PEHA of Comparative Examples 11-14, Examples 1-2 and Comparative Example 15 after irradiation for 3 minutes are shown in Figure B. Figure 2 It can be seen from Figure B that: when the PEHA concentration is 1.67mM, 3.34mM, 6.67mM, and 16.67mM, observation under an optical microscope found that the intensity of the sample in dark field mode was higher than that in bright field mode, and there were a large number of particles, proving that copper nanoparticles were obtained; when the PEHA concentration is 10mM and 13.33mM, observation under an optical microscope found that the brightness of the sample in bright field mode was significantly higher than that in dark field mode, and the number of particles in dark field mode was greatly reduced, proving that a continuous membrane structure was formed.

[0100] Comparative Example 16

[0101] First, copper chloride, sodium ascorbate, and allylamine are dissolved in deionized water to prepare 1 mol / L copper chloride mother solution, 1 mol / L sodium ascorbate mother solution, and 1 mol / L allylamine mother solution, respectively; wherein the allylamine is synthesized from an allylamine hydrochloride solution and a sodium hydroxide solution.

[0102] Secondly, 100 μL of sodium ascorbate mother solution and 10 μL, 20 μL, 40 μL, 60 μL, 80 μL, and 100 μL of allylamine mother solution and 870 μL, 860 μL, 840 μL, 820 μL, 800 μL, and 780 μL of H O were added to 20 μL of copper chloride solution and mixed evenly to prepare a precursor solution;

[0103] Next, 300 μL of the precursor solution was dropped onto the surface of the ceramic substrate, and a UV lamp with a wavelength of 365 nm was used to vertically irradiate the precursor solution for 3 min.

[0104] like Figure 7 As shown, copper nanoparticles were generated after light irradiation, but no copper film was generated ( Figure 7 ). This is caused by replacing PEHA with a neutral monodentate ligand.

[0105] The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, various simple variations of the technical solution of the present invention may be made, including combining the various technical features in any other appropriate manner. These simple variations and combinations should also be regarded as disclosed in the present invention and fall within the scope of protection of the present invention.

Claims

1. A method for photochemically depositing copper on a substrate surface, characterized in that: The method includes: (I-1) separately contacting a copper salt, a photoreducing agent, and a neutral multidentate ligand with first deionized water to prepare a copper salt mother solution, a photoreducing agent mother solution, and a neutral multidentate ligand mother solution; (I-2) mixing the copper salt mother solution, the photoreducing agent mother solution, the neutral multidentate ligand mother solution, and a second deionized water to prepare a precursor solution; (I-3) dropping the precursor solution onto a substrate surface, irradiating the substrate with ultraviolet light to cause a photochemical reaction, and depositing a copper film on the substrate surface; Wherein, the copper salt is selected from one or more of copper chloride, copper sulfate and copper nitrate; The photoreducing agent includes one or more of sodium ascorbate, sodium tartrate and sodium oxalate; The neutral multidentate ligand includes one or more of ethylenediamine, diethylenetriamine, pentaethylenehexamine, pentamethyldiethylenetriamine and 1,1,4,7,10,10-hexamethyltriethylenetetramine; The concentration of the copper salt mother solution is 0.1-10 mol / L; The concentration of the photoreducing agent mother solution is 0.1-10 mol / L; The concentration of the neutral multidentate ligand mother solution is 0.1-10 mol / L; In step (I-2) and / or step (II-2), the amount of the second deionized water used is 100-1000 μL relative to the total amount of the copper salt mother solution, the photoreducing agent mother solution, and the neutral multidentate ligand mother solution (1000 μL); In the precursor solution, the concentration of copper ions is 1-100 mM; In the precursor solution, the concentration ratio of copper ions to the photoreducing agent is (0.1-2):1; wherein, in the precursor solution, the concentration ratio of copper ions to the neutral multidentate ligand is (0.2-10):

1.

2. A method for conformal photochemical deposition of copper patterning on the inner wall of a device, characterized in that: The method includes: (II-1) separately contacting a copper salt, a photoreducing agent, and a neutral multidentate ligand with first deionized water to prepare a copper salt mother solution, a photoreducing agent mother solution, and a neutral multidentate ligand mother solution; (II-2) mixing the copper salt mother solution, the photoreducing agent mother solution, the neutral multidentate ligand mother solution, and a second deionized water to prepare a precursor solution; (II-3) pouring the precursor solution into the interior of the device so that it fills the inner wall of the device; (II-4) focusing the patterned light field onto the inner wall of the device, irradiating the device with ultraviolet light to perform a photochemical reaction, and conformally depositing a patterned copper film on the inner wall of the device; Wherein, the copper salt is selected from one or more of copper chloride, copper sulfate and copper nitrate; The photoreducing agent includes one or more of sodium ascorbate, sodium tartrate and sodium oxalate; The neutral multidentate ligand includes one or more of ethylenediamine, diethylenetriamine, pentaethylenehexamine, pentamethyldiethylenetriamine and 1,1,4,7,10,10-hexamethyltriethylenetetramine; The concentration of the copper salt mother solution is 0.1-10 mol / L; The concentration of the photoreducing agent mother solution is 0.1-10 mol / L; The concentration of the neutral multidentate ligand mother solution is 0.1-10 mol / L; In step (I-2) and / or step (II-2), the amount of the second deionized water used is 100-1000 μL relative to the total amount of the copper salt mother solution, the photoreducing agent mother solution, and the neutral multidentate ligand mother solution (1000 μL); In the precursor solution, the concentration of copper ions is 1-100 mM; In the precursor solution, the concentration ratio of copper ions to the photoreducing agent is (0.1-2):1; wherein, in the precursor solution, the concentration ratio of copper ions to the neutral multidentate ligand is (0.2-10):

1.

3. The method according to claim 1 or 2, wherein: The copper salt is copper chloride; and / or, the photoreducing agent is sodium ascorbate; And / or, the neutral multidentate ligand is pentaethylenehexamine.

4. The method according to claim 1 or 2, wherein: The illumination time is 1-15 min.

5. The method according to claim 4, wherein The illumination time is 2-10 min.

6. The method according to claim 1 or 2, wherein: The method further comprises chemically modifying the substrate and / or the inner wall of the device.

7. The method according to claim 6, wherein: The chemical modification includes: (1) using a solvent and / or plasma to clean and / or hydroxylate the substrate and / or the inner wall of the device; (2) Then, the substrate and / or the inner wall of the device is soaked in a terminal amino-containing silicone solution.

8. The method according to claim 7, wherein: Solvent cleaning is performed by alternating deionized water and anhydrous isopropyl alcohol; And / or, the terminal amino-containing siloxane solution is an ethanol solution of 3-amino-propyl-trimethoxysilane.

9. The method according to claim 8, wherein The concentration of the ethanol solution of 3-amino-propyl-trimethoxysilane is 0.1-10 wt %.

10. The method according to claim 7, wherein: The time for solvent cleaning is 1-10 min; and / or, the plasma cleaning time is 1-10 min; And / or, the soaking time is 10-24 h.

11. Use of the method according to any one of claims 1 to 10 in one or more of the fields of sensors, wearable devices, chips, microfluidic devices containing narrow and long tubes, and optical fibers.

Images