Organic semiconductor array transfer method based on flexible substrate

Abstract

The present invention discloses a method for transferring an organic semiconductor array based on a flexible substrate. According to a preset array form, a silicon wafer including a silicon column array is prepared; the silicon column is surface treated to make the top of the surface of the silicon column hydrophilic and the side wall hydrophobic; the top surface of the silicon column after the surface treatment is covered with an organic semiconductor solution; the surface of the intermediate substrate coated with a metal film is bonded to the top surface covered with the organic semiconductor solution and then treated to make the organic semiconductor solution self-assemble on the surface of the metal film to form a semiconductor array on the surface of the metal film; then, the semiconductor array is transferred to the flexible substrate. This method uses the metal film on the intermediate substrate as an intermediate medium to solve the problem that the flexible substrate is not resistant to high temperature and cannot be directly used as a substrate to prepare an organic micro-nano array, thereby providing a new method for preparing an organic semiconductor array.

Description

Technical Field

[0001] The invention relates to the field of semiconductor technology, and in particular to an organic semiconductor array transfer method based on a flexible substrate. Background Art

[0002] At present, liquid-phase micro-nano processing technology has made great technological breakthroughs, especially the capillary liquid bridge induction method has made great achievements in controllable arrays and patterning. However, for organic semiconductor solutions, it is impossible to grow directly on the surface of flexible substrates to form micro-nano arrays. Summary of the invention

[0003] In view of the above problems, the present invention provides a method for transferring an organic semiconductor array based on a flexible substrate, which overcomes the above problems or at least partially solves the above problems.

[0004] On the one hand, the present application provides the following technical solution through an embodiment of the present application:

[0005] An organic semiconductor array transfer method based on a flexible substrate, the method comprising:

[0006] According to a preset array form, a silicon wafer including a silicon pillar array is prepared;

[0007] Performing surface treatment on the silicon pillar to make the top of the surface of the silicon pillar hydrophilic and the side wall hydrophobic;

[0008] Covering the top surface of the silicon pillar after surface treatment with an organic semiconductor solution;

[0009] The surface of the intermediate substrate coated with the metal film is bonded to the top surface covered with the organic semiconductor solution and then processed to allow the organic semiconductor solution to self-assemble on the surface of the metal film to form a semiconductor array on the surface of the metal film;

[0010] The semiconductor array is transferred to a flexible substrate.

[0011] Optionally, the surface treatment of the silicon pillar includes:

[0012] Under vacuum conditions, allowing a hydrophobic treatment agent to adhere to the sidewalls of the silicon column;

[0013] The silicon column to which the hydrophobic treatment agent has been attached is heated to 80-120° C. and maintained for 2-4 hours.

[0014] Optionally, the hydrophobic treatment agent is fluorosilane or octadecyltrichlorosilane.

[0015] Optionally, the step of laminating the surface of the intermediate substrate coated with the metal film to the top surface covered with the organic semiconductor solution and then performing the treatment comprises:

[0016] A first pressure of 35-90N is applied to the bonded intermediate substrate and the silicon wafer, and the substrate is dried in an environment of 60-80°C for 18-48h.

[0017] Optionally, transferring the semiconductor array to a flexible substrate comprises:

[0018] When the flexible substrate is in an unsolidified state, the surface of the intermediate substrate forming the semiconductor array is bonded to the flexible substrate, and a second pressure of 45-90N is applied;

[0019] The second pressure is maintained for a preset time, and after the flexible substrate solidifies, the metal film is removed by chemical reaction to obtain a semiconductor array having the preset array form on the flexible substrate.

[0020] Optionally, the flexible substrate comprises polydimethylsiloxane;

[0021] Before transferring the semiconductor array onto a flexible substrate, the method further comprises:

[0022] Mixing polydimethylsiloxane and a hardener in a ratio of 10:1 to obtain a mixture;

[0023] The mixture is heated to 60-100° C. and maintained for 2-4 hours to soften the flexible substrate.

[0024] Optionally, the metal film is a copper film.

[0025] Optionally, removing the metal film by chemical reaction includes:

[0026] The metal film is removed by using a ferric chloride solution to react with the metal film.

[0027] Optionally, the method further includes:

[0028] A metal thin film is deposited on the surface of the intermediate substrate by atomic layer deposition.

[0029] On the other hand, the present application provides a semiconductor material array through another embodiment of the present application, and the semiconductor material array is prepared according to the above-mentioned flexible substrate-based organic semiconductor array transfer method.

[0030] One or more technical solutions provided in the embodiments of the present application have at least the following technical effects or advantages:

[0031] First, according to the preset array form, a silicon wafer including a silicon column array is prepared; then, the silicon column is surface treated to make the top of the surface of the silicon column hydrophilic and the side wall hydrophobic; the top surface of the silicon column after surface treatment is covered with an organic semiconductor solution; then, the surface of the intermediate substrate coated with a metal film is bonded to the top surface covered with the organic semiconductor solution and then treated to make the organic semiconductor solution self-assemble on the surface of the metal film, and form a semiconductor array on the surface of the metal film; then, the semiconductor array is transferred to a flexible substrate. It can be seen that this method uses the metal film on the intermediate substrate as an intermediate medium to replace the flexible substrate in contact with the silicon column, so that the organic semiconductor solution self-assembles on the metal film and then transfers it to the flexible substrate. Avoiding the flexible substrate directly contacting the silicon column to transfer the array causes the flexible substrate to soften and deform under a long-term high temperature and pressure environment, and the organic semiconductor array cannot be obtained. Therefore, the problem that the flexible substrate is not resistant to high temperature and cannot be directly used as a substrate to prepare an organic micro-nano array is solved, thereby providing a new method for preparing an organic semiconductor array. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0033] Figure 1 It is a schematic flow chart of an organic semiconductor array transfer method based on a flexible substrate according to an embodiment of the present invention;

[0034] Figure 2 yes Figure 1 A three-dimensional schematic diagram of the silicon wafer and the intermediate substrate;

[0035] Figure 3 yes Figure 1 Schematic diagram of the process of self-assembly of organic semiconductor materials on the surface of the metal film;

[0036] Figure 4 yes Figure 1 Schematic diagram of a semiconductor array formed on the surface of a metal film;

[0037] Figure 5 yes Figure 1 Schematic diagram of the process of transferring the semiconductor array to the flexible substrate. DETAILED DESCRIPTION

[0038] The embodiments of the present application provide an organic semiconductor array transfer method based on a flexible substrate, thereby solving the problem that the flexible substrate is not resistant to high temperatures and cannot be directly used as a substrate to prepare an organic micro-nano array.

[0039] The technical solution of the embodiment of the present application is to solve the above technical problems, and the overall idea is as follows:

[0040] First, a silicon wafer including a silicon pillar array is prepared according to a preset array form; then, the silicon pillars are surface treated to make the top of the surface of the silicon pillars hydrophilic and the side walls hydrophobic; the top surfaces of the silicon pillars after the surface treatment are covered with an organic semiconductor solution; then, the surface of the intermediate substrate coated with a metal film is bonded to the top surface covered with the organic semiconductor solution and then treated to make the organic semiconductor solution self-assemble on the surface of the metal film to form a semiconductor array on the surface of the metal film; then, the semiconductor array is transferred to a flexible substrate.

[0041] It can be seen that this method uses the metal film on the intermediate substrate as an intermediate medium to replace the flexible substrate in contact with the silicon pillars, so that the organic semiconductor solution is self-assembled on the metal film and then transferred to the flexible substrate. Avoiding the flexible substrate directly contacting the silicon pillars to transfer the array leads to the softening and deformation of the flexible substrate under long-term high temperature and pressure environment, and the inability to obtain an organic semiconductor array. Therefore, the problem that the flexible substrate is not resistant to high temperature and cannot be directly used as a substrate to prepare an organic micro-nano array is solved, thereby providing a new method for preparing an organic semiconductor array.

[0042] In order to better understand the above technical solution, the above technical solution will be described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0043] First of all, the term "and / or" in this article is only a description of the association relationship of the associated objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0044] In addition, the “inside” and “outside” that appear in the text are inside and outside in the conventional sense, which are for the convenience of clear description and are not any limitation.

[0045] Embodiment 1

[0046] See also Figure 1 As shown, this embodiment provides an organic semiconductor array transfer method based on a flexible substrate, the method comprising:

[0047] S101, preparing a silicon wafer including a silicon pillar array according to a preset array form;

[0048] S102, performing surface treatment on the silicon pillar to make the top of the surface of the silicon pillar hydrophilic and the side wall hydrophobic;

[0049] S103, covering the top surface of the silicon pillar after surface treatment with an organic semiconductor solution;

[0050] S104, laminating the surface of the intermediate substrate coated with the metal film and the top surface covered with the organic semiconductor solution, and then processing the top surface to allow the organic semiconductor solution to self-assemble on the surface of the metal film to form a semiconductor array on the surface of the metal film;

[0051] S105, transferring the semiconductor array onto a flexible substrate.

[0052] In the method of this embodiment, the organic semiconductor material processed by liquid phase can be transferred to a flexible substrate.

[0053] First, S101 is executed to prepare a silicon wafer including a silicon pillar array according to a preset array form.

[0054] In the specific implementation process, the preset array form can be set according to the product's needs for the semiconductor array. It should be noted that in the semiconductor field, due to functional needs, it often involves array processing of organic semiconductor materials on a flexible substrate, or pattern processing. Therefore, the array in this embodiment includes not only the traditionally defined regularly arranged graphics, but also regular or irregular patterns formed by arrays, and even patterns formed by non-arrays.

[0055] Specifically, in S101, the silicon wafer including the silicon pillar array is prepared in order to subsequently attach the organic semiconductor material to the surface of the silicon pillars and realize the transfer. Therefore, it is necessary to prepare a silicon wafer including the silicon pillar array matching the preset array form according to the preset array form to be processed in the design. Among them, the number, size, and spacing of the silicon pillars all need to be processed according to the preset array form.

[0056] For example, a single crystal silicon wafer, 4 inches, N-doped, <100> , 525μm thick, each silicon wafer is cut into small silicon wafers of size 1cm×1cm, and each wafer has a silicon column array in a preset array form. Among them: the spacing between each column of silicon columns is 5μm, each column of silicon columns is 2μm wide and 20μm deep. The silicon column array can be prepared by photolithography and etching methods.

[0057] In addition, as an optional embodiment, a metal film is deposited on the surface of the intermediate substrate by atomic layer deposition for later use.

[0058] See also Figure 2 , is a three-dimensional schematic diagram of a silicon wafer and an intermediate substrate.

[0059] Next, S102 is executed to perform surface treatment on the silicon pillars to make the top of the surface of the silicon pillars hydrophilic and the sidewalls hydrophobic.

[0060] In the specific implementation process, the surface treatment refers to chemically modifying the surface of the silicon column.

[0061] As an optional implementation manner, the surface treatment of the silicon pillar comprises:

[0062] Under vacuum conditions, allowing a hydrophobic treatment agent to adhere to the sidewalls of the silicon pillars;

[0063] The silicon column to which the hydrophobic treatment agent has been attached is heated to 80-120° C. and maintained for 2-4 hours.

[0064] In the specific implementation process, surface treatment of the silicon pillars can make the side walls of the silicon pillars superhydrophobic and the tops of the silicon pillars hydrophilic, so that the subsequent organic semiconductor solution can self-assemble onto the metal film according to the array shape of the tops of the silicon pillars through the dewetting process.

[0065] Exemplarily, the hydrophobic treatment agent is fluorosilane or octadecyltrichlorosilane. First, photoresist SU8 can be evenly coated on the top of the silicon column, and then the silicon column is placed in a vacuum drying oven, 10-20 μl of perfluorosilane (FAS) is added, and vacuum is drawn for 30 minutes; then the column is placed in an oven and heated to 80-120°C for 3 hours, allowing the FAS atmosphere to fill the dryer and react with the exposed side walls of the silicon column to eventually form a monomolecular layer of perfluorosilane on the side walls, and finally the SU8 photoresist on the top of the silicon column is washed off to obtain a silicon column with hydrophilic top and hydrophobic sidewall modification.

[0066] Next, S103 is performed to cover the top surface of the silicon pillar after the surface treatment with an organic semiconductor solution.

[0067] In the specific implementation process, the silicon column template can be placed on a glass slide with the top facing upward, and 8-15 μl of the prepared organic semiconductor solution can be dropped on the silicon column to evenly cover it.

[0068] Next, S104 is performed to bond the surface of the intermediate substrate coated with the metal film to the top surface covered with the organic semiconductor solution, and then process the surface to allow the organic semiconductor solution to self-assemble on the surface of the metal film to form a semiconductor array on the surface of the metal film.

[0069] In the specific implementation process, after executing S103, the intermediate substrate with one side of the silicon wafer coated with a metal film is placed on the surface of the silicon column, covered with a glass slide, and clamped between the two glass slides with a metal clamp, with a pressure of 35N-90N. Then, it is placed in a drying oven, and the temperature is between 60°C-80°C and the time is between 18h-48h according to the properties of the material, so that the organic semiconductor solution is self-assembled onto the metal film according to the array shape at the top of the silicon column through the dewetting process. Then the silicon column is separated from the intermediate substrate. Due to the presence of the metal film, the silicon column can be easily separated from the intermediate substrate, and a semiconductor array with a metal film is formed on the surface of the metal film. As an optional embodiment, the metal film is a copper film.

[0070] Figure 3 It is a schematic diagram of the process of self-assembly of organic semiconductor materials on the surface of the metal film.

[0071] It should be noted that since the self-assembly process takes 18h-48h and the temperature is maintained at 60℃-80℃, if the flexible substrate is used directly, the flexible substrate will soften at high temperature and deform under pressure during the self-assembly process, resulting in the inability to obtain a semiconductor array. In this embodiment, the metal film on the intermediate substrate is used as an intermediate medium to replace the flexible substrate in contact with the silicon pillar, so that the organic semiconductor solution self-assembles on the metal film and then transfers it to the flexible substrate. Avoiding direct contact between the flexible substrate and the silicon pillar to transfer the array will cause the flexible substrate to soften and deform under long-term high temperature and pressure environment, and the organic semiconductor array cannot be obtained.

[0072] Next, S105 is performed to transfer the semiconductor array onto a flexible substrate.

[0073] In a specific implementation process, the flexible substrate may be polydimethylsiloxane; in order to perform array transfer, before transferring the semiconductor array to the flexible substrate, the method further includes:

[0074] Mixing polydimethylsiloxane and a hardener in a ratio of 10:1 to obtain a mixture;

[0075] The mixture is heated to 60-100° C. and maintained for 2-4 hours to soften the flexible substrate.

[0076] In the specific implementation process, polydimethylsiloxane (PDMS), a type of silicone, has good adhesion and good chemical inertness.

[0077] Specifically, the mixture can be vacuumed to allow bubbles to float to the surface and burst, and then placed in an oven for baking at 80°C for 3 hours to soften the flexible substrate. When the flexible substrate is in an unsolidified state, the top surface of the silicon column forming a semiconductor array with a metal film is bonded to the flexible substrate, and appropriate external force is applied to transfer the semiconductor array to the flexible substrate.

[0078] As an optional embodiment, transferring the semiconductor array onto a flexible substrate includes:

[0079] When the flexible substrate is in an unsolidified state, the surface of the intermediate substrate forming the semiconductor array is bonded to the flexible substrate, and a second pressure of 45-90N is applied;

[0080] The second pressure is maintained for a preset time, and after the flexible substrate solidifies, the metal film is removed by chemical reaction to obtain a semiconductor array having the preset array form on the flexible substrate.

[0081] In the specific implementation process, the preset time can be set as needed, for example, 30 minutes. When it is judged that it is in an unsolidified state, tweezers can be used to judge the indentation and viscosity. The process of transferring the semiconductor array to the flexible substrate can be seen in Figure 4 .

[0082] In the specific implementation process, the ferric chloride (FeCl3) solution can be used to react with the metal film to remove the metal film, so that the semiconductor array is separated from the intermediate substrate, and the semiconductor array on the metal film is transferred to the PDMS substrate. Figure 5 ,In the figure, the execution processes are abc in sequence, and finally the semiconductor array is obtained in c.

[0083] Among them, the reaction conditions are selected according to the actual material properties, vacuum or atmosphere; the material selection of organic semiconductors should be mainly polymers, which have good flexibility. Semiconductor array processing on flexible substrates provides important progress ideas for the field of wearable electronic devices.

[0084] In addition, after obtaining the organic semiconductor material array having the preset array form on the flexible substrate, the obtained sample is observed and tested by electron microscope. Specifically, the array is observed by optical microscope, the thickness and array crystallization are measured by AFM, and the surface morphology is measured by SEM.

[0085] Embodiment 2

[0086] This embodiment provides a semiconductor material array, which is obtained according to the method of Embodiment 1. Please refer to Embodiment 1 for the specific implementation method, which will not be described in detail here.

[0087] Although the preferred embodiments of the present invention have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0088] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A method for transferring an organic semiconductor array based on a flexible substrate, characterized in that: The method comprises: According to a preset array form, a silicon wafer including a silicon pillar array is prepared; Performing surface treatment on the silicon pillar to make the top of the surface of the silicon pillar hydrophilic and the side wall hydrophobic; Covering the top surface of the silicon pillar after surface treatment with an organic semiconductor solution; The surface of the intermediate substrate coated with the metal film is bonded to the top surface covered with the organic semiconductor solution and then processed to allow the organic semiconductor solution to self-assemble on the surface of the metal film to form a semiconductor array on the surface of the metal film; transferring the semiconductor array to a flexible substrate; The flexible substrate comprises polydimethylsiloxane; Before transferring the semiconductor array onto a flexible substrate, the method further comprises: Mixing polydimethylsiloxane and a hardener in a ratio of 10:1 to obtain a mixture; The mixture is heated to 60-100° C. and maintained for 2-4 hours to soften the flexible substrate.

2. The method according to claim 1, characterized in that The surface treatment of the silicon pillar comprises: Under vacuum conditions, allowing a hydrophobic treatment agent to adhere to the sidewalls of the silicon column; The silicon column to which the hydrophobic treatment agent has been attached is heated to 80-120° C. and maintained for 2-4 hours.

3. The method according to claim 2, characterized in that The hydrophobic treatment agent is fluorosilane or octadecyltrichlorosilane.

4. The method according to claim 1, characterized in that The processing after laminating the surface of the intermediate substrate coated with the metal film to the top surface covered with the organic semiconductor solution comprises: A first pressure of 35-90N is applied to the bonded intermediate substrate and the silicon wafer, and the substrate is dried in an environment of 60-80°C for 18-48h.

5. The method according to claim 1, characterized in that The step of transferring the semiconductor array to a flexible substrate comprises: When the flexible substrate is in an unsolidified state, the surface of the intermediate substrate forming the semiconductor array is bonded to the flexible substrate, and a second pressure of 45-90N is applied; The second pressure is maintained for a preset time, and after the flexible substrate solidifies, the metal film is removed by chemical reaction to obtain a semiconductor array having the preset array form on the flexible substrate.

6. The method according to claim 1 or 4, characterized in that: The metal film is a copper film.

7. The method according to claim 5, characterized in that The step of removing the metal film by chemical reaction comprises: The metal film is removed by using a ferric chloride solution to react with the metal film.

8. The method according to claim 1, characterized in that The method further comprises: A metal thin film is deposited on the surface of the intermediate substrate by atomic layer deposition.

9. A semiconductor material array, characterized in that: The semiconductor material array is obtained according to the flexible substrate-based organic semiconductor array transfer method according to any one of claims 1-8.

Images