Double-sided silicon compound contact masks and their fabrication methods; methods for fabricating halide perovskite quantum dot patterns using masks.

Abstract

This invention discloses a double-sided silicon compound contact mask. The mask uses a silicon substrate as an intermediate layer. A first SiO2 thin film is deposited on one side of the silicon substrate, and a second SiO2 thin film is deposited on the other side. Patterns are etched onto both the first and second SiO2 films. The pattern on the first SiO2 film is consistent with the pattern of halide perovskite quantum dots, while the pattern on the second SiO2 film is an enlarged version of the halide perovskite quantum dot pattern along the same Z-axis. The invention also provides a corresponding preparation method and a method for preparing halide perovskite quantum dot patterns using this mask. This invention utilizes inductively coupled plasma etching (ICP-C) technology and a double-sided silicon compound contact mask to perform micron-level patterning of perovskite quantum dot films. It is applicable to all perovskite thin film materials, broadening the compatibility for manufacturing various functional materials and providing a new patterning scheme and process strategy for the fabrication of perovskite quantum dot array devices.

Description

Technical Field

[0001] This invention belongs to the field of perovskite quantum dot patterning technology, specifically relating to double-sided silicon compound contact masks and their preparation methods, and methods for preparing halide perovskite quantum dot patterns using masks. Background Technology

[0002] Quantum dots are novel materials composed of a finite number of atoms, with three-dimensional dimensions all at the nanometer level, typically ranging from 1 to 10 nm. Traditional quantum dots are mainly composed of group II-VI, III-V, or IV-VI elements, such as the more traditional quantum dots CdSe, CdS, and ZnS, which exhibit excellent optical properties and are often used in the fabrication of various optoelectronic devices, such as light-emitting diodes and single-photon source devices.

[0003] In recent years, cesium lead halide perovskite quantum dots (hereinafter referred to as perovskite quantum dots) have demonstrated wide color gamut and narrow full width at half maximum (FWHM). Color matching can be achieved by controlling the size of the quantum dots or adjusting the mixing ratio of Cl-Br, and they offer high cost-effectiveness. Combined with their inherent flexibility, they hold great potential for ultra-high-definition flexible displays. Furthermore, they exhibit exciton-polaron properties at room temperature, which can drive research on polaron condensation, superfluidity, and quantum vortex phenomena under room-temperature operation. Their optical devices can realize room-temperature polaron lasers, polaron logic devices, and neuromorphic computing. In conclusion, lead halide perovskite quantum dots are currently an important material for novel high-performance optoelectronic devices.

[0004] However, halide perovskite materials are highly susceptible to corrosion and damage from water and oxygen in the air, and cannot be exposed to polar solvents such as water, ethanol, and acetone. In the field of micro- and nanoelectronics, photolithography (directly using photoresist) is a common method for patterning micro- and nanoelectronic devices. However, because photoresist contains a large amount of polar solvent components, this patterning method is not suitable for halide perovskite quantum dot films. Another commonly used micro- and nanoelectronics patterning method is the indirect use of photoresist, which involves depositing silicon compounds, such as silicon dioxide and silicon nitride, on the surface of a functional film as a mask layer in the etching process. However, the subsequent patterning of silicon compound materials using photolithography and the removal of the remaining silicon compound film both require contact with polar solvents. Therefore, this method is also unsuitable for perovskite quantum dot patterning.

[0005] Currently, researchers are focusing on patterning techniques for three-dimensional halide perovskite materials, using the hydrophilic-hydrophobic principle to grow three-dimensional halide perovskite particles (particle size > 100 nm) in situ on patterned regions. However, the fabrication of halide perovskite quantum dots (particle size < 10 nm) is far more difficult than that of three-dimensional halide perovskites, and the hydrophilic-hydrophobic patterning method is not applicable to patterned perovskite quantum dots. To date, no relevant literature has documented any techniques for patterning halide perovskite quantum dots. Summary of the Invention

[0006] The present invention aims to provide a double-sided silicon compound contact mask, and also to provide a corresponding preparation method thereof and a method for preparing halide perovskite quantum dot patterns using the mask.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] A double-sided silicon compound contact mask is provided, wherein a silicon substrate is used as an intermediate layer, a first SiO2 thin film is deposited on one side of the silicon substrate, and a second SiO2 thin film is deposited on the other side of the silicon substrate. The first and second SiO2 thin films are respectively etched with patterns. The pattern on the first SiO2 thin film is consistent with the halide perovskite quantum dot pattern, and the pattern on the second SiO2 thin film is a halide perovskite quantum dot pattern enlarged by a certain factor along the same Z-axis direction. The exposed silicon substrate portion is removed by a wet etching process.

[0009] The pattern on the second SiO2 film is a halide perovskite quantum dot pattern enlarged by 1.2-4 times along the same Z-axis. If there are overlapping patterns, they are directly merged into one layer for photolithography.

[0010] The thickness of the silicon substrate is 30-100 µm, and the thickness of the first SiO2 film and the second SiO2 film are both 200-350 nm.

[0011] A method for preparing a double-sided silicon compound contact mask, characterized by comprising the following steps:

[0012] a. Deposition of the first SiO2 film and the second SiO2 film on the silicon substrate: After the silicon substrate is pretreated, the first SiO2 film and the second SiO2 film are deposited by plasma chemical vapor deposition.

[0013] b. Pattern fabrication using laser direct writing lithography: Photoresist is coated on the second SiO2 film, soft-baked, and the pattern is imported into the laser direct writing software. The pattern is exposed using laser direct writing, and the photoresist forms a micro-nano structure in the exposed area. After development and post-baking, the desired pattern is formed on the photoresist. Photoresist is then coated on the first SiO2 film, and the above pattern fabrication steps on the film are repeated.

[0014] c. Thin film pattern etching using inductively coupled plasma etching technology: Place the second SiO2 thin film facing upward in the rapid sample injection chamber of the inductively coupled plasma etching system, evacuate the vacuum, transfer it to the etching chamber, perform pattern etching of the second SiO2 thin film, remove it, and repeat the above thin film etching steps with the first SiO2 thin film facing upward, and remove it.

[0015] d. Etching the silicon substrate using a wet etching process: At room temperature, immerse the mask with the thin film pattern etched in step c in the etching solution until the exposed silicon substrate is removed. Take it out and immerse it in acetone and isopropanol in sequence, and then air dry it at room temperature to obtain a double-sided silicon compound contact mask.

[0016] In step a, the double-sided polished silicon substrate is ultrasonically cleaned in acetone, ethanol, deionized water, and anhydrous ethanol in sequence, then placed in the rapid sample inlet chamber of the plasma chemical vapor deposition equipment and transferred to the plasma reaction chamber for deposition. The plasma excitation temperature is set to 130-170℃, the reaction temperature to 220-280℃, the atmosphere combination to be N2O and 5% SiH4 / Ar (silane mixture, silane mass percentage is 5%), the N2O gas flow rate to be 400-500 sccm, the 5% SiH4 / Ar gas flow rate to be 90-110 sccm, the gas pressure to be 70-90 Pa, the plasma excitation power to be 30-50 Pa, and a SiO2 thin film with a thickness of 200-350 nm is grown. After removal, the silicon substrate with the side without SiO2 film deposited is placed facing upwards, and the above deposition steps are repeated.

[0017] In step c, the process parameters for inductively coupled plasma etching are as follows: Ar gas flow rate is 5-15 sccm, CHF gas flow rate is 10-30 sccm, total gas pressure is 2-8 mTorr, upper electrode plasma excitation power is 500-1500 W, lower electrode power is 20-50 W, lower electrode bias voltage is 100-200 V, back helium pressure is 5-15 Torr, and reaction tray temperature is 8-12 ℃; in step d, the etching solution is a 30% (w / w) potassium hydroxide aqueous solution.

[0018] The method for preparing halide perovskite quantum dot patterns using the mask plate obtained by the above method includes the following steps:

[0019] 1) Fabrication of halide perovskite quantum dot thin films on a substrate;

[0020] 2) Ion etching of quantum dot pattern: A mask is placed on the halide perovskite quantum dot film in step 1), with the second SiO2 film facing upwards. The pattern formed by the mask corresponds to the position of the halide perovskite quantum dot pattern. After etching using inductively coupled plasma etching technology, the mask is removed to form the halide perovskite quantum dot pattern.

[0021] In step 2), the etching method includes the following steps:

[0022] a) Cover the halide perovskite quantum dot film from step 1) with a mask, with the second SiO2 film facing upwards. After positioning and fixing, place it in the rapid sample feed chamber of an inductively coupled plasma etching (ICP) system under vacuum conditions (vacuum degree is 1.0 e) during transport. -2 The vacuum level (Pa) is transferred to the etching chamber at a vacuum level of 1.0 e. -7 -1.0 e -9 Pa;

[0023] b. Etching the perovskite film: Introduce a combined gas and etch for 0.5-2 min at an upper electrode power of 100-500 W, a lower electrode power of 10-90 W, a gas flow rate of 10-100 sccm, and a pressure of 2-3 mTorr; the combined gas must include at least a chlorine-based atmosphere.

[0024] ICP-induced Cl - Anions are the main active ions in this etching process. Taking CsPbBr3 as an example, the reaction formula is as follows:

[0025] Pb 2+ + Cl - → PbCl2(g)

[0026] Cs + + Cl - → CsCl (g)

[0027] Br - + H + → HBr (g)

[0028] In step 2), step b, the chlorine-based atmosphere is one or a combination of two of Cl2 and BCl3, and the combined gas also includes one or more of CHF3, C4F8, and Ar.

[0029] The halide perovskite quantum dot film in step 1) is a cesium lead halide perovskite quantum dot film; in step 2), in step b, the flow rate of the chlorine atmosphere is 2-50 sccm, the flow rate of CHF3 is 2-10 sccm, the flow rate of C4F8 is 2-10 sccm, and the flow rate of Ar is 5-15 sccm.

[0030] In step 1), the method for preparing halide perovskite quantum dot films on a substrate (taking green perovskite quantum dot films as an example) is as follows: A certain amount of PbBr2 and CsBr are dissolved in DMF solvent to prepare PbBr2 solutions and CsBr solutions with a molar concentration of 1 mol / L, respectively. The two solutions are thoroughly mixed at a molar ratio of PbBr2 to CsBr of 1:1 to form a transparent mixed solution. Then, oleylamine and oleic acid (mass ratio of oleylamine to oleic acid of 1:1) are added. The ratio of the volume of DMF solvent to the sum of the volumes of oleylamine and oleic acid in the mixed solution is 2:1. The mixture is stirred thoroughly to obtain a precursor solution for perovskite quantum dots. The precursor solution is dripped into the stirred chloroform solvent at a certain rate. When the chloroform solvent turns green, the CsPbBr3 perovskite quantum dot precursor solution is prepared. After vacuum degassing the precursor solution for 1-2 minutes, a certain amount of the precursor solution was extracted with a syringe and injected into a mold on the surface of the substrate carrying the perovskite quantum dot film. After freezing at -18 ℃ for 24 h, the quantum dots crystallized from the precursor into perovskite quantum dot crystals. Then, it was placed in a vacuum drying oven and dried at 80 ℃ and 0.1 MPa for 2 h. After removing chloroform, a smooth green halide perovskite quantum dot film was obtained.

[0031] The substrate material is ITO, FTO, ZnO, TiO2 or PET, etc.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] 1) This invention utilizes inductively coupled plasma etching (ICP-C) technology, along with a double-sided silicon compound contact mask, to pattern perovskite quantum dot films at the micrometer scale (1-50 µm). This avoids the problem of perovskite corrosion by solvents and is not limited by the type of perovskite, making it applicable to all types of perovskite film materials. This broadens the compatibility for manufacturing various functional materials and provides a new patterning scheme and process strategy for the fabrication of perovskite quantum dot array devices. Compared with the hydrophilic-hydrophobic template method for perovskite patterning, this method is simpler, uses cheaper equipment, and is compatible with all MEMS-scale manufacturing plants, reducing manufacturing costs.

[0034] 2) The process of this invention is completed in a high vacuum environment, which avoids the perovskite from coming into contact with water molecules in the air and avoids the problem of film deterioration leading to performance degradation. Attached Figure Description

[0035] To more clearly illustrate the technical solution of the present invention, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0036] Figure 1 This is a schematic diagram of the mask layout design on both sides of Example 1;

[0037] Figure 2 This is a simplified diagram and process of the double-sided silicon compound contact mask in Example 1;

[0038] Figure 3 This is a schematic diagram illustrating the usage of the double-sided silicon compound contact mask in Example 1.

[0039] Figure 4 The image shown is an optical microscope photograph of a double-sided silicon compound contact mask from Example 1, with a 5.5 µm aperture.

[0040] Figure 5 This is a schematic diagram of a double-sided silicon compound contact mask halide perovskite quantum dot pattern using a 5.5 µm aperture pattern, as shown in Example 1. Detailed Implementation

[0041] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention are described in detail below. However, the following embodiments are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other implementation methods obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0042] Example 1

[0043] A double-sided silicon compound contact mask is disclosed, wherein a 100 µm thick silicon substrate is used as the intermediate layer. A first SiO2 film is deposited on one side of the silicon substrate, and a second SiO2 film is deposited on the other side. Both the first and second SiO2 films are 200 nm thick and are etched with patterns. The pattern on the first SiO2 film is consistent with the halide perovskite quantum dot pattern, and the pattern on the second SiO2 film is a halide perovskite quantum dot pattern enlarged by 1.5 times along the same Z-axis. The exposed silicon substrate portion is removed by a wet etching process, forming trapezoidal grooves. If there are overlapping patterns, they are directly merged into a single layer for photolithography.

[0044] Schematic diagram of the layout design on both sides of the photomask is shown below. Figure 1As shown, the perovskite quantum dot layer has four rectangular patterns. Each pattern is enlarged by a factor of 1.5 along the same Z-axis, resulting in four overlapping rectangles that merge to form a large rectangular pattern. This large rectangle represents the second SiO2 thin film layer pattern on the other side of the photomask. The pattern is formed on the SiO2 thin film layer using double-sided photolithography.

[0045] A method for preparing a double-sided silicon compound contact mask, characterized by comprising the following steps:

[0046] a. Deposition of the first and second SiO2 films on the silicon substrate: After ultrasonically cleaning the double-sided polished silicon substrate in acetone, ethanol, deionized water and anhydrous ethanol for 5 min each, place the double-sided polished silicon substrate with one side facing up in the rapid sample injection chamber of the plasma chemical vapor deposition (PECVD) equipment and transfer it to the plasma reaction chamber for deposition. Set the plasma excitation temperature to 150℃, the reaction temperature to 250℃, the atmosphere combination to N2O and 5% SiH4 / Ar (silane mixture, silane mass percentage is 5%, the same below), the N2O gas flow rate to 460 sccm, the 5% SiH4 / Ar gas flow rate to 100 sccm, the gas pressure to 80 Pa, the plasma excitation power to 40 Pa, and grow a first SiO2 film with a thickness of 200 nm. Remove the substrate, and repeat the above deposition steps with the side of the silicon substrate without SiO2 film facing up.

[0047] b. Pattern fabrication using laser direct writing lithography: Photoresist (AR1813) is coated onto the second SiO2 film. The coating method is as follows: spin coating at 500 rpm for 5 seconds, followed by spin coating at 3000 rpm for 30 seconds; bake at 100℃ for 1 minute; import the pattern into the laser direct writing software and expose the pattern using laser direct writing. The photoresist forms micro-nano structures in the exposed area. Develop with S319 developer for 1 minute, remove and quickly rinse with deionized water, then dry with an N2 air gun. Post-bake on a 110℃ heating plate for 1 minute to form the desired pattern on the photoresist; then coat the first SiO2 film with photoresist and repeat the above pattern fabrication steps.

[0048] c. Thin film patterning using inductively coupled plasma etching (ICP): With the second SiO2 film facing upwards, place the mask on the equipment reaction tray, then place it in the rapid sample introduction chamber of the ICP system. After evacuating to 200 Torr, transfer it to the etching chamber. Adjust the vacuum to 35 m Torr and perform the second SiO2 film patterning. Remove the mask, then repeat the above thin film etching steps with the first SiO2 film facing upwards, and remove the mask.

[0049] ICP process parameters: Ar gas flow rate is 10 sccm, CHF gas flow rate is 20 sccm, total gas pressure is 5 mTorr, upper electrode plasma excitation power is 1000 W, lower electrode power is 35 W, lower electrode bias voltage is 150 V, back helium pressure is 10 Torr, and reaction tray temperature is 10 ℃.

[0050] d. Wet etching process for silicon substrate: At 25°C, the mask with the thin film pattern etched in step c is immersed in a 30% (w / w) potassium hydroxide aqueous solution. The potassium hydroxide aqueous solution contacts the Si from the SiO2 film removal area (the Si substrate exposed area), guided by the Si substrate crystal. This wet etching is anisotropic and penetrates deeply, eventually forming an etching angle until the Si substrate is completely consumed down to the first SiO2 film. The mask is then removed and sequentially immersed in acetone and isopropanol, and air-dried at room temperature to obtain a double-sided silicon compound contact mask. A simplified diagram of the mask and the process are shown below. Figure 2 As shown. Optical microscope image of the mask plate. Figure 4 As shown, the figure represents a 5.5 µm hole.

[0051] The method for preparing halide perovskite quantum dot patterns using the mask plate prepared by the above method is illustrated in the schematic diagram below. Figure 3 As shown, it includes the following steps:

[0052] 1) Preparation of halide perovskite quantum dot films (green CsPbBr3 quantum dot films) on ITO substrates: A certain amount of PbBr2 and CsBr were dissolved in DMF solvent to prepare PbBr2 solutions and CsBr solutions with a molar concentration of 1 mol / L. The two solutions were thoroughly mixed at a molar ratio of PbBr2 to CsBr of 1:1 to form a transparent mixed solution. Then, oleylamine and oleic acid (mass ratio of oleylamine to oleic acid of 1:1) were added. The ratio of the volume of DMF solvent to the sum of the volumes of oleylamine and oleic acid in the mixed solution was 2:1. The mixture was stirred thoroughly to obtain a precursor solution for perovskite quantum dots. The precursor solution was dripped into chloroform solvent while stirring at a certain rate (0.5 mL / s). When the chloroform solvent turned green, the preparation of the CsPbBr3 perovskite quantum dot precursor solution was completed. After vacuum degassing the precursor solution for 2 minutes, a certain amount of the precursor solution was extracted with a syringe and injected into a mold on the surface of the substrate supporting the perovskite quantum dot film. After freezing at -18 °C for 24 h, the quantum dots crystallized from the precursor into perovskite quantum dot crystals. Then, it was placed in a vacuum drying oven and dried at 80 °C and 0.1 MPa for 2 h. After removing chloroform, a smooth green halide perovskite quantum dot film was obtained.

[0053] 2) Ion Etching of Quantum Dot Patterns: A mask is placed over the halide perovskite quantum dot film from step 1), with the second SiO2 film facing upwards. The pattern formed by the mask corresponds to the position of the halide perovskite quantum dot pattern. After etching using inductively coupled plasma etching (ICP-E), the mask is removed, forming the halide perovskite quantum dot pattern, as shown below. Figure 5 As shown.

[0054] In step 2), the etching method includes the following steps:

[0055] a) Cover the halide perovskite quantum dot film from step 1) with a mask, the second SiO2 film facing upwards, and fix it in place (using an optical microscope or substrate transfer platform to calibrate the position of the mask on the perovskite film etching pattern, completing the alignment operation. After the mask is aligned, use resin adhesive or spring clips to fix the mask and the perovskite film substrate. The adhesive resin adhesive can buffer the micro-movements between the mask and the perovskite quantum dot film substrate; the spring clips provide elastic cushioning. Both can prevent displacement between the mask and the perovskite film substrate, improving the accuracy of the perovskite quantum dot film etching pattern. After adhering the film to be etched to the equipment reaction tray with thermally conductive silicone oil, and applying polyimide high-temperature tape around the film to ensure the stability of the etching rate), place it in the rapid sample introduction chamber of the inductively coupled plasma etching system (ICP) under vacuum conditions (vacuum degree 1.0e during transport). -2 The vacuum level (Pa) is transferred to the etching chamber at a vacuum level of 1.0 e. -9 Pa;

[0056] b. Etching the perovskite film: The stage temperature was set to 30℃, the back helium pressure was 10 Torr, and a combined gas was introduced. The upper electrode (ICP) power was 500 W, the lower electrode (Bias) power was 80 W, and the pressure was 2.4 mTorr. The etching was carried out for 2 min. The combined gas was a mixed atmosphere composed of Cl2, CHF3, C4F8, and Ar. The flow rate of Cl2 was 5 sccm, the flow rate of CHF3 was 2 sccm, the flow rate of C4F8 was 8 sccm, and the flow rate of Ar was 5 sccm.

[0057] ICP-induced Cl - Anions are the main active ions in this etching process, and the reaction formula is as follows:

[0058] Pb 2+ + Cl - → PbCl2(g)

[0059] Cs + + Cl - → CsCl (g)

[0060] Br- + H + → HBr (g)

[0061] Depend on Figure 5 It is known that perovskite quantum dot films can be etched with a hole pattern of about 5.4 µm based on the hole pattern of about 5.5 µm circular holes on a double-sided silicon compound contact mask.

[0062] Example 2

[0063] The difference between this embodiment and Embodiment 1 is that:

[0064] A double-sided silicon compound contact mask is used, with an 80 µm thick silicon substrate as the intermediate layer. A first SiO2 film is deposited on one side of the silicon substrate, and a second SiO2 film is deposited on the other side. Both the first and second SiO2 films are 300 nm thick and are etched with patterns. The pattern on the first SiO2 film is consistent with the halide perovskite quantum dot pattern, while the pattern on the second SiO2 film is a halide perovskite quantum dot pattern enlarged by a factor of two along the same Z-axis. The exposed silicon substrate portion is removed by a wet etching process, forming trapezoidal grooves. If there are overlapping patterns, they are directly merged into a single layer for photolithography.

[0065] A method for preparing a double-sided silicon compound contact mask, characterized by comprising the following steps:

[0066] a. Deposition of the first and second SiO2 films on the silicon substrate: After ultrasonically cleaning the double-sided polished silicon substrate in acetone, ethanol, deionized water, and anhydrous ethanol for 5 min each, place the double-sided polished silicon substrate with one side facing up in the rapid sample injection chamber of the plasma chemical vapor deposition (PECVD) equipment and transfer it to the plasma reaction chamber for deposition. Set the plasma excitation temperature to 170℃, the reaction temperature to 220℃, the atmosphere combination to N2O and 5% SiH4 / Ar (silane mixture), the N2O gas flow rate to 400 sccm, the 5% SiH4 / Ar gas flow rate to 90 sccm, the gas pressure to 90 Pa, the plasma excitation power to 30 Pa, and grow a first SiO2 film with a thickness of 300 nm. Remove the substrate, place the side of the silicon substrate with the undeposited SiO2 film facing up, and repeat the above deposition steps.

[0067] b. Pattern fabrication using laser direct writing lithography: Photoresist (AR1813) is coated onto the second SiO2 film. The coating method is as follows: spin coating at 500 rpm for 5 seconds, followed by spin coating at 3000 rpm for 30 seconds; bake at 100℃ for 1 minute; import the pattern into the laser direct writing software and expose the pattern using laser direct writing. The photoresist forms micro-nano structures in the exposed area. Develop with S319 developer for 1 minute, remove and quickly rinse with deionized water, then dry with an N2 air gun. Post-bake on a 110℃ heating plate for 1 minute to form the desired pattern on the photoresist; then coat the first SiO2 film with photoresist and repeat the above pattern fabrication steps.

[0068] c. Thin film patterning using inductively coupled plasma etching technology: With the second SiO2 film facing upwards, place the mask on the equipment reaction tray, and then place it in the rapid sample introduction chamber of the inductively coupled plasma etching system (ICP). After evacuation, transfer it to the etching chamber for patterning of the second SiO2 film. Remove it, and then repeat the above thin film etching steps with the first SiO2 film facing upwards. Remove it.

[0069] ICP process parameters: Ar gas flow rate is 15 sccm, CHF gas flow rate is 10 sccm, total gas pressure is 8 mTorr, upper electrode plasma excitation power is 600 W, lower electrode power is 50 W, lower electrode bias voltage is 110 V, back helium pressure is 10 Torr, and reaction tray temperature is 12 ℃.

[0070] d. Wet etching process for silicon substrate: At 25°C, the mask with the thin film pattern etched in step c is immersed in a 30% (w / w) potassium hydroxide aqueous solution. The potassium hydroxide aqueous solution contacts the Si from the SiO2 film removal area (the Si substrate exposed area), guided by the Si substrate crystal. This wet etching is anisotropic and penetrates deeply, eventually forming an etching angle until the Si substrate is completely consumed down to the first SiO2 film. The mask is then removed and sequentially immersed in acetone and isopropanol, and air-dried at room temperature to obtain a double-sided silicon compound contact mask. A simplified diagram of the mask and the process are shown below. Figure 2 As shown.

[0071] In the method for preparing halide perovskite quantum dot patterns using the mask plate obtained by the above method, step 2) includes the following etching methods:

[0072] a) Cover the halide perovskite quantum dot film from step 1) with a mask, the second SiO2 film facing upwards, and fix it in place (using an optical microscope or substrate transfer platform to calibrate the position of the mask on the perovskite film etching pattern, completing the alignment operation. After the mask is aligned, use resin adhesive or spring clips to fix the mask and the perovskite film substrate. The adhesive resin adhesive can buffer the micro-movements between the mask and the perovskite quantum dot film substrate; the spring clips provide elastic cushioning. Both can prevent displacement between the mask and the perovskite film substrate, improving the accuracy of the perovskite quantum dot film etching pattern. After adhering the film to be etched to the equipment reaction tray with thermally conductive silicone oil, and applying polyimide high-temperature tape around the film to ensure the stability of the etching rate), place it in the rapid sample introduction chamber of the inductively coupled plasma etching system (ICP) under vacuum conditions (vacuum degree 1.0e during transport). -2 The vacuum level (Pa) is transferred to the etching chamber at a vacuum level of 1.0 e. -7 Pa;

[0073] b. Etching the perovskite film: The stage temperature was set to 30℃, the back helium pressure was 10 Torr, and a combined gas was introduced. The upper electrode (ICP) power was 200 W, the lower electrode (Bias) power was 20 W, and the pressure was 2 mTorr. The etching was carried out for 2 min. The combined gas was a mixed atmosphere composed of Cl2, CHF3, and Ar. The flow rate of Cl2 was 8 sccm, the flow rate of CHF3 was 10 sccm, and the flow rate of Ar was 15 sccm.

[0074] Example 3

[0075] The difference between this embodiment and Embodiment 1 is that:

[0076] A double-sided silicon compound contact mask is used, with a 50 µm thick silicon substrate as the intermediate layer. A first SiO2 film is deposited on one side of the silicon substrate, and a second SiO2 film is deposited on the other side. Both the first and second SiO2 films are 350 nm thick and are etched with patterns. The pattern on the first SiO2 film is consistent with the halide perovskite quantum dot pattern, while the pattern on the second SiO2 film is a halide perovskite quantum dot pattern enlarged by three times along the same Z-axis. The exposed silicon substrate portion is removed by a wet etching process, forming trapezoidal grooves. If there are overlapping patterns, they are directly merged into a single layer for photolithography.

[0077] A method for preparing a double-sided silicon compound contact mask, characterized by comprising the following steps:

[0078] a. Deposition of the first and second SiO2 films on the silicon substrate: After ultrasonically cleaning the double-sided polished silicon substrate in acetone, ethanol, deionized water, and anhydrous ethanol for 5 min each, place the double-sided polished silicon substrate with one side facing up in the rapid sample injection chamber of the plasma chemical vapor deposition (PECVD) equipment and transfer it to the plasma reaction chamber for deposition. Set the plasma excitation temperature to 140℃, the reaction temperature to 270℃, the atmosphere combination to N2O and 5% SiH4 / Ar (silane mixture), the N2O gas flow rate to 490 sccm, the 5% SiH4 / Ar gas flow rate to 105 sccm, the gas pressure to 75 Pa, the plasma excitation power to 50 Pa, and grow a first SiO2 film with a thickness of 350 nm. Remove the substrate, place the side of the silicon substrate without SiO2 film facing up, and repeat the above deposition steps.

[0079] b. Pattern fabrication using laser direct writing lithography: Photoresist (AR1813) is coated onto the second SiO2 film. The coating method is as follows: spin coating at 500 rpm for 5 seconds, followed by spin coating at 3000 rpm for 30 seconds; bake at 100℃ for 1 minute; import the pattern into the laser direct writing software and expose the pattern using laser direct writing. The photoresist forms micro-nano structures in the exposed area. Develop with S319 developer for 1 minute, remove and quickly rinse with deionized water, then dry with an N2 air gun. Post-bake on a 110℃ heating plate for 1 minute to form the desired pattern on the photoresist; then coat the first SiO2 film with photoresist and repeat the above pattern fabrication steps.

[0080] c. Thin film patterning using inductively coupled plasma etching technology: With the second SiO2 film facing upwards, place the mask on the equipment reaction tray, and then place it in the rapid sample introduction chamber of the inductively coupled plasma etching system (ICP). After evacuation, transfer it to the etching chamber for patterning of the second SiO2 film. Remove it, and then repeat the above thin film etching steps with the first SiO2 film facing upwards. Remove it.

[0081] ICP process parameters: Ar gas flow rate is 6 sccm, CHF gas flow rate is 26 sccm, total gas pressure is 3 mTorr, upper electrode plasma excitation power is 1400 W, lower electrode power is 25 W, lower electrode bias voltage is 180 V, back helium pressure is 10 Torr, and reaction tray temperature is 8 ℃.

[0082] d. Wet etching process for silicon substrate: At 25°C, the mask with the thin film pattern etched in step c is immersed in a 30% (w / w) potassium hydroxide aqueous solution. The potassium hydroxide aqueous solution contacts the Si from the SiO2 film removal area (the Si substrate exposed area), guided by the Si substrate crystal. This wet etching is anisotropic and penetrates deeply, eventually forming an etching angle until the Si substrate is completely consumed down to the first SiO2 film. The mask is then removed and sequentially immersed in acetone and isopropanol, and air-dried at room temperature to obtain a double-sided silicon compound contact mask. A simplified diagram of the mask and the process are shown below. Figure 2 As shown.

[0083] In the method for preparing halide perovskite quantum dot patterns using the mask plate obtained by the above method, step 2) includes the following etching methods:

[0084] a) Cover the halide perovskite quantum dot film from step 1) with a mask, the second SiO2 film facing upwards, and fix it in place (using an optical microscope or substrate transfer platform to calibrate the position of the mask on the perovskite film etching pattern, completing the alignment operation. After the mask is aligned, use resin adhesive or spring clips to fix the mask and the perovskite film substrate. The adhesive resin adhesive can buffer the micro-movements between the mask and the perovskite quantum dot film substrate; the spring clips provide elastic cushioning. Both can prevent displacement between the mask and the perovskite film substrate, improving the accuracy of the perovskite quantum dot film etching pattern. After adhering the film to be etched to the equipment reaction tray with thermally conductive silicone oil, and applying polyimide high-temperature tape around the film to ensure the stability of the etching rate), place it in the rapid sample introduction chamber of the inductively coupled plasma etching system (ICP) under vacuum conditions (vacuum degree 1.0e during transport). -2 The vacuum level (Pa) is transferred to the etching chamber at a vacuum level of 1.0 e. -9 Pa;

[0085] b. Etching the perovskite film: The stage temperature was set to 30 ℃, the back helium pressure was 10 Torr, and a combined gas was introduced. The upper electrode (ICP) power was 450 W, the lower electrode (Bias) power was 90 W, and the pressure was 3 mTorr. The etching was carried out for 2 min. The combined gas was a mixed atmosphere composed of Cl2, CHF3 and Ar. The flow rate of Cl2 was 6 sccm, the flow rate of CHF3 was 8 sccm, and the flow rate of Ar was 12 sccm.

Claims

1. A method for preparing a double-sided silicon compound contact mask, characterized in that, Includes the following steps: a. Deposition of the first SiO2 film and the second SiO2 film on the silicon substrate: After the silicon substrate is pretreated, the first SiO2 film and the second SiO2 film are deposited by plasma chemical vapor deposition. b. Pattern fabrication using laser direct writing lithography: Photoresist is coated on the second SiO2 film, soft-baked, the pattern is imported into the laser direct writing software, the pattern is exposed using laser direct writing, the photoresist forms micro-nano structures in the exposed area, development and post-baking are performed, and the desired pattern is formed on the photoresist. Then, photoresist is coated onto the first SiO2 film, and the above steps for fabricating the pattern on the film are repeated. c. Thin film pattern etching using inductively coupled plasma etching technology: Place the second SiO2 thin film facing upward in the rapid sample injection chamber of the inductively coupled plasma etching system, evacuate the vacuum, transfer it to the etching chamber, perform pattern etching of the second SiO2 thin film, remove it, and repeat the above thin film etching steps with the first SiO2 thin film facing upward, and remove it. d. Etching the silicon substrate using a wet etching process: At room temperature, immerse the mask with the thin film pattern etched in step c in the etching solution until the exposed silicon substrate is removed. Take it out and immerse it in acetone and isopropanol in sequence, and then air dry it at room temperature to obtain a double-sided silicon compound contact mask.

2. The method for preparing a double-sided silicon compound contact mask as described in claim 1, characterized in that, In step a, the double-sided polished silicon substrate is ultrasonically cleaned in acetone, ethanol, deionized water, and anhydrous ethanol in sequence, then placed in the rapid sample inlet chamber of the plasma chemical vapor deposition equipment and transferred to the plasma reaction chamber for deposition. The plasma excitation temperature is set to 130-170 ℃, the reaction temperature to 220-280 ℃, the atmosphere combination to be N2O and 5% SiH4 / Ar, the N2O gas flow rate to be 400-500 sccm, the 5% SiH4 / Ar gas flow rate to be 90-110 sccm, the gas pressure to be 70-90 Pa, the plasma excitation power to be 30-50 Pa, and a SiO2 thin film with a thickness of 200-350 nm is grown. After removal, the silicon substrate with the side without SiO2 film deposited is placed facing upwards, and the above deposition steps are repeated.

3. The method for preparing a double-sided silicon compound contact mask as described in claim 2, characterized in that, In step c, the process parameters for inductively coupled plasma etching are as follows: Ar gas flow rate is 5-15 sccm, CHF gas flow rate is 10-30 sccm, total gas pressure is 2-8 mTorr, upper electrode plasma excitation power is 500-1500 W, lower electrode power is 20-50 W, lower electrode bias voltage is 100-200 V, back helium pressure is 5-15 Torr, and reaction tray temperature is 8-12℃; in step d, the etching solution is a 30% (w / w) potassium hydroxide aqueous solution.

4. A double-sided silicon compound contact mask prepared by any one of the preparation methods described in claims 1-3, characterized in that, The mask uses a silicon substrate as an intermediate layer. A first SiO2 thin film is deposited on one side of the silicon substrate, and a second SiO2 thin film is deposited on the other side. Patterns are etched on the first and second SiO2 thin films respectively. The pattern on the first SiO2 thin film is consistent with the halide perovskite quantum dot pattern, and the pattern on the second SiO2 thin film is a halide perovskite quantum dot pattern enlarged by 1.2-4 times along the same Z-axis direction. The exposed silicon substrate portion is removed by a wet etching process.

5. The double-sided silicon compound contact mask as described in claim 4, characterized in that, The thickness of the silicon substrate is 30-100 µm, and the thickness of the first SiO2 film and the second SiO2 film are both 200-350 nm.

6. A method for preparing halide perovskite quantum dot patterns using the double-sided silicon compound contact mask as described in claim 4, characterized in that, Includes the following steps: 1) Fabrication of halide perovskite quantum dot thin films on a substrate; 2) Ion etching of quantum dot pattern: A mask is placed on the halide perovskite quantum dot film in step 1), with the second SiO2 film facing upwards. The pattern formed by the mask corresponds to the position of the halide perovskite quantum dot pattern. After etching using inductively coupled plasma etching technology, the mask is removed to form the halide perovskite quantum dot pattern.

7. The method for preparing halide perovskite quantum dot patterns as described in claim 6, characterized in that, In step 2), the etching method includes the following steps: a) Cover the halide perovskite quantum dot film in step 1) with a mask plate, with the second SiO2 film facing upwards. After positioning and fixing, place it in the rapid sample introduction chamber of the inductively coupled plasma etching system and transfer it to the etching chamber under vacuum conditions. b. Etching the perovskite film: Introduce a combined gas and etch for 0.5-2 min at an upper electrode power of 100-500 W, a lower electrode power of 10-90 W, a gas flow rate of 10-100 sccm, and a pressure of 2-3 mTorr; the combined gas must include at least a chlorine-based atmosphere.

8. The method for preparing halide perovskite quantum dot patterns as described in claim 7, characterized in that, In step 2), step b, the chlorine-based atmosphere is one or a combination of two of Cl2 and BCl3, and the combined gas also includes one or more of CHF3, C4F8, and Ar.

9. The method for preparing halide perovskite quantum dot patterns as described in claim 8, characterized in that, The halide perovskite quantum dot film in step 1) is a cesium lead halide perovskite quantum dot film; in step 2), in step b, the flow rate of the chlorine atmosphere is 2-50 sccm, the flow rate of CHF3 gas is 2-10 sccm, the flow rate of C4F8 gas is 2-10 sccm, and the flow rate of Ar gas is 5-15 sccm.

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