Double-sided silicon compound contact type mask plate and preparation method thereof, and method for preparing halide perovskite quantum dot pattern by using mask plate

Abstract

The invention discloses a double-sided silicon compound contact type mask plate, which takes a silicon substrate as a middle layer, a first SiO2 film is deposited on one surface of the silicon substrate, a second SiO2 film is deposited on the other surface of the silicon substrate, patterns are respectively etched on the first SiO2 film and the second SiO2 film, the pattern on the first SiO2 film is consistent with the pattern of halide perovskite quantum dots, and the pattern on the second SiO2 film is consistent with the pattern of halide perovskite quantum dots. And the pattern of the second SiO2 thin film is a pattern obtained by enlarging the halide perovskite quantum dot pattern by a certain multiple along the same Z-axis direction. Meanwhile, the invention provides a corresponding preparation method and a method for preparing a halide perovskite quantum dot pattern by using the same. According to the invention, the perovskite quantum dot film is subjected to micron-scale patterning by using the inductive coupling plasma etching technology and the double-sided silicon compound contact type mask plate, so that the method is suitable for all perovskite film materials, and the compatibility of manufacturing various functional materials is widened; and a new graphical scheme process strategy is provided for preparation of the perovskite quantum dot array device.

Description

Technical Field

[0001] The present invention belongs to the technical field of perovskite quantum dot patterning, and in particular relates to a double-sided silicon compound contact mask plate and a preparation method thereof, and a method for preparing a halide perovskite quantum dot pattern using the mask plate. Background Art

[0002] Quantum dots are new materials composed of a limited number of atoms with three-dimensional dimensions at the nanometer level, usually between 1 and 10 nm in size. Traditional quantum dots are mainly composed of II-VI, III-V or IV-VI elements, such as the more traditional quantum dots CdSe, CdS, ZnS, etc., which have excellent optical characteristics and are often used in the manufacture of various optoelectronic devices, such as light-emitting diode devices, single-photon source devices, etc.

[0003] In recent years, cesium lead halide perovskite quantum dots (hereinafter referred to as perovskite quantum dots) have the characteristics of wide color gamut and narrow half-width. The color matching can be achieved by adjusting the size of the quantum dots or the mixing ratio of Cl-Br. It is cost-effective and has great potential in ultra-high-definition flexible displays due to the flexibility of the material itself. In addition, it also exhibits exciton-polariton properties at room temperature, which can promote the study of polaritons condensation, superfluids, and quantum vortex phenomena under room temperature operation. Its optical devices can realize room-temperature polariton lasers, polariton logic devices, and neuromorphic computing. In short, lead halide perovskite quantum dots are an important material for new high-performance optoelectronic devices.

[0004] However, halide perovskite materials are easily corroded and damaged by water and oxygen in the air, and cannot be exposed to polar solvents such as water, ethanol, acetone, etc. In the field of micro-nanoelectronics technology, photolithography (direct use of photoresist) is a common solution for the development of micro-nanoelectronic device patterning, but because photoresist contains a large amount of polar solvent components, this patterning solution is not suitable for halide perovskite quantum dot films; another commonly used micro-nanoelectronics patterning process is the indirect use of photoresist, that is, depositing silicon compounds such as silicon dioxide, silicon nitride, etc. on the surface of the functional film as a mask layer in the etching process, but the subsequent photolithography patterning of silicon compound materials and the removal of the remaining silicon compound film must be exposed to polar solvents, so this solution cannot be used as a perovskite quantum dot patterning process.

[0005] At present, researchers are committed to the patterning scheme of three-dimensional halide perovskite materials. With the help of the hydrophilic-hydrophobic principle, three-dimensional halide perovskite particles (particle size>100 nm) are grown in situ on the patterned area. However, the process preparation of halide perovskite quantum dots (particle size <10 nm) is much more difficult than the preparation of three-dimensional halide perovskites. The hydrophilic-hydrophobic patterning scheme cannot be applied to patterned perovskite quantum dots. So far, there is no relevant literature recording the technology of halide perovskite quantum dot patterning process. Summary of the invention

[0006] The object of the present invention is to provide a double-sided silicon compound contact mask plate, and at the same time, providing a corresponding preparation method thereof and a method for preparing halide perovskite quantum dot patterns using the same is another invention object of the present invention.

[0007] Based on the above purpose, the present invention adopts the following technical solutions: A double-sided silicon compound contact mask plate, wherein the mask plate uses a silicon substrate as an 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 of the silicon substrate, the first SiO2 film and the second SiO2 film are respectively etched with patterns, the pattern on the first SiO2 film is consistent with the halide perovskite quantum dot pattern, the pattern on the second SiO2 film is a pattern of the halide perovskite quantum dot pattern enlarged a certain multiple along the same Z-axis direction, and the exposed silicon substrate portion is removed by a wet etching process.

[0008] The pattern on the second SiO2 film is a pattern of halide perovskite quantum dot pattern enlarged 1.2-4 times along the same Z-axis direction. If there is an overlapping part of the pattern, it is directly merged into one layer for photolithography.

[0009] 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.

[0010] A method for preparing a double-sided silicon compound contact mask plate, characterized in that it comprises the following steps: a. Depositing a first SiO2 film and a second SiO2 film on a silicon substrate: After pretreatment of the silicon substrate, the first SiO2 film and the second SiO2 film are deposited respectively by a plasma chemical vapor deposition method; b. Use laser direct writing lithography technology to make graphics: apply photoresist on the second SiO2 film, soft bake, import the layout into laser direct writing software, use laser direct writing to expose the layout, the photoresist forms a micro-nano structure in the exposed area, develop, post-bake, and form the required graphics on the photoresist; then apply photoresist on the first SiO2 film, and repeat the above steps of making graphics on the film; c. Use inductively coupled plasma etching technology to etch thin film patterns: place the second SiO2 film upward in the fast sampling chamber of the inductively coupled plasma etching system, evacuate the vacuum chamber, transfer it to the etching chamber, etch the second SiO2 film pattern, take it out, and then repeat the above film etching steps with the first SiO2 film facing upward and take it out; d. Etch the silicon substrate using a wet etching process: At room temperature, soak the mask plate with the thin film pattern etched in step c in an etching solution until the exposed silicon substrate is partially removed, take it out, soak it in acetone and isopropanol in turn, and dry it at room temperature to obtain a double-sided silicon compound contact mask plate.

[0011] In step a, the double-sided polished silicon substrate is placed in acetone, ethanol, deionized water, and anhydrous ethanol for ultrasonic cleaning in sequence, and then placed in the fast sampling 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°C, the reaction temperature is set to 220-280°C, the atmosphere combination is N2O and 5% SiH4 / Ar (silane mixed gas, silane mass proportion is 5%), the N2O gas flow rate is 400-500 sccm, the 5% SiH4 / Ar gas flow rate is 90-110 sccm, the gas pressure is 70-90 Pa, the plasma excitation power is 30-50 Pa, and a SiO2 film with a thickness of 200-350 nm is grown. The film is taken out, the side of the silicon substrate on which the SiO2 film is not deposited faces up, and the above deposition steps are repeated.

[0012] In step c, the process parameters of the inductively coupled plasma etching technology are: 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 ° C; in step d, the etching solution is a potassium hydroxide aqueous solution with a mass concentration of 30%.

[0013] The method for preparing a halide perovskite quantum dot pattern using the mask plate prepared by the above method comprises the following steps: 1) Preparation of halide perovskite quantum dot thin films on substrates; 2) Ion etching quantum dot pattern: Cover the halide perovskite quantum dot film in step 1) with a mask plate, with the second SiO2 film facing upwards. The pattern formed by the mask plate corresponds to the position of the halide perovskite quantum dot pattern. After etching using inductively coupled plasma etching technology, remove the mask plate to form a halide perovskite quantum dot pattern.

[0014] In step 2), the etching method comprises 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 being fixed in position, place it in the fast sample chamber of the inductively coupled plasma etching system (ICP) under vacuum conditions (the vacuum degree is 1.0e during the transfer process). -2 Pa), transferred to the etching chamber, the vacuum degree is 1.0 e -7 -1.0 e -9 Pa; b. Etching perovskite film: introducing a combination of gases, etching 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 combination of gases includes at least a chlorine-based atmosphere.

[0015] ICP-excited Cl - Anions are the main active ions in this etching process. Taking CsPbBr3 as an example, the reaction formula is as follows: Pb 2+ + Cl - → PbCl2(g) Cs + + Cl - → CsCl (g) Br - + H + → HBr (g) In step 2), in step b, the chlorine-based atmosphere is a combination of one or two of Cl2 and BCl3, and the combination gas further includes a combination of one or more of CHF3, C4F8, and Ar.

[0016] 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 chlorine-based atmosphere gas flow rate is 2-50 sccm, the CHF3 gas flow rate is 2-10 sccm, the C4F8 gas flow rate is 2-10 sccm, and the Ar gas flow rate is 5-15 sccm.

[0017] In step 1), a method for preparing a halide perovskite quantum dot film on a substrate (taking a green perovskite quantum dot film as an example) is as follows: a certain amount of PbBr2 and CsBr are respectively dissolved in a DMF solvent to prepare a PbBr2 solution and a CsBr solution with a molar concentration of 1 mol / L, respectively, and the two solutions are fully mixed at a molar ratio of PbBr2 to CsBr of 1:1 to form a transparent mixed solution, and then oleylamine and oleic acid (the mass ratio of oleylamine to oleic acid is 1:1) are added, and the ratio of the volume of the DMF solvent to the sum of the volumes of oleylamine and oleic acid in the mixed solution is 2:1, and the mixture is fully stirred to obtain a precursor solution of perovskite quantum dots, and the precursor solution is dripped into a stirring chloroform solvent at a certain rate. When the chloroform solvent appears green, the preparation of the CsPbBr3 perovskite quantum dot precursor solution is completed. After the precursor liquid is vacuum degassed for 1-2 min, a certain amount of the precursor liquid is drawn through a needle and injected into the mold on the surface of the substrate carrying the perovskite quantum dot film. After freezing for 24 h at -18 °C, the quantum dots crystallize from the precursor into perovskite quantum dot crystals. Then, it is placed in a vacuum drying oven at 80 °C and 0.1 Mpa for 2 h. After removing the chloroform, a smooth green halide perovskite quantum dot film is obtained.

[0018] The material of the substrate is ITO, FTO, ZnO, TiO2 or PET, etc.

[0019] Compared with the prior art, the present invention has the following beneficial effects: 1) The present invention utilizes inductively coupled plasma etching technology and a double-sided silicon compound contact mask to pattern the perovskite quantum dot film at the micron level (1-50 µm in size), thereby avoiding the problem of perovskite being corroded by solvents and being not restricted by the type of perovskite. It is applicable to all types of perovskite film materials, broadens the compatibility of manufacturing various functional materials, and provides a new patterning process strategy for the preparation of perovskite quantum dot array devices. Compared with the perovskite patterning process using the hydrophilic-hydrophobic template method, the present invention is simpler, has cheaper equipment, and is compatible with all MEMS scale manufacturing plants, thus reducing manufacturing costs. 2) The process of the present invention is completed in a high vacuum environment, avoiding the perovskite from contacting water molecules in the air and avoiding the problem of film deterioration leading to performance degradation. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solution of the present invention, the drawings required for use 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 paying creative work.

[0021] Figure 1This is a schematic diagram of the layout design on both sides of the mask plate in Example 1; Figure 2 A schematic diagram and process of a double-sided silicon compound contact mask of Example 1; Figure 3 This is a schematic diagram of the method for using the double-sided silicon compound contact mask plate of Example 1; Figure 4 This is an optical microscope photo of the double-sided silicon compound contact mask of Example 1, and the pattern is a 5.5 µm hole; Figure 5 This is a schematic diagram of a halide perovskite quantum dot pattern using a double-sided silicon compound contact mask with a 5.5 µm hole pattern in Example 1. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical scheme and advantages of the present invention clearer, the technical scheme of the present invention is described in detail below, but the following embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other implementation methods obtained by those skilled in the art without making creative work belong to the scope of protection of the present invention.

[0023] Example 1 Double-sided silicon compound contact mask, the mask uses a silicon substrate with a thickness of 100 µm as the middle 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 of the silicon substrate, the thickness of the first SiO2 film and the second SiO2 film are both 200 nm, and the two are respectively 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 pattern of the halide perovskite quantum dot pattern enlarged 1.5 times along the same Z-axis direction, and the exposed silicon substrate portion is removed by a wet etching process to form a trapezoidal groove. If there is an overlapping part of the pattern, it is directly merged into one layer for photolithography.

[0024] The schematic diagram of the layout design on both sides of the mask is as follows Figure 1 As shown. The perovskite quantum dot layer has four rectangular patterns. After each pattern is enlarged 1.5 times along the same Z axis, the four rectangular patterns overlap each other and merge to form a large rectangular pattern, which is the second SiO2 film layer pattern on the other side of the mask. The pattern is formed on the SiO2 film layer by double-sided photolithography.

[0025] A method for preparing a double-sided silicon compound contact mask plate, characterized in that it comprises the following steps: a. Deposition of the first SiO2 film and the second SiO2 film on the silicon substrate: the double-sided polished silicon substrate was placed in acetone, ethanol, deionized water, and anhydrous ethanol in turn for ultrasonic cleaning for 5 min each, and then the double-sided polished silicon substrate was placed with one side facing up in the rapid injection chamber of a plasma chemical vapor deposition device (PECVD), and transferred to the plasma reaction chamber for deposition, and the plasma excitation temperature was set to 150°C, the reaction temperature was set to 250°C, the atmosphere combination was N2O and 5% SiH4 / Ar (silane mixed gas, silane mass ratio was 5%, the same below), the N2O gas flow rate was 460 sccm, the 5% SiH4 / Ar gas flow rate was 100 sccm, the gas pressure was 80 Pa, the plasma excitation power was 40 Pa, and a first SiO2 film with a thickness of 200 nm was grown. The film was taken out, and the side of the silicon substrate without the SiO2 film deposited was facing up, and the above deposition steps were repeated; b. Use laser direct writing lithography technology to make graphics: Coat photoresist on the second SiO2 film. AR1813 can be used as photoresist. The coating method is to first spin coat the glue at 500 rpm for 5 s, and then spin coat the glue at 3000 rpm for 30 s; bake at a soft baking temperature of 100°C for 1 min; import the layout into the laser direct writing software, use laser direct writing to expose the layout, and the photoresist forms a micro-nano structure in the exposed area. Place it in S319 developer for 1 min, take it out and quickly rinse it with deionized water, blow it dry with a N2 air gun, and place it on a heating plate at 110°C for 1 min to form the desired graphics on the photoresist; then coat the photoresist on the first SiO2 film, and repeat the above steps of making graphics on the film; c. Use inductively coupled plasma etching technology to etch thin film patterns: Place the second SiO2 film upward, place the mask on the equipment reaction tray, and then place it in the fast sampling chamber of the inductively coupled plasma etching system (ICP). After evacuating to 200 Torr, transfer it to the etching chamber, adjust the vacuum degree to 35 m Torr, etch the second SiO2 film pattern, take it out, and then repeat the above film etching steps with the first SiO2 film facing upward and take it out; 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, reaction tray temperature is 10 °C; d. Use wet etching process to etch silicon substrate: At 25°C, place the mask plate with thin film pattern etched in step c in a 30% potassium hydroxide aqueous solution. The potassium hydroxide aqueous solution contacts Si from the SiO2 film removal area (Si substrate exposed area) and is guided by the Si base crystal. The wet etching is anisotropic and deeply etches, and eventually forms an etching angle until the Si substrate is consumed to the first SiO2 film. Take it out, soak it in acetone and isopropanol in turn, and dry it at room temperature to obtain a double-sided silicon compound contact mask plate. The mask plate schematic and process are as follows: Figure 2 As shown. The optical microscope photo of the mask is shown in Figure 4 As shown, the pattern is a 5.5 µm hole.

[0026] A method for preparing a halide perovskite quantum dot pattern using the mask plate prepared by the above method is shown in the schematic diagram Figure 3 As shown, the following steps are included: 1) Preparation of halide perovskite quantum dot film (green CsPbBr3 quantum dot film) on ITO substrate: a certain amount of PbBr2 and CsBr were dissolved in DMF solvent to prepare PbBr2 solution and CsBr solution with a molar concentration of 1 mol / L, respectively. The two solutions were fully mixed at a molar ratio of PbBr2 to CsBr of 1:1 to form a transparent mixed solution, and then oleylamine and oleic acid (the mass ratio of oleylamine to oleic acid was 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, and the mixture was fully stirred to obtain a precursor solution of perovskite quantum dots. The precursor solution was dripped into the stirring chloroform solvent 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 the precursor liquid was vacuum degassed for 2 minutes, a certain amount of the precursor liquid was drawn through a needle and injected into the mold on the surface of the substrate carrying the perovskite quantum dot film. After freezing for 24 hours at -18 °C, the quantum dots crystallized from the precursor into perovskite quantum dot crystals. Then, it was placed in a vacuum drying oven at 80 °C and 0.1 MPa for 2 hours. After removing the chloroform, a smooth green halide perovskite quantum dot film was obtained.

[0027] 2) Ion etching quantum dot pattern: Cover the halide perovskite quantum dot film in step 1) with a mask plate, with the second SiO2 film facing upwards. The pattern formed by the mask plate corresponds to the position of the halide perovskite quantum dot pattern. After etching using inductively coupled plasma etching technology, remove the mask plate to form a halide perovskite quantum dot pattern, such as Figure 5 shown.

[0028] In step 2), the etching method comprises the following steps: a. Cover the halide perovskite quantum dot film in step 1) with the mask plate, the second SiO2 film facing up, and fix it relatively (with the help of an optical microscope or a substrate transfer platform, calibrate the position of the mask plate on the perovskite film etching pattern to complete the alignment operation. After the mask plate is aligned, use resin glue or spring pressure piece to fix the mask plate and the perovskite film substrate. Among them, the viscous resin glue can buffer the micro-movement between the mask plate and the perovskite quantum dot film substrate; the spring pressure piece can provide elastic buffering. Both can prevent the movement between the mask plate and the perovskite film substrate and improve the accuracy of the perovskite quantum dot film etching pattern. With the help of thermal conductive silicone oil, the film to be etched is adhered to the reaction tray of the equipment, and polyimide high-temperature tape is attached around the film to ensure the stability of the etching rate), and then placed in the fast sampling chamber of the inductively coupled plasma etching system (ICP) under vacuum conditions (the vacuum degree is 1.0e during the transfer process). -2 Pa), transferred to the etching chamber, the vacuum degree is 1.0e -9 Pa; b. Etching perovskite film: the sample stage temperature was set to 30°C, the back helium pressure was 10 Torr, and the 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 of Cl2, CHF3, C4F8, and Ar. The Cl2 atmosphere gas flow rate was 5 sccm, the CHF3 gas flow rate was 2 sccm, the C4F8 gas flow rate was 8 sccm, and the Ar gas flow rate was 5 sccm.

[0029] ICP-excited Cl - Anions are the main active ions in this etching process, and the reaction formula is as follows: Pb 2+ + Cl - → PbCl2(g) Cs + + Cl - → CsCl (g) Br - + H + → HBr (g) Depend on Figure 5 It can be seen that the perovskite quantum dot film is etched into a hole pattern of about 5.4 µm based on the hole pattern of about 5.5 µm circular hole pattern of the double-sided silicon compound contact mask.

[0030] Example 2 This embodiment is different from Embodiment 1 in that: Double-sided silicon compound contact mask, the mask uses a silicon substrate with a thickness of 80 µm as the middle 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 of the silicon substrate, the thickness of the first SiO2 film and the second SiO2 film are both 300 nm, and the two are respectively 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 pattern of the halide perovskite quantum dot pattern enlarged 2 times along the same Z-axis direction, and the exposed silicon substrate portion is removed by a wet etching process to form a trapezoidal groove. If there is an overlapping part of the pattern, it is directly merged into one layer for photolithography.

[0031] A method for preparing a double-sided silicon compound contact mask plate, characterized in that it comprises the following steps: a. Deposition of a first SiO2 film and a second SiO2 film on a silicon substrate: a double-sided polished silicon substrate was placed in acetone, ethanol, deionized water, and anhydrous ethanol in turn for ultrasonic cleaning for 5 min each, and then the double-sided polished silicon substrate was placed with one side facing up in the rapid injection chamber of a plasma chemical vapor deposition device (PECVD), and transferred to a plasma reaction chamber for deposition, and the plasma excitation temperature was set to 170°C, the reaction temperature was set to 220°C, the atmosphere was N2O and 5% SiH4 / Ar (silane mixed gas), the N2O gas flow rate was 400 sccm, the 5% SiH4 / Ar gas flow rate was 90 sccm, the gas pressure was 90 Pa, the plasma excitation power was 30 Pa, and a first SiO2 film with a thickness of 300 nm was grown. The film was taken out, and the side of the silicon substrate without the SiO2 film deposited was placed upward, and the above deposition steps were repeated; b. Use laser direct writing lithography technology to make graphics: Coat photoresist on the second SiO2 film. AR1813 can be used as photoresist. The coating method is to first spin coat the glue at 500 rpm for 5 s, and then spin coat the glue at 3000 rpm for 30 s; bake at a soft baking temperature of 100°C for 1 min; import the layout into the laser direct writing software, use laser direct writing to expose the layout, and the photoresist forms a micro-nano structure in the exposed area. Place it in S319 developer for 1 min, take it out and quickly rinse it with deionized water, blow it dry with a N2 air gun, and place it on a heating plate at 110°C for 1 min to form the desired graphics on the photoresist; then coat the photoresist on the first SiO2 film, and repeat the above steps of making graphics on the film; c. Use inductively coupled plasma etching technology to etch thin film patterns: put the second SiO2 film upward, place the mask plate on the equipment reaction tray, and then put it in the fast sampling chamber of the inductively coupled plasma etching system (ICP). After vacuuming, transfer it to the etching chamber to etch the second SiO2 film pattern, take it out, and then repeat the above film etching steps with the first SiO2 film facing upward and take it out; 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, reaction tray temperature is 12 °C; d. Use wet etching process to etch silicon substrate: At 25°C, place the mask plate with thin film pattern etched in step c in a 30% potassium hydroxide aqueous solution. The potassium hydroxide aqueous solution contacts Si from the SiO2 film removal area (Si substrate exposed area) and is guided by the Si base crystal. The wet etching is anisotropic and deeply etches, and eventually forms an etching angle until the Si substrate is consumed to the first SiO2 film. Take it out, soak it in acetone and isopropanol in turn, and dry it at room temperature to obtain a double-sided silicon compound contact mask plate. The mask plate schematic and process are as follows: Figure 2 shown.

[0032] In the method for preparing a halide perovskite quantum dot pattern using the mask plate prepared by the above method, in step 2), the etching method comprises the following steps: a. Cover the halide perovskite quantum dot film in step 1) with the mask plate, the second SiO2 film facing up, and fix it relatively (with the help of an optical microscope or a substrate transfer platform, calibrate the position of the mask plate on the perovskite film etching pattern to complete the alignment operation. After the mask plate is aligned, use resin glue or spring pressure piece to fix the mask plate and the perovskite film substrate. Among them, the viscous resin glue can buffer the micro-movement between the mask plate and the perovskite quantum dot film substrate; the spring pressure piece can provide elastic buffering. Both can prevent the movement between the mask plate and the perovskite film substrate and improve the accuracy of the perovskite quantum dot film etching pattern. With the help of thermal conductive silicone oil, the film to be etched is adhered to the reaction tray of the equipment, and polyimide high-temperature tape is attached around the film to ensure the stability of the etching rate), and then placed in the fast sampling chamber of the inductively coupled plasma etching system (ICP) under vacuum conditions (the vacuum degree is 1.0e during the transfer process). -2 Pa), transferred to the etching chamber, the vacuum degree is 1.0e -7 Pa; b. Etching perovskite film: the sample stage temperature was set to 30°C, the back helium pressure was 10 Torr, and the 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 performed for 2 min. The combined gas was a mixed atmosphere of Cl2, CHF3, and Ar. The Cl2 atmosphere gas flow rate was 8 sccm, the CHF3 gas flow rate was 10 sccm, and the Ar gas flow rate was 15 sccm.

[0033] Example 3 This embodiment is different from Embodiment 1 in that: Double-sided silicon compound contact mask, the mask uses a silicon substrate with a thickness of 50 µm as the middle 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 of the silicon substrate, the thickness of the first SiO2 film and the second SiO2 film are both 350 nm, and the two are respectively 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 pattern of the halide perovskite quantum dot pattern enlarged 3 times along the same Z-axis direction, and the exposed silicon substrate portion is removed by a wet etching process to form a trapezoidal groove. If there is an overlapping part of the pattern, it is directly merged into one layer for photolithography.

[0034] A method for preparing a double-sided silicon compound contact mask plate, characterized in that it comprises the following steps: a. Deposition of the first SiO2 film and the second SiO2 film on the silicon substrate: The double-sided polished silicon substrate was placed in acetone, ethanol, deionized water, and anhydrous ethanol in turn for ultrasonic cleaning for 5 min each, and then the double-sided polished silicon substrate was placed with one side facing up in the rapid injection chamber of a plasma chemical vapor deposition device (PECVD), and transferred to a plasma reaction chamber for deposition, and the plasma excitation temperature was set to 140°C, the reaction temperature was set to 270°C, the atmosphere combination was N2O and 5% SiH4 / Ar (silane mixed gas), the N2O gas flow rate was 490 sccm, the 5% SiH4 / Ar gas flow rate was 105 sccm, the gas pressure was 75 Pa, the plasma excitation power was 50 Pa, and a first SiO2 film with a thickness of 350 nm was grown. The film was taken out, and the side of the silicon substrate without the SiO2 film deposited was facing up, and the above deposition steps were repeated; b. Use laser direct writing lithography technology to make graphics: Coat photoresist on the second SiO2 film. AR1813 can be used as photoresist. The coating method is to first spin coat the glue at 500 rpm for 5 s, and then spin coat the glue at 3000 rpm for 30 s; bake at a soft baking temperature of 100°C for 1 min; import the layout into the laser direct writing software, use laser direct writing to expose the layout, and the photoresist forms a micro-nano structure in the exposed area. Place it in S319 developer for 1 min, take it out and quickly rinse it with deionized water, blow it dry with a N2 air gun, and place it on a heating plate at 110°C for 1 min to form the desired graphics on the photoresist; then coat the photoresist on the first SiO2 film, and repeat the above steps of making graphics on the film; c. Use inductively coupled plasma etching technology to etch thin film patterns: put the second SiO2 film upward, place the mask plate on the equipment reaction tray, and then put it in the fast sampling chamber of the inductively coupled plasma etching system (ICP). After vacuuming, transfer it to the etching chamber to etch the second SiO2 film pattern, take it out, and then repeat the above film etching steps with the first SiO2 film facing upward and take it out; 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, reaction tray temperature is 8 °C; d. Use wet etching process to etch silicon substrate: At 25°C, place the mask plate with thin film pattern etched in step c in a 30% potassium hydroxide aqueous solution. The potassium hydroxide aqueous solution contacts Si from the SiO2 film removal area (Si substrate exposed area) and is guided by the Si base crystal. The wet etching is anisotropic and deeply etches, and eventually forms an etching angle until the Si substrate is consumed to the first SiO2 film. Take it out, soak it in acetone and isopropanol in turn, and dry it at room temperature to obtain a double-sided silicon compound contact mask plate. The mask plate schematic and process are as follows: Figure 2 shown.

[0035] In the method for preparing a halide perovskite quantum dot pattern using the mask plate prepared by the above method, in step 2), the etching method comprises the following steps: a. Cover the halide perovskite quantum dot film in step 1) with the mask plate, the second SiO2 film facing up, and fix it relatively (with the help of an optical microscope or a substrate transfer platform, calibrate the position of the mask plate on the perovskite film etching pattern to complete the alignment operation. After the mask plate is aligned, use resin glue or spring pressure piece to fix the mask plate and the perovskite film substrate. Among them, the viscous resin glue can buffer the micro-movement between the mask plate and the perovskite quantum dot film substrate; the spring pressure piece can provide elastic buffering. Both can prevent the movement between the mask plate and the perovskite film substrate and improve the accuracy of the perovskite quantum dot film etching pattern. With the help of thermal conductive silicone oil, the film to be etched is adhered to the reaction tray of the equipment, and polyimide high-temperature tape is attached around the film to ensure the stability of the etching rate), and then placed in the fast sampling chamber of the inductively coupled plasma etching system (ICP) under vacuum conditions (the vacuum degree is 1.0e during the transfer process). -2 Pa), transferred to the etching chamber, the vacuum degree is 1.0e -9 Pa; b. Etching perovskite film: the sample stage temperature was set to 30 °C, the back helium pressure was 10 Torr, and the 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 of Cl2, CHF3, and Ar. The Cl2 atmosphere gas flow rate was 6 sccm, the CHF3 gas flow rate was 8 sccm, and the Ar gas flow rate was 12 sccm.

Claims

1. Double-sided silicon compound contact mask, characterized in that: The mask plate uses a silicon substrate as an 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 of the silicon substrate. The first SiO2 film and the second SiO2 film are respectively 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 pattern of the halide perovskite quantum dot pattern enlarged a certain multiple along the same Z-axis direction. The exposed portion of the silicon substrate is removed by a wet etching process.

2. The double-sided silicon compound contact mask according to claim 1, characterized in that: The pattern on the second SiO2 film is a pattern of halide perovskite quantum dots enlarged 1.2-4 times along the same Z-axis direction.

3. The double-sided silicon compound contact mask according to claim 2, 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.

4. A method for preparing a double-sided silicon compound contact mask as claimed in any one of claims 1 to 3, characterized in that: The following steps are involved: a. Depositing a first SiO2 film and a second SiO2 film on a silicon substrate: After pretreatment of the silicon substrate, the first SiO2 film and the second SiO2 film are deposited respectively by a plasma chemical vapor deposition method; b. Use laser direct writing lithography technology to make graphics: coat photoresist on the second SiO2 film, soft bake, import the layout into laser direct writing software, use laser direct writing to expose the layout, the photoresist forms a micro-nano structure in the exposed area, develop, post-bake, and form the required graphics on the photoresist; Then, a photoresist is coated on the first SiO2 film, and the above-mentioned steps of patterning on the film are repeated; c. Use inductively coupled plasma etching technology to etch thin film patterns: place the second SiO2 film upward in the fast sampling chamber of the inductively coupled plasma etching system, evacuate the vacuum chamber, transfer it to the etching chamber, etch the second SiO2 film pattern, take it out, and then repeat the above film etching steps with the first SiO2 film facing upward and take it out; d. Etch the silicon substrate using a wet etching process: At room temperature, soak the mask plate with the thin film pattern etched in step c in an etching solution until the exposed silicon substrate is partially removed, take it out, soak it in acetone and isopropanol in turn, and dry it at room temperature to obtain a double-sided silicon compound contact mask plate.

5. The method for preparing a double-sided silicon compound contact mask according to claim 4, characterized in that: In step a, the double-sided polished silicon substrate is placed in acetone, ethanol, deionized water, and anhydrous ethanol for ultrasonic cleaning in sequence, and then placed in the fast sampling 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 ° C, the reaction temperature is 220-280 ° C, the atmosphere combination is N2O and 5% SiH4 / Ar, the N2O gas flow rate is 400-500 sccm, the 5% SiH4 / Ar gas flow rate is 90-110 sccm, the gas pressure is 70-90Pa, the plasma excitation power is 30-50 Pa, and a SiO2 film with a thickness of 200-350 nm is grown. The film is taken out, the side of the silicon substrate on which the SiO2 film is not deposited faces upward, and the above deposition steps are repeated.

6. The method for preparing a double-sided silicon compound contact mask according to claim 5, characterized in that: In step c, the process parameters of the inductively coupled plasma etching technology are: 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°C; in step d, the etching solution is a potassium hydroxide aqueous solution with a mass concentration of 30%.

7. A method for preparing a halide perovskite quantum dot pattern using a mask plate prepared by the method according to any one of claims 5 to 6, characterized in that: The following steps are involved: 1) Preparation of halide perovskite quantum dot thin films on substrates; 2) Ion etching quantum dot pattern: Cover the halide perovskite quantum dot film in step 1) with a mask plate, with the second SiO2 film facing upwards. The pattern formed by the mask plate corresponds to the position of the halide perovskite quantum dot pattern. After etching using inductively coupled plasma etching technology, remove the mask plate to form a halide perovskite quantum dot pattern.

8. The method for preparing halide perovskite quantum dot patterns using a mask plate according to claim 7, characterized in that: In step 2), the etching method comprises 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, and place it in the fast injection chamber of the inductively coupled plasma etching system after being fixed in position, and transfer it to the etching chamber under vacuum conditions; b. Etching perovskite film: introducing a combination of gases, etching 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 combination of gases at least includes a chlorine-based atmosphere.

9. The method for preparing halide perovskite quantum dot patterns using a mask plate according to claim 8, characterized in that: In step 2), in step b, the chlorine-based atmosphere is a combination of one or two of Cl2 and BCl3, and the combination gas further includes a combination of one or more of CHF3, C4F8, and Ar.

10. The method for preparing halide perovskite quantum dot patterns using a mask plate according to claim 9, 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 chlorine-based atmosphere gas flow rate is 2-50 sccm, the CHF3 gas flow rate is 2-10 sccm, the C4F8 gas flow rate is 2-10 sccm, and the Ar gas flow rate is 5-15 sccm.

Images