Zinc-ethylimidazole coordination compact film and preparation and etching method thereof

Abstract

The invention belongs to the technical field of semiconductor device manufacturing, and relates to preparation and etching of electron beam induced resist films, in particular to a zinc-ethylimidazole coordination compact film and a preparation and etching method thereof. Comprising the steps that atomic layer deposition and molecular layer deposition are alternately used for preparing a zinc-ethylimidazole coordination compact film, and hexafluoroacetylacetone is used for etching, liquid solvents are not used for deposition film forming and etching, no chemical waste liquid is generated, environmental friendliness is achieved, the film is loaded on 5A zeolite, electron beam induced corrosion resistance is achieved, and when electron beam irradiation is not carried out, the film can be used for preparing the zinc-ethylimidazole coordination compact film. The silicon substrate can be etched by hexafluoroacetylacetone, cannot be etched by hexafluoroacetylacetone after being irradiated by electron beams, has the potential of being used for manufacturing high-precision patterns by electron beam lithography, and provides a potential scheme for depositing an electron beam induced resist film on the silicon substrate and a reaction gas etching process. The problems that a liquid solvent is used and the film thickness is uneven in the electron beam induced resist film forming process are solved, and the method can be applied to the manufacturing fields of advanced node transistors, quantum dot devices and the like.

Description

Technical Field

[0001] The present invention belongs to the technical field of semiconductor device manufacturing, and relates to the preparation and etching of electron beam resist films. Specifically, it is a zinc-ethylimidazole coordination dense film and its preparation and etching methods. Background Art

[0002] The quality of the electron beam resist film itself is crucial for the quality of the pattern after etching, especially performance parameters such as the film thickness uniformity, electron beam response sensitivity, and contrast of the electron beam resist film. Currently, raw materials for forming electron beam resist films include polymethyl methacrylate, epoxy-based photoresist SU-8, hydrogen silsesquioxane, etc. The film-forming methods for these liquid raw materials are generally wet methods, such as spin coating, spraying, dip coating, knife coating, and roll coating. The wet film-forming process usually includes a pre-baking step to remove excess solvent, but this will generate precursor and organic solvent waste liquids, which need to be treated harmlessly. In addition, it is difficult to obtain a film with uniform texture by wet film-forming, especially for films with a thickness of only a few nanometers. The gas-phase atomic / molecular layer deposition method (ALD / MLD) is to deposit atoms / molecules layer by layer on the substrate surface with gaseous precursors, which can precisely control the film thickness and does not use liquid solvents, thus overcoming the disadvantages of wet film-forming. However, there is currently no mature method for preparing electron beam resist films by gas-phase atomic / molecular layer deposition.

[0003] After the electron beam resist film is formed, it is exposed with an electron beam and then etched, also known as developed, to remove the exposed area (positive resist film) or the unexposed area (negative resist film), thereby forming a pattern on the resist film. The etching process can be divided into wet etching and dry etching. Wet etching has problems such as pattern deformation caused by resist film swelling, pattern collapse caused by capillary force during solvent evaporation, solvent storage and treatment, and potential environmental pollution caused by chemical waste liquids. Dry etching can use plasma etching, but there are potential problems such as the generation of polluting by-products and thermal damage to the substrate due to high temperature. Therefore, it is necessary to develop a dry etching method not based on plasma, such as reactive gas etching, which generates volatile products through the directional reaction of gaseous chemical reagents with the electron beam resist film, achieving high-precision and low-damage removal of the target area, avoiding the damage of plasma to sensitive materials, and being suitable for fields such as semiconductor nanostructures, flexible sensors, solid-state battery interface engineering, and high-density electronic device manufacturing.

[0004] Therefore, there is an urgent need to develop atomic / molecular layer deposition dry film-forming and corresponding reactive gas etching technologies for electron beam resist films, improve the film-forming quality and etching accuracy, avoid using liquid solvents, and enhance environmental protection to promote the development of industries such as semiconductor manufacturing. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a zinc-ethylimidazole coordination dense film and its preparation and etching methods. The present invention preliminarily demonstrates the film-forming possibility and etching feasibility of the zinc-ethylimidazole coordination dense film as an electron beam resist film, providing a potential solution for depositing an electron beam resist film on a silicon substrate and fabricating high-precision patterns by reactive gas etching, and having great application potential in the fields of advanced node transistor and quantum dot device manufacturing, etc.

[0006] The technical solution adopted is as follows: A method for preparing and etching a zinc-ethylimidazole coordination dense film, comprising the following steps: (1) Load 5A zeolite into a reactor, introduce argon while evacuating to remove impurity gases in the reaction system, and heat to perform dehydration and degassing treatment on the 5A zeolite; (2) Sequentially and cyclically pulse-feed the film-forming precursors diethylzinc and 2-ethylimidazole into the reactor treated in step (1), and during this process, introduce argon while evacuating for purging to perform deposition and film formation; (3) Perform activation treatment on the solid obtained in step (2) to obtain a zinc-ethylimidazole coordination dense film / 5A zeolite; (4) Load the zinc-ethylimidazole coordination dense film / 5A zeolite sample (or the sample irradiated by an electron beam) obtained in step (3) into the reactor, introduce argon while evacuating to remove impurity gases in the reaction system; (5) Pulse-feed the etchant hexafluoroacetylacetone into the reactor treated in step (4), and then purge with argon; then pulse-feed the etchant hexafluoroacetylacetone again and purge with argon, and perform etching cyclically; the number of cyclic etching times is at least two; (6) Perform activation treatment on the solid obtained after the treatment in step (5) to obtain the zinc-ethylimidazole coordination dense film / 5A zeolite after being irradiated by an electron beam and etched with hexafluoroacetylacetone.

[0007] Preferably, in step (1), the 5A zeolite is subjected to dehydration and degassing treatment at 200 °C for 60 min.

[0008] Preferably, in step (2), the deposition and film formation temperature is 140 - 170 °C.

[0009] Preferably, in step (2), the number of deposition and film formation cycles is 5 - 30 times.

[0010] Preferably, in step (3), the activation treatment temperature is 120 °C and the activation treatment time is 60 min.

[0011] Preferably, in step (5), the etching temperature is 110 - 140 °C.

[0012] Preferably, in the step (6), the activation treatment temperature is 120 °C and the activation treatment time is 60 min.

[0013] A zinc-ethylimidazole coordination dense film prepared by a method for preparing and etching a zinc-ethylimidazole coordination dense film, the film is loaded on 5A zeolite and has electron beam resistibility. When not irradiated with an electron beam, it can be etched with hexafluoroacetylacetone, while after being irradiated with an electron beam, it has etching resistance to hexafluoroacetylacetone and is a negative resist film. The denseness and etchability of the film are tested by CO 2 gas adsorption (CO 2 adsorption amount), and the thickness (denseness) of the film is controlled by the number of atomic layer deposition-molecular layer deposition (the number of alternating deposition cycles), and no liquid solvent is used during the film formation process.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) The zinc-ethylimidazole coordination dense film has electron beam resistibility. When not irradiated with an electron beam, it can be etched with hexafluoroacetylacetone, while after being irradiated with an electron beam, it will not be etched by hexafluoroacetylacetone, and has the potential for fabricating high-precision patterns by electron beam lithography, initially demonstrating the film formation possibility and etching feasibility of the zinc-ethylimidazole coordination dense film as an electron beam resist film, providing a potential solution for depositing an electron beam resist film and a reactive gas etching process on a silicon substrate, and can solve the problems of using liquid solvents during the film formation process of the electron beam resist film and uneven film thickness. It can be used in fields such as the manufacture of advanced node transistors and quantum dot devices.

[0015] (2) The thickness (denseness) of the zinc-ethylimidazole coordination dense film is precisely controlled by the number of atomic layer deposition-molecular layer deposition (the number of alternating deposition cycles). The film texture is uniform, and the film material contains transition metal zinc. When exposed with an electron beam, it is beneficial to improve the exposure sensitivity, contrast, and energy deposition efficiency of incident electrons.

[0016] (3) No liquid solvent is used during the deposition and film formation process of the zinc-ethylimidazole coordination dense film, no pre-baking step is required, no precursor and organic solvent waste liquid will be generated. When etching, hexafluoroacetylacetone gas is used, and no liquid solvent is used either. There is no film swelling problem and no chemical waste liquid is generated, which is environmentally friendly. Description of the Drawings

[0017] Figure 1This is a schematic diagram of the device used in this embodiment for preparing a zinc-ethylimidazole coordination dense film and etching with hexafluoroacetylacetone. The device includes: 1. Argon gas cylinder, 2. Argon gas control valve, 3. Diethylzinc control valve, 4. Diethylzinc sample cell, 5. Hexafluoroacetylacetone control valve, 6. Hexafluoroacetylacetone sample cell, 7. 2-Ethylimidazole control valve, 8. 2-Ethylimidazole sample cell, 9. Fixed-bed reactor, 10. Vacuum pump. Each component is connected in sequence. The 2-ethylimidazole sample cell and the fixed-bed reactor are respectively controlled by a temperature controller for the heating temperature.

[0018] Figure 2 This is the X-ray diffraction pattern of the zinc-ethylimidazole coordination dense film / 5A zeolite in Example 1.

[0019] Figure 3 This is the scanning electron microscope photograph of the zinc-ethylimidazole coordination dense film / 5A zeolite in Example 1.

[0020] Figure 4 This is the CO 2 gas adsorption curve of the zinc-ethylimidazole coordination dense film / 5A zeolite in Example 1, the zinc-ethylimidazole coordination dense film / 5A zeolite after etching directly with hexafluoroacetylacetone without electron beam irradiation, and the original 5A zeolite.

[0021] Figure 5 This is the elemental composition comparison diagram of the zinc-ethylimidazole coordination dense film / 5A zeolite in Example 1 before and after etching with hexafluoroacetylacetone.

[0022] Figure 6 This is the CO 2 gas adsorption curve of the zinc-ethylimidazole coordination dense film / 5A zeolite with different atomic layer deposition-molecular layer deposition film formation cycle numbers (20, 5, 10, and 30 times respectively) in Examples 1 to 4.

[0023] The drawings are only for illustrative purposes; for those skilled in the art, some well-known structures and their descriptions in the drawings may be omitted. Therefore, it should not be construed as a limitation to the present invention. Detailed implementation manners

[0024] If not otherwise specified, the chemical substances and instruments used in the present invention can be obtained through conventional commercial channels.

[0025] The denseness, etchability, and electron beam resistibility of the prepared zinc-ethylimidazole coordination dense film are characterized by testing the CO 2 gas adsorption of the zinc-ethylimidazole coordination dense film / 5A zeolite sample, the sample etched directly with hexafluoroacetylacetone without electron beam irradiation, and the sample etched with hexafluoroacetylacetone after electron beam irradiation. When there is no dense film blocking on the surface of the 5A zeolite, the 5A zeolite is very easy to adsorb CO2 Gas (adsorption equilibrium is reached in 10 min, and the adsorption capacity is 2.44 mmol / g); while when there is a dense zinc-ethylimidazole coordination film blocking on the surface of 5A zeolite, CO cannot be adsorbed inside the 5A zeolite particles 2 gas, and only a small amount of CO is adsorbed on the particle surface 2 gas (adsorption capacity < 0.2 mmol / g). Specific CO 2 gas adsorption test method: In a glove box (model Lab2000, manufactured by Itrex inert gas system Co., Ltd., with oxygen content < 0.1 ppm and water content < 0.1 ppm in the glove box) protected by argon filling, weigh about 0.1 g of the sample and place it in the sample cell of a high-pressure gas adsorption instrument (model PCT-Pro 2000, manufactured by Setaram Instruments Company, France). Then evacuate the high-pressure gas adsorption instrument to < 1 mbar, and then at a temperature of 25 °C, a system reference volume of 17.10 mL, and an initial CO 2 gas pressure of 80 kPa, test the change of CO 2 gas adsorption capacity of the sample with adsorption time.

[0026] Specific electron beam irradiation method: Take about 0.1 g of the prepared zinc-ethylimidazole coordination film / 5A zeolite sample and spread it flat on the stage of a scanning electron microscope (model SU3500 VP, Hitachi, Japan). The sample spreading area is about 1 cm 2 ², without sputtering the sample with gold. Use an energy-dispersive X-ray spectrometer according to the operation method of elemental surface distribution analysis, and irradiate the sample with an electron beam. Among them, the electron beam acceleration voltage is 15 kV (electron beam energy is 15 keV), the electron beam current is 5 nA, the sample is divided into 9 sub-regions, each sub-region has 512 × 512 pixels, and the dwell time at each point is 5 ms. After irradiating once, turn the sample over and irradiate again. Repeat turning the sample over and irradiating 5 times, and a total of 6 irradiations are carried out to make the sample receive a relatively uniform and sufficient electron beam irradiation.

[0027] The technical principle of the present invention: When forming a film on the solid surface, the precursor diethylzinc reacts with 2-ethylimidazole. The diethylzinc molecule decomposes into zinc cations and ethyl anions. Among them, the zinc cations are deposited on the solid surface (atomic layer deposition). The 2-ethylimidazole molecule dissociates into 2-ethylimidazole anions and hydrogen protons. Among them, the 4,5-dichloroimidazole anions are deposited on the solid surface (molecular layer deposition). A coordination bond is formed between the zinc cations and 2-ethylimidazole anions. The ethyl anions in the gas phase combine with hydrogen protons to form ethane. After multiple cycles of atomic layer deposition and molecular layer deposition, the zinc cations and 2-ethylimidazole anions are alternately deposited on the solid surface, thereby forming a dense zinc-ethylimidazole coordination film.

[0028] During film etching, hexafluoroacetylacetone is used as a reactive gas etchant for dry etching. Without electron beam irradiation, the film will be etched by hexafluoroacetylacetone. Hexafluoroacetylacetone dissociates into hexafluoroacetylacetone anions and hydrogen protons. Then, the hexafluoroacetylacetone anions complex with zinc cations on the solid surface to make the zinc cations enter the gas phase, and the hydrogen protons combine with 2-ethylimidazole anions on the solid surface to form 2-ethylimidazole molecules, making the 2-ethylimidazole anions enter the gas phase, thus achieving continuous etching. When irradiated with an electron beam, according to the dissociative electron attachment (DEA) mechanism, the 2-ethylimidazole anions in the film capture low-energy electrons (<20 eV) to form transient negative ions, which then dissociate into neutral fragments and negative ions, and then polymerization reactions occur, so that the film will not be etched by hexafluoroacetylacetone.

[0029] The present invention will be further described in detail below with specific examples.

[0030] Example 1: A method for preparing and etching a zinc-ethylimidazole coordination dense film, comprising the following steps: (I) Preparation of the zinc-ethylimidazole coordination dense film.

[0031] (1) In the device shown in Figure 1 , 0.3 g of 5A zeolite (Sigma-Aldrich 233676, <10 μm) sample is dispersed into glass wool and loaded into the reactor; 0.5 g of diethylzinc (CAS No. 557-20-0, purity 95%) is loaded into the diethylzinc sample cell; 0.5 g of 2-ethylimidazole (CAS No. 1072-62-4, purity 99%) is loaded into the 2-ethylimidazole sample cell; 0.5 g of hexafluoroacetylacetone (1,1,1,5,5,5-hexafluoro-acetylacetone, CAS No. 1522-22-1, purity 98%) is loaded into the hexafluoroacetylacetone sample cell. With the argon valve, diethylzinc valve, 2-ethylimidazole valve, and hexafluoroacetylacetone valve closed, the vacuum pump is turned on to evacuate the reaction system to <1 mbar and maintained for 5 min; then the argon valve is opened to introduce argon (purity 99.999%, the same below) at a flow rate of 10 mL / min while evacuating for 5 min; then under the dynamic vacuum condition of introducing argon at a flow rate of 10 mL / min while evacuating, the reactor is heated to 200 °C to perform dehydration and degassing treatment on the 5A zeolite for 60 min to remove gases such as adsorbed water and carbon dioxide in the 5A zeolite. The 2-ethylimidazole sample cell is heated to 120 °C for subsequent film deposition.

[0032] (2) Under the dynamic vacuum condition of introducing argon at a flow rate of 10 mL / min while evacuating, cool the reactor containing 5A zeolite that has been dehydrated and degassed in step (1) to the etching temperature of 160 °C, keep it at a constant temperature for 10 min, then close the argon gas, and continue to evacuate for 5 min; then sequentially and cyclically pulse-feed the film-forming precursors diethylzinc and 2-ethylimidazole into the reactor (cyclic atomic layer deposition - molecular layer deposition), during which introduce argon gas while evacuating for purging to remove reaction by-products and unreacted precursors in the reaction system. Each cycle includes: ① Diethylzinc pulse for 1 s; ② Introduce argon at a flow rate of 10 mL / min while evacuating for 300 s; ③ Close the argon gas and evacuate for 120 s; ④ 2-ethylimidazole pulse for 2 s; ⑤ Introduce argon at a flow rate of 10 mL / min while evacuating for 480 s; ⑥ Close the argon gas and evacuate for 120 s. A total of 20 cycles of atomic layer deposition - molecular layer deposition film formation are carried out, and the pressure in the reactor during the film formation process is about 3 - 8 mbar.

[0033] (3) Under the dynamic vacuum condition of introducing argon at a flow rate of 10 mL / min while evacuating, cool the reactor containing the film-deposited sample in step (2) to 120 °C, activate it at this temperature for 60 min, and then naturally cool it to room temperature to obtain a zinc-ethylimidazole coordination dense film / 5A zeolite, where the zinc-ethylimidazole coordination dense film is deposited on the surface of 5A zeolite particles.

[0034] (II) Etching of the zinc-ethylimidazole coordination dense film with hexafluoroacetylacetone.

[0035] Disperse the prepared zinc-ethylimidazole coordination dense film / 5A zeolite sample into glass wool and load it into Figure 1 the reactor of the prepared device; with the argon valve, diethylzinc valve, 2-ethylimidazole valve, and hexafluoroacetylacetone valve closed, turn on the vacuum pump to evacuate the reaction system to <1 mbar and maintain it for 5 min; then open the argon valve to introduce argon at a flow rate of 10 mL / min while evacuating for 5 min; then raise the temperature of the reactor to 120 °C, keep it at a constant temperature for 10 min, and then close the argon gas; then etch the zinc-ethylimidazole coordination dense film with hexafluoroacetylacetone at 120 °C according to the following steps. Each etching includes: ① Open the hexafluoroacetylacetone valve and pulse-feed hexafluoroacetylacetone into the reactor for 10 s; ② Close the hexafluoroacetylacetone valve and maintain it for 300 s; ③ Open the argon valve to introduce argon at a flow rate of 10 mL / min while evacuating for 480 s; ④ Close the argon gas and evacuate for 120 s. A total of 5 times of hexafluoroacetylacetone etching are carried out. Then, under the dynamic vacuum condition of introducing argon at a flow rate of 10 mL / min while evacuating, activate it at 120 °C for 60 min, and then naturally cool it to room temperature to obtain the zinc-ethylimidazole coordination dense film / 5A zeolite etched with hexafluoroacetylacetone.

[0036] The X-ray diffraction of the zinc-ethylimidazole coordination dense film / 5A zeolite sample prepared in this example (Rigaku Smartlab X-ray diffractometer, Cu target Kα ray, scanning step 0.01°, scanning speed 2° / min) is as Figure 2 shown. From Figure 2 it can be seen that there are only diffraction peaks of 5A zeolite in the sample, and there are no obvious diffraction peaks of other crystal phases, indicating that the zinc-ethylimidazole coordination dense film is amorphous.

[0037] The scanning electron microscope (Hitachi SU3500 VP type) photograph of the zinc-ethylimidazole coordination dense film / 5A zeolite sample prepared in this example is as Figure 3 shown. From Figure 3 it can be seen that the particle size of 5A zeolite is about 4 μm, and the morphology of 5A zeolite particles does not change after depositing the zinc-ethylimidazole coordination dense film.

[0038] Take the zinc-ethylimidazole coordination dense film / 5A zeolite sample prepared in this example, and measure the change of its CO 2 gas adsorption amount with adsorption time. The results are shown in Figure 4 From Figure 4 it can be seen that the sample particles do not adsorb CO 2 gas, and only a small amount of CO 2 gas is adsorbed on the particle surface. The adsorption amount is 0.08 mmol / g at 20 min, indicating that the zinc-ethylimidazole coordination dense film in this example has good denseness.

[0039] Take the sample of the zinc-ethylimidazole coordination dense film / 5A zeolite in this example that is directly etched with hexafluoroacetylacetone at 120 °C without electron beam irradiation, and measure the change of its CO 2 gas adsorption amount with adsorption time. The results are shown in Figure 4 From Figure 4 it can be seen that after etching with hexafluoroacetylacetone, the CO 2 gas adsorption amount of the sample is similar to that of the original 5A zeolite without depositing the zinc-ethylimidazole coordination dense film, and it is 2.36 mmol / g at 20 min, indicating that hexafluoroacetylacetone etching can remove the zinc-ethylimidazole coordination dense film on the surface of 5A zeolite.

[0040] The elemental composition comparison diagram of the zinc-ethylimidazole coordination dense film / 5A zeolite prepared in this example before and after etching with hexafluoroacetylacetone (tested by Hitachi SU3500 VP type scanning electron microscope-energy dispersive X-ray spectrometer) is as Figure 5As shown, before etching, the typical constituent elements Zn, N, and C of the zinc-ethylimidazole coordination dense film were present in the sample; after etching with hexafluoroacetylacetone, the elements Zn, N, and C were not present in the sample, indicating that hexafluoroacetylacetone etching could completely remove the zinc-ethylimidazole coordination dense film.

[0041] Example 2: The difference between this example and Example 1 is that when depositing a film by cyclic deposition of diethylzinc and 2-ethylimidazole, a total of 5 cycles were carried out, and the remaining steps were the same as in Example 1 to obtain a zinc-ethylimidazole coordination dense film / 5A zeolite.

[0042] Taking the zinc-ethylimidazole coordination dense film / 5A zeolite sample prepared in this example, the change in its CO 2 gas adsorption amount with adsorption time was measured, and the results are shown in Figure 6 . From Figure 6 it can be seen that compared with Example 1, the zinc-ethylimidazole coordination dense film / 5A zeolite in this example had a relatively obvious adsorption of CO 2 gas, which was 0.26 mmol / g at 20 min, indicating that the compactness of the zinc-ethylimidazole coordination dense film in this example was slightly poor, that is, when the number of cycles of film deposition was too small (5 cycles), the compactness of the prepared film would be significantly reduced.

[0043] Example 3: The difference between this example and Example 1 is that when depositing a film by cyclic atomic layer deposition - molecular layer deposition of diethylzinc and 2-ethylimidazole, a total of 10 cycles were carried out, and the remaining steps were the same as in Example 1 to obtain a zinc-ethylimidazole coordination dense film / 5A zeolite.

[0044] Taking the zinc-ethylimidazole coordination dense film / 5A zeolite sample prepared in this example, the change in its CO 2 gas adsorption amount with adsorption time was measured, and the results are shown in Figure 6 . From Figure 6 it can be seen that CO 2 gas could enter the interior of the sample particles, and the adsorption amount was 0.14 mmol / g at 20 min, indicating that when the number of cycles of deposition of diethylzinc and 2-ethylimidazole was small (10 cycles), the prepared film would have certain pores.

[0045] Example 4: The difference between this example and Example 1 is that when depositing a film by cyclic atomic layer deposition - molecular layer deposition of diethylzinc and 2-ethylimidazole, a total of 30 cycles were carried out, and the remaining steps were the same as in Example 1 to obtain a zinc-ethylimidazole coordination dense film / 5A zeolite.

[0046] Taking the zinc-ethylimidazole coordination dense film / 5A zeolite sample prepared in this example, the change in its CO 2 gas adsorption amount with adsorption time was measured, and the results are shown in Figure 6 . FromFigure 6 It can be seen that the inside of the sample particles does not adsorb CO 2 gas, and only a small amount of CO is adsorbed on the particle surface 2 gas. The adsorption amount at 20 min is 0.06 mmol / g, indicating that the zinc-ethylimidazole coordination dense film of this example has good densification.

[0047] Take the sample of the zinc-ethylimidazole coordination dense film / 5A zeolite of this example without electron beam irradiation and directly etched with hexafluoroacetylacetone at 120 °C, and measure its CO 2 gas adsorption amount at 20 min is 2.30 mmol / g, which is similar to the original 5A zeolite without depositing the zinc-ethylimidazole coordination dense film, indicating that hexafluoroacetylacetone etching can remove the zinc-ethylimidazole coordination dense film on the surface of 5A zeolite.

[0048] By comparing the densification of the films prepared with different deposition cycle numbers in Examples 1 to 4, it can be seen that regarding the number of alternating deposition cycles of atomic layer deposition - molecular layer deposition, 5 and 10 cycles are not sufficient to prepare a zinc-ethylimidazole coordination dense film with good densification. The film prepared with 30 cycles will be slightly thicker, and the appropriate number of cycles is 20.

[0049] Example 5: The difference between this example and Example 1 is that when forming a film by cyclic atomic layer deposition - molecular layer deposition with diethylzinc and 2-ethylimidazole, the temperature is 140 °C, and the rest of the steps are the same as in Example 1, and a zinc-ethylimidazole coordination dense film / 5A zeolite is prepared.

[0050] Take the sample of the zinc-ethylimidazole coordination dense film / 5A zeolite prepared in this example, and measure its CO 2 gas adsorption amount at 20 min is 1.94 mmol / g, indicating that the formed film has slightly poor densification.

[0051] Example 6: The difference between this example and Example 1 is that when forming a film by cyclic atomic layer deposition - molecular layer deposition with diethylzinc and 2-ethylimidazole, the temperature is 150 °C, and the rest of the steps are the same as in Example 1, and a zinc-ethylimidazole coordination dense film / 5A zeolite is prepared.

[0052] Take the sample of the zinc-ethylimidazole coordination dense film / 5A zeolite prepared in this example, and measure its CO 2 gas adsorption amount at 20 min is 0.72 mmol / g, indicating that the formed film has certain pores.

[0053] Example 7: The difference between this example and Example 1 is that when forming a film by cyclic atomic layer deposition - molecular layer deposition with diethylzinc and 2-ethylimidazole, the temperature is 170 °C, and the rest of the steps are the same as in Example 1, and a zinc-ethylimidazole coordination dense film / 5A zeolite is prepared.

[0054] Take the zinc-ethylimidazole coordination dense film / 5A zeolite sample prepared in this example, and measure its CO 2 gas adsorption amount at 20 min is 0.05 mmol / g, indicating that the formed film has good densification.

[0055] Through the measurement and comparison of the films prepared at different temperatures in Example 1 and Examples 5-7, it can be seen that regarding the deposition film formation temperature, the zinc-ethylimidazole coordination films prepared at 160 °C and 170 °C both have good densification. Considering factors such as the thermal expansion of the substrate material, pattern fidelity, and energy consumption, it is appropriate to deposit the film at 160 °C.

[0056] Example 8: The difference between this example and Example 1 is that: at 110 °C, hexafluoroacetylacetone is used to etch the zinc-ethylimidazole coordination dense film loaded on 5A zeolite, and the remaining steps are the same as those in Example 1.

[0057] Take the sample of the zinc-ethylimidazole coordination dense film / 5A zeolite of this example that is directly etched with hexafluoroacetylacetone at 110 °C without electron beam irradiation, and measure its CO 2 gas adsorption amount at 20 min is 1.02 mmol / g, indicating that hexafluoroacetylacetone can etch the zinc-ethylimidazole coordination dense film, but the etching is relatively slow at lower temperatures.

[0058] Example 9: The difference between this example and Example 1 is that: at 130 °C, hexafluoroacetylacetone is used to etch the zinc-ethylimidazole coordination dense film loaded on 5A zeolite, and the remaining steps are the same as those in Example 1.

[0059] Take the sample of the zinc-ethylimidazole coordination dense film / 5A zeolite of this example that is directly etched with hexafluoroacetylacetone at 130 °C without electron beam irradiation, and measure its CO 2 gas adsorption amount at 20 min is 2.40 mmol / g, indicating that hexafluoroacetylacetone can fully etch the zinc-ethylimidazole coordination dense film at 130 °C.

[0060] Example 10: The difference between this example and Example 1 is that: at 140 °C, hexafluoroacetylacetone is used to etch the zinc-ethylimidazole coordination dense film loaded on 5A zeolite, and the remaining steps are the same as those in Example 1.

[0061] Take the sample of the zinc-ethylimidazole coordination dense film / 5A zeolite of this example that is directly etched with hexafluoroacetylacetone at 140 °C without electron beam irradiation, and measure its CO 2 gas adsorption amount at 20 min is 2.38 mmol / g, indicating that hexafluoroacetylacetone can fully etch the zinc-ethylimidazole coordination dense film at 140 °C.

[0062] Comparative Example 1: The difference between this comparative example and Example 1 is that the zinc-ethylimidazole coordination dense film / 5A zeolite was irradiated with an electron beam and then etched with hexafluoroacetylacetone at 120 °C, and the remaining steps were the same as in Example 1.

[0063] A sample of the zinc-ethylimidazole coordination dense film / 5A zeolite of Comparative Example 1 after being irradiated with an electron beam and etched with hexafluoroacetylacetone at 120 °C was taken, and its CO 2 gas adsorption amount was 0.12 mmol / g at 20 min, indicating that the zinc-ethylimidazole coordination dense film could not be etched by hexafluoroacetylacetone at 120 °C after being irradiated with an electron beam, that is, the zinc-ethylimidazole coordination dense film has electron beam-induced corrosion resistance.

[0064] Comparative Example 2: The difference between this comparative example and Example 1 is that the zinc-ethylimidazole coordination dense film / 5A zeolite was irradiated with an electron beam and then etched with hexafluoroacetylacetone at 140 °C, and the remaining steps were the same as in Example 1.

[0065] A sample of the zinc-ethylimidazole coordination dense film / 5A zeolite of Comparative Example 2 after being irradiated with an electron beam and etched with hexafluoroacetylacetone at 140 °C was taken, and its CO 2 gas adsorption amount was 0.16 mmol / g at 20 min, indicating that the zinc-ethylimidazole coordination dense film could not be etched by hexafluoroacetylacetone at 140 °C after being irradiated with an electron beam, that is, the zinc-ethylimidazole coordination dense film has electron beam-induced corrosion resistance.

[0066] By comparing the etching effects of Example 1, Example 4, Examples 8-10, Comparative Example 1, and Comparative Example 2 on the zinc-ethylimidazole coordination dense film with hexafluoroacetylacetone at different temperatures, it can be seen that when the zinc-ethylimidazole coordination dense film is not irradiated with an electron beam, it can be fully etched with hexafluoroacetylacetone in the temperature range of 120-140 °C, while after being irradiated with an electron beam, it will not be etched. Considering factors such as etching contrast, energy consumption, and the possibility of high-temperature decomposition of organic substances, the etching temperature is preferably 120 °C.

[0067] Using diethylzinc and 2-ethylimidazole as precursors and 5A zeolite as a carrier, a zinc-ethylimidazole coordination dense film can be prepared by cyclic atomic layer deposition-molecular layer deposition method. When this film is not irradiated with an electron beam, it can be etched with hexafluoroacetylacetone as a reaction gas etchant, while after being irradiated with an electron beam, it will no longer be etched by hexafluoroacetylacetone, that is, it has corrosion resistance to hexafluoroacetylacetone, is an electron beam-induced corrosion-resistant film, and is a negative resist film.

[0068] In summary, the preferred process conditions for preparing the zinc-ethylimidazole coordination dense film are as follows: the atomic layer deposition-molecular layer deposition film formation temperature of the precursors diethylzinc and 2-ethylimidazole is 160 °C, the number of cyclic depositions is 20 times, and the etching temperature using hexafluoroacetylacetone as the reaction gas etchant is 120 °C.

[0069] Of course, the above description is not a limitation of the present invention, and the present invention is not limited to the above examples. Changes, modifications, additions or substitutions made by those skilled in the art within the scope of the essence of the present invention should also fall within the protection scope of the present invention.

Claims

1. A method for preparing and etching a zinc-ethylimidazole coordinated dense film, characterized in that: The steps include: (1) 5A zeolite is loaded into a reactor, argon gas is introduced and vacuum is applied to remove impurity gases in the reaction system, and the 5A zeolite is heated to perform dehydration and degassing treatment; (2) introducing film-forming precursors diethylzinc and 2-ethylimidazole into the reactor treated in step (1) in a cyclic pulse manner, introducing argon gas and evacuating the reactor to form a film; (3) activating the solid obtained in step (2) to obtain zinc-ethylimidazole coordinated dense membrane / 5A zeolite; (4) placing the zinc-ethylimidazole coordinated dense membrane / 5A zeolite sample prepared in step (3) into a reactor, introducing argon gas and simultaneously evacuating the reactor to remove impurity gases in the reaction system; Or, the prepared zinc-ethylimidazole coordinated dense film / 5A zeolite sample is irradiated with an electron beam, and then loaded into a reactor, and argon gas is introduced and vacuumed to remove impurity gases in the reaction system; (5) Pulsing the etchant hexafluoroacetylacetone into the reactor treated in step (4), then purging with argon gas and performing etching in a cycle; (6) Activating the solid obtained in step (5) to obtain a zinc-ethylimidazole coordination dense film / 5A zeolite after hexafluoroacetylacetone etching.

2. The method for preparing and etching a zinc-ethylimidazole coordination dense film according to claim 1, characterized in that: In the step (1), the 5A zeolite is subjected to a dehydration and degassing treatment at 200° C. for 60 minutes.

3. The method for preparing and etching a zinc-ethylimidazole coordination dense film according to claim 1, characterized in that: In the step (2), the deposition film forming temperature is 140 to 170°C.

4. The method for preparing and etching a zinc-ethylimidazole coordination dense film according to claim 1, characterized in that: In the step (2), the deposition film forming cycle number is 5 to 30 times.

5. The method for preparing and etching a zinc-ethylimidazole coordination dense film according to claim 1, characterized in that: In the step (3), the activation treatment temperature is 120° C. and the activation treatment time is 60 min.

6. The method for preparing and etching a zinc-ethylimidazole coordination dense film according to claim 1, characterized in that: In the step (5), the etching temperature is 110-140°C.

7. The method for preparing and etching a zinc-ethylimidazole coordination dense film according to claim 1, characterized in that: In the step (6), the activation treatment temperature is 120° C. and the activation treatment time is 60 min.

8. The dense film prepared by the method for preparing and etching a zinc-ethylimidazole coordinated dense film according to any one of claims 1 to 7, characterized in that: The membrane is supported on 5A zeolite and is resistant to electron beam erosion.

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