A zinc-dichloroimidazole coordination dense membrane and a preparation method thereof

Abstract

The application belongs to the technical field of semiconductor device manufacturing, and relates to preparation of a positive electron beam resist film, in particular to a zinc-dichloroimidazole coordination dense film and a preparation method thereof. The preparation method comprises film deposition by alternately adopting atomic layer deposition and molecular layer deposition, and the film material contains an electron beam sensitive leaving group, is a positive resist film, cannot be etched by hexafluoroacetylacetone when not irradiated by an electron beam, and can be etched by hexafluoroacetylacetone after irradiation by an electron beam. Neither film deposition nor etching uses a liquid solvent, no chemical waste liquid is generated, and the method is environmentally friendly. The film is loaded on 5A zeolite and has potential for electron beam lithography for manufacturing high-precision patterns, provides a potential scheme for a process of depositing a positive electron beam resist film on a silicon substrate, can solve the problems of using a liquid solvent in the film deposition process of the electron beam resist film and uneven film thickness, and has important application in semiconductor advanced processes and the like.

Description

Technical Field

[0001] This invention belongs to the field of semiconductor device manufacturing technology, and relates to the preparation of positive electron beam resist films, specifically to a zinc-dichloroimidazole coordination dense film and its preparation method. Background Technology

[0002] Thinning of electron beam resist films helps suppress electron scattering during electron beam irradiation and improves lithography resolution. However, thinning reduces the energy deposition efficiency of incident electrons, and the film's inhomogeneity becomes more pronounced. Film materials using inorganic materials or inorganic-organic hybrid materials containing metal elements, such as those containing Sb, Zr, Zn, Hf, and Sn, are beneficial because the electron scattering cross-section of metal atoms is higher than that of carbon, oxygen, and hydrogen atoms in organic polymers, thus improving exposure sensitivity and contrast and enhancing the energy deposition efficiency of incident electrons. Atomic / molecular layer deposition (ALD / MLD) dry deposition involves depositing atoms / molecules layer by layer on a substrate surface using gaseous precursors. This allows for precise control of film thickness and can be used to prepare uniform nanoscale films. Furthermore, it eliminates the need for organic solvents and pre-baking during the deposition process, avoiding precursor decomposition byproducts and organic solvent waste. In addition, dry etching is also used to avoid problems such as organic solvent storage and handling, pattern collapse caused by capillary force during solvent evaporation, pattern deformation caused by film swelling, and environmental pollution caused by chemical waste liquid. Constructing a fully dry photolithography process can make the process inherently green.

[0003] Compared to negative resist films, positive resist lithography offers advantages in resolution, edge quality, process compatibility, sensitivity adjustment range, and suitability for specific applications. A key challenge in preparing positive electron beam resist films using atomic / molecular layer deposition (ALD) is selecting the optimal precursor; suitable precursors should possess radiation sensitivity. Traditional inorganic precursors used in ALD (such as metal halides and metal alkyl compounds) and organic monomers used in molecular layer deposition (such as diamines / diols) lack electron beam responsive groups and cannot provide sufficient exposure contrast. Technical approaches to address the lack of electron beam-sensitive leaving groups include: first, employing inorganic-organic hybrids, such as atomic layer deposition (ALD) to prepare HfO2 / Al2O3 films, and alternating atomic and molecular layer deposition to prepare zirconium-based metal-organic framework films (e.g., UiO-66); second, designing radiation-sensitive monomers, such as co-depositing diazonoquinone derivatives with silane coupling agents; and third, post-functionalization strategies, such as first atomically depositing Al2O3 films and then vapor-permeating and implanting triphenylsulfonium salts, a photoacid generator. However, there is currently no mature dry etching technology for these films. In summary, there is a lack of film-forming precursors that combine radiation sensitivity, volatility, thermal stability, and layer-by-layer growth characteristics, making it difficult for the prepared positive electron beam resist films to simultaneously possess good exposure sensitivity and reactive gas etching selectivity.

[0004] Therefore, it is urgent to select film-forming precursors containing electron beam-sensitive leaving groups, prepare positive electron beam resist films using atomic / molecular layer deposition dry method, and develop corresponding reactive gas etching processes. Summary of the Invention

[0005] The technical problem to be solved by this invention is to provide a zinc-dichloroimidazole coordination dense film and its preparation method. This film is loaded onto 5A zeolite and contains electron beam-sensitive leaving groups, making it a positive resist film. Without electron beam irradiation, it is not etched by hexafluoroacetylacetone, but after electron beam irradiation, it can be etched with hexafluoroacetylacetone. The film's density and etchability are tested using propylene gas adsorption (propylene adsorption amount). The film thickness (density) is controlled by the number of atomic layer deposition and molecular layer deposition layers (number of deposition cycles). No liquid solvent is used during the deposition and etching processes.

[0006] The technical solution adopted is as follows:

[0007] A method for preparing a zinc-dichloroimidazole coordination dense membrane includes the following steps:

[0008] (1) 5A zeolite is loaded into the reactor, argon gas is introduced and vacuum is drawn to remove impurity gases in the reaction system, and the 5A zeolite is heated to dehydrate and degas.

[0009] (2) The film-forming precursors diethylzinc and 4,5-dichloroimidazole are sequentially circulated and pulsed into the reactor treated in step (1), while argon gas is introduced and vacuum is purged during the process to deposit a film.

[0010] (3) The solid obtained in step (2) is activated to obtain zinc-dichloroimidazole coordination dense film / 5A zeolite.

[0011] Preferably, in step (1), the 5A zeolite is dehydrated and degassed at 200°C for 60 minutes.

[0012] Preferably, in step (2), the deposition temperature is 160–190°C.

[0013] Preferably, in step (2), the number of deposition film cycles is 5 to 15.

[0014] Preferably, in step (3), the activation temperature is 120°C and the activation time is 60 min.

[0015] A method for preparing a zinc-dichloroimidazole coordination dense film: The dense film is loaded on 5A zeolite and contains electron beam sensitive leaving groups; it is a positive resist film that is not etched by hexafluoroacetylacetone when not irradiated by an electron beam, but can be etched by hexafluoroacetylacetone after irradiation by an electron beam.

[0016] Preferably, the method of etching with hexafluoroacetylacetone after electron beam irradiation includes:

[0017] S1. Load the zinc-dichloroimidazole coordination dense membrane / 5A zeolite sample into the reactor, introduce argon gas and simultaneously evacuate the system to remove impurity gases from the reaction system.

[0018] S2. The etching agent hexafluoroacetylacetone is pulsed into the reactor treated in step S1, and then purged with argon gas and etched in a cycle.

[0019] S3. The solid obtained in step S2 is activated to obtain a zinc-dichloroimidazole coordinated dense film / 5A zeolite etched with hexafluoroacetylacetone.

[0020] As a further preferred option, in step S2, the etching temperature is 90–105°C.

[0021] As a further preferred embodiment, in step S3, the activation temperature is 120°C and the activation time is 60 min.

[0022] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0023] (1) The electron beam resist film preparation method of the present invention adopts atomic layer deposition and molecular layer deposition alternately. The film material contains electron beam sensitive leaving groups and is a positive resist film. It will not be etched by hexafluoroacetylacetone when not irradiated by electron beam, but can be etched by hexafluoroacetylacetone after electron beam irradiation. No liquid solvent is used for film formation and etching, and no chemical waste liquid is generated, which is environmentally friendly.

[0024] (2) The thickness (density) of the zinc-dichloroimidazole coordination dense film is precisely controlled by the number of atomic layer deposition and molecular layer deposition (number of deposition cycles), and the film texture is uniform.

[0025] (3) The zinc-dichloroimidazole coordination dense film was etched with hexafluoroacetylacetone. This is a dry etching method using reactive gases, and there is no problem of film swelling.

[0026] (4) When irradiating the zinc-dichloroimidazole coordination dense film with an electron beam, solid magnesium hydride is added to the sample. The hydrogen generated by the magnesium hydride passesivates the dissociation products of the dichloroimidazole ligand, and there is no need to introduce hydrogen gas. Attached Figure Description

[0027] Figure 1This is a schematic diagram of the apparatus used in this embodiment for preparing a zinc-dichloroimidazole coordination dense film and etching with hexafluoroacetylacetone. The apparatus includes: 1. an argon cylinder, 2. an argon control valve, 3. a diethylzinc control valve, 4. a diethylzinc sample cell, 5. a hexafluoroacetylacetone control valve, 6. a hexafluoroacetylacetone sample cell, 7. a 4,5-dichloroimidazole control valve, 8. a 4,5-dichloroimidazole sample cell, 9. a fixed-bed reactor, and 10. a vacuum pump, connected in sequence. The heating temperature of the 4,5-dichloroimidazole sample cell and the fixed-bed reactor is controlled by a temperature controller.

[0028] Figure 2 The images show the propylene gas adsorption curves of the zinc-dichloroimidazole coordination dense film / 5A zeolite from Example 1, after etching with hexafluoroacetylacetone at 100°C without electron beam irradiation and after etching with hexafluoroacetylacetone at 100°C after electron beam irradiation, as well as the propylene gas adsorption curve of the original 5A zeolite.

[0029] Figure 3 The image shows the X-ray photoelectron spectrum of the zinc-dichloroimidazole coordination dense film / 5A zeolite of Example 1 after electron beam irradiation and etching with hexafluoroacetylacetone at 100°C.

[0030] The accompanying drawings are for illustrative purposes only; certain well-known structures and their descriptions may be omitted from the drawings by those skilled in the art, and therefore should not be construed as limiting the invention. Detailed Implementation

[0031] Unless otherwise specified, the chemical substances and instruments used in this invention are available through conventional commercial channels.

[0032] This invention provides a method for preparing a zinc-dichloroimidazole coordination dense membrane, comprising the following steps:

[0033] (1) 5A zeolite is loaded into the reactor, argon gas is introduced and vacuum is drawn to remove impurity gases in the reaction system, and 5A zeolite is dehydrated and degassed at 200℃ for 60 min.

[0034] (2) The film-forming precursors diethylzinc and 4,5-dichloroimidazole are sequentially pulsed into the reactor treated in step S1 at 160-190°C, while argon gas is introduced and vacuum is purged. The number of cycles is 5-15.

[0035] (3) The solid obtained in step S2 is activated at 120°C for 60 min.

[0036] A method for preparing a zinc-dichloroimidazole coordination dense film includes the following steps: The dense film prepared by electron beam irradiation is etched with hexafluoroacetylacetone.

[0037] S1. The zinc-dichloroimidazole coordination dense membrane / 5A zeolite is loaded into the reactor, and argon gas is introduced while a vacuum is drawn to remove impurity gases in the reaction system.

[0038] S2. The etchant hexafluoroacetylacetone is pulsed into the reactor treated in step E1 at 90-105°C, and then purged with argon gas. The etching is repeated 5 times.

[0039] S3. Activate the solid treated in step E2 at 100°C for 60 min.

[0040] The compactness and etchability of the prepared zinc-dichloroimidazole coordination dense film were characterized by testing the propylene gas adsorption of the zinc-dichloroimidazole coordination dense film / 5A zeolite sample, the zinc-dichloroimidazole coordination dense film / 5A zeolite sample etched directly with hexafluoroacetylacetone without electron beam irradiation, and the zinc-dichloroimidazole coordination dense film / 5A zeolite sample irradiated with electron beam and then etched with hexafluoroacetylacetone. 5A zeolite is porous and can adsorb a large amount of propylene gas, but when the particle surface is covered with a dense film layer, it no longer adsorbs propylene gas. Propylene was used as the adsorbate instead of carbon dioxide because magnesium hydride was added as a hydrogen source during electron beam irradiation. If carbon dioxide were used as the adsorbate, it would react chemically with magnesium species, affecting the accurate determination of the gas adsorption amount, while propylene does not react with magnesium species. The specific method for propylene gas adsorption testing is as follows: In an argon-protected glove box (Lab2000 model, manufactured by ITEX Inert Gas Systems Ltd., with oxygen content <0.1ppm and water content <0.1ppm), weigh approximately 0.1g of sample and place it into the sample cell of a high-pressure gas adsorption instrument (PCT-Pro 2000 model, manufactured by CETRAM Instruments Ltd., France). Then, evacuate the high-pressure gas adsorption instrument to <1mbar. Finally, at a temperature of 25℃, a system reference volume of 17.10mL, and an initial propylene gas pressure of 100kPa, test the change in propylene adsorption capacity of the sample over adsorption time.

[0041] The specific electron beam irradiation method is as follows: Take approximately 0.1 g of the prepared zinc-dichloroimidazole coordination dense film / 5A zeolite, and dope it with approximately 0.01 g of magnesium hydride (MgH2, CAS No. 7693-27-8, purity 98%). Spread the solid sample evenly on the stage of a scanning electron microscope (Hitachi SU3500 VP type, Japan), with a sample spreading area of ​​approximately 1 cm². 2No gold sputtering was performed on the sample. The system was operated in low vacuum mode and energy-dispersive X-ray spectrometry was used to irradiate the sample with an electron beam according to the operation method of elemental surface distribution analysis. The electron beam accelerating voltage was 15kV (electron beam energy 15keV) and the electron beam current was 5nA. The sample was divided into 9 sub-regions, each with 512×512 pixels and a dwell time of 5ms per point. After one irradiation, the sample was flipped and irradiated again. The process of flipping the sample and irradiating was repeated 5 times, for a total of 6 irradiations, to ensure that the sample received relatively uniform and sufficient electron beam irradiation.

[0042] Technical principle of the invention:

[0043] When depositing a film on a solid surface, the precursor diethylzinc (Zn(C2H5)2) reacts chemically with 4,5-dichloroimidazole (Cl2ImH). The diethylzinc molecule dissociates into zinc cations and ethyl anions (as shown in formula (1) below). The zinc cations are deposited on the solid surface (atomic layer deposition), and the 4,5-dichloroimidazole molecule dissociates into 4,5-dichloroimidazole anions and hydrogen protons (as shown in formula (2) below). The 4,5-dichloroimidazole anions are deposited on the solid surface (molecular layer deposition). Coordinate bonds are formed between the zinc cations and the 4,5-dichloroimidazole anions (as shown in formula (3) below). The ethyl anions in the gas phase combine with the hydrogen protons to form ethane (as shown in formula (4) below). After multiple cycles of atomic layer deposition and molecular layer deposition, the zinc cations and 4,5-dichloroimidazole anions are alternately deposited on the solid surface, thereby forming a zinc-dichloroimidazole coordinated dense film.

[0044] During film etching, hexafluoroacetylacetone is used as the reactive gas etchant for dry etching. Without electron beam irradiation, the film will not be etched by hexafluoroacetylacetone. When magnesium hydride is added to the film sample and irradiated with an electron beam, according to the dissociative electron attachment mechanism (DEA), the C-Cl bond in the 4,5-dichloroimidazole anion in the film is cleaved into imidazole anions and chlorine free radicals. The generated chlorine free radicals attach electrons and become chlorine anions that enter the gas phase (Equation (5) below). The chlorine anions can lose electrons and become chlorine free radicals again (Equation (6) below). At the same time, magnesium hydride generates hydrogen free radicals under electron beam irradiation (Equation (7) below). Then, the free radical sites generated by the dissociation of 4,5-dichloroimidazole anions combine with hydrogen free radicals and passivate into imidazole anions (Equation (8) below). The chlorine free radicals combine with hydrogen free radicals to form hydrogen chloride molecules (Equation (9) below). When etching with hexafluoroacetylacetone (hfacH), hexafluoroacetylacetone dissociates into hexafluoroacetylacetone anions and hydrogen protons (Equation (10)). Then, the hexafluoroacetylacetone anions complex with the zinc cations on the solid surface, allowing the zinc cations to enter the gas phase (Equation (11)). The hydrogen protons combine with the imidazole anions on the solid surface to form imidazole molecules, allowing the imidazole anions to enter the gas phase (Equation (12)), thereby achieving continuous etching.

[0045] Zn(C2H5)2(g)→Zn 2+ (s)+2C2H5 - (g) (1)

[0046] Cl2ImH(g)→(Cl2Im) - (s)+H + (g) (2)

[0047] nZn 2+ (s)+2n(Cl2Im) - (s)→[Zn(Cl2Im)2] n (s) (3)

[0048] C2H5 - (g)+H + (g)→C2H6(g) (4)

[0049] (Cl2Im) - (s)+2e - →·Im - (s)+2Cl - (g) (5)

[0050] Cl - (g)→Cl·(g)+e - (6)

[0051] MgH2(s)→Mg(s)+2H·(g) (7)

[0052] ·Im - (s) + 2H·(g) → Im - (s) (8)

[0053] Cl·(g) + H·(g) → HCl(g) (9)

[0054] hfacH(g)→(hfac) 2- (g) + 2H + (g) (10)

[0055] (hfac) 2- (g)+Zn 2+ (s)→Zn(hfac)2(g) (11)

[0056] H + (s)+Im - (s)→ImH(g) (12)

[0057] The present invention will be further described in detail below with reference to specific embodiments.

[0058] Example 1

[0059] (I) Preparation of zinc-dichloroimidazole coordination dense membrane.

[0060] A method for preparing a zinc-dichloroimidazole coordination dense membrane includes the following steps:

[0061] (1) In Figure 1 In the apparatus shown, 0.3 g of 5A zeolite (Sigma-Aldrich 233676, <10 μm) sample was dispersed in glass wool and loaded into the reactor; 0.5 g of diethylzinc (CAS No. 557-20-0, purity 95%) was loaded into the diethylzinc sample cell; 0.5 g of 4,5-dichloroimidazole (CAS No. 15965-30-7, purity 98%) was loaded into the 4,5-dichloroimidazole sample cell; and 0.5 g of hexafluoroacetylacetone (1,1,1,5,5,5-hexafluoroacetylacetone, CAS No. 1522-22-1, purity 98%) was loaded into the hexafluoroacetylacetone sample cell. With the argon valve, diethylzinc valve, 4,5-dichloroimidazole valve, and hexafluoroacetylacetone valve closed, turn on the vacuum pump to evacuate the reaction system to <1 mbar and maintain this state for 5 min. Then, open the argon valve and introduce argon gas (99.999% purity) at a flow rate of 10 mL / min while evacuating for 5 min. Under dynamic vacuum conditions of introducing argon gas at a flow rate of 10 mL / min while evacuating, heat the reactor to 200℃ to dehydrate and degas the 5A zeolite for 60 min to remove adsorbed moisture and impurities such as carbon dioxide from the 5A zeolite. Heat the 4,5-dichloroimidazole sample cell to 180℃ for subsequent film deposition.

[0062] (2) Under dynamic vacuum conditions, with argon gas introduced at a flow rate of 10 mL / min and vacuuming simultaneously, the reactor containing 5A zeolite that has undergone dehydration and degassing treatment in step (1) is cooled to the deposition film temperature of 180°C, kept at the temperature for 10 min, and then the argon gas is turned off and vacuuming continues for 5 min; then the film-forming precursors diethylzinc and 4,5-dichloroimidazole are sequentially pulsed into the reactor in a cyclic manner (cyclic atomic / molecular layer deposition), during which argon gas is introduced and vacuuming is performed to purge the reaction system to remove reaction byproducts and unreacted precursors. Each cycle includes: ① diethylzinc pulse for 1 s; ② argon gas introduced at a flow rate of 10 mL / min and vacuuming for 300 s; ③ argon gas turned off and vacuuming for 120 s; ④ 4,5-dichloroimidazole pulse for 2 s; ⑤ argon gas introduced at a flow rate of 10 mL / min and vacuuming for 480 s; ⑥ argon gas turned off and vacuuming for 120 s. A total of 10 cycles of atomic / molecular layer deposition were performed to form a film, with the pressure inside the reactor being approximately 3–8 mbar during the film formation process.

[0063] (3) Under dynamic vacuum conditions of passing argon gas at a flow rate of 10 mL / min and simultaneously evacuating the vacuum, the reactor containing the film sample deposited in step (2) was cooled to 120°C, activated at this temperature for 60 min, and then naturally cooled to room temperature to obtain a zinc-dichloroimidazole coordination dense film / 5A zeolite, wherein the zinc-dichloroimidazole coordination dense film is deposited on the surface of 5A zeolite particles.

[0064] (ii) Hexafluoroacetylacetone etching of zinc-dichloroimidazole coordinated dense film.

[0065] The prepared zinc-dichloroimidazole coordination dense film / 5A zeolite sample was dispersed in glass wool and then packed into... Figure 1 In the reactor of the fabricated apparatus, with the argon valve, diethylzinc valve, 4,5-dichloroimidazole valve, and hexafluoroacetylacetone valve closed, the vacuum pump was turned on to evacuate the reaction system to <1 mbar and maintain this state for 5 min. Then, the argon valve was opened to introduce argon gas at a flow rate of 10 mL / min while evacuating for 5 min. The reactor was then heated to the etching temperature of 100 °C and held at this temperature for 10 min before the argon gas was turned off. The zinc-dichloroimidazole coordination dense film was then etched at 100 °C using hexafluoroacetylacetone according to the following steps: ① the hexafluoroacetylacetone valve was opened, and hexafluoroacetylacetone was pulsed into the reactor for 10 s; ② the hexafluoroacetylacetone valve was closed and maintained for 300 s; ③ the argon valve was opened, and argon gas was introduced at a flow rate of 10 mL / min while evacuating for 480 s; ④ the argon gas was turned off and evacuated for 120 s. A total of 5 hexafluoroacetylacetone etching cycles were performed. Then, under dynamic vacuum conditions of argon gas flowing at a flow rate of 10 mL / min while evacuating, the material was activated at 100 °C for 60 min and then naturally cooled to room temperature to obtain a zinc-dichloroimidazole coordinated dense film / 5A zeolite etched with hexafluoroacetylacetone.

[0066] The zinc-dichloroimidazole coordination dense membrane / 5A zeolite sample prepared in this example was used to measure the change in propylene adsorption capacity with adsorption time. The results are shown in [Figure 1]. Figure 2 ,Depend on Figure 2 It can be seen that the sample does not adsorb propylene gas, indicating that the zinc-dichloroimidazole coordination dense membrane of this embodiment has good compactness.

[0067] The zinc-dichloroimidazole coordination dense film / 5A zeolite sample of this embodiment, etched directly with hexafluoroacetylacetone at 100°C without electron beam irradiation, was used to measure the change in propylene adsorption capacity with adsorption time. The results are shown in [Figure number missing]. Figure 2 ,Depend on Figure 2 It can be seen that the sample does not adsorb propylene gas after etching without electron beam irradiation, indicating that the zinc-dichloroimidazole coordination dense film is still dense, that is, it will not be etched by hexafluoroacetylacetone without electron beam irradiation.

[0068] The zinc-dichloroimidazole coordination dense film / 5A zeolite of this embodiment was irradiated with an electron beam and then etched with hexafluoroacetylacetone at 100°C. The change in propylene adsorption capacity with adsorption time was measured, and the results are shown in the figure. Figure 2 ,Depend on Figure 2 It can be seen that the propylene adsorption capacity at 20 min is 2.11 mmol / g, which is similar to that of the original 5A zeolite, indicating that the zinc-dichloroimidazole coordination dense film can be completely etched by hexafluoroacetylacetone at 100℃ after electron beam irradiation.

[0069] The X-ray photoelectron spectra of the zinc-dichloroimidazole coordinated dense film / 5A zeolite in this embodiment, and its subsequent etching with hexafluoroacetylacetone at 100°C after electron beam irradiation, are shown below (Shimadzu Axis Supra XPS spectrometer, Al Kα rays, 300W power). Figure 3 ,Depend on Figure 3 It can be seen that the sample contains Zn, N, C and Cl elements from diethylzinc and 4,5-dichloroimidazole. However, after electron beam irradiation and etching with hexafluoroacetylacetone, these elements in the film are gone, and Si, Al and O elements of 5A zeolite appear. This indicates that the zinc-dichloroimidazole coordinated dense film has been completely etched away, exposing the surface of 5A zeolite.

[0070] Example 2

[0071] The difference between this embodiment and Example 1 is that when cyclically depositing the film with diethylzinc and 4,5-dichloroimidazole, a total of 5 cycles were performed, and the remaining steps were the same as in Example 1, to obtain a zinc-dichloroimidazole coordinated dense film / 5A zeolite.

[0072] The zinc-dichloroimidazole coordination dense membrane / 5A zeolite sample prepared in this embodiment was tested, and its propylene adsorption capacity was measured to be 0.25 mmol / g at 20 min. This indicates that the density of the zinc-dichloroimidazole coordination dense membrane in this embodiment is slightly poor. That is, if the number of deposition cycles is too small (5 cycles), the density of the prepared membrane will be reduced.

[0073] Example 3

[0074] The difference between this embodiment and Example 1 is that: when using diethylzinc and 4,5-dichloroimidazole for cyclic atomic / molecular layer deposition to form a film, a total of 8 cycles are performed, and the remaining steps are the same as in Example 1, to obtain a zinc-dichloroimidazole coordinated dense film / 5A zeolite.

[0075] The zinc-dichloroimidazole coordination dense membrane / 5A zeolite sample prepared in this example was tested, and its propylene adsorption capacity was measured to be 0.09 mmol / g at 20 min. This indicates that when the number of cycles for deposition of diethylzinc and 4,5-dichloroimidazole is 8, the prepared membrane is basically dense.

[0076] Example 4

[0077] The difference between this embodiment and Example 1 is that when using diethylzinc and 4,5-dichloroimidazole for cyclic atomic / molecular layer deposition to form a film, a total of 15 cycles are performed, and the remaining steps are the same as in Example 1, to obtain a zinc-dichloroimidazole coordinated dense film / 5A zeolite.

[0078] The zinc-dichloroimidazole coordination dense membrane / 5A zeolite sample prepared in this embodiment was tested, and its propylene adsorption capacity was measured to be 0.01 mmol / g at 20 min, indicating that the zinc-dichloroimidazole coordination dense membrane of this embodiment has good compactness.

[0079] Example 5

[0080] The difference between this embodiment and Example 1 is that when using diethylzinc and 4,5-dichloroimidazole to cyclically deposit atomic / molecular layers to form a film, the deposition temperature is 160°C, and the remaining steps are the same as in Example 1, to obtain a zinc-dichloroimidazole coordinated dense film / 5A zeolite.

[0081] The zinc-dichloroimidazole coordination dense membrane / 5A zeolite sample prepared in this example was tested, and its propylene adsorption capacity was measured to be 0.84 mmol / g at 20 min, indicating that the density of the formed membrane was slightly poor.

[0082] Example 6

[0083] The difference between this embodiment and Example 1 is that when using diethylzinc and 4,5-dichloroimidazole to cyclically deposit atomic / molecular layers, the deposition temperature is 170°C, and the remaining steps are the same as in Example 1, to obtain a zinc-dichloroimidazole coordinated dense film / 5A zeolite.

[0084] The zinc-dichloroimidazole coordination dense membrane / 5A zeolite sample prepared in this example was tested, and its propylene adsorption capacity was measured to be 0.11 mmol / g at 20 min, indicating that the formed membrane is basically dense.

[0085] Example 7

[0086] The difference between this embodiment and Example 1 is that when using diethylzinc and 4,5-dichloroimidazole for cyclic atomic / molecular layer deposition to form a film, the deposition temperature is 190°C, and the remaining steps are the same as in Example 1, to obtain a zinc-dichloroimidazole coordinated dense film / 5A zeolite.

[0087] The zinc-dichloroimidazole coordination dense membrane / 5A zeolite sample prepared in this example was tested, and its propylene adsorption capacity was measured to be 0.02 mmol / g at 20 min, indicating that the formed membrane is dense.

[0088] Example 8

[0089] The difference between this embodiment and Embodiment 1 is that the zinc-dichloroimidazole coordination dense film / 5A zeolite is first irradiated with an electron beam and then etched with hexafluoroacetylacetone at 90°C. The remaining steps are the same as in Embodiment 1.

[0090] The zinc-dichloroimidazole coordination dense film / 5A zeolite of this embodiment was irradiated with an electron beam and then etched with hexafluoroacetylacetone at 90°C. The propylene adsorption amount was measured to be 1.78 mmol / g after 20 min, indicating that the zinc-dichloroimidazole coordination dense film can be etched by hexafluoroacetylacetone at 90°C after electron beam irradiation, but the etching rate is relatively slow.

[0091] Example 9

[0092] The difference between this embodiment and Embodiment 1 is that the zinc-dichloroimidazole coordination dense film / 5A zeolite is first irradiated with an electron beam and then etched with hexafluoroacetylacetone at 105°C. The remaining steps are the same as in Embodiment 1.

[0093] The zinc-dichloroimidazole coordination dense film / 5A zeolite of this embodiment was irradiated with an electron beam and then etched with hexafluoroacetylacetone at 105°C. The propylene adsorption amount was measured to be 2.04 mmol / g after 20 min, indicating that the zinc-dichloroimidazole coordination dense film can be completely etched by hexafluoroacetylacetone at 105°C after electron beam irradiation.

[0094] Comparative Example 1

[0095] The difference between this comparative example and Example 1 is that the zinc-dichloroimidazole coordination dense film / 5A zeolite is etched directly with hexafluoroacetylacetone at 105°C without electron beam irradiation, and the remaining steps are the same as in Example 1.

[0096] The zinc-dichloroimidazole coordination dense film / 5A zeolite sample of this comparative example was directly etched with hexafluoroacetylacetone at 105℃ without electron beam irradiation. The propylene adsorption amount was measured to be 0.14 mmol / g after 20 min, indicating that the zinc-dichloroimidazole coordination dense film can hardly be etched by hexafluoroacetylacetone at 105℃ without electron beam irradiation.

[0097] Table 1 summarizes the propylene adsorption amounts of Examples 1-9, Comparative Example 1, and the original 5A zeolite zinc-dichloroimidazole coordination dense film / 5A zeolite and hexafluoroacetylacetone etched samples after 20 min.

[0098] Table 1 Propylene adsorption capacity of samples after 20 min

[0099]

[0100] As shown in Table 1, a zinc-dichloroimidazole coordination dense film can be prepared by atomic / molecular layer deposition using diethylzinc and 4,5-dichloroimidazole as precursors and 5A zeolite as support. This film is not etched by hexafluoroacetylacetone when not irradiated by an electron beam, but can be etched by hexafluoroacetylacetone after electron beam irradiation, thus it is a positive electron beam resist film.

[0101] The preferred process conditions for preparing zinc-dichloroimidazole coordination dense films are as follows: the atomic / molecular layer deposition temperature of the precursor diethylzinc and 4,5-dichloroimidazole is 180℃, the number of deposition cycles is 10, and the etching temperature using hexafluoroacetylacetone as the reactive gas etchant after electron beam irradiation is 100℃.

[0102] Of course, the above description is not intended to limit the present invention, and the present invention is not limited to the examples given above. Any changes, modifications, additions or substitutions made by those skilled in the art within the scope of the present invention should also fall within the protection scope of the present invention.

Claims

1. A zinc-dichloroimidazole coordination dense membrane, characterized in that, The film is loaded on 5A zeolite and is prepared by alternating atomic layer deposition and molecular layer deposition of the precursor diethylzinc and 4,5-dichloroimidazole on the surface of 5A zeolite particles. Without electron beam irradiation, the film is not etched by hexafluoroacetylacetone, but after adding solid magnesium hydride and irradiating with an electron beam, it can be etched with hexafluoroacetylacetone, thus being a positive resist film.

2. The zinc-dichloroimidazole coordination dense membrane according to claim 1, characterized in that, The method for preparing the membrane includes the following steps: (1) 5A zeolite is loaded into the reactor, argon gas is introduced and vacuum is drawn to remove impurity gases in the reaction system, and the 5A zeolite is heated to dehydrate and degas; wherein, the 5A zeolite is dehydrated and degassed at 200℃ for 60 min. (2) The film-forming precursors diethylzinc and 4,5-dichloroimidazole are sequentially pulsed into the reactor treated in step (1), and argon gas is introduced during the process while vacuuming is performed to purge the reactor. Atomic layer deposition and molecular layer deposition are performed alternately to form a film. The number of film-forming cycles is 5 to 15. (3) The solid obtained in step (2) is activated to obtain a zinc-dichloroimidazole coordination dense film / 5A zeolite; wherein the activation temperature is 120℃ and the activation time is 60min.

3. The zinc-dichloroimidazole coordination dense membrane according to claim 2, characterized in that, In step (2), the deposition temperature is 160–190°C.

4. The zinc-dichloroimidazole coordination dense membrane according to claim 1, characterized in that, The steps of adding solid magnesium hydride to a zinc-dichloroimidazole coordinated dense film / 5A zeolite and then etching it with hexafluoroacetylacetone after electron beam irradiation include: S1. Load the sample into the reactor, introduce argon gas and simultaneously evacuate the system to remove impurity gases from the reaction system. S2. The etching agent hexafluoroacetylacetone is pulsed into the reactor treated in step S1, and then purged with argon gas and etched in a cycle. S3. The solid obtained in step S2 is activated to obtain a zinc-dichloroimidazole coordinated dense film / 5A zeolite etched with hexafluoroacetylacetone.

5. The zinc-dichloroimidazole coordination dense membrane according to claim 4, characterized in that, In step S2, the etching temperature is 90–105°C.

6. The zinc-dichloroimidazole coordination dense membrane according to claim 4, characterized in that, In step S3, the activation temperature is 120℃ and the activation time is 60min.

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