Zinc-dichloroimidazole coordination dense membrane and preparation method thereof

Abstract

The invention belongs to the technical field of semiconductor device manufacturing, and relates to preparation of a positive electron beam anti-corrosion film, in particular to a zinc-dichloroimidazole coordination compact film and a preparation method thereof. According to the preparation method, atomic layer deposition and molecular layer deposition are adopted for alternate deposition to form a film, and a film material contains electron beam sensitive leaving groups, is a positive anti-corrosion film, cannot be etched by hexafluoroacetylacetone when not irradiated by electron beams, can be etched by hexafluoroacetylacetone after being irradiated by the electron beams, and can be etched by hexafluoroacetylacetone after being irradiated by the electron beams. A liquid solvent is not used for film forming and etching, chemical waste liquid is not generated, environmental friendliness is achieved, the film is loaded on the 5A zeolite and has the potential for manufacturing high-precision patterns through electron beam photoetching, a potential scheme is provided for the process of depositing the positive electron beam anti-corrosion film on the silicon substrate, and the method is suitable for large-scale popularization and application. The method can solve the problems that a liquid solvent is used and the film thickness is not uniform in the film forming process of the electron beam anti-corrosion film, and has important application in the aspects of advanced semiconductor manufacturing procedures and the like.

Description

Technical Field

[0001] The invention belongs to the technical field of semiconductor device manufacturing, relates to the preparation of a positive electron beam resist film, and particularly relates to a zinc-dichloroimidazole coordination dense film and a preparation method thereof. Background Art

[0002] Thinning electron beam resist films helps suppress electron scattering during electron beam irradiation and improve photolithographic resolution. However, thinning reduces the energy deposition efficiency of incident electrons and increases film non-uniformity. Film materials made of inorganic materials or inorganic-organic hybrid materials containing metallic elements, such as Sb, Zr, Zn, Hf, and Sn, can improve exposure sensitivity and contrast, as the electron scattering cross-section of metal atoms is higher than that of carbon, oxygen, and hydrogen atoms in organic polymers. Atomic / molecular layer deposition (ALD / MLD) is a dry deposition method that deposits atoms / molecules layer by layer on a substrate using a gaseous precursor. This allows for precise control of film thickness and can be used to produce uniform nanoscale thin films. Organic solvents are not used, and a pre-bake step is not required during film formation, thus avoiding the production of precursor decomposition byproducts and the discharge of organic solvent waste. In addition, the dry method is also used for membrane etching, which can avoid problems such as storage and handling of organic solvents, capillary force causing pattern collapse during solvent evaporation, membrane swelling causing pattern deformation, and chemical waste liquid causing environmental pollution. Constructing a fully dry lithography process can make the process inherently green.

[0003] Compared to negative resists, positive resist lithography offers advantages in terms of resolution, edge quality, process compatibility, sensitivity adjustment range, and suitability for specific applications. The key issue in preparing positive electron beam resists using atomic / molecular layer deposition (ALD) is the optimal precursor selection, which should be radiation-sensitive. The inorganic precursors used in traditional ALD (such as metal halides and metal alkyl compounds) and the organic monomers used in MLD (diamines / diols) lack electron beam-responsive groups and cannot provide sufficient exposure contrast. There are two technical approaches to solving the problem of lack of electron beam sensitive leaving groups. First, use inorganic-organic hybridization, such as atomic layer deposition to prepare HfO2 / Al2O3 film, and alternate atomic deposition and molecular layer deposition to prepare zirconium-based metal organic framework film (such as UiO-66); second, design radiation-sensitive monomers, such as diazonaphthoquinone derivatives and silane coupling agents co-deposition film; third, post-functionalization strategy, such as first atomic layer deposition of Al2O3 film and then vapor infiltration injection of photoacid generator triphenylsulfonium salt. However, there is no mature dry etching technology for etching these films. In short, there is currently a lack of film-forming precursors that have both radiation sensitivity, volatility, thermal stability and layer-by-layer growth characteristics. The prepared positive electron beam resist film is difficult to have both good exposure sensitivity and reactive gas etching selectivity.

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

[0005] The technical problem to be solved by the present invention is to provide a zinc-dichloroimidazole coordination dense film and a preparation method thereof. The film is supported on 5A zeolite and contains electron beam-sensitive leaving groups in the film material, resulting in a positive resist film. Without electron beam irradiation, it is resistant to etching by hexafluoroacetylacetone, but can be etched by hexafluoroacetylacetone after electron beam irradiation. The film's compactness and etchability are tested using propylene gas adsorption (propylene adsorption amount), and the film thickness (compactness) is controlled using the number of atomic layer deposition (ALD) and molecular layer deposition (MLD) layers (number of deposition cycles). No liquid solvent is used during the deposition and etching processes.

[0006] The technical solutions adopted are:

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

[0008] (1) 5A zeolite was placed in a reactor, argon was introduced and vacuum was applied to remove impurity gases in the reaction system, and the 5A zeolite was heated to dehydrate and degas;

[0009] (2) introducing film-forming precursors diethylzinc and 4,5-dichloroimidazole into the reactor treated in step (1) in a cyclic pulse manner, while introducing argon gas and simultaneously evacuating the reactor for purging, to deposit the film;

[0010] (3) Activating the solid obtained in step (2) to obtain zinc-dichloroimidazole coordinated dense membrane / 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 film forming temperature is 160-190°C.

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

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

[0015] A dense film prepared by a method for preparing a zinc-dichloroimidazole coordination dense film is supported on 5A zeolite and contains electron beam sensitive leaving groups. The film is a positive resist film that cannot be etched by hexafluoroacetylacetone before electron beam irradiation, but can be etched by hexafluoroacetylacetone after electron beam irradiation.

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

[0017] S1. The zinc-dichloroimidazole coordination dense film / 5A zeolite sample was loaded into the reactor, and argon gas was introduced while vacuuming the reaction system to remove impurity gases;

[0018] S2 is passed through the reactor treated in step S1 pulse etchant hexafluoroacetylacetone, after which argon is purged and the etching cycle is performed;

[0019] S3. Activate the solid obtained in step S2 to obtain a zinc-dichloroimidazole coordination dense film / 5A zeolite after hexafluoroacetylacetone etching.

[0020] As a further preference, in step S2, the etching temperature is 90-105°C.

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

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[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. When not irradiated by electron beam, it will not be etched by hexafluoroacetylacetone. After irradiation by electron beam, it can be etched by hexafluoroacetylacetone. No liquid solvent is used in film formation and etching, no chemical waste liquid is generated, and the film is environmentally friendly.

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

[0025] (3) Hexafluoroacetylacetone is used to etch the zinc-dichloroimidazole coordination dense film. This is a dry etching method using reactive gases, and there is no film swelling problem.

[0026] (4) When the zinc-dichloroimidazole coordination dense film is irradiated with an electron beam, solid magnesium hydride is added to the sample and the hydrogen generated by the magnesium hydride is used to passivate the dissociation product of the dichloroimidazole ligand without the need to introduce hydrogen. BRIEF DESCRIPTION OF THE DRAWINGS

[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 comprises: 1. an argon gas cylinder, 2. an argon gas 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, all connected in sequence. The heating temperatures of the 4,5-dichloroimidazole sample cell and the fixed-bed reactor are controlled by temperature controllers.

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

[0029] Figure 3 This is an X-ray photoelectron spectrum of the zinc-dichloroimidazole coordination dense film / 5A zeolite of Example 1 and its electron beam irradiation and subsequent etching with hexafluoroacetylacetone at 100°C.

[0030] The accompanying drawings are for illustrative purposes only. For those skilled in the art, some well-known structures and their descriptions in the accompanying drawings may be omitted, and therefore, they should not be understood as limiting the present invention. DETAILED DESCRIPTION

[0031] Unless otherwise specified, the chemicals and instruments used in the present invention can be obtained through conventional commercial channels.

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

[0033] (1) 5A zeolite was placed in a reactor, argon was introduced and vacuum was applied to remove impurity gases in the reaction system, and the 5A zeolite was dehydrated and degassed at 200°C for 60 minutes.

[0034] (2) Diethylzinc and 4,5-dichloroimidazole as film-forming precursors are introduced into the reactor treated in step S1 in a cyclic pulse manner at 160-190° C., while argon is introduced and vacuum is purged for 5-15 cycles.

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

[0036] A method for preparing a zinc-dichloroimidazole coordination dense film, wherein the dense film is irradiated with an electron beam and then etched with hexafluoroacetylacetone, comprising the following steps:

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

[0038] S2. Pulse the etchant hexafluoroacetylacetone into the reactor treated in step E1 at 90-105°C, then purge with argon gas and perform etching for 5 cycles.

[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 adsorption properties of the zinc-dichloroimidazole coordination dense film / 5A zeolite sample, the zinc-dichloroimidazole coordination dense film / 5A zeolite sample etched 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 chosen as the adsorbate rather than 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 the magnesium species, affecting the accurate measurement of the gas adsorption amount, while propylene does not react with magnesium species. Specific propylene gas adsorption test method: In an argon-filled glove box (Lab2000 model, manufactured by E-Tex Inert Gas Systems Co., Ltd., with an oxygen content of <0.1ppm and a water content of <0.1ppm in the glove box), approximately 0.1g of sample was weighed and placed in the sample cell of a high-pressure gas adsorption instrument (PCT-Pro 2000 model, manufactured by Sethram Instruments, France). The high-pressure gas adsorption instrument was then evacuated to <1mbar. The propylene adsorption amount of the sample was then tested at a temperature of 25°C, a system reference volume of 17.10mL, and an initial propylene gas pressure of 100kPa to determine the change in adsorption time.

[0041] The specific electron beam irradiation method is as follows: about 0.1 g of the prepared zinc-dichloroimidazole coordination dense film / 5A zeolite is taken and doped with about 0.01 g of magnesium hydride (MgH2, CAS No. 7693-27-8, purity 98%). The solid sample is spread flat on the stage of a scanning electron microscope (SU3500 VP model, Hitachi, Japan) with a sample spreading area of ​​about 1 cm 2The sample was not subjected to gold spraying treatment and was operated in low vacuum mode. The sample was irradiated with an electron beam using an energy dispersive X-ray spectrometer according to the operating method of elemental surface distribution analysis. The electron beam acceleration voltage was 15 kV (electron beam energy 15 keV), the electron beam current was 5 nA, and the sample was divided into 9 sub-areas. Each sub-area had 512 × 512 pixels and the dwell time at each point was 5 ms. After one irradiation, the sample was turned over and irradiated again. The turning and irradiation of the sample were repeated 5 times, for a total of 6 irradiations, so that the sample could receive more uniform and sufficient electron beam irradiation.

[0042] Technical principle of the present invention:

[0043] When depositing a film on a solid surface, the precursor diethylzinc (Zn(C2H5)2) reacts chemically with 4,5-dichloroimidazole (Cl2ImH), and the diethylzinc molecule dissociates into zinc cations and ethyl anions (as shown in the following formula (1)). 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 (the following formula (2)). The 4,5-dichloroimidazole anions are deposited on the solid surface (molecular layer deposition). A coordination bond is formed between the zinc cation and the 4,5-dichloroimidazole anion (the following formula (3)). The ethyl anions in the gas phase combine with the hydrogen protons to form ethane (the following formula (4)). 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 coordination dense film.

[0044] When etching the membrane, hexafluoroacetylacetone is used as the reactive gas etchant for dry etching. Without electron beam irradiation, the membrane will not be etched by hexafluoroacetylacetone. However, when magnesium hydride is added to the membrane sample and irradiated with an electron beam, according to the dissociative electron attachment mechanism (DEA), the C-Cl bond in the 4,5-dichloroimidazolium anion in the membrane is split into imidazolium anions with free radicals and chloride radicals. The generated chloride radicals attach electrons to become chloride anions and enter the gas phase (Formula (5) below). The chloride anions can lose electrons and become chloride radicals again (Formula (6) below). At the same time, magnesium hydride generates hydrogen radicals under electron beam irradiation (Formula (7) below). Then, the radical sites generated by the dissociation of 4,5-dichloroimidazolium anions combine with hydrogen radicals to passivate into imidazolium anions (Formula (8) below). The chloride radicals combine with hydrogen radicals to form hydrogen chloride molecules (Formula (9) below). When hexafluoroacetylacetone (hfacH) is used for etching, hexafluoroacetylacetone dissociates into hexafluoroacetylacetone anions and hydrogen protons (Formula (10) below). Then, the hexafluoroacetylacetone anions complex with zinc cations on the solid surface, causing the zinc cations to enter the gas phase (Formula (11) below), and the hydrogen protons combine with imidazole anions on the solid surface to form imidazole molecules, causing the imidazole anions to enter the gas phase (Formula (12) below), 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] (1) Preparation of zinc-dichloroimidazole coordination dense film.

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

[0061] (1) Figure 1 In the device 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 diethyl zinc (CAS No. 557-20-0, purity 95%) was loaded into the diethyl zinc 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-hexafluoro-acetylacetone, CAS No. 1522-22-1, purity 98%) was loaded into the hexafluoroacetylacetone sample cell. With the argon, diethylzinc, 4,5-dichloroimidazole, and hexafluoroacetylacetone valves closed, the vacuum pump was turned on to evacuate the reaction system to <1 mbar and maintain the pressure for 5 minutes. The argon valve was then opened and argon (99.999% purity, the same below) was introduced at a rate of 10 mL / min while evacuating the reaction system for 5 minutes. Under dynamic vacuum conditions, while evacuating the reaction system at a rate of 10 mL / min, the reactor was heated to 200°C to dehydrate and degas the 5A zeolite for 60 minutes to remove adsorbed water and impurities such as carbon dioxide. The 4,5-dichloroimidazole sample cell was heated to 180°C for subsequent film deposition.

[0062] (2) Under dynamic vacuum conditions with argon introduced at a flow rate of 10 mL / min and vacuum pumping, the reactor containing the 5A zeolite dehydrated and degassed in step (1) was cooled to a deposition film temperature of 180°C, kept at this temperature for 10 minutes, then the argon was turned off and the vacuum was continued for 5 minutes; then the film-forming precursors diethylzinc and 4,5-dichloroimidazole were pulsed into the reactor in sequence (cyclic atomic / molecular layer deposition), during which argon was introduced and vacuum was pumped to remove reaction by-products and unreacted precursors in the reaction system. Each cycle included: ① a diethylzinc pulse for 1 second; ② an argon was introduced at a flow rate of 10 mL / min and vacuum was pumped for 300 seconds; ③ the argon was turned off and vacuum was pumped for 120 seconds; ④ a 4,5-dichloroimidazole pulse for 2 seconds; ⑤ an argon was introduced at a flow rate of 10 mL / min and vacuum was pumped for 480 seconds; ⑥ the argon was turned off and vacuum was pumped for 120 seconds. A total of 10 cycles of atomic / molecular layer deposition were performed to form the film, and the pressure in the reactor during the film formation process was about 3 to 8 mbar.

[0063] (3) Under dynamic vacuum conditions with argon flowing at a flow rate of 10 mL / min and vacuuming simultaneously, the reactor containing the film-deposited sample of 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 was deposited on the surface of the 5A zeolite particles.

[0064] (2) Hexafluoroacetylacetone etching of zinc-dichloroimidazole coordination dense film.

[0065] The prepared zinc-dichloroimidazole coordination dense film / 5A zeolite sample was dispersed into glass wool and loaded into Figure 1 In the reactor of the fabricated device, with the argon valve, diethylzinc valve, 4,5-dichloroimidazole valve, and hexafluoroacetylacetone valve closed, a vacuum pump was turned on to evacuate the reaction system to <1 mbar and maintain the pressure for 5 minutes. The argon valve was then opened to introduce argon at a rate of 10 mL / min while evacuating the system for 5 minutes. The reactor was then heated to an etching temperature of 100°C, held at that temperature for 10 minutes, and then the argon gas was turned off. The zinc-dichloroimidazole coordination dense film was then etched with hexafluoroacetylacetone at 100°C according to the following steps: ① Open the hexafluoroacetylacetone valve and pulse hexafluoroacetylacetone into the reactor for 10 seconds; ② Close the hexafluoroacetylacetone valve and maintain the pressure for 300 seconds; ③ Open the argon valve to introduce argon at a rate of 10 mL / min while evacuating the system for 480 seconds; ④ Close the argon gas and evacuate the system for 120 seconds. A total of five hexafluoroacetylacetone etching cycles were performed. Then, under dynamic vacuum conditions with argon flowing at a flow rate of 10 mL / min and vacuuming simultaneously, activation treatment was carried out at 100° C. for 60 min, and then naturally cooled to room temperature to obtain hexafluoroacetylacetone-etched zinc-dichloroimidazole coordination dense film / 5A zeolite.

[0066] The zinc-dichloroimidazole coordinated dense film / 5A zeolite sample prepared in this example was taken to measure the change of its propylene adsorption capacity with adsorption time. The results are shown in FIG. 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 film of this embodiment has good density.

[0067] The zinc-dichloroimidazole coordinated dense film / 5A zeolite sample of this embodiment was directly etched with hexafluoroacetylacetone at 100°C without electron beam irradiation, and the propylene adsorption amount thereof was measured as a function of adsorption time. The results are shown in FIG. Figure 2 ,Depend on Figure 2 It can be seen that after etching without electron beam irradiation, the sample still does not adsorb propylene gas, 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 coordinated dense film / 5A zeolite sample of this embodiment was irradiated with an electron beam and then etched with hexafluoroacetylacetone at 100°C. The propylene adsorption capacity was measured as a function of adsorption time. The results are shown in FIG. Figure 2 ,Depend on Figure 2 It can be seen that the propylene adsorption capacity is 2.11 mmol / g at 20 min, which is close to that of the original 5A zeolite, indicating that the zinc-dichloroimidazole coordination dense film can be completely etched by hexafluoroacetylacetone at 100°C after electron beam irradiation.

[0069] The X-ray photoelectron spectrum of the zinc-dichloroimidazole coordinated dense film / 5A zeolite of this embodiment and the X-ray photoelectron spectrum after electron beam irradiation and etching with hexafluoroacetylacetone at 100° C. (Shimadzu Axis Supra XPS spectrometer, Al Kα radiation, tested at a power of 300 W) is shown in FIG. 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. After electron beam irradiation and then etching with hexafluoroacetylacetone, these elements in the film disappeared, and Si, Al and O elements of 5A zeolite appeared, indicating 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 embodiment 1 is that when diethyl zinc and 4,5-dichloroimidazole are used for cyclic deposition to form a film, a total of 5 cycles are performed, and the remaining steps are the same as those in embodiment 1 to obtain zinc-dichloroimidazole coordinated dense film / 5A zeolite.

[0072] The zinc-dichloroimidazole coordination dense film / 5A zeolite sample prepared in this example was taken, and its propylene adsorption amount was measured to be 0.25 mmol / g at 20 min, indicating that the density of the zinc-dichloroimidazole coordination dense film in this example is slightly poor, that is, when the number of deposition cycles is too small (5 cycles), the density of the prepared film will be reduced.

[0073] Example 3

[0074] The difference between this embodiment and embodiment 1 is that when diethyl zinc and 4,5-dichloroimidazole are used 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 those in embodiment 1 to obtain zinc-dichloroimidazole coordinated dense film / 5A zeolite.

[0075] The zinc-dichloroimidazole coordinated dense membrane / 5A zeolite sample prepared in this example was taken, and its propylene adsorption capacity was measured to be 0.09 mmol / g at 20 min, indicating that when the number of cycles of diethyl zinc and 4,5-dichloroimidazole deposition film formation was 8 times, the prepared membrane was basically dense.

[0076] Example 4

[0077] The difference between this embodiment and embodiment 1 is that when diethyl zinc and 4,5-dichloroimidazole are used 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 those in embodiment 1 to obtain zinc-dichloroimidazole coordinated dense film / 5A zeolite.

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

[0079] Example 5

[0080] The difference between this embodiment and embodiment 1 is that when diethyl zinc and 4,5-dichloroimidazole are used for cyclic atomic / molecular layer deposition, the deposition temperature is 160° C. The remaining steps are the same as those in embodiment 1 to obtain zinc-dichloroimidazole coordinated dense film / 5A zeolite.

[0081] The zinc-dichloroimidazole coordinated dense membrane / 5A zeolite sample prepared in this example was taken, 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 embodiment 1 is that when diethyl zinc and 4,5-dichloroimidazole are used for cyclic atomic / molecular layer deposition, the deposition temperature is 170° C. The remaining steps are the same as those in embodiment 1 to obtain zinc-dichloroimidazole coordinated dense film / 5A zeolite.

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

[0085] Example 7

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

[0087] The zinc-dichloroimidazole coordinated dense membrane / 5A zeolite sample prepared in this example was taken, and its propylene adsorption capacity was measured to be 0.02 mmol / g at 20 min, indicating that the formed membrane was 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., and the remaining steps are the same as those in embodiment 1.

[0090] A sample of the zinc-dichloroimidazole coordination dense film / 5A zeolite of this example was taken after electron beam irradiation and then etching with hexafluoroacetylacetone at 90°C. The propylene adsorption amount was measured to be 1.78 mmol / g at 20 minutes, 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 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., and the remaining steps are the same as those in embodiment 1.

[0093] A sample of the zinc-dichloroimidazole coordination dense film / 5A zeolite of this example was taken after electron beam irradiation and then etching with hexafluoroacetylacetone at 105°C. The propylene adsorption capacity was measured to be 2.04 mmol / g at 20 minutes, 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 coordinated dense film / 5A zeolite is not irradiated with an electron beam but is directly etched with hexafluoroacetylacetone at 105° C. The remaining steps are the same as in Example 1.

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

[0097] The propylene adsorption amounts of Examples 1 to 9, Comparative Example 1, the zinc-dichloroimidazole coordinated dense film of the original 5A zeolite / 5A zeolite, and the sample after hexafluoroacetylacetone etching at 20 minutes are summarized in Table 1.

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

[0099]

[0100] It can be seen from the data in Table 1 that a zinc-dichloroimidazole coordination dense film can be prepared by using diethyl zinc and 4,5-dichloroimidazole as precursors and 5A zeolite as a carrier using the atomic / molecular layer deposition method. The film will not be etched by hexafluoroacetylacetone when not irradiated by an electron beam, but can be etched by hexafluoroacetylacetone after irradiation by an electron beam, and is a positive electron beam resist film.

[0101] The optimal process conditions for preparing zinc-dichloroimidazole coordination dense film are: the atomic / molecular layer deposition film forming temperature of the precursors diethylzinc and 4,5-dichloroimidazole is 180°C, the number of cyclic deposition is 10 times, and the etching temperature after electron beam irradiation using hexafluoroacetylacetone as the reactive gas etchant is 100°C.

[0102] 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 technicians in this technical field within the essential scope of the present invention should also fall within the scope of protection of the present invention.

Claims

1. A method for preparing a zinc-dichloroimidazole coordination dense film, characterized in that: The steps include: (1) 5A zeolite was placed in a reactor, argon was introduced and vacuum was applied to remove impurity gases in the reaction system, and the 5A zeolite was heated to dehydrate and degas; (2) introducing film-forming precursors diethylzinc and 4,5-dichloroimidazole into the reactor treated in step (1) in a cyclic pulse manner, while introducing argon gas and simultaneously evacuating the reactor for purging, to deposit the film; (3) Activating the solid obtained in step (2) to obtain zinc-dichloroimidazole coordinated dense membrane / 5A zeolite.

2. The method for preparing a zinc-dichloroimidazole 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 a zinc-dichloroimidazole coordination dense film according to claim 1, characterized in that: In the step (2), the deposition film forming temperature is 160-190°C.

4. The method for preparing a zinc-dichloroimidazole coordination dense film according to claim 1, characterized in that: In the step (2), the deposition film forming cycle number is 5 to 15 times.

5. The method for preparing a zinc-dichloroimidazole 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 zinc-dichloroimidazole coordination dense film prepared by the method for preparing a zinc-dichloroimidazole coordination dense film according to any one of claims 1 to 5, characterized in that: The film is loaded on 5A zeolite and contains electron beam sensitive leaving groups. It is a positive resist film that will not be etched by hexafluoroacetylacetone when not irradiated by an electron beam, but can be etched by hexafluoroacetylacetone after irradiation by an electron beam.

7. The zinc-dichloroimidazole coordination dense film according to claim 6, characterized in that: After electron beam irradiation, the method of etching with hexafluoroacetylacetone includes: S1. The zinc-dichloroimidazole coordination dense film / 5A zeolite sample was loaded into the reactor, and argon gas was introduced while vacuuming the reaction system to remove impurity gases; S2 is passed through the reactor treated in step S1 pulse etchant hexafluoroacetylacetone, after which argon is purged and the etching cycle is performed; S3. Activate the solid obtained in step S2 to obtain a zinc-dichloroimidazole coordination dense film / 5A zeolite after hexafluoroacetylacetone etching.

8. The zinc-dichloroimidazole coordination dense film according to claim 7, characterized in that: In step S2, the etching temperature is 90-105°C.

9. The zinc-dichloroimidazole coordination dense film according to claim 7, characterized in that: In step S3, the activation treatment temperature is 120° C. and the activation treatment time is 60 minutes.

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