CN101957559A - Optical reversible nanoimprint photoresist as well as preparation method and application method thereof - Google Patents

Abstract

A photoreversible nanoimprint photoresist in the field of semiconductor manufacturing technology and its preparation and application method. 5% to 80% and 0.1% to 15% of photopolymerization initiator or photoacid generator, wherein the structural formula of the photoreversible crosslinking agent is:

The photoresist prepared by the invention has low viscosity, is convenient for spin-coating coating and embossing process operation, is photoreversible and has good etching resistance.

Description

Photoreversible nanoimprint photoresist and its preparation and application method

technical field

The invention relates to a material and a method in the technical field of micro-nano processing, in particular to a photoreversible nano-imprint photoresist and a preparation and application method thereof.

Background technique

Nanoimprint Lithography (NIL) was first proposed by Professor Stephen Y.Chou of Princeton University in 1995, and has received a lot of attention and development in recent years. Compared with other lithography technologies, NIL has the advantages of low cost, high resolution, and high productivity due to the omission of the cost of optical lithography masks and optical imaging equipment. At the same time, its characteristics of preparing high-resolution micro/nano-scale graphics make it applicable to a wide range of fields, including electronics, biology, and photonic crystals.

At present, the biggest challenge for the industrialization of nanoimprinting technology is the repeatability of imprinting and the utilization rate of the template, because in the imprinting process, the carrier template for traditional imprinting is made of quartz, which is not only expensive, but also easily broken After repeated work, the etching glue is easy to stick to the surface of the template, and these residual cured polymers can easily damage the replication precision of the structure. Therefore, it is very necessary to avoid residual colloid sticking to the surface of the template. Recently, the development of nanoimprint technology has basically focused on the development of new soft templates, fluorinated template surface technology, or directly adding fluorine-containing surfactants to self-assemble colloids to form surface monomolecular layers (SAM) to improve surface hydrophobicity. In order to improve the utilization rate of the formwork and reduce the cost of industrialization. However, the problem with these methods is that high-temperature heat treatment and high pressure are required for surface treatment of the template. At the same time, surface fluorination is not once and for all. The surface affects the process requirements for large-scale production. The present invention aims to develop a new type of photoreversible photoresist, which can degrade the cured polymer and redissolve it in an organic solvent by using the photoreversible property, so as to reduce the damage to the template caused by the conventional method of cleaning the template surface, and at the same time Residual cured photoresist can be cleaned with a simple treatment process, reducing the number of surface fluorination processes.

After searching the existing technologies, it is found that there are relatively few methods for photoresists with reversible properties, and most of the reversible adhesives are thermally reversible, which requires high temperature treatment to decompose and cure photoresists, and the process is cumbersome. At the same time, during the heat treatment process, the fluorine-containing compound modified on the surface of the template will be damaged, and acidic or alkaline substances may be produced during the thermally reversible reaction process, which will damage the microstructure of the quartz template. Aiming at the above shortcomings, the present invention invents a photoreversible cross-linking agent, and further prepares a photoreversible nano-imprint glue. Taking advantage of the photoreversible property, the residual polymer on the template surface can be decomposed and dissolved in the solvent under mild conditions. The whole process has basically no effect on the fluorine-containing layer of the template. utilization rate.

Contents of the invention

The present invention aims at the above-mentioned deficiencies in the prior art, and provides a photoreversible nanoimprint photoresist and its preparation and application method. The photoreversible characteristics of the prepared photoresist effectively reduce the conventional method of cleaning the surface of the template. damage to the template, and at the same time, the photoresist is used to prepare a large-area and high-precision nanometer-sized pattern structure, and has high etching resistance.

The present invention is achieved through the following technical solutions:

The present invention relates to a kind of crosslinking agent for preparing photoresist, and its molecular structural formula is:

Among them: R ₁ , R ₂ , R ₃ and R ₄ are hydrogen atom, C ₁ -C ₁₀ alkyl, C ₁ -C ₁₀ alkoxy, halogen, cyano, hydroxyl, C ₂ -C ₁₀ alkenyl, C ₂ -C ₁₀ alkynyl or C ₃ -C ₁₀ cycloalkyl, n is an integer of 1-10.

The R ₁ is preferably hydrogen, C ₁ -C ₆ alkyl, C ₁ -C ₆ alkoxy, halogen, cyano, hydroxyl, C ₂ -C ₆ alkenyl, C ₂ -C ₆ alkynyl or C ₃ -C ₆ cycloalkyl; more preferably hydrogen or methyl.

The R ₂ is preferably hydrogen, C ₁ -C ₆ alkyl, C ₁ -C ₆ alkoxy, halogen, cyano, hydroxyl, C ₂ -C ₆ alkenyl, C ₂ -C ₆ alkynyl or C ₃ -C ₆ cycloalkyl; more preferably hydrogen or methyl.

The R ₃ is preferably hydrogen atom, C ₁ -C ₁₀ alkyl, C ₁ -C ₁₀ alkoxy, halogen, cyano, hydroxyl, C ₂ -C ₁₀ alkenyl, C ₂ -C ₁₀ alkynyl or C ₃ -C ₁₀ cycloalkyl; further preferably hydrogen or methyl.

The R ₄ is preferably a hydrogen atom, C ₁ -C ₁₀ alkyl, C ₁ -C ₁₀ alkoxy, halogen, cyano, hydroxyl, C ₂ -C ₁₀ alkenyl, C ₂ -C ₁₀ alkynyl or C ₃ -C ₁₀ cycloalkyl; further preferably hydrogen or methyl.

Said n is preferably an integer of 1-8; more preferably 2 or 3.

The described cross-linking agent for preparing photoresist, its molecular structural formula is preferably:

The present invention relates to the preparation method of above-mentioned linking agent, comprises the steps:

The first step is to react the coumarin compound and the halogenated alcohol to form the coumarin derivative shown in the following structure:

The structural formula of described coumarin compound is:

The structural formula of described halohydrin is:

In the formula: R ₁ is selected from hydrogen atom, C ₁ -C ₁₀ alkyl, C ₁ -C ₁₀ alkoxy, halogen, cyano, hydroxyl, C ₂ -C ₁₀ alkenyl, C ₂ -C ₁₀ alkynyl and C ₃ -C ₁₀ cycloalkyl; X is halogen; n represents an integer of 1-10;

The second step is to react the coumarin derivative and the haloacetyl compound to prepare a crosslinking agent;

The structural formula of the haloacetyl compound is:

In the formula: X is halogen; R ₂ , R ₃ and R ₄ are each independently selected from hydrogen atom, C ₁ -C ₁₀ alkyl, C ₁ -C ₁₀ alkoxy, halogen, cyano, hydroxyl, C ₂ -C ₁₀ alkenyl, C ₂ -C ₁₀ alkynyl and C ₃ -C ₁₀ cycloalkyl.

The photoreversible nanoimprint photoresist prepared by the above-mentioned cross-linking agent of the present invention has components and mass percentages of: 5-50% of photo-reversible cross-linking agent, 5-80% of photopolymerizable compound and 0.1%-15% of photopolymerization initiator or photoacid generator, and the weight sum of each component is 100%.

The photoreversible crosslinking agent is preferably 2-[(4-methylcoumarinyl-7-yl)oxy]-ethyl acrylate (AHEMC), 2-[(2-oxo-2H-1 -benzopyran-7-yl)oxy]-ethyl ester (AHEC) or 2-[(4-methylcoumarinyl-7-yl)oxy]-ethyl methacrylate (MAHEMC).

The photopolymerizable compound refers to: a photopolymerizable compound having at least one polymerizable group includes: acrylate compound, methacrylate compound, epoxy compound, oxetane compound, vinyl ether compound or One or a combination of styrene compounds, such as: phenoxydiol (meth)acrylate, phenoxyethylene glycol (meth)acrylate, 2-phenoxyethyl (meth)acrylate , (meth) phenoxy polyethylene glycol acrylate, n-butyl (meth) acrylate, tert-butyl (meth) acrylate, methoxy triethylene glycol (meth) acrylate, (meth) ) methoxypolyethylene glycol acrylate, (meth)acrylic acid mountain

Alcohol esters, benzyl (meth)acrylate, 1-adamantyl (meth)acrylate, isobornyl (meth)acrylate, tridecyl (meth)acrylate, lauryl alcohol (meth)acrylate Esters, Octyloxypolyethylene glycol (meth)acrylate, 2-Hydroxy-3-phenoxypropyl (meth)acrylate, Isostearyl (meth)acrylate, Lauryl (meth)acrylate Alcohol Esters, Polyethylene Glycol Di(meth)acrylate, Ethoxylated Bisphenol A Di(meth)acrylate, Propoxylated Bisphenol A Di(meth)acrylate, Di(meth) 1,10-Decanediol Acrylate, Cyclodecane Dimethanol Di(meth)acrylate, Ethoxylated-2-Methyl 1,3-Propanediol Di(meth)acrylate, Di(methyl) Diethylene glycol acrylate, 1,4-butylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 2,2,3,3,4 di(meth)acrylate, 4,5,5-octafluoro-1,6-hexyl ester, 2-hydroxy-3-acryloyloxypropyl (meth)acrylate, ethylene di(meth)acrylate, propoxylated ethoxy Bisphenol A di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, but not limited thereto. These can be used individually or in combination of 2 or more types.

The epoxy compound includes: bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, bisphenol S diglycidyl ether, brominated bisphenol A diglycidyl ether, brominated bisphenol F diglycidyl ether Ether, brominated bisphenol S diglycidyl ether, hydrogenated bisphenol A diglycidyl ether, hydrogenated bisphenol F diglycidyl ether, hydrogenated bisphenol S diglycidyl ether, 1,4-butanediol diglycidyl ether , 1,6-hexanediol diglycidyl ether, glycerin triglycidyl ether, trimethylolpropane triglycidyl ether, polyethylene glycol diglycidyl ether, etc., but not limited thereto. These can be used individually or in combination of 2 or more types.

Described oxetane compound comprises: 3-ethyl-3-hydroxymethyl oxetane, 3-(methyl) allyloxymethyl-3-ethyl oxetane, (3-Ethyl-3-oxetanylmethoxy)methylbenzene, 4-fluoro-[1-(3-ethyl-3-oxetanylmethoxy)methyl]benzene, 4-methoxy Base-[1-(3-ethyl-3-oxetanylmethoxy)methyl]benzene, [1-(3-ethyl-3-oxetanylmethoxy)ethyl]phenyl ether, Isobutoxymethyl (3-ethyl-3-oxetanylmethyl) ether, isobornyloxyethyl (3-ethyl-3-oxetanylmethyl) ether, isobornyl (3- Ethyl-3-oxetanylmethyl) ether, etc., but not limited thereto. These can be used individually or in combination of 2 or more types.

The vinyl ether compounds include: n-propyl vinyl ether, n-butyl vinyl ether, n-hexyl vinyl ether, tert-butyl vinyl ether, tertiary amino vinyl ether, cyclohexyl vinyl ether, aryl Vinyl ether, dodecyl vinyl ether, ethylene glycol butyl vinyl ether, ethylhexyl vinyl ether, isobutyl vinyl ether, polyethylene glycol methyl vinyl ether, triethylene glycol methyl Diethylene glycol divinyl ether, triethylene glycol divinyl ether, butanediol divinyl ether, cyclohexanedimethanol divinyl ether, diethylene glycol divinyl ether, hexanediol divinyl ether, four Ethylene glycol divinyl ether, 1,4-butanediol divinyl ether, tricyclodecane dimethanol divinyl ether, trimethoxypropane trivinyl ether, etc., but not limited thereto. These can be used individually or in combination of 2 or more types.

Described styrene compound comprises: styrene, p-methylstyrene, p-methoxystyrene, β-methylstyrene, p-methyl-β-methylstyrene, α-methylstyrene, p- Methoxy-β-methylstyrene, p-hydroxystyrene, etc., but not limited thereto. These can be used individually or in combination of 2 or more types.

The photopolymerizable compound is preferably a photopolymerizable compound with a cyclic structure having at least one polymerizable group, and the cyclic structure is an aliphatic ring or an aromatic ring;

The aliphatic ring includes: a cycloalkyl group with 4 to 12 carbons and a group obtained by replacing the hydrogen atoms of these groups with any substituent;

The aromatic ring includes: phenyl, naphthyl, furyl, pyrrolyl, etc., and groups in which the hydrogen atoms of these groups are replaced by any substituents.

The polymerizable group is preferably an ethylenically unsaturated bond, more preferably any one of (meth)acrylate, vinyl ether, allyl ether or styrene, from the curability of the photosensitive resin composition From the viewpoint of (meth)acrylate is more preferable. In a preferred example of the present invention, it is selected from benzyl methacrylate and phenoxyethylene glycol acrylate.

The photopolymerizable compound is a photopolymerizable compound with a cyclic structure having two or more polymerizable groups, and its mass percentage in the photoreversible nanoimprint photoresist is 5-60%, more preferably 15-40%.

The photopolymerization initiator includes: 2,2-dimethoxy-1,2-diphenylethane-1-ketone, 1-hydroxyl-cyclohexyl-phenyl-ketone, 2-hydroxyl-2- Methyl-1-phenyl-propan-1-one, benzophenone, 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propane-1 -ketone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-propane-1-one, 2-benzyl-2-dimethylamino-1-(4 -morpholinophenyl)-butanone-1, bis(2,6-dimethoxybenzoyl)-2,4,4-trimethyl-pentylphosphine oxide, 2-hydroxy-2-methyl Base-1-phenyl-propan-1-one, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, bis(η5-2,4-cyclopentadien-1-yl )-bis(2,6-difluoro-3-(1H-pyrrol-1-yl)-phenyl)titanium, 2-(dimethylamino)-2-[(4-methylphenyl)methyl ]-1-[4-(4-morpholino)phenyl]-1-butanone, preferably 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-propane -1-one.

The photoacid generator includes: diazonium salt, iodine salt, bromine salt, chloride salt, sulfur salt, selenium salt, pyryl salt, thiopyryl salt, pyridinium salt and other salts; three (trihalomethyl)- Halogenated compounds such as s-triazine and its derivatives; 2-nitrobenzyl ester of sulfonic acid; iminosulfonate; 1-oxo-2-diazonaphthoquinone-4-sulfonate derivatives; Hydroxyiminosulfonate; tris(methylsulfonyloxy)benzene derivatives; bissulfonyldiazomethanes; sulfonylcarbonylalkanes; sulfonylcarbonyldiazomethanes; disulfone compounds, etc.

The invention relates to a preparation method of the photoreversible nano-imprint photoresist. The photoreversible nano-imprint photoresist is prepared by mixing a photoreversible crosslinking agent, a photoinitiator and a photopolymerizable compound.

The present invention relates to the application method of the above-mentioned photoreversible nanoimprint photoresist, by dissolving the photoresist in anhydrous chloroform and diluting it to a mass concentration of 5%, and passing the photoresist solution through a 0.2 micron filter After microfiltration, store it in a dark and frozen environment or use it to etch semiconductor silicon wafers.

The monomers and oligomers of the photoreversible nanoimprint photoresist are liquid at normal temperature (15-30° C.), and the viscosity at 25° C. is in the range below 20 mPa·s, preferably at It is within the range of 3 to 15 mPa·s, more preferably within the range of 8 to 13 mPa·s. By making it have such a viscosity, it is possible to impart the ability to form a fine uneven pattern, coating performance, and other processability before curing, and to impart resolution, residual film characteristics, substrate adhesion, and many other aspects after curing. Good film properties. When the viscosity of the photosensitive resin composition exceeds 20 mPa·s, the followability to the concave-convex pattern is poor, and it takes longer time and stronger pressure to fill the mold.

Aiming at the difficult technical problem of traditional imprinting photoresist, the invention designs and synthesizes a cross-linking agent with photoreversible properties, and then prepares photoresist suitable for nano-imprinting. Compared with existing photoresists, its technical effects include:

1. Low viscosity, easy to spin coating and embossing process operation.

2. The light is reversible, which is convenient to clean the surface of the template and improve the working efficiency of the template.

3. Low pressure, fully reduce the damage to the formwork caused by high pressure.

4. Low shrinkage, to ensure the minimum amount of deformation during the curing process, to ensure high replication accuracy.

5. Good etching resistance, can improve the etching efficiency of the substrate, facilitate pattern transfer, and ensure etching accuracy.

Description of drawings

Figure 1 depicts the NMR spectrum of the intermediate HEMC of the present invention.

Figure 2 depicts the nuclear magnetic resonance spectrum of the cross-linking agent AHEMC of the present invention.

Figure 3 describes the process flow of imprinting and pattern transfer.

Figure 4 depicts the SEM image of AHEMC-photoresist-1 after imprinting.

Figure 5 depicts a SEM image of pattern transfer to a silicon substrate.

Figure 6a depicts the UV spectrum of the photoresist coating after UV exposure in the 365 nm band.

Figure 6b depicts the UV spectrum of the photoresist coating after UV exposure in the 254 nm band.

Detailed ways

The embodiments of the present invention are described in detail below. This embodiment is implemented on the premise of the technical solution of the present invention, and detailed implementation methods and specific operating procedures are provided, but the protection scope of the present invention is not limited to the following implementation example.

Example 1 Preparation of Photoreversible Crosslinking Agent Acrylic acid 2-[(4-methylcoumarin-7-yl)oxy]-ethyl ester (AHEMC)

Take 10.0g (56.7mmol) of 4-methylcoumarin, 100mmol of 2-bromoethanol, and 120mmol of potassium carbonate in a three-necked flask, and measure 450ml of acetone solvent for dissolution. The mixture was refluxed at 60°C for 3 hours and filtered off with suction. The obtained solution was rotary evaporated to evaporate the solvent to dryness, and then recrystallized in ethanol to obtain the intermediate product HEMC with a yield of 95%.

Take 2g HEMC, 2g triethanolamine (TEA), and 40ml chloroform in a three-necked flask. In an ice-water bath, 3 g of acrylamide (AC) was added dropwise, and the reaction was stirred for 2 hours. The reaction was continued to stir at room temperature for 6 hours. Stop the reaction, let stand to separate layers, then wash the chloroform layer with water and dilute sulfuric acid three times, and then add anhydrous magnesium sulfate to the chloroform layer to remove residual unreacted substances. Finally, the obtained chloroform solution was evaporated to dryness on a rotary basis to obtain the final desired photoreversible cross-linking agent AHEMC with a yield of 70%-75%.

Example 2 Preparation of Photoreversible Imprint Adhesive AHEMC-Photoresist-1

Take by weighing respectively the photoreversible crosslinking agent AHEMC 0.1g of embodiment 1 gained, photoinitiator I-907 (Changzhou Qiangli Electronic New Material Co., Ltd.) 0.015g, monomer phenoxyethylene glycol acrylate (New Nakamura Chemical Industry Co., Ltd.) Company) 1.0 g was added into the reagent bottle one by one, stirred and mixed evenly to obtain a photoresist. 1.0 g of the obtained photoresist was weighed and diluted with anhydrous chloroform to a mass concentration of 5%. Microfilter the photoresist solution using a 0.2 micron filter and store frozen in the dark.

Example 3 Preparation of Photoreversible Imprint Adhesive AHEMC-Photoresist-2

Take by weighing embodiment 1 gained photoreversible crosslinking agent AHEMC 0.3g respectively, photoinitiator I-907 (Changzhou Qiangli Electronic New Material Co., Ltd.) 0.015g, monomer phenoxyethylene glycol acrylate (New Nakamura Chemical Industry Co., Ltd.) Company) 1.0 g was added into the reagent bottle one by one, stirred and mixed evenly to obtain a photoresist. 1.0 g of the obtained photoresist was weighed and diluted with anhydrous chloroform to a mass concentration of 5%. Microfilter the photoresist solution using a 0.2 micron filter and store frozen in the dark.

Example 4 Preparation of Photoreversible Imprint Adhesive AHEMC-Photoresist-3

Weigh 0.3g of the photoreversible crosslinking agent AHEMC obtained in Example 1, 0.030g of the photoinitiator I-907 (Changzhou Qiangli Electronic New Material Co., Ltd.), and 1.0g of the monomer benzyl methacrylate (Bailingwei) into the reagents one by one. In the bottle, stir and mix evenly to obtain a photoresist. 1.0 g of the obtained photoresist was weighed and diluted with anhydrous chloroform to a mass concentration of 5%. Microfilter the photoresist solution using a 0.2 micron filter and store frozen in the dark.

Example 5 Preparation of photoreversible imprinting adhesive AHEMC-photoresist-4

Take by weighing 0.3g of the photoreversible crosslinking agent AHEMC obtained in Example 1, photoinitiator Irgacure 184 (1-hydroxycyclohexyl phenyl ketone) (Changzhou Qiangli Electronic New Materials Co., Ltd.) 0.030g, monomer 1.0g methacrylic acid Benzyl ester (Baringwei) was added into the reagent bottle one by one, stirred and mixed evenly to obtain a photoresist. 1.0 g of the obtained photoresist was weighed and diluted with anhydrous chloroform to a mass concentration of 5%. Microfilter the photoresist solution using a 0.2 micron filter and store frozen in the dark.

Embodiment 6 AHEMC-photoresist-1 reversible glue imprinting and pattern transfer process

Figure 3 describes the process and conditions of the imprinting and pattern transfer of the photoresist of the present invention.

1. Substrate modification: place the silicon substrate to be modified in a mixed solution of 98% H ₂ SO ₄ : 30% H ₂ O ₂ with a volume ratio of 3: 1, and treat it at 150° C. for 3 hours. Then, it was rinsed several times with acetone and alcohol successively, dried, and then vacuum-dried at 120°C for 12 hours. The dried silicon wafer was immersed in an anhydrous toluene solution of 0.2 wt% 3-(trimethoxysilyl)propyl-2-methyl-2-acrylate (MAPTES), and sealed for 4 hours. The wafers were cleaned with acetone and dried with nitrogen gas for later use.

2. Use the spin coating process to spin the glue on the silicon wafer: AHEMC-photoresist-1 obtained in Example 2, at a low speed of 300 rpm for 10 s; at a high speed of 3000 rpm for 20 s.

3. Cover the colloid with a quartz template of a lattice structure with a period of 1.4 μm, and put it into a nanoimprinter together with a silicon wafer. As shown in Figure 2-B, vacuumize for 3 minutes, apply a pressure of 10 psi to the template, and hold the pressure for 20 minutes.

4. As shown in Figure 1-C, the silicon wafer and the quartz template were exposed to a 365nm ultraviolet light source for 15 minutes. After the photoresist is cured, the demoulding is performed directly. Figure 4 is a SEM image of the cured polymer after imprinting, illustrating that the photoresist of the present invention can support high resolution levels.

5. Place the demolded sample in a reactive ion etching vacuum chamber for etching, and the background vacuum of the vacuum chamber is 5×10 ^-3 Pa. Etching gas SF ₆ . Etch until the underlying silicon substrate is exposed, as shown in Figure 1-E, the flow rate is 20sccm, the power is 40w, the pressure is 60mTorr, and the etching time is 120s.

Embodiment 7AHEMC-photoresist-2 reversible glue imprinting

The entire process steps and parameters remain unchanged, except that the AHEMC-photoresist-2 photoresist obtained in Example 3 is used.

Embodiment 8 AHEMC-photoresist-3 reversible glue imprinting

The entire process steps and parameters remain unchanged, except that the AHEMC-photoresist-3 photoresist obtained in Example 4 is used.

Embodiment 9AHEMC-photoresist-4 reversible glue imprinting

The whole process steps and parameters remain unchanged, except that the AHEMC-photoresist-4 photoresist obtained in Example 5 is used.

Example 10 Photoreversible dissolution of cured reversible adhesive AHEMC-photoresist 1

After demoulding in Step 5 of Experimental Example 6, place the cured patterned polymer film under a 254nm point light source for continuous exposure for 2 hours, and then place it in chloroform solvent, and the polymer film will gradually rupture and dissolve. As shown in Figure 5b, after UV exposure in the 254nm band, the intensity of the characteristic absorption peak increases. Compared with the UV exposure spectrum in the 365nm band in Figure 5a, it shows that the cured polymer can be reversibly degraded. After 3 hours, the polymer film Basically dissolved in chloroform solvent.

Example 11 Photoreversible dissolution of cured reversible adhesive AHEMC-photoresist 2

The released AHEMC-photoresist 2 polymer film was placed under a 254nm point light source for continuous exposure for 2 hours, and then placed in a chloroform solvent, the polymer film gradually ruptured and dissolved. It is consistent with the result obtained in Experimental Example 10.

Example 12 Photoreversible dissolution of cured reversible adhesive AHEMC-photoresist 3

Place the demoulded AHEMC-photoresist 3 polymer film under a 254nm point light source for continuous exposure for 2 hours, and then place it in a chloroform solvent, the polymer film gradually ruptures and dissolves. It is consistent with the result obtained in Experimental Example 10.

Example 13 Photoreversible dissolution of cured reversible adhesive AHEMC-photoresist 4

The released AHEMC-photoresist 4 polymer film was placed under a 254nm point light source for continuous exposure for 2 hours, and then placed in a chloroform solvent, the polymer film gradually ruptured and dissolved. It is consistent with the result obtained in Experimental Example 10.

Comparative Example 1 Commercial glue Watershed 11110 embossing and pattern transfer

Whole process step and parameter are basically identical with embodiment 6, difference is to use commercially available commercial photoresist Watershed-Resist (Germany DSM Somos company). Due to the high viscosity of the commercial adhesive, the spin-coating process should be slightly adjusted. The method is as follows: Use the spin-coating process to spin the glue on the silicon wafer: low speed 300rpm, time 10s; medium speed 2000rpm, time 20s; high speed 4000rpm, time 20s . The commercial glue Watershed-Resist is not reversibly degradable.

Comparative Example 2 Commercial glue mr-NIL 6000 embossing and pattern transfer

Whole process step is identical with parameter basic embodiment 6, difference is to use commercially available commercial photoresist mr-NIL 6000 (U.S. micro resist technology GmbH company). Due to the high viscosity of the commercial adhesive, the spin-coating process should be slightly adjusted. The method is as follows: Use the spin-coating process to spin the glue on the silicon wafer: low speed 300rpm, time 10s; medium speed 2000rpm, time 20s; high speed 6000rpm, time 40s . The commercial glue Resist 6000 is not reversibly degradable.

Various performance tests were carried out on the above-mentioned three kinds of UV-curable resists for nanoimprinting, and the results are shown in Table 1. The current commercial nano-imprinting glue basically has no reversible properties. The residual polymer adhering to the template is generally decomposed by concentrated sulfuric acid at high temperature, which will not only destroy the fluorine-containing compounds on the surface, but also damage the microstructure of the template after multiple treatments. , and the processed template should be re-modified with fluorine-containing compounds. Compared with ordinary commercial glue, the photoresist provided by the present invention, due to its photoreversible property, the residual polymer on the template surface can be decomposed and dissolved in the solvent under mild conditions during the nanoimprinting process, without damage to the template structure , and basically has no effect on the fluorine-containing compounds modified by the template, which greatly improves the utilization rate of the template.

The sample viscosity is calculated by the Ubbelohde viscometer at 25°C through the flow time of the liquid sample and water, the sample density and the viscosity of water. The specific calculation formula is as follows:

$\frac{{\mathrm{<span\; class="notranslate">\; \&eta;</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}}{{\mathrm{<span\; class="notranslate">\; \&eta;</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; \&rho;</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}{\mathrm{<span\; class="notranslate">\; t</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}}{{\mathrm{<span\; class="notranslate">\; \&rho;</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="0"\; label="t"\; filenames="HDA0000025341130000032.png,HDA0000025341130000033.png"\; state="\{\{state\}\}">t</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}}$

Among them, ρ _i and ρ ₀ are the density of the sample and water respectively, t _i and t ₀ are the time required for the sample and water to flow through the same volume respectively, if the viscosity of the reference liquid H ₂ O at a certain temperature is known as η ₀ and ρ ₀ , and measure ρ _i , t ₀ , t _i to obtain the viscosity of the sample at this temperature.

The degree of vacuum and the exposure time correspond to the degree of vacuum of the embossing machine and the exposure time of the UV photoresist during the imprinting process, such as the schemes of steps 3 and 4 in Embodiment 6.

SF ₆ etch rate and etch selectivity method:

Etching rate: V=H/t, where H is the depth of etching, and t is the time required for etching.

Etching selectivity: Etching selectivity refers to the rate ratio of photoresist and substrate etching.

The whole etching process is completed in the plasma etching machine provided by Alcatel.

Claims (29)

1. a crosslinking chemical for preparing photoresist is characterized in that, its molecular structural formula is:

Wherein: R ₁, R ₂, R ₃And R ₄Be respectively hydrogen atom, C ₁-C ₁₀Alkyl, C ₁-C ₁₀Alkoxy, halogen, cyano group, hydroxyl, C ₂-C ₁₀Thiazolinyl, C ₂-C ₁₀Alkynyl or C ₃-C ₁₀Naphthenic base, n is the integer of 1-10.

2. the crosslinking chemical of preparation photoresist according to claim 1 is characterized in that, described R ₁Be hydrogen, C ₁-C ₆Alkyl, C ₁-C ₆Alkoxy, halogen, cyano group, hydroxyl, C ₂-C ₆Thiazolinyl, C ₂-C ₆Alkynyl or C ₃-C ₆Naphthenic base.

3. the crosslinking chemical of preparation photoresist according to claim 1 is characterized in that, described R ₂Be hydrogen, C ₁-C ₆Alkyl, C ₁-C ₆Alkoxy, halogen, cyano group, hydroxyl, C ₂-C ₆Thiazolinyl, C ₂-C ₆Alkynyl or C ₃-C ₆Naphthenic base.

4. the crosslinking chemical of preparation photoresist according to claim 1 is characterized in that, described R ₃Be hydrogen atom, C ₁-C ₁₀Alkyl, C ₁-C ₁₀Alkoxy, halogen, cyano group, hydroxyl, C ₂-C ₁₀Thiazolinyl, C ₂-C ₁₀Alkynyl or C ₃-C ₁₀Naphthenic base.

5. the crosslinking chemical of preparation photoresist according to claim 1 is characterized in that, described R ₄Be hydrogen atom, C ₁-C ₁₀Alkyl, C ₁-C ₁₀Alkoxy, halogen, cyano group, hydroxyl, C ₂-C ₁₀Thiazolinyl, C ₂-C ₁₀Alkynyl or C ₃-C ₁₀Naphthenic base.

6. the crosslinking chemical of preparation photoresist according to claim 1 is characterized in that, described n is the integer of 1-8.

7. according to the crosslinking chemical of arbitrary described preparation photoresist in the claim 1 to 6, it is characterized in that described R ₁, R ₂, R ₃And R ₄Be respectively hydrogen or methyl, n is 2 or 3.

8. the crosslinking chemical of preparation photoresist according to claim 1 is characterized in that, the crosslinking chemical of described preparation photoresist, and its molecular structural formula is:

9. the preparation method according to the described crosslinking chemical of above-mentioned arbitrary claim is characterized in that, comprises the steps:

The first step, make the reaction of coumarin compound and halohydrin, form the coumarin derivative shown in the following structure:

The structural formula of described coumarin compound is:

The structural formula of described halohydrin is:

In the formula: R ₁Be selected from hydrogen atom, C ₁-C ₁₀Alkyl, C ₁-C ₁₀Alkoxy, halogen, cyano group, hydroxyl, C ₂-C ₁₀Thiazolinyl, C ₂-C ₁₀Alkynyl and C ₃-C ₁₀Naphthenic base; X is a halogen; N represents the integer of 1-10;

Second goes on foot, makes coumarin derivative and the reaction of halo acetyl compound, prepares crosslinking chemical;

The structural formula of described halo acetyl compound is:

In the formula: X is a halogen; R ₂, R ₃And R ₄Be selected from hydrogen atom, C independently of one another ₁-C ₁₀Alkyl, C ₁-C ₁₀Alkoxy, halogen, cyano group, hydroxyl, C ₂-C ₁₀Thiazolinyl, C ₂-C ₁₀Alkynyl and C ₃-C ₁₀Naphthenic base.

10. reversible nano-imprint lithography glue of light for preparing according to the described crosslinking chemical of above-mentioned arbitrary claim, it is characterized in that, its component and mass percentage content are: light reversible cross-linking agent 5～50%, optical polymerism compound 5～80% and be Photoepolymerizationinitiater initiater or photoacid generator 0.1%～15%, the weight sum of each component is 100%.

11. reversible nano-imprint lithography glue of light for preparing according to the described crosslinking chemical of above-mentioned arbitrary claim, it is characterized in that, the nano-imprint lithography glue that described light is reversible, its component and mass percentage content are: light reversible cross-linking agent 15～40%, optical polymerism compound 15～60% and Photoepolymerizationinitiater initiater or photoacid generator 0.5～5%, the weight sum of each component is 100%.

12. the reversible nano-imprint lithography glue of light for preparing according to claim 10 or 11 described crosslinking chemicals, it is characterized in that described smooth reversible cross-linking agent is acrylic acid 2-[(4-methylcoumarin base-7-yl) the oxygen base]-ethyl ester, acrylic acid 2-[(2-oxo-2H-1-chromene-7-yl) the oxygen base]-ethyl ester or methacrylic acid 2-[(4-methylcoumarin base-7-yl) the oxygen base]-ethyl ester.

13. the reversible nano-imprint lithography glue of light according to claim 10 or 11 described crosslinking chemicals prepare is characterized in that described optical polymerism compound is meant: the optical polymerism compound with at least one polymerizable group.

14. the nano-imprint lithography glue that the light that crosslinking chemical according to claim 13 prepares is reversible, it is characterized in that described optical polymerism compound with at least one polymerizable group comprises: a kind of or its combination in acrylate compounds, methacrylate compound, epoxy compound, oxetane compound, vinyl ether compound or the distyryl compound.

15. the nano-imprint lithography glue that the light that crosslinking chemical according to claim 14 prepares is reversible, it is characterized in that, described epoxy compound comprises: bisphenol A diglycidyl ether, the Bisphenol F diglycidyl ether, bisphenol-S diglycidyl ether, brominated bisphenol A diglycidyl ether, brominated bisphenol F diglycidyl ether, brominated bisphenol S diglycidyl ether, the hydrogenated bisphenol A diglycidyl ether, A Hydrogenated Bisphenol A F diglycidyl ether, A Hydrogenated Bisphenol A S diglycidyl ether, 1, the 4-butanediol diglycidyl ether, 1, the 6-hexanediol diglycidyl ether, T 55, a kind of or its combination in trihydroxymethylpropanyltri diglycidyl ether or the polyethyleneglycol diglycidylether.

16. the nano-imprint lithography glue that the light that crosslinking chemical according to claim 14 prepares is reversible, it is characterized in that described oxetane compound comprises: 3-ethyl-3-methylol oxetanes, 3-(methyl) allyloxy methyl-3-ethyl oxetanes, (3-ethyl-3-oxa-cyclobutyl methoxy base) methylbenzene, 4-fluoro-(1-(3-ethyl-3-oxa-cyclobutyl methoxy base) methyl) benzene, 4-methoxyl-(1-(3-ethyl-3-oxa-cyclobutyl methoxy base) methyl) benzene, (1-(3-ethyl-3-oxa-cyclobutyl methoxy base) ethyl) phenyl ether, isobutoxy methyl (3-ethyl-3-oxa-cyclobutylmethyl) ether, a kind of or its combination in isoborneol oxygen base ethyl (3-ethyl-3-oxa-cyclobutylmethyl) ether or isobornyl (3-ethyl-3-oxa-cyclobutylmethyl) ether.

17. the nano-imprint lithography glue that the light that crosslinking chemical according to claim 14 prepares is reversible, it is characterized in that, described vinyl ether compound comprises: n-propyl vinyl ether, n-butyl vinyl ether, the n-hexyl vinyl ether, tert-Butyl vinyl ether, uncle's amido vinyl ether, cyclohexyl vinyl ether, vinyl aryl ether, dodecyl vinyl, the ethylene glycol butyl vinyl ether, the ethylhexyl vinyl ether, IVE, the polyglycol methyl vinyl ether, the triethylene glycol methyl vinyl ether, the triethylene glycol divinyl ether, the butylene glycol divinyl ether, the cyclohexanedimethanol divinyl ether, the diethylene glycol divinyl ether, the hexanediol divinyl ether, the TEG divinyl ether, 1,4-butylene glycol divinyl ether, a kind of or its combination in tristane dimethanol divinyl ether or the trimethoxy propane trivinyl ether.

18. the nano-imprint lithography glue that the light that crosslinking chemical according to claim 14 prepares is reversible, it is characterized in that described distyryl compound comprises: styrene, p-methylstyrene, to methoxy styrene, Beta-methyl styrene, to methyl-Beta-methyl styrene, α-Jia Jibenyixi, to a kind of or its combination in methoxyl-Beta-methyl styrene or the para hydroxybenzene ethene.

19. the reversible nano-imprint lithography glue of light according to claim 10 or 11 described crosslinking chemicals prepare is characterized in that described optical polymerism compound is preferably the optical polymerism compound of the ring texture with at least one polymerizable group.

20. the nano-imprint lithography glue that the light that crosslinking chemical according to claim 19 prepares is reversible is characterized in that, described ring texture is aliphatics ring or aromatic ring.

21. the nano-imprint lithography glue that the light that crosslinking chemical according to claim 20 prepares is reversible is characterized in that, described aliphatics ring comprises: the naphthenic base of carbon number 4～12 and the hydrogen atom of these groups be optionally substituted that base replaces and group; Described aromatic ring comprises: the hydrogen atom of phenyl, naphthyl, furyl, pyrrole radicals etc. and these groups be optionally substituted that base replaces and group.

22. the nano-imprint lithography glue that the light that crosslinking chemical according to claim 19 prepares is reversible is characterized in that, described polymerizable group is the ethylenic unsaturated link.

23. the reversible nano-imprint lithography glue of light according to claim 19 or 22 described crosslinking chemicals prepare is characterized in that described polymerizable group is (methyl) acrylate, vinyl ether, allyl ether or styrene.

24. the reversible nano-imprint lithography glue of light for preparing according to claim 10 or 11 described crosslinking chemicals, it is characterized in that, described optical polymerism compound is the optical polymerism compound with ring texture of the polymerizable group more than two, and its mass percent that is arranged in the reversible nano-imprint lithography glue of light is 15～40%.

25. the reversible nano-imprint lithography glue of light for preparing according to claim 10 or 11 described crosslinking chemicals; it is characterized in that; described Photoepolymerizationinitiater initiater comprises: 2; 2-dimethoxy-1; 2-diphenylethane-1-ketone; 1-hydroxyl-cyclohexyl-phenyl-ketone; 2-hydroxy-2-methyl-1-phenyl-propane-1-ketone; benzophenone; 1-[4-(2-hydroxyl-oxethyl)-phenyl-2-hydroxy-2-methyl-1-propane-1-ketone; 2-methyl isophthalic acid-[4-(methyl mercapto) phenyl-2-morpholino-propane-1-ketone; 2-benzyl-2-dimethylamino-1-(4-morpholino phenyl)-butanone-1; two (2; 6-dimethoxy benzoyl)-2; 4; 4-trimethyl-amyl group phosphine oxide; 2-hydroxy-2-methyl-1-phenyl-propane-1-ketone; two (2; 4; the 6-trimethylbenzoyl)-phenyl phosphine oxide; two (η 5-2; 4-cyclopentadiene-1-yl)-two (2,6-two fluoro-3-(1H-pyrroles-1-yl)-phenyl) titanium; 2-(dimethylamino)-2-[(4-aminomethyl phenyl) methyl]-1-[4-(4-morpholinyl) phenyl-1-butanone.

26. the reversible nano-imprint lithography glue of light for preparing according to claim 10 or 11 described crosslinking chemicals, it is characterized in that described photoacid generator comprises: the 2-nitrobenzyl ester of diazo salt, salt compounded of iodine, bromine salt, villaumite, sulfosalt, selenium salt, pyralium salt, thiapyran salt, pyridiniujm, halogenated compound, sulfonic acid; Imino group sulphonic acid ester, 1-oxo-2-diazo naphthoquinone-4-sulfonate derivatives, N-oxyimino sulphonic acid ester, three (mesyloxy) benzene derivative, two sulfonyl diazomethane class, sulfonyl carbonyl paraffinic, sulfonyl carbonyl diazomethane class or two sulphones.

27. preparation method according to the reversible nano-imprint lithography glue of arbitrary described light in the claim 9 to 26, it is characterized in that, by preparing the reversible nano-imprint lithography glue of light after light reversible cross-linking agent, light trigger and the optical polymerism compound.

28. application process according to the reversible nano-imprint lithography glue of arbitrary described light in the claim 9 to 26, it is characterized in that, by after being dissolved in described photoresist in the anhydrous chloroform and being diluted to mass concentration 5%, by 0.2 micron filtrator photoresist solution is carried out micro-filtration and be placed on and preserve under the lucifuge freezing environment or be used for the etching semiconductor silicon chip.

29. application process according to claim 28 is characterized in that, the reversible nano-imprint lithography glue of described light is in a liquid state at 15～30 ℃ of following monomer whoses and oligomer, in the scope of the viscosity under 25 ℃ below 20mPas.

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