CN1719338B - Ultraviolet ray solidification cation type etching glue for nano embossing - Google Patents

Abstract

The UV-curable cationic etching glue for nanoimprinting disclosed by the present invention is composed of: 10%-60% of cycloaliphatic epoxy, 0%-30% of silicone epoxy resin, and vinyl ether 10%-40%, polycaprolactone polyol 0%-20%, long-chain aliphatic epoxy 0%-15%, photoinitiator 1%-10%, additives 0%-8%, each component The sum of the weights is 100%, wherein the photoinitiator is selected from one or more of the following compositions: diaryl iodonium phosphate, triaryl sulfonium hexafluoroantimonate or triaryl sulfonium hexafluoro Arsenate, additives include organosilane coupling agent, organosilane leveling agent, organic alcohol or polyether alkyl co-modified silicone oil defoamer. Compared with the positive or negative glue used in the current microelectronics industry, the etching glue of the present invention has no volatile solvent, low viscosity, fast curing speed, low shrinkage, high adhesion, and high corrosion resistance. Photocurable etchant for imprint manufacturing.

Description

UV Curable Cationic Etching Adhesive for Nanoimprinting

technical field

The invention relates to an etching glue, in particular to an ultraviolet light curing cationic etching glue used in the manufacture of nano imprinting.

Background technique

In the traditional photolithographic integrated circuit manufacturing process, the shape or inversion of the integrated circuit is formed in the designated area of the photoresist by mask exposure method. The photoresist used is positive photoresist or negative photoresist. , in order to facilitate the formation of a certain thickness of the film, the positive or negative photoresist contains volatile solvents, after the film is coated, it is necessary to dry the volatile solvents. However, in the process of manufacturing fine features (including integrated circuits) by nanoimprinting, positive or negative photoresists are completely unsuitable due to their shortcomings such as volatile solvents and large shrinkage.

To manufacture fine features (including integrated circuits) by nanoimprinting, first coat a layer of liquid photocurable etchant on the substrate (polysilicon or other materials), and then engrave the transparent quartz template with fine features (100-500 nanometers) Press down on the liquid etching glue, wait until the liquid etching glue is completely squeezed into the microcavity with fine features, and then irradiate and expose with ultraviolet light. After being irradiated by ultraviolet light, the liquid etching glue undergoes photopolymerization and solidifies , so as to form the inverse micro-features corresponding to the micro-mold features on the etchant, and then open the mold and perform plasma etching on the stripped etchant, and transfer the micro-features to the substrate to form a single-layer structure. integrated circuits or microfeatures. In this process, since traditional photoresists (positive or negative photoresist) contain volatile solvents, after coating, the micro-mold is pressed down to seal the volatile solvents in the microcavity, and bubbles or bubbles will be generated during exposure and curing. The curing strength becomes lower, so that the accuracy of the replica becomes worse; if post-baking treatment is performed after coating to volatilize the solvent, the etching glue after post-baking treatment becomes solid or semi-solid, and the pressure of the transparent quartz micro-mold It is basically impossible to squeeze the solid or semi-solid etchant into the micro-featured cavity during the process, so the traditional etchant is not suitable for the nanoimprint manufacturing process.

Contents of the invention

The purpose of the present invention is to provide a UV-curable cationic etchant for nanoimprinting, which solves the problem that in the nanoimprint manufacturing process, the traditional etchant tends to generate bubbles or reduce the curing strength, thereby reducing the precision of the replica. Problems with poor or insufficient extrusion into the fine feature cavities of the mold.

The technical scheme adopted in the present invention is that the UV-curable cationic etching glue for nanoimprinting is composed of:

Alicyclic epoxy 10% ~ 60%;

γ-glycidyl etheroxypropyltrimethoxysilane 3% or β-(3,4 epoxycyclohexyl)-ethyltrimethoxysilane 10%;

Vinyl ether 10% ~ 40%;

Polycaprolactone diol or polycaprolactone triol 10%, or polycaprolactone triol 20%;

1,2-epoxydodecane 5%;

Photoinitiator 1% ~ 10%;

Auxiliary 0% ~ 8%; the sum of the weight of each component is 100%,

Wherein, the photoinitiator is selected from one or more of the following compositions: diaryl iodonium phosphate, triaryl sulfonium hexafluoroantimonate or triaryl sulfonium hexafluoroarsenate,

Auxiliaries include organosilane coupling agent, organosilane leveling agent, organic alcohol or polyether alkyl co-modified silicone oil defoamer.

The present invention is also characterized in that:

Alicyclic epoxy is selected from the following one or more combinations: 3,4-epoxy cyclohexyl carboxylate-3',4'-epoxy cyclohexyl methyl ester, bis-(3,4- Epoxycyclohexyl)-adipate, dicyclopentadiene dioxide, 3,4-epoxy-6-methyl-cyclohexylcarboxylate-3′,4′-epoxy-6′-methanol Dicyclohexyl methyl ester, α-dicyclopentyl ether, β-dicyclopentyl ether, dicyclopentadiene glycol ether or vinylcyclohexene monoxide.

Silicone epoxy resin is selected from one or more of the following compositions: linear polydimethylsiloxane modified dicyclohexyl epoxy, β-(3,4 epoxycyclohexyl)-ethyl Trimethoxysilane, gamma-glycidoxypropyltrimethoxysilane.

Vinyl ether is selected from the following one or a combination of more than one: triethylene glycol divinyl ether, 1,4-cyclohexyl dimethanol divinyl ether, glycerol carbonate propenyl ether or dodecyl vinyl ether ether.

Polycaprolactone polyol is polycaprolactone diol or polycaprolactone triol.

The long-chain aliphatic epoxy is 1,2-epoxyhexadecane or 1,2-epoxydodecane.

The UV-curable cationic etching glue for nanoimprinting of the present invention has the following properties:

1. Low viscosity, easy to spin coating process operation to form a film below 1 micron.

2. Low shrinkage ensures minimum deformation during curing, and small deformation can ensure high replication accuracy.

3. High curing speed can ensure high nanoimprint replication efficiency.

4. The stability of film formation is good, and the film is uniform, which ensures the accuracy and efficiency of imprinting and replicating.

5. Good adhesion, which can better protect the substrate during etching, and the fine features will not lose their shape after etching.

6. Good corrosion resistance, which can improve the etching efficiency of the substrate and ensure the etching accuracy.

Description of drawings

Figure 1 is a schematic diagram of the micro-feature manufacturing process by nanoimprinting, in which a is the pressing process of the quartz template, b is the curing and molding process of the etching glue, and c is the shape after demoulding.

Figure 2 is the shape of the etchant after embossing.

In the figure, 1. Quartz template, 2. Micro-cavity, 3. Etching glue, 4. Silicon wafer.

Detailed ways

The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments.

The UV-curable cationic etching glue for nanoimprinting of the present invention is composed of: 10%-60% of alicyclic epoxy resin, 0%-30% of silicone epoxy resin, and 10% of vinyl ether. %～40%, polycaprolactone polyol 0%～20%, long chain aliphatic epoxy 0%～15%, photoinitiator 1%～10%, additive 0%～8%, each component The sum of the weights is 100%, wherein the photoinitiator is selected from one or more than one of the following compositions: diaryl iodonium phosphate, triaryl sulfonium hexafluoroantimonate or triaryl sulfonium hexafluoroarsenic Acid salts, additives include organosilane coupling agent, organosilane leveling agent, organic alcohol or polyether alkyl modified silicone oil defoamer.

The cycloaliphatic epoxy and silicone epoxy resin in the etching glue of the present invention are film-forming substances, and are the main components that determine the physical and mechanical properties of the UV-curable etching glue. , Viscosity, curing speed, adhesion, flexibility, water resistance, corrosion resistance, etc. have a great influence. Alicyclic epoxy has a large ring-opening tension due to the epoxy group connected to the saturated aliphatic six-membered ring, and can undergo cationic ring-opening polymerization. Due to the existence of the saturated six-membered alicyclic ring, it can endow the etchant with better Excellent hardness and etching resistance, by adjusting the chain segment structure between the alicyclic rings, the etching glue has a certain degree of flexibility at the same time, which is convenient for demoulding after curing without causing brittle fracture of fine features. Among the present invention, cycloaliphatic epoxy is selected from the following one or more compositions: 3,4-epoxy cyclohexyl formic acid-3', 4'-epoxy cyclohexyl methyl ester, bis-(3 , 4-epoxycyclohexyl)-adipate, dicyclopentadiene dioxide, 3,4-epoxy-6-methyl-cyclohexylcarboxylate-3′,4′-epoxy-6 '-Methylcyclohexyl methyl ester, α-dicyclopentyl ether, β-dicyclopentyl ether, dicyclopentadiene glycol ether or ethylene cyclohexene monoxide, choose more than one In the composition, there is no content ratio requirement among the components, as long as the ratio of the total content in the etchant satisfies 10% to 60%.

Silicone epoxy resin also has epoxy bonds and can undergo cationic ring-opening polymerization. At the same time, due to the presence of silicon-oxygen bonds, it can endow the etchant with a lower surface energy, so that the etchant can be imprinted and shaped during the process of being stamped and detached. When molding, the adhesion between the etchant and the micro-mold is small, which is convenient for demolding, and can also improve the number of times and life of the mold. Cycloaliphatic epoxy and silicone epoxy undergo ring-opening polymerization, and the polymerization process is a transformation from covalent bond to covalent bond, so it has the characteristics of small volume shrinkage. In the present invention, the organosilicon epoxy resin is selected from one or more of the following compositions: linear and bulk polydimethylsiloxane modified dicyclohexyl epoxy, β-(3,4 epoxycyclohexyl) -Ethyltrimethoxysilane, γ-glycidyloxypropyltrimethoxysilane, when more than one composition is selected, there is no requirement for the content ratio of each component.

The vinyl ether group structure allows it to undergo cationic photopolymerization. At the same time, because vinyl ether has a very low viscosity and has a good dilution effect, it can make the etchant have a lower viscosity, which is convenient for processing. Spin-coating uniform coating process to form sub-micron films. In the present invention, vinyl ether is selected from the following one or more compositions: triethylene glycol divinyl ether, 1,4-cyclohexyl dimethanol divinyl ether, glycerol carbonate propenyl ether or dodecane Base vinyl ether, when more than one combination is selected, there is no requirement for the content ratio between the components.

Polycaprolactone polyol has hydroxyl groups, so it can participate in cationic polymerization reaction. At the same time, polycaprolactone polyol can endow the etchant with good toughness and improve the degree of crosslinking, so that the etchant has the characteristics of hard and tough , Improve the corrosion resistance of the etchant. The polycaprolactone polyol in the present invention is preferably polycaprolactone diol or polycaprolactone triol.

Long-chain aliphatic epoxy has an epoxy group, which is a monofunctional active monomer, and can undergo cationic ring-opening reaction. The long aliphatic chain in the molecule endows the etchant with good flexibility and flatness. The low viscosity can also act as a diluent to reduce the viscosity of the etchant. The long-chain aliphatic epoxy in the present invention is preferably 1,2-epoxyhexadecane or 1,2-epoxydodecane.

The photoinitiator is used in a small amount in the photocurable resist, but it has a great influence on the curing speed and storage stability of the resist. The present invention adopts one or more compositions of diaryl iodonium phosphate, triaryl sulfonium hexafluoroantimonate or triaryl sulfonium hexafluoroarsenate, and there is no content ratio requirement in the composition .

Auxiliaries play the role of eliminating bubbles in the etchant, forming a flat film and a stable film. The auxiliary agent of the present invention includes organosilane coupling agent, organosilane leveling agent, organic alcohol or polyether alkyl modified silicone oil defoamer, and antioxidant and thermal stabilizer can also be added to the auxiliary agent.

0％～20％的聚己内酯多元醇 

0％～15％的长链脂肪族环氧加入装置中高速搅拌，搅拌混合2小时后形成均匀液体B，然后加入溶液A，再混合搅拌2小时得到均匀液体C，之后边搅拌边依次加入总重量比为0％～8％的消泡剂、流平剂、偶联剂等助剂，加完助剂后再搅拌2小时即得到纳米压印用紫外光固化阳离子型刻蚀胶。When making the resist of the present invention, at first select the component of photoinitiator: one or one of diaryl iodonium phosphate, triaryl sulfonium hexafluoroantimonate or triaryl sulfonium hexafluoroarsenate More than one composition, the photoinitiator is controlled to account for 1% to 10% of the total etching glue weight. When the initiator contains diaryliodonium phosphate, the diaryliodonium phosphate is heated at 50 ° C. Dissolve with vinyl ether, cool to room temperature after dissolving, then add triarylsulfonium hexafluoroantimonate or triarylsulfonium hexafluoroarsenate and stir evenly, the amount of vinyl ether is 10% of the total weight ratio ~40% to form a homogeneous solution A; the total weight ratio of 10% to 60% of cycloaliphatic epoxy 0%～30% silicone epoxy resin

0%～20% polycaprolactone polyol

Add 0% to 15% long-chain aliphatic epoxy into the device and stir at high speed. After stirring and mixing for 2 hours, a uniform liquid B is formed, then add solution A, and mix and stir for another 2 hours to obtain a uniform liquid C. Then add the total solution while stirring. The weight ratio is 0%-8% of additives such as defoaming agent, leveling agent, coupling agent, etc. After adding the additives, it is stirred for 2 hours to obtain the UV-curable cationic etching glue for nanoimprinting.

Figure 1 shows a schematic diagram of the process of manufacturing fine features by nanoimprinting. The base material is a silicon wafer 4, and the etchant 3 is uniformly spin-coated or sprayed on the silicon wafer 4, and then the transparent quartz template 1 engraved with fine features (100-500 nanometers) is pressed down on the liquid etchant 3 After the liquid etchant 3 is completely squeezed into the microcavity of the microcavity 2 with fine features, it is irradiated and exposed with ultraviolet light for 0.1 second to 1 second, and the liquid etchant 3 emits light after being irradiated by ultraviolet light. Polymerization reaction and solidification, thereby forming on the etchant 3 the anti-type fine features corresponding to the characteristics of the imprint mold 2, and then opening the mold and performing plasma etching on the stripped etchant 3 to transfer the fine features to the silicon Integrated circuits or fine features having a single-layer structure are formed on the wafer 4 .

Example 1

15％的线性聚二甲基硅氧烷 10％的聚己内酯二元醇加入装置中高速搅拌，搅拌混合2小时后形成均匀液体B，然后加入溶液A，再混合搅拌2小时得到均匀液体C，之后边搅拌边加入总重量比分别为0.4％的有机醇消泡剂、1％的聚醚改性二甲基硅氧烷流平剂、2％的有机硅烷类偶联剂助剂，加完助剂后再搅拌2小时即得到纳米压印用紫外光固化阳离子型刻蚀胶。First choose the mixture of diaryliodonium phosphate and triarylsulfonium hexafluoroantimonate as photoinitiator, the weight of photoinitiator is 3% of total etching glue weight, wherein diaryliodonium phosphate accounts for 70% of photoinitiator, triarylsulfonium hexafluoroantimonate accounts for 30% of photoinitiator, gets the triethylene glycol divinyl ether of gross weight 15%, photoinitiator diaryliodonium phosphate is in Dissolve in triethylene glycol divinyl ether at 50°C, add triarylsulfonium hexafluoroantimonate after cooling to room temperature and stir to form a homogeneous solution A; 3′,4′-epoxycyclohexylmethyl cyclohexanecarboxylate

15% linear polydimethylsiloxane Add 10% polycaprolactone diol into the device and stir at high speed, stir and mix for 2 hours to form a uniform liquid B, then add solution A, and mix and stir for 2 hours to obtain a uniform liquid C, then add the total weight ratio while stirring 0.4% of organic alcohol defoamer, 1% of polyether modified dimethyl siloxane leveling agent, 2% of organic silane coupling agent auxiliary agent, after adding the auxiliary agent, stir for 2 hours to obtain UV-curable cationic resists for nanoimprinting.

Example 2

Firstly, the mixture of 1% diaryliodonium phosphate and 1% triarylsulfonium hexafluoroarsenate is selected as the photoinitiator in the total weight ratio, and the photoinitiator diaryliodonium phosphate is heated at 50° C. Dissolve with 1,4-cyclohexyldimethanol divinyl ether, the amount of 1,4-cyclohexyldimethanol divinyl ether is 10% of the total weight ratio, after dissolving, cool to room temperature and add triarylsulfonium hexafluoroarsenic Acid acid salt is stirred to form a homogeneous solution A; the total weight ratio is respectively 40% of 3,4-epoxy cyclohexanecarboxylic acid-3',4'-epoxy cyclohexyl methyl ester and 20% of bis-(3 , a mixture of 4-epoxycyclohexyl)-adipate Add 20% polycaprolactone trihydric alcohol into the device and stir at a high speed. After stirring and mixing for 2 hours, a uniform liquid B is formed, then add solution A, and then mix and stir for 2 hours to obtain a uniform liquid C. Then add the total weight ratio while stirring. 8% polyether alkyl co-modified silicone oil defoamer, leveling agent and coupling agent auxiliary agent, after adding the auxiliary agent, stir for 2 hours to obtain the UV-curable cationic etching glue for nanoimprinting.

Example 3

15％的1，2-环氧基十六烷放入装置中高速搅拌，搅拌混合2小时后形成均匀液体B，然后加入溶液A，再混合搅拌2小时得到均匀液体C，之后边搅拌边加入总重量比为4％的助剂，助剂包括聚醚烷基共改性硅油消泡剂、流平剂、偶联剂、抗氧化剂和热稳定剂，加完助剂后再搅拌2小时即得到纳米压印用紫外光固化阳离子型刻蚀胶。First select the mixture of 0.2% diaryl iodonium phosphate and 0.8% triaryl sulfonium hexafluoroantimonate as the photoinitiator in the total weight ratio, and make the diaryl iodonium phosphate photoinitiator at 50°C Dissolve with the mixed solution of glycerol carbonate propenyl ether and dodecyl vinyl ether, the mixed solution of glycerol carbonate propenyl ether and dodecyl vinyl ether is 40% of the total weight ratio, after dissolving, cool to Stir at room temperature and add triarylsulfonium hexafluoroantimonate to form a homogeneous solution A; 3,4-epoxy-6-methyl-cyclohexylcarboxylic acid-3', 4' with a total weight ratio of 10% - Epoxy-6'-methylcyclohexyl methyl ester and 30% bulk dimethicone

Put 15% 1,2-epoxyhexadecane into the device and stir at a high speed. After stirring and mixing for 2 hours, a uniform liquid B is formed, then add solution A, and mix and stir for 2 hours to obtain a uniform liquid C, and then add it while stirring The total weight ratio is 4% auxiliary agent, which includes polyether alkyl co-modified silicone oil defoamer, leveling agent, coupling agent, antioxidant and heat stabilizer, and after adding the auxiliary agent, stir for 2 hours. The UV-curable cationic etching glue for nanoimprinting is obtained.

Example 4

10％的聚己内酯三元醇 

5％的1，2-环氧基十二烷放入装置中高速搅拌，搅拌混合2小时后形成均匀液体B，然后加入溶液A，再混合搅拌2小时得到均匀液体C，液体C即是纳米压印用紫外光固化阳离子型刻蚀胶。The diaryliodonium phosphate photoinitiator that the total weight ratio is 10% is dissolved with dodecyl vinyl ether at 50°C, and the amount of dodecyl vinyl ether is 30% of the total weight ratio to form a uniform Solution A; the total weight ratio is respectively 35% of β-dioxycyclopentyl ether and 10% of β-(3,4 epoxycyclohexyl)-ethyltrimethoxysilane

10% polycaprolactone triol

Put 5% 1,2-epoxydodecane into the device and stir at a high speed. After stirring and mixing for 2 hours, a uniform liquid B is formed, then add solution A, and mix and stir for 2 hours to obtain a uniform liquid C. Liquid C is nano UV-curable cationic resist for imprinting.

Example 5

The triarylsulfonium hexafluoroarsenate photoinitiator with a total weight ratio of 8% is dissolved at room temperature with glycerol carbonate propenyl ether, and the amount of glycerol carbonate propenyl ether is 25% of the total weight ratio to form a homogeneous solution A; total weight ratio is respectively 20% dicyclopentadiene dioxide 27% 3,4-epoxy-6-methyl-cyclohexylcarboxylate-3' 4′-Epoxy-6′-methylcyclohexylmethyl ester and 3% of γ-glycidyloxypropyltrimethoxysilane Put 15% 1,2-epoxyhexadecane into the device and stir at a high speed. After stirring and mixing for 2 hours, a uniform liquid B is formed, then add solution A, and mix and stir for 2 hours to obtain a uniform liquid C, and then add it while stirring The total weight ratio is 2% auxiliary agent, the auxiliary agent includes polyether alkyl co-modified silicone oil defoamer, leveling agent and coupling agent, after adding the auxiliary agent, stir for 2 hours to obtain the ultraviolet light for nanoimprinting Curing cationic etchant.

Various performance tests were carried out on the above five UV-curable cationic etching glues for nanoimprinting, and the results are shown in Table 1.

Compared with the positive or negative glue used in the current microelectronics industry, the UV-curable cationic etching glue for nanoimprinting of the present invention has the advantages of no volatile solvent, low viscosity, fast curing speed, low shrinkage, and high adhesion. High strength and high corrosion resistance, it is an excellent and environmentally friendly photocurable etchant for nanoimprint manufacturing.

Claims (3)

1. A UV-curable cationic etchant for nanoimprinting, which consists of 10% to 60% cycloaliphatic epoxy by weight percentage; γ-glycidyl etheroxypropyltrimethoxysilane 3% or β-(3,4 epoxycyclohexyl)-ethyltrimethoxysilane 10%; Vinyl ether 10% ~ 40%; Polycaprolactone diol or polycaprolactone triol 10%, or polycaprolactone triol 20%; 1,2-epoxydodecane 5%; Photoinitiator 1% ~ 10%; Auxiliary 0% ~ 8%; the sum of the weight of each component is 100%, Wherein, the photoinitiator is selected from one or more of the following compositions: diaryl iodonium phosphate, triaryl sulfonium hexafluoroantimonate or triaryl sulfonium hexafluoroarsenate, Auxiliaries include organosilane coupling agent, organosilane leveling agent, organic alcohol or polyether alkyl co-modified silicone oil defoamer. 2. The etchant according to claim 1, wherein the alicyclic epoxy is selected from one or more of the following compositions: 3,4-epoxycyclohexylcarboxylic acid-3' , 4'-epoxycyclohexyl methyl ester, bis-(3,4-epoxycyclohexyl)-adipate, dicyclopentadiene dioxide, 3,4-epoxy-6-methyl -Cyclohexyl carboxylic acid-3', 4'-epoxy-6'-methylcyclohexyl methyl ester, α-dicyclopentyl ether dioxide, β-dicyclopentyl ether dioxide, dicyclopentadiene ethylene dioxide Glycol ethers or vinylcyclohexene monoxide. 3. The etchant according to claim 1, wherein the vinyl ether is selected from one or more of the following compositions: triethylene glycol divinyl ether, 1,4-cyclohexyl di Methanol divinyl ether, glycerol carbonate propenyl ether or dodecyl vinyl ether. After becoming solid or semi-solid, it is basically impossible to squeeze the solid or semi-solid etchant into the micro-featured cavity during the pressing process of the transparent quartz micro-mold, so the traditional etchant is not suitable for the nanoimprint manufacturing process.