Tricyclodecane-based asymmetric liquid spiro orthocarbonates and methods for their preparation

Abstract

The application belongs to the field of photoresists and electronic packaging materials, and particularly relates to an asymmetric liquid spiro orthocarbonate based on tricyclodecane and a preparation method thereof. The application belongs to the field of electronic materials, and the preparation process is as follows: tricyclodecane dimethyl alcohol, 2-butyl-2-ethyl-1,3-propanediol and tetraethyl orthocarbonate are reacted through statistical copolymerization ester exchange and azeotropic dealcoholization under the action of an acidic catalyst to obtain the compound. The compound is a transparent liquid at room temperature, has good mutual solubility with photoresist solvents such as propylene glycol methyl ether acetate, meanwhile, retains the high etching resistance of the tricyclodecane skeleton, and has cation ring-opening expansion characteristics. The resin after curing has excellent dimensional stability, etching resistance and processing performance, and is particularly suitable for high-end semiconductor photoresists and advanced packaging materials.

Description

Technical Field

[0001] This invention belongs to the field of photoresist and electronic packaging materials, specifically relating to an asymmetric liquid spirocyclic orthocarbonate based on tricyclodecane and its preparation method. Background Technology

[0002] As semiconductor manufacturing processes advance to more advanced nodes, photoresist materials face extremely high performance challenges. During photolithography patterning, the volume shrinkage during resin curing can cause the collapse or deformation of precise patterns, severely impacting yield. To address this issue, introducing spirocyclic orthocarbonate (SOC) monomers with a volume expansion mechanism has become an effective solution.

[0003] However, existing SOC monomers have significant drawbacks. Traditional aliphatic SOCs have poor resistance to dry etching and cannot meet the requirements of semiconductor processes; while high carbon density SOC monomers based on norbornene or tricyclodecane, due to their highly symmetrical structure, are usually high-melting-point crystalline solids, which have extremely poor solubility in common photoresist solvents such as propylene glycol methyl ether acetate, making it difficult to formulate high-concentration photoresist formulations, and they are prone to crystal precipitation during film formation, causing defects.

[0004] Therefore, developing a novel expanding monomer that retains the excellent etch resistance of the tricyclodecane backbone, is liquid at room temperature, and has excellent miscibility with photoresist solvents is a key technical problem that urgently needs to be solved. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide an asymmetric liquid spirocyclic orthocarbonate based on tricyclodecane and its preparation method. This compound, by introducing an asymmetric structure and flexible side chains, disrupts the crystallinity of the molecule, achieving a balance between "high etch resistance" and "excellent solubility".

[0006] The objective of this invention is achieved through the following technical solution: an asymmetric liquid spirocyclic orthocarbonate based on tricyclodecane, the main components of which are described by the following structural features: the molecular core is a 1,5,7,11-tetraoxaspiro[5.5]undecane skeleton, with tricyclodecyl groups and branched alkyl groups attached to both sides. This compound is prepared by a statistical copolyester exchange reaction of tricyclodecanediethanol, 2-butyl-2-ethyl-1,3-propanediol, and tetraethyl orthocarbonate.

[0007] A method for preparing an asymmetric liquid spirocyclic orthocarbonate based on tricyclodecane, characterized by the following steps: adding tetraethyl orthocarbonate, an organic solvent, and a catalyst to a reaction vessel equipped with a thermometer, cooling pipe, azeotropic distillation separator (water separator), stirrer, and gas protection device; heating to 110–140°C; dropwise adding a mixture of tricyclodecanediethanol and 2-butyl-2-ethyl-1,3-propanediol; maintaining reflux throughout the process; cooling and separating the azeotrope formed by the ethanol and organic solvent generated in the reaction; removing the ethanol and refluxing the organic solvent back into the reaction vessel; after the reaction is complete, cooling and adding an alkaline terminator to neutralize the catalyst; filtering to remove salt precipitates; and heating and vacuum distillation to remove the organic solvent to obtain the asymmetric liquid spirocyclic orthocarbonate based on tricyclodecane.

[0008] Preferably, the molar ratio of tricyclodecanediethanol, 2-butyl-2-ethyl-1,3-propanediol, and tetraethyl orthocarbonate is 1:1:1.

[0009] Preferably, the organic solvent is one or more of toluene, xylene, and cyclohexane.

[0010] Preferably, the catalyst is one or more of p-toluenesulfonic acid, methanesulfonic acid, and strong acid cation exchange resin; the amount of catalyst used is 0.1% to 1% of the total mass of the reactants.

[0011] Preferably, the alkaline terminating agent is triethylamine, pyridine, or sodium bicarbonate.

[0012] The beneficial effects of this invention are:

[0013] 1. Liquid properties and high solubility: The spirocyclic orthocarbonate prepared by this invention is a transparent viscous liquid at 25°C, which can be dissolved in any proportion in common photoresist solvents such as propylene glycol methyl ether acetate and cyclohexanone, thus solving the problem of easy crystallization and precipitation of traditional tricyclic decane derivatives.

[0014] 2. Excellent etch resistance: It retains the high carbon density tricyclodecane skeleton, and its dry etching resistance is significantly better than that of pure aliphatic monomers, meeting the requirements of dry etching process.

[0015] 3. Anti-shrinkage performance: Utilizing the cationic double ring-opening expansion mechanism of spirocyclic carbonate, it effectively counteracts the volume shrinkage during the photoresist curing process and prevents the pattern from collapsing.

[0016] 4. Simple preparation process: The one-pot statistical copolymerization method is adopted, the raw materials are cheap and readily available, the production cost is low, and it is suitable for industrial production. Detailed Implementation

[0017] The technical solution of the present invention will be described in further detail below, but the scope of protection of the present invention is not limited to the following description.

[0018] Example 1: A method for preparing an asymmetric liquid spirocyclic orthocarbonate based on tricyclodecane, comprising the following steps: 19.6 g (0.1 mol) tricyclodecanediethanol and 16.0 g (0.1 mol) 2-butyl-2-ethyl-1,3-propanediol are dissolved in 300 mL toluene and mixed thoroughly as a dropping solution. 19.2 g (0.1 mol) tetraethyl orthocarbonate, 200 mL toluene, and 0.1 g p-toluenesulfonic acid (approximately 0.18% of the total mass of the reactants) are added to a reaction vessel and heated to 110 °C. The above mixture is added dropwise over 2 hours. After the addition is complete, the reaction continues for 6 hours, with ethanol removed using a water separator throughout the process. After the reaction is complete, the temperature is lowered to room temperature, and 0.5 mL of triethylamine is added to neutralize the acidic catalyst. The resulting white precipitate is removed by filtration. The filtrate is then subjected to reduced pressure rotary evaporation at 60 °C and -0.09 MPa to remove toluene, finally yielding a pale yellow, transparent, viscous liquid product.

[0019] Example 2: A method for preparing an asymmetric liquid spirocyclic orthocarbonate based on tricyclodecane, comprising the following steps: 19.6 g (0.1 mol) tricyclodecanediethanol and 16.0 g (0.1 mol) 2-butyl-2-ethyl-1,3-propanediol are dissolved in 300 mL xylene and mixed thoroughly as a dropping solution. 19.2 g (0.1 mol) tetraethyl orthocarbonate, 200 mL xylene, and 0.2 g methanesulfonic acid (approximately 0.36% of the total mass of the reactants) are added to a reaction vessel and heated to 135–140 °C. The above mixture is added dropwise over 2 hours. After the addition is complete, the reaction continues for 5 hours, with ethanol removed using a water separator throughout the process. After the reaction is complete, the mixture is cooled to room temperature, and 0.5 g sodium bicarbonate is added to neutralize the acidic catalyst. The resulting white precipitate is removed by filtration. The filtrate is then subjected to reduced pressure rotary evaporation at 60 °C and -0.09 MPa to remove xylene, finally yielding a pale yellow, transparent, viscous liquid product.

[0020] 19.6 g (0.1 mol) tricyclodecanediethanol, 16.0 g (0.1 mol) 2-butyl-2-ethyl-1,3-propanediol, 19.2 g (0.1 mol) tetraethyl orthocarbonate, and 200 mL xylene were added to a reaction vessel equipped with a thermometer, cooling tube, azeotropic distillation separator, and stirrer. The mixture was heated until the xylene was refluxed. Ethanol generated during the reaction was carried away by the azeotropic distillation with xylene; after separation by a water separator, only the xylene was refluxed into the flask. The reaction was continued for 5 hours until no more ethanol distilled from the water separator and thin-layer chromatography showed the disappearance of the starting material spot. After the reaction was complete, the mixture was cooled to room temperature, and a neutralizing acidic catalyst was added. The resulting white precipitate was removed by filtration. The filtrate was then subjected to rotary evaporation under reduced pressure at 60 °C and -0.09 MPa to remove the xylene, yielding a colorless, transparent, viscous liquid.

[0021] Example 3: A method for preparing an asymmetric liquid spirocyclic orthocarbonate based on tricyclodecane, comprising the following steps: 98.0 g (0.5 mol) tricyclodecanediethanol and 80.0 g (0.5 mol) 2-butyl-2-ethyl-1,3-propanediol are dissolved in 300 mL toluene and mixed thoroughly as a dropping solution. 96.0 g (0.5 mol) tetraethyl orthocarbonate, 200 mL toluene, and 1.0 g of strongly acidic cation exchange resin (approximately 0.36% of the total reactants) are added to a reaction vessel and heated to 110 °C. The above mixture is added dropwise over 2 hours. After the addition is complete, the reaction continues for 4 hours, with ethanol removed using a water separator throughout the process. After the reaction is complete, the temperature is lowered to room temperature, and 1.0 mL of neutralizing acidic catalyst is added. The ion exchange resin and precipitate are removed by filtration. The filtrate is then subjected to reduced pressure rotary evaporation at 60 °C and -0.09 MPa to remove toluene, finally yielding a transparent liquid product.

[0022] Comparative Example 1: Preparation of a symmetrical tricyclic decane-based spirocyclic orthocarbonate (TCD-SOC-TCD): 39.2 g (0.2 mol) of tricyclic decanediethanol, 20.0 g of tetraethyl orthocarbonate, 150 mL of toluene, and 0.1 g of p-toluenesulfonic acid were added to a reaction flask. The reaction conditions were the same as in Example 1. After solvent removal, a grayish-white hard solid product was obtained.

[0023] Comparative Example 2: Preparation of a symmetric spirocyclic orthocarbonate based on 2-butyl-2-ethyl-1,3-propanediol (BEPD-SOC-BEPD): 32.0 g (0.2 mol) of 2-butyl-2-ethyl-1,3-propanediol was reacted with tetraethyl orthocarbonate under the same conditions as in Example 1. A low-viscosity, colorless liquid was obtained.

[0024] The compounds of the present invention prepared in Examples 1-3 and the compounds prepared in the comparative examples were subjected to physical property and photoresist application performance tests.

[0025] 1. Solubility test: Add the product to PGMEA (propylene glycol methyl ether acetate) at a concentration of 50 wt% and observe the solubility.

[0026] 2. Curing shrinkage test: Prepare a formula containing 30% test monomer, 67% alicyclic epoxy resin, and 3% thioonium salt initiator, and calculate the shrinkage rate by testing the density change before and after UV curing.

[0027] 3. Relative Etching Rate (RER): Based on standard polymethyl methacrylate (PMMA) photoresist (RER = 1.0), the lower the value, the better the etching resistance.

[0028] Table 1 Performance test data of embodiments and comparative examples of the present invention

[0029]

[0030] Results Analysis: As shown in Table 1, Comparative Example 1 (pure TCD structure) exhibits the best etch resistance (RER 0.78) and high expansion rate, but it is a solid and insoluble in PGMEA, making it unsuitable for photoresist formulations. Comparative Example 2 (pure BEPD structure), although liquid, suffers from poor etch resistance (RER 1.15), failing to meet semiconductor process requirements. The asymmetric spirocyclic monomers prepared in Examples 1-3 of this invention successfully achieved liquefaction (facilitating processing), and their etch resistance rate (0.85) is significantly superior to ordinary resins, approaching that of pure TCD structures. Simultaneously, they achieved micro-expansion in cured volume, perfectly resolving the impossible triangle of "solubility-etch resistance-shrinkage rate" in the photoresist field.

[0031] The above description is merely a preferred embodiment of the present invention. It should be understood that the present invention is not limited to the forms disclosed herein and should not be construed as excluding other embodiments. It can be used in various other combinations, modifications, and environments, and can be altered within the scope of the concept described herein through the above teachings or related technologies or knowledge. Modifications and variations made by those skilled in the art that do not depart from the spirit and scope of the present invention should be within the protection scope of the appended claims.

Claims

1. An asymmetric liquid spirocyclic protocarbonate based on tricyclodecane and its preparation method, characterized in that: Includes the following steps: Tetraethyl carbonate, organic solvent, and catalyst were added to a reactor equipped with a thermometer, cooling pipe, azeotropic distillation separator (water separator), stirrer, and gas protection device. The mixture was heated to 110–140 °C, and a mixture of tricyclodecanediethanol and 2-butyl-2-ethyl-1,3-propanediol was added dropwise. The entire process was carried out under reflux. The azeotrope formed by the ethanol and organic solvent produced in the reaction was cooled and separated. The ethanol was removed, and the organic solvent was refluxed back into the reactor. After the reaction was completed, the temperature was lowered, and an alkaline terminator was added to neutralize the catalyst. The salt precipitate was removed by filtration, and the organic solvent was removed by heating and vacuum distillation to obtain an asymmetric liquid spirocyclic orthocarbonate based on tricyclodecane.

2. The asymmetric liquid spirocyclic protocarbonate based on tricyclodecane and its preparation method according to claim 1, characterized in that: The molar ratio of tricyclodecanediethanol, 2-butyl-2-ethyl-1,3-propanediol, and tetraethyl orthocarbonate is 1:1:

1.

3. The asymmetric liquid spirocyclic protocarbonate based on tricyclodecane and its preparation method according to claim 1, characterized in that: The organic solvent is one or more of toluene, xylene, and cyclohexane.

4. The asymmetric liquid spirocyclic protocarbonate based on tricyclodecane and its preparation method according to claim 1, characterized in that: The catalyst is one or more of p-toluenesulfonic acid, methanesulfonic acid, and strong acid cation exchange resin; the amount of catalyst used is 0.1% to 1% of the total mass of the reactants.

5. The asymmetric liquid spirocyclic protocarbonate based on tricyclodecane and its preparation method according to claim 1, characterized in that: The alkaline terminating agent is triethylamine, pyridine, or sodium bicarbonate.

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