Silsesquioxane-based chemical amplification type photoresist as well as preparation method and application thereof

Abstract

The invention discloses a chemical amplification type photoresist based on silsesquioxane, which comprises incompletely condensed polysilsesquioxane, a photoacid generator and an organic solvent, the incompletely condensed polysilsesquioxane is cage type polysilsesquioxane, and is one or more of compounds shown in a formula (1); compared with the prior art, the chemical amplification type photoresist based on silsesquioxane has the advantages that the sensitivity and the stability are obviously improved, and the chemical amplification type photoresist can be used for electron beam lithography, deep ultraviolet lithography or extreme ultraviolet lithography and has important application value and wide market prospect. (1) (R1SiO1.5) l (R2SiO1.5) m (R3SiO1.5) n-l-m (H2O) 1.5 n-x (1).

Description

Technical Field

[0001] The present invention relates to a photoresist and a preparation method and application thereof, and particularly to a chemically amplified photoresist based on sesquisiloxane and a preparation method and application thereof. Background Art

[0002] Hydrogen silsesquioxane photoresist (HSQ) is the most commonly used negative electron beam photoresist at present. This inorganic silicon-based photoresist has higher etching resistance, mechanical strength, and smaller molecular volume compared with polymer-based photoresists, so that it has more excellent resolution and line edge roughness. The disadvantages of HSQ photoresist are as follows: its sensitivity is one order of magnitude lower than that of chemically amplified photoresist (CAR), which exacerbates the low throughput problem of electron beam lithography (EBL); secondly, the stability of HSQ photoresist is very poor, and obvious gelation phenomenon appears after being placed at room temperature for 30 h.

[0003] Extreme ultraviolet lithography technology is the most advanced lithography technology at present. Due to its own characteristics such as large molecular volume and low etching resistance, traditional deep ultraviolet chemically amplified photoresists are difficult to be directly applied to extreme ultraviolet lithography. The characteristics of high etching resistance, high mechanical strength and small molecular volume exhibited by HSQ make it have the potential for extreme ultraviolet lithography applications. However, due to the poor sensitivity and stability of HSQ, it is currently mainly applied to electron beam lithography (US9917057B2, CN101625522A, CN111564363B), and there are few related applications in extreme ultraviolet lithography or deep ultraviolet lithography.

[0004] Therefore, how to improve the sensitivity and stability of HSQ photoresist on the premise of retaining its excellent resolution is an important optimization direction of HSQ photoresist, and also an important way to improve the throughput of electron beam lithography and expand the applications of extreme ultraviolet lithography. Summary of the Invention

[0005] The invention aim of the present invention is to provide a partially condensed sesquisiloxane-based photoresist composition aiming at the deficiencies of the prior art, and improve the sensitivity and stability of the photoresist through formula improvement.

[0006] In order to achieve the above invention aim, the technical scheme adopted by the present invention is as follows:

[0007] A chemically amplified photoresist based on sesquisiloxane, the photoresist comprising a partially condensed polysesquisiloxane, a photoacid generator and an organic solvent, and the partially condensed polysesquisiloxane being one or more of the compounds shown in formula (1);

[0008] (R1SiO 1.5 ) l (R2SiO 1.5 ) m(R3SiO 1.5 ) n-l-m (H2O) 1.5n-x (1)

[0010] In the formula (1), each of R1 and R2 is independently H, a group represented by formula A, a group represented by formula B, or the following groups which are unsubstituted or substituted by one or more substituent A: C1-C 20 alkyl, C3-C 30 cycloalkyl, C4-C 30 silyl, C6-C 30 aryl, C3-C 30 heterocyclic group or C5-C 30 heteroaryl, or the above groups containing one or more of O, S, N, Si, P atoms in the carbon chain, and the substituent A includes halogen atom, hydroxyl group, mercapto group, trifluoromethyl group, C1-C 20 branched or straight-chain alkyl, C1-C 20 branched or straight-chain alkoxy, C3-C 20 branched or straight-chain cycloalkyl, C6-C 30 aryl, C5-C 30 heteroaryl, or one or more of them; the C3-C 30 cycloalkyl includes cycloalkyl with monocyclic or polycyclic structure;

[0011] Preferably, R1 is H, a group represented by formula A, a group represented by formula B, or the following groups which are unsubstituted or substituted by one or more substituent A: C1-C8 alkyl, C3-C 12 cycloalkyl, C6-C 12 aryl, or the above groups containing O, S, N or Si atom in the carbon chain, wherein the C3-C 12 cycloalkyl includes cycloalkyl with monocyclic or polycyclic structure, and the substituent A is preferably halogen atom, C1-C5 alkyl, trifluoromethyl group, hydroxyl group or mercapto group; the cycloalkyl with polycyclic structure can be adamantane, norbornane, etc.

[0012] Preferably, R2 is H, a group represented by formula A, a group represented by formula B, or the following groups which are unsubstituted or substituted by one or more substituent A: C1-C8 alkyl, C3-C 12 cycloalkyl, C6-C 12 aryl, or the above groups containing O, S, N or Si atom in the carbon chain, wherein the C3-C 12 cycloalkyl includes cycloalkyl with monocyclic or polycyclic structure, and the substituent A is preferably halogen atom, C1-C5 alkyl, trifluoromethyl group, hydroxyl group or mercapto group;

[0013] In the formula (1), R3 is a group represented by formula A or a group represented by formula B;

[0014]

[0015] represents a connecting bond;

[0016] In formula A or formula B, K1 is 0, or is the following group which is unsubstituted or substituted by one or more substituents B: C1-C 20 alkylene, C3-C 30 cycloalkylene, C6-C 30 arylene, or is the above group containing an oxygen or silicon atom in the carbon chain, and the substituent B is C1-C 10 alkyl or C1-C 10 alkoxy, and the C3-C 30 cycloalkylene in the cycloalkylene contains a monocyclic or polycyclic cycloalkylene structure;

[0017] Preferably, K1 is 0, C1-C8 alkylene, C3-C 12 cycloalkylene, phenylene, or is the above group containing an oxygen or silicon atom in the carbon chain, and the C3-C 12 cycloalkylene in the cycloalkylene contains a monocyclic or polycyclic cycloalkylene structure;

[0018] K2 is 0, an ester group, a carbonate group or an amide group; preferably, K2 is 0 or an ester group;

[0019] K1 being 0 means that K1 does not exist; K2 being 0 means that K2 does not exist; K1 and K2 can be 0 simultaneously, that is, both do not exist, that is, R4 is directly connected to the silicon atom, or R5 is directly connected to the ethylene group.

[0020] R4 is C1-C 20 alkenyl, C5-C 30 cycloalkenyl, C1-C 20 alkynyl, and the cycloalkenyl in the cycloalkenyl contains a monocyclic or polycyclic cycloalkenyl structure;

[0021] Preferably, R4 is C1-C 10 alkenyl, C5-C 12 cycloalkenyl or C1-C 10 alkynyl, and the cycloalkenyl in the cycloalkenyl contains a monocyclic or polycyclic cycloalkenyl structure;

[0022] R5 is C2-C 20 epoxy group, or is the above group containing an oxygen or sulfur atom in the carbon chain; preferably, R5 is C2-C9 epoxy group; the epoxy group includes a monocyclic or polycyclic epoxy group;

[0023] In the formula (1), l represents the number of R1 in the incompletely condensed poly(silsesquioxane), and l is an integer from 0 to 20; preferably an integer from 0 to 14; l being 0 means that R1 does not exist;

[0024] m represents the number of R2 in the incompletely condensed poly(silsesquioxane), and m is an integer from 0 to 20; preferably an integer from 0 to 14; m being 0 means that R2 does not exist;

[0025] n represents the total number of R1, R2, and R3 in the incompletely condensed poly(silsesquioxane), and n is an integer from 7 to 20; preferably an integer from 7 to 14;

[0026] n - l - m is an integer greater than or equal to 1;

[0027] That is, in the formula (1), R1 and R2 may not exist, but R3 must exist.

[0028] R1 and R2 may be the same substituents or different substituents. When R1 and R2 are the same substituents, l and m in the formula (1) can be combined.

[0029] Similarly, R1 and R3 may be the same substituents or different substituents. R2 and R3 may be the same substituents or different substituents. The three substituents R1, R2, and R3 may also all be the same, but in this case, they must all be R3, being the group shown in formula A or the group shown in formula B

[0030] x represents the number of water molecules generated during the preparation of the incompletely condensed poly(silsesquioxane), and x is an integer from 9 to 29; preferably an integer from 9 to 20;

[0031] 3n - 2x represents the number of silicon - hydroxyl (Si - OH) groups in the incompletely condensed poly(silsesquioxane). 3n - 2x is an integer greater than or equal to 1, and the preferred range is 2 to 6.

[0032] Furthermore, preferably, in the incompletely condensed poly(silsesquioxane), the ratio of the number of Si - OH groups to the number of Si elements is 5 - 45%, preferably 10 - 30%.

[0033] In the incompletely condensed poly(silsesquioxane), when both R1 and R2 do not exist, or when neither R1 nor R2 is H, the content of silicon - hydrogen (Si - H) groups in the incompletely condensed poly(silsesquioxane) is 0, and the content of organic groups (the ratio of the number of silicon - organic groups to the total number of silicon - organic groups and silicon - hydrogen bonds) is 100%.

[0034] In the present invention, preferably, the content of organic groups in the incompletely condensed poly(silsesquioxane) is 30% - 100%, more preferably 50 - 100%.

[0035] In the present invention, the incompletely condensed polyhedral oligomeric silsesquioxane is a cage-type polyhedral oligomeric silsesquioxane.

[0036] Furthermore, preferably, the chemical formula of the incompletely condensed polyhedral oligomeric silsesquioxane is one or more of the following general cage structure formulas: wherein the R6 group is selected from any one of the R1, R2, and R3 groups, and for any one cage structure, at least one of the R6 groups is R3, and all of the R6 groups cannot be R1 or R2; the definitions of the R1, R2, and R3 groups are as described above:

[0037]

[0038]

[0039] It should be noted that the incompletely condensed polyhedral oligomeric silsesquioxane is a mixture of molecules with various cage structures. The molecular weights of different cage structures are different. Generally, based on the average molecular weight of the incompletely condensed polyhedral oligomeric silsesquioxane, the possible cage structure can be speculated. However, the actual polymer is a mixture of cage structures with various molecular weights, and the molecular number ratios of various cage structures are different, so the average molecular weights are different. The above chemical structural formulas are the structural formulas closest to the average molecular weight of a certain polymer, but it does not mean that the polymer only contains one cage structure.

[0040] Moreover, for each cage molecular structural formula, which of the R1, R2, and R3 groups the substituent R6 is, and the contents of the R1, R2, and R3 groups in the structural formula can be determined by raw material feeding and product detection, but the specific positions of each R1, R2, and R3 group in the cage molecular structural formula cannot be determined.

[0041] Furthermore, in the cage structure of the incompletely condensed polyhedral oligomeric silsesquioxane, the R6 group is selected from any one of the R1, R2, and R3 groups, and at least one R6 group is R3, and all of the R6 groups cannot be R1 or R2; R1 and R2 are preferably one of the following groups: H, C1-C8 alkyl, C6-C 10 aryl,

[0042] Preferably, R3 is selected from one of the following groups:

[0043]

[0044] The present invention also provides a preparation method for the incompletely condensed polyhedral oligomeric silsesquioxane, and the method is one of the following:

[0045] (1) When none of R1, R2, and R3 is the group shown in Formula B, the method is as follows: Mix the silane raw materials shown in Formulas (2) to (4) according to the molar ratio of l:m:(n - l - m), and slowly add the mixture dropwise to concentrated acid. Under the action of the concentrated acid, a hydrolysis and condensation reaction is carried out to obtain the incompletely condensed polyhedral oligomeric silsesquioxane shown in Formula (1).

[0046] The concentrated acid is concentrated sulfuric acid, fuming sulfuric acid, concentrated hydrochloric acid or concentrated nitric acid; preferably concentrated hydrochloric acid.

[0047]

[0048] In Formulas (2) to (4), the definitions of R1 to R3 are as described above, and R 10 is selected from one of the following groups: Preferably, R 10 is

[0049] The molar ratio of the concentrated acid to the total molar amount of the silane raw materials shown in Formulas (2) to (4) is 1 to 20:1. Further, when the concentrated acid is concentrated hydrochloric acid or concentrated nitric acid, the molar ratio of the concentrated acid to the total molar amount of the silane raw materials shown in Formulas (2) to (4) is preferably 1 to 2:1. When the concentrated acid is concentrated sulfuric acid or fuming sulfuric acid, the molar ratio of the concentrated acid to the total molar amount of the silane raw materials shown in Formulas (2) to (4) is preferably 15 to 20:1.

[0050] The temperature of the hydrolysis and condensation reaction is 0 to 60 °C, preferably 0 °C.

[0051] Preferably, the steps of the hydrolysis and condensation reaction are as follows:

[0052] Charge the silane raw materials shown in Formulas (2) to (4) according to the molar ratio of l:m:(n - l - m), dissolve them in organic solvent A, and then slowly add the above raw material solution dropwise to the mixed solution of concentrated acid and organic solvent A for hydrolysis and condensation reaction; the dropping time is usually 1 - 6 h, and after the dropping is completed, continue to stir for 1 - 24 h.

[0053] The organic solvent A is usually one or more of tetrahydrofuran, hexane, cyclohexane, benzene, toluene, ethylene glycol dimethyl ether; preferably hexane.

[0054] The volume of organic solvent A used to dissolve the silane raw materials is usually 0.5 - 3 mL / mmol based on the total molar amount of the silane raw materials shown in Formulas (2) to (4); the volume of organic solvent A used to mix with the concentrated acid is usually 0.1 - 5 mL / mmol based on the molar amount of the concentrated acid.

[0055] After the hydrolysis and condensation reaction, the reaction solution is post-treated to obtain the incompletely condensed polyhedral oligomeric silsesquioxane represented by the formula (1). The post-treatment method of the reaction solution is usually as follows: after the reaction is completed, it is washed with water until neutral, then concentrated and crystallized, the crystalline substances are removed by filtration, and the solvent is evaporated to dryness to prepare the incompletely condensed polyhedral oligomeric silsesquioxane represented by the formula (1).

[0056] Furthermore, the preferred post-treatment method of the reaction solution is: after the reaction is completed, deionized water is added for washing until the system is neutral, then the organic phase is separated by liquid separation. After the organic phase is dried, it is distilled under reduced pressure until crystals are formed. Then, the insoluble crystalline substances are removed by centrifugation. After the supernatant is further distilled under reduced pressure to remove the solvent, the incompletely condensed polyhedral oligomeric silsesquioxane represented by the formula (1) is obtained (if no crystals are formed during the concentration process, the centrifugation step is omitted).

[0057] (2) When any one of R1, R2, and R3 is the group represented by the formula B, taking R3 as the group represented by the formula B as an example, the method is as follows: the silane raw materials represented by the formula (2), the formula (3), and the formula (5) are mixed according to the molar ratio of l:m:(n - l - m), and slowly added dropwise to concentrated acid. Under the action of the concentrated acid, a hydrolysis and condensation reaction is carried out. After the reaction is completed, it is washed with water until neutral, then concentrated and crystallized, the crystalline substances are removed by centrifugation, and the solvent is evaporated to dryness to obtain an intermediate product. Then, under the catalytic action of the Karstedt catalyst, the intermediate product and the vinyl compound represented by the formula (6) are subjected to a hydrosilylation reaction to prepare the incompletely condensed polyhedral oligomeric silsesquioxane represented by the formula (1).

[0058] When R1 or R2 is the group represented by the formula B, the feeding is changed according to this method.

[0059] The concentrated acid is concentrated sulfuric acid, fuming sulfuric acid, concentrated hydrochloric acid or concentrated nitric acid; preferably concentrated hydrochloric acid;

[0060]

[0061] In the formula (5) and the formula (6), the definitions of K1, K2, and R5 are as described above, and R 10 is selected from one of the following groups: Preferably, R 10 is

[0062] The molar ratio of the concentrated acid to the total molar amount of the silane raw materials represented by the formula (2), the formula (3), and the formula (5) is 1 - 20:1.

[0063] The temperature of the hydrolysis and condensation reaction is 0 - 60 °C, preferably 0 °C.

[0064] The steps of the hydrolysis and condensation reaction are preferably as follows: The silane raw materials represented by formula (2), formula (3), and formula (5) are fed in a molar ratio of l:m:(n-l-m), dissolved in organic solvent A, and then the above raw material solution is slowly added dropwise to a mixed solution of concentrated acid and organic solvent A for the hydrolysis and condensation reaction; the dropping time is usually 1-6 h, and after the dropping is completed, stirring is continued for 1-24 h.

[0065] The organic solvent A is usually one or more of: tetrahydrofuran, hexane, cyclohexane, benzene, toluene, ethylene glycol dimethyl ether; preferably hexane.

[0066] The volume dosage of organic solvent A used to dissolve the silane raw materials is usually 0.5-3 mL / mmol based on the amount of substance of the silane raw materials represented by formula (2), formula (3), and formula (5); the volume dosage of organic solvent A used for mixing with concentrated acid is usually 0.1-5 mL / mmol based on the amount of substance of the concentrated acid.

[0067] After the hydrolysis and condensation reaction, the reaction solution is post-treated to obtain an intermediate product. The post-treatment method of the reaction solution is usually: adding deionized water to wash until the system is neutral, then separating the organic phase by liquid separation. After the organic phase is dried, it is distilled under reduced pressure until crystals are formed, and then insoluble substances are removed by centrifugation. After the supernatant is further distilled under reduced pressure to remove the solvent, an intermediate product is obtained (if no crystals are formed during the concentration process, the centrifugation step is omitted).

[0068] The temperature of the hydrosilylation reaction is 60-90 °C, preferably 80-90 °C.

[0069] The steps of the hydrosilylation reaction are preferably as follows:

[0070] The intermediate product, the raw material represented by formula (6), and Karstedt catalyst are dissolved in organic solvent B, and stirred and reacted at a temperature of 80-90 °C. The reaction time is usually 3-9 h.

[0071] The molar ratio of the vinyl compound represented by formula (6) to the Si-H bond in the intermediate product is 0.1-1.2:1.

[0072] The content of Si-H groups in the incompletely condensed polyhedral oligomeric silsesquioxane product is related to the molar ratio of the vinyl compound to the Si-H bond in the intermediate product. When the molar ratio of the vinyl compound to the Si-H bond in the intermediate product is 1:1, the content of Si-H groups in the incompletely condensed polyhedral oligomeric silsesquioxane product is 0, and the content of organic groups (the ratio of the number of silicon-organic groups to the total number of silicon-organic groups and Si-H bonds) is 100%. However, when the Si-H bond content of the target product is 0, a slightly larger amount of vinyl compound can be fed to ensure the complete reaction of the Si-H bond.

[0073] When the molar ratio of the vinyl compound to the silicon-hydrogen bond in the intermediate product is less than 1:1, the content of the silicon-hydrogen group (Si-H) in the incompletely condensed polyhedral oligomeric silsesquioxane of the product is greater than 0, and the specific content can be estimated according to the feeding amount.

[0074] The organic solvent B is usually one or more of: tetrahydrofuran, hexane, cyclohexane, benzene, toluene; preferably toluene.

[0075] The mass dosage of the organic platinum complex in the Karstedt catalyst is usually 10 - 30 ppm of the total mass of the intermediate product and the vinyl compound shown in formula (6); the volume dosage of the organic solvent B is usually 0.5 - 5 mL / g based on the total mass of the intermediate product and the raw materials shown in formula (6).

[0076] After the hydrosilylation reaction, the obtained reaction solution b is post-treated to obtain the incompletely condensed polyhedral oligomeric silsesquioxane shown in formula (1). The post-treatment method of the reaction solution b is usually: after the hydrosilylation reaction is completed, diatomaceous earth is added to adsorb the Karstedt catalyst, then filtered, the filtrate is collected, and then the solvent and unreacted raw materials are removed by vacuum distillation of the filtrate to obtain the incompletely condensed polyhedral oligomeric silsesquioxane shown in formula (1).

[0077] Furthermore, in the photoresist of the present invention, by mass percentage, the content of the incompletely condensed polyhedral oligomeric silsesquioxane is 1 - 20%, the content of the photoacid generator is 0.01 - 4%, and the balance is the organic solvent.

[0078] Preferably, the content of the incompletely condensed polyhedral oligomeric silsesquioxane is 1 - 10%, the content of the photoacid generator is 0.1 - 1%, and the balance is the organic solvent.

[0079] The photoacid generator is a sulfonium salt or an iodonium salt, which consists of a cation and an anion, and the anion is selected from one of the following structures: The cation is selected from one of the following structures:

[0080]

[0081] The organic solvent is selected from one or more of methyl ethyl ketone, methyl isobutyl ketone, ethyl lactate, tetrahydrofuran, propylene glycol monomethyl ether acetate, toluene, chloroform, hexane, ethyl acetate, 1,4 - dioxane, pyridine; preferably methyl isobutyl ketone.

[0082] The photoresist is generally prepared by the following method: at room temperature, the incompletely condensed polyhedral oligomeric silsesquioxane, the photoacid generator and the organic solvent are added in sequence according to the formulation ratio, and the mixture is ultrasonically irradiated in the dark for 0.5 - 1 hour to dissolve it fully; then it is filtered through a 0.1 μm pore size filter head to remove suspended particulate impurities, and the filtrate is collected to obtain the required photoresist composition.

[0083] The photoresist provided by the present invention can be applied to electron beam lithography, deep ultraviolet lithography or extreme ultraviolet lithography.

[0084] Furthermore, the application method of the photoresist includes the following steps:

[0085] 1) Spin-coat the photoresist solution on the surface of the substrate;

[0086] 2) Perform exposure treatment on a specific area using a corresponding exposure light source;

[0087] 3) Perform post-exposure baking using a hot plate;

[0088] 4) Develop using a developer to form a pattern;

[0089] 5) Fix using a fixing solution.

[0090] Among them, the substrate in step 1) is a silicon wafer, a metal germanium, a silicon wafer covered with graphene or graphene oxide, or other semiconductor materials.

[0091] The post-exposure baking temperature in step 3) is 40 - 200 °C, and the time is 30 - 120 seconds.

[0092] The developer in step 4) is selected from one of 2.38% aqueous solution of tetramethylammonium hydroxide (TMAH), 10% TMAH aqueous solution, 25% TMAH aqueous solution, 1% NaOH + 4% NaCl aqueous solution, acetone, methyl isobutyl ketone, and methyl ethyl ketone; the development time is 30 - 240 seconds.

[0093] When the developer in step 4) is selected from one of 2.38% aqueous solution of tetramethylammonium hydroxide (TMAH), 10% TMAH aqueous solution, 25% TMAH aqueous solution, and 1% NaOH + 4% NaCl aqueous solution, the fixing solution in step 5) is water, and the fixing time is 15 - 60 seconds; when the developer in step 4) is selected from one of acetone, methyl isobutyl ketone, and methyl ethyl ketone, the fixing solution in step 5) is isopropyl alcohol; the fixing time is 15 - 60 seconds.

[0094] The present invention also provides the application of the incompletely condensed polyhedral oligomeric silsesquioxane in the preparation of a chemically amplified photoresist.

[0095] Compared with the prior art, the advantages of the present invention are as follows: In the photoresist composition of the present invention, an incompletely condensed polyhedral oligomeric silsesquioxane is used as the film-forming resin. Moreover, the incompletely condensed polyhedral oligomeric silsesquioxane used in the present invention has a cage-like structure molecule. Compared with the random polyhedral oligomeric silsesquioxane molecule, the cage-like molecular volume is smaller, and the smaller molecular volume can bring higher resolution. The cage-like polyhedral oligomeric silsesquioxane also exhibits higher rigidity compared to the random polyhedral oligomeric silsesquioxane, which can prevent the collapse of the photolithographic pattern.

[0096] In addition, compared with the conventional cage-like polyhedral oligomeric silsesquioxane, the incompletely condensed polyhedral oligomeric silsesquioxane of the present invention has a large number of uncompletely dehydrated and condensed silanol groups. These silanol groups will undergo dehydration condensation during the photolithography process, thereby improving the sensitivity of the photoresist. However, the content of the silanol group structure cannot be too high, as too high a content of the silanol group will reduce the stability of the photoresist.

[0097] The incompletely condensed polyhedral oligomeric silsesquioxane used in the present invention is modified with unsaturated organic groups, and a sulfonium salt or an iodonium salt is also introduced as a photoacid generator. Under the action of an electron beam lithography and a photoacid, these unsaturated carbon-carbon double bonds will undergo a cross-linking reaction between the double bonds, thereby greatly improving the sensitivity of the photoresist; at the same time, the introduction of the sulfonium salt or the iodonium salt is beneficial to combine with the hydroxide ions in the environment and prevent the cross-linking deterioration reaction of the polyhedral oligomeric silsesquioxane caused by the hydroxide ions, thereby greatly improving the stability of the photoresist. The photoresist of the present invention significantly improves the sensitivity on the premise of maintaining good stability, and has important application value and broad market prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0098] Figure 1 It is a schematic diagram of a photoresist imaging method. Among them, 1 is an incompletely condensed polyhedral oligomeric silsesquioxane type photoresist film, 2 is a substrate, and 3 is an exposure light source.

[0099] Figure 2 It is the nuclear magnetic resonance hydrogen spectrum of the incompletely condensed polyhedral oligomeric silsesquioxane A in Example 1.

[0100] Figure 3 It is the nuclear magnetic resonance carbon spectrum of the incompletely condensed polyhedral oligomeric silsesquioxane A in Example 1.

[0101] Figure 4 It is the nuclear magnetic resonance hydrogen spectrum of the incompletely condensed polyhedral oligomeric silsesquioxane B in Example 2.

[0102] Figure 5 It is the nuclear magnetic resonance carbon spectrum of the incompletely condensed polyhedral oligomeric silsesquioxane B in Example 2.

[0103] Figure 6 It is the nuclear magnetic resonance hydrogen spectrum of the incompletely condensed polyhedral oligomeric silsesquioxane C in Example 3.

[0104] Figure 7 13C NMR spectrum of the incompletely condensed poly(silsesquioxane) C in Example 3.

[0105] Figure 8 1H NMR spectrum of the incompletely condensed poly(silsesquioxane) D in Example 4.

[0106] Figure 9 13C NMR spectrum of the incompletely condensed poly(silsesquioxane) D in Example 4.

[0107] Figure 10 1H NMR spectrum of the incompletely condensed poly(silsesquioxane) E in Example 5.

[0108] Figure 11 13C NMR spectrum of the incompletely condensed poly(silsesquioxane) E in Example 5.

[0109] Figure 12 1H NMR spectrum of the incompletely condensed poly(silsesquioxane) F in Example 6.

[0110] Figure 13 13C NMR spectrum of the incompletely condensed poly(silsesquioxane) F in Example 6.

[0111] Figure 14 SEM micrograph of the film after exposure treatment of the photoresist composition R-A in Example 7.

[0112] Figure 15 SEM micrograph of the film after exposure treatment of the photoresist composition R-B in Example 8.

[0113] Figure 16 SEM micrograph of the film after exposure treatment of the photoresist composition R-C in Example 9.

[0114] Figure 17 SEM micrograph of the film after exposure treatment of the photoresist composition R-D in Example 10.

[0115] Figure 18 Optical micrograph of the film after exposure treatment of the photoresist composition R-E in Example 11.

[0116] Figure 19 Optical micrograph of the film after exposure treatment of the photoresist composition R-F in Example 12.

[0117] Figure 20 29Si NMR spectrum of the random poly(silsesquioxane) G in Example 14.

[0118] Figure 211H NMR spectrum of the incompletely condensed polyhedral oligomeric silsesquioxane A in Example 1. Detailed implementation manners

[0119] To make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific implementation manners described herein are only used to explain the present invention and do not limit the protection scope of the present invention.

[0120] Example 1

[0121] The structure and synthesis route of an incompletely condensed polyhedral oligomeric silsesquioxane A are as follows:

[0122]

[0123] 5.2 ml (30 mmol, 1 molar equivalent) of triethoxysilane and 7.6 ml (36 mmol, 1.2 molar equivalents) of trimethoxy(4-vinylphenyl)silane were dissolved in 60 ml of hexane to obtain a monomer mixed solution. 7.1 ml (mass concentration 37%) of concentrated hydrochloric acid (82.5 mmol, 2.75 molar equivalents) was added to 200 ml of hexane, and the mixture was stirred at 0 °C for 0.5 h. Subsequently, the above monomer mixed solution was added dropwise to the continuously stirred 0 °C mixture of concentrated hydrochloric acid and hexane within 2 h. After the addition was completed, the mixture was continuously stirred at 0 °C for 3 h.

[0124] After the hydrolysis and condensation reaction was completed, the reaction solution was washed with deionized water (3 × 200 ml), and then the organic phase was separated by liquid separation. The organic phase was dried with anhydrous magnesium sulfate and then filtered to remove the magnesium sulfate solid. Subsequently, the solvent was gradually evaporated under reduced pressure until a large amount of crystals were formed. After filtering off the crystal substances, the solvent was completely evaporated to obtain 1.4 g of incompletely condensed polyhedral oligomeric silsesquioxane A, with a molecular weight of 1.2 kDa and a molecular weight distribution of 1.09. The 1H NMR spectrum is as Figure 2 shown, and the 13C NMR spectrum is as Figure 3 shown. According to the molecular weight, its molecular structure is estimated to be as shown in Formula A. However, actual polyhedral oligomeric silsesquioxanes are all mixtures of various cage-like molecular structures, and only the content ratio of the substituents can be determined, and their specific substitution positions cannot be determined. The following molecular structures are all estimated and will not be elaborated.

[0125] Example 2

[0126] The structure and synthesis route of an incompletely condensed polyhedral oligomeric silsesquioxane B are as follows:

[0127]

[0128] Dissolve 2.3 ml (15 mmol, 1 molar equivalent) of trimethoxyvinylsilane and 10.3 ml (45 mmol, 3 molar equivalents) of trimethoxy(p-chlorobenzyl)silane in 60 ml of hexane to obtain a monomer mixed solution. Add 6.5 ml of concentrated hydrochloric acid aqueous solution (75 mmol, 5 molar equivalents) to 200 ml of hexane, and stir at 0 °C for 0.5 h. Subsequently, gradually add the above monomer mixed solution dropwise to the continuously stirred 0 °C mixture of concentrated hydrochloric acid and hexane within 2 h. After the addition is completed, continue to stir at 0 °C for 6 h.

[0129] After the hydrolysis and condensation reaction is completed, wash the reaction solution with deionized water (3×200 ml), and then separate the organic phase by liquid separation. Dry the organic phase with anhydrous magnesium sulfate and then filter to remove the magnesium sulfate solid. Subsequently, gradually evaporate the solvent under reduced pressure until a large amount of crystals are formed. After filtering to remove the crystal substances, completely evaporate the solvent to obtain 2.0 g of incompletely condensed polyhedral oligomeric silsesquioxane B, with a molecular weight of 1.8 kDa and a molecular weight distribution of 1.21. The proton nuclear magnetic resonance spectrum is as Figure 4 shown, and the carbon nuclear magnetic resonance spectrum is as Figure 5 shown.

[0130] Example 3

[0131] The structure and synthesis route of an incompletely condensed polyhedral oligomeric silsesquioxane C are as follows:

[0132]

[0133] Dissolve 4.4 ml (24 mmol, 1.3 molar equivalents) of triethoxysilane, 3.9 ml (18 mmol, 1 molar equivalent) of trimethoxy(p-chlorobenzyl)silane, and 4.4 ml (18 mmol, 1 molar equivalent) of trimethoxy(7-octenyl)silane in 60 ml of hexane to obtain a monomer mixed solution. Add 10.5 ml of concentrated hydrochloric acid aqueous solution (120 mmol, 6.6 molar equivalents) to 200 ml of hexane, and stir at 0 °C for 0.5 h. Subsequently, gradually add the above monomer mixed solution dropwise to the continuously stirred 0 °C mixture of concentrated hydrochloric acid and hexane within 3 h. After the addition is completed, continue to stir at 0 °C for 2 h.

[0134] After the hydrolysis and condensation reaction is completed, wash the reaction solution with deionized water (3×200 ml), and then separate the organic phase by liquid separation. Dry the organic phase with anhydrous magnesium sulfate and then filter to remove the magnesium sulfate solid. Subsequently, gradually evaporate the solvent under reduced pressure until a large amount of crystals are formed. After filtering to remove the crystal substances, completely evaporate the solvent to obtain 1.2 g of incompletely condensed polyhedral oligomeric silsesquioxane C, with a molecular weight of 1.1 kDa and a molecular weight distribution of 1.15. The proton nuclear magnetic resonance spectrum is as Figure 6 shown, and the carbon nuclear magnetic resonance spectrum is as Figure 7 shown.

[0135] Example 4

[0136] The structure and synthesis route of an incompletely condensed poly(silsesquioxane) D are as follows:

[0137]

[0138] 5.2 ml (30 mmol, 1 molar equivalent) of triethoxysilane and 6.4 ml (30 mmol, 1 molar equivalent) of 5-(trimethoxysilyl)bicyclo[2.2.1]hept-2-ene were dissolved in 60 ml of hexane to obtain a monomer mixed solution. 5.2 ml of concentrated hydrochloric acid aqueous solution (60 mmol, 2 molar equivalents) was added to 200 ml of hexane, and the mixture was stirred at 0 °C for 0.5 h. Subsequently, the above monomer mixed solution was added dropwise to the continuously stirred mixture of concentrated hydrochloric acid and hexane at 0 °C within 1 h. After the addition, the mixture was continuously stirred at 0 °C for 4 h.

[0139] After the hydrolysis and condensation reaction was completed, the reaction solution was washed with deionized water (3 × 200 ml), and then the organic phase was separated by liquid separation. The organic phase was dried with anhydrous magnesium sulfate and then filtered to remove the magnesium sulfate solid. Subsequently, the solvent was gradually evaporated under reduced pressure until a large amount of crystals were formed. After filtering off the crystal substances, the solvent was completely evaporated to obtain 1.9 g of incompletely condensed poly(silsesquioxane) D, with a molecular weight of 1.4 kDa and a molecular weight distribution of 1.31. The 1H NMR spectrum is as Figure 8 shown, and the 13C NMR spectrum is as Figure 9 shown.

[0140] Example 5

[0141] The structure and synthesis route of an incompletely condensed poly(silsesquioxane) E are as follows:

[0142]

[0143] 10.4 ml (60 mmol, 1 molar equivalent) of triethoxysilane was dissolved in 60 ml of hexane to obtain a monomer mixed solution. 6.5 ml of concentrated hydrochloric acid aqueous solution (75 mmol, 1.25 molar equivalents) was added to 200 ml of hexane, and the mixture was stirred at 0 °C for 0.5 h. Subsequently, the above monomer mixed solution was added dropwise to the continuously stirred mixture of concentrated hydrochloric acid and hexane at 0 °C within 2 h. After the addition, the mixture was continuously stirred at 0 °C for 3 h.

[0144] After the hydrolysis and condensation reaction was completed, the reaction solution was washed with deionized water (3 × 200 ml), and then the organic phase was separated by liquid separation. The organic phase was dried with anhydrous magnesium sulfate and then filtered to remove the magnesium sulfate solid. Subsequently, the solvent was gradually evaporated under reduced pressure until a large amount of crystals were formed. After filtering off the crystal substances, the solvent was completely evaporated to obtain 1.9 g of intermediate 1.

[0145] 1.9 g of intermediate 1, 2.44 g of 6-vinyl-3-oxatricyclo[3.2.1.0 2,4 octane and 90 μL of 0.1 wt% Karstedt catalyst (solvent: toluene) were dissolved in 6 ml of toluene, and the mixture was heated at 80 °C for 6 h. Subsequently, the catalyst was adsorbed with diatomaceous earth, the reaction solution was filtered, and the filtrate was further distilled under reduced pressure to remove the solvent and unreacted monomers, obtaining 1.3 g of incompletely condensed polyhedral oligomeric silsesquioxane D with a molecular weight of 1.4 kDa and a molecular weight distribution of 1.24. The 1H NMR spectrum is as Figure 10 shown, and the 13C NMR spectrum is as Figure 11 shown.

[0146] Example 6

[0147]

[0148] The structure and synthesis route of an incompletely condensed polyhedral oligomeric silsesquioxane F are as follows:

[0149] 10.4 ml (60 mmol, 1 molar equivalent) of triethoxysilane was dissolved in 60 ml of hexane as an intermediate product. 15.6 ml of concentrated hydrochloric acid aqueous solution (180 mmol, 3 molar equivalents) was added to 200 ml of hexane, and the mixture was stirred at 0 °C for 0.5 h. Subsequently, the above monomer mixed solution was added dropwise to the continuously stirred 0 °C mixture of concentrated hydrochloric acid and hexane within 4 h. After the addition was completed, the mixture was continuously stirred at 0 °C for 3 h.

[0150] After the hydrolysis and condensation reaction was completed, the reaction solution was washed with deionized water (3 × 200 ml), and then the organic phase was separated by liquid separation. The organic phase was dried with anhydrous magnesium sulfate and then filtered to remove the magnesium sulfate solid. Subsequently, the solvent was gradually distilled off under reduced pressure until a large amount of crystals were formed. After filtering off the crystal substances, the solvent was completely distilled off, obtaining 2.5 g of intermediate 2.

[0151] 2.5 g of intermediate 2, 2.92 g of 4-vinylcyclohexene oxide, and 110 μL of 0.1 wt% Karstedt catalyst (solvent: toluene) were dissolved in 7 ml of toluene, and the mixture was heated at 80 °C for 6 h. Subsequently, the reaction solution was filtered with diatomaceous earth, and the filtrate was further distilled under reduced pressure to remove the solvent and unreacted monomers, obtaining 1.9 g of incompletely condensed polyhedral oligomeric silsesquioxane F with a molecular weight of 1.0 kDa and a molecular weight distribution of 1.22. The 1H NMR spectrum is as Figure 12 shown, and the 13C NMR spectrum is as Figure 13 shown.

[0152] Example 7

[0153] The preparation method and imaging method of a lithography resist composition R-A of an incompletely condensed silsesquioxane A are as follows:

[0154] In a clean 20 ml glass bottle, add 10 mg of diphenyliodonium trifluoromethanesulfonate and 1.99 g of methyl isobutyl ketone, and then ultrasonically treat for 0.5 h to fully dissolve the photoacid generator. Subsequently, in a 1 ml glass bottle, add 25 mg of incompletely condensed silsesquioxane A, 250 mg of the above photoacid generator solution, and 225 mg of methyl isobutyl ketone, and ultrasonically treat the above photoresist solution for 0.5 h to fully mix it. Then filter the photoresist solution through a 0.1 micron filter. Spin-coat the above photoresist solution onto a silicon wafer at a speed of 3000 revolutions per minute to obtain a 98 nm thick film. After completion, perform a photolithography test.

[0155] As Figure 1 shown, using a FEI Nova Nano SEM field emission scanning electron microscope and an NPGS electron beam exposure system, at a voltage of 20 kV, expose the incompletely condensed silsesquioxane A photoresist film with 50 different doses ranging from 1 μC / cm 2 to 100 μC / cm 2 . After exposure, post-bake at 100 °C for 60 s, then develop with a 10% (mass fraction) tetramethylammonium hydroxide (TMAH) solution for 1 min, and fix with water for 30 s. Measure the difference between the film thickness of 50 exposed areas and the original thickness with a surface profiler, and obtain the sensitivity of the incompletely condensed silsesquioxane A photoresist under this condition as 7.9 μC / cm 2 , and the contrast γ = 4.09.

[0156] Subsequently, at a voltage of 20 kV and a dose of 15 μC / cm 2 , expose the photoresist film with different exposure periods, and the post-bake, development, and fixing conditions are the same as the above conditions. As Figure 14 shown, obtain its resolution of 16 nm.

[0157] Example 8

[0158] A method for preparing and imaging an incompletely condensed silsesquioxane B photoresist composition R-B is as follows:

[0159] In a clean 20 ml glass bottle, add 10 mg of triphenylsulfonium trifluoromethanesulfonate and 1.99 g of methyl isobutyl ketone, and then ultrasonically treat for 0.5 h to fully dissolve the photoacid generator. Subsequently, in a 1 ml glass bottle, add 25 mg of incompletely condensed silsesquioxane B, 250 mg of the above photoacid generator solution, and 225 mg of methyl isobutyl ketone, and ultrasonically treat the above photoresist solution for 0.5 h to fully mix it. Then filter the photoresist solution through a 0.1 micron filter. Spin-coat the above photoresist solution onto a silicon wafer at a speed of 3000 revolutions per minute to obtain a 105 nm thick film. After completion, perform a photolithography test.

[0160] Using a FEI NovaNano SEM field emission scanning electron microscope and an NPGS electron beam exposure system, at a voltage of 20 kV, expose the incompletely condensed silsesquioxane B photoresist film with 50 different doses ranging from 1 μC / cm 2 to 100 μC / cm 2 . After exposure, post-bake at 100 °C for 60 s, then develop with methyl isobutyl ketone for 1 min and fix with isopropyl alcohol for 30 s. Use a surface profiler to measure the difference in film thickness between the 50 exposed areas and the original thickness, and obtain the sensitivity of the incompletely condensed silsesquioxane B photoresist under this condition as 22.4 μC / cm 2 , and the contrast γ = 2.07.

[0161] Subsequently, at a voltage of 20 kV and a dose of 50 μC / cm 2 , expose the photoresist film with different exposure periods, and the post-baking, developing, and fixing conditions are the same as the above conditions. As Figure 15 shown, its resolution is 26 nm.

[0162] Example 9

[0163] A method for preparing and imaging an incompletely condensed silsesquioxane C photoresist composition R-C is as follows:

[0164] In a clean 20 ml glass bottle, add 10 mg of triphenylsulfonium 1,1,2,2,3,3,4,4,4-nonafluorobutane-1-sulfonate and 1.99 g of methyl isobutyl ketone, and then ultrasonically treat for 0.5 h to fully dissolve the photoacid generator. Subsequently, in a 1 ml glass bottle, add 25 mg of incompletely condensed silsesquioxane C, 250 mg of the above photoacid generator solution, and 225 mg of methyl isobutyl ketone, and ultrasonically treat the above photoresist solution for 0.5 h to fully mix it. Then filter the photoresist solution through a 0.1 micron filter. Spin-coat the above photoresist solution onto a silicon wafer at a speed of 3000 revolutions per minute to obtain a 111 nm thick film. After completion, perform a photolithography test.

[0165] Using a FEI NovaNano SEM field emission scanning electron microscope and an NPGS electron beam exposure system, at a voltage of 20 kV, the incompletely condensed silsesquioxane C photoresist film was exposed with 50 different doses ranging from 1 μC / cm 2 to 100 μC / cm 2 After exposure, post-baking was carried out at 100 °C for 60 s, and then developed with a 10% (mass fraction) tetramethylammonium hydroxide (TMAH) solution for 1 min and fixed with water for 30 s. The difference between the film thickness of 50 exposed areas and the original thickness was measured using a surface profiler, and the sensitivity of the incompletely condensed silsesquioxane C photoresist under this condition was obtained as 31.6 μC / cm 2 , and the contrast γ = 1.53.

[0166] Subsequently, at a voltage of 20 kV and a dose of 50 μC / cm 2 , the photoresist film was exposed with different exposure periods. After exposure, post-baking was carried out at 100 °C for 60 s, and then developed with an acetone solution for 1 min and fixed with isopropyl alcohol for 30 s.. As Figure 16 shown, its resolution was obtained as 48 nm.

[0167] Example 10

[0168] A method for preparing and imaging an incompletely condensed silsesquioxane D photoresist composition R-D is as follows:

[0169] In a clean 20 ml glass bottle, 10 mg of triphenylsulfonium 1,1,2,2,3,3,4,4,4-nonafluorobutane-1-sulfonate and 1.99 g of methyl isobutyl ketone were added, and then ultrasonic treatment was carried out for 0.5 h to fully dissolve the photoacid generator. Subsequently, in a 1 ml glass bottle, 25 mg of incompletely condensed silsesquioxane D, 250 mg of the above photoacid generator solution, and 225 mg of methyl isobutyl ketone were added, and the above photoresist solution was ultrasonicated for 0.5 h to fully mix. Then the photoresist solution was filtered through a 0.1 μm filter. The above photoresist solution was spin-coated onto a silicon wafer at a speed of 3000 revolutions per minute to obtain a film with a thickness of 89 nm. After completion, a photolithography test was carried out.

[0170] Using a FEI NovaNano SEM field emission scanning electron microscope and an NPGS electron beam exposure system, at a voltage of 20 kV, with doses ranging from 1 μC / cm 2 to 100 μC / cm 2Fifty different doses were used to expose the incompletely condensed sesquisiloxane C photoresist film. After exposure, post-baking was carried out at 100 °C for 60 s, followed by development with a 10% (mass fraction) tetramethylammonium hydroxide (TMAH) solution for 1 min and fixing with water for 30 s. The difference in film thickness between the 50 exposed areas and the original thickness was measured using a surface profiler, and the sensitivity of the incompletely condensed sesquisiloxane D photoresist under these conditions was found to be 4.3 μC / cm 2 , and the contrast γ = 5.10.

[0171] Subsequently, at a voltage of 20 kV and a dose of 12 μC / cm 2 , the photoresist film was exposed with different exposure periods. After exposure, post-baking was carried out at 100 °C for 60 s, followed by development with a 25% (mass fraction) tetramethylammonium hydroxide (TMAH) solution for 4 min and fixing with water for 60 s. As Figure 17 shown, its resolution was 28 nm.

[0172] Example 11

[0173] A method for preparing and an imaging method for an incompletely condensed sesquisiloxane E photoresist composition R-E are as follows:

[0174] In a clean 20 ml glass bottle, 10 mg of triphenylsulfonium trifluoromethanesulfonate and 1.99 g of methyl isobutyl ketone were added, and then ultrasonic treatment was carried out for 0.5 h to fully dissolve the photoacid generator. Subsequently, in a 1 ml glass bottle, 25 mg of incompletely condensed sesquisiloxane E, 250 mg of the above photoacid generator solution, and 225 mg of methyl isobutyl ketone were added, and the above photoresist solution was ultrasonic treated for 0.5 h to fully mix it. Then the photoresist solution was filtered through a 0.1 μm filter. The above photoresist solution was spin-coated onto a silicon wafer at a speed of 3000 revolutions per minute to obtain a 95 nm thick film. After completion, a photolithography test was carried out.

[0175] Using a 254 nm contact alignment deep ultraviolet lithography machine with a wavelength of 254 nm, 25 different doses from 1 mJ / cm 2 to 20 mJ / cm 2 were used to expose the incompletely condensed sesquisiloxane E photoresist film. After exposure, post-baking was carried out at 100 °C for 60 s, followed by development with a 10% (mass fraction) tetramethylammonium hydroxide (TMAH) solution for 1 min and fixing with water for 30 s. The difference in film thickness between the 25 exposed areas and the original thickness was measured using a surface profiler, and the sensitivity of the incompletely condensed sesquisiloxane E photoresist under these conditions was found to be 14.7 mJ / cm 2 , and the contrast γ = 3.07.

[0176] Subsequently, at 20 mJ / cm 2At a dose of, the photoresist film was exposed with different exposure periods, and the post-baking, development, and fixing conditions were the same as the above conditions. As Figure 18 shown, a resolution of 1.5 μm was obtained.

[0177] Example 12

[0178] A method for preparing an incompletely condensed silsesquioxane F photoresist composition R-F and an imaging method are as follows:

[0179] In a clean 20 ml glass bottle, 10 mg of triphenylsulfonium trifluoromethanesulfonate and 1.99 g of methyl isobutyl ketone were added, and then ultrasonic treatment was carried out for 0.5 h to fully dissolve the photoacid generator. Subsequently, in a 1 ml glass bottle, 25 mg of incompletely condensed silsesquioxane F, 250 mg of the above photoacid generator solution, and 225 mg of methyl isobutyl ketone were added, and the above photoresist solution was ultrasonic-treated for 0.5 h to fully mix it. Then the photoresist solution was filtered through a 0.1 μm filter. The above photoresist solution was spin-coated onto a silicon wafer at a speed of 3000 revolutions per minute to obtain a film with a thickness of 121 nm. After completion, a photolithography test was carried out.

[0180] Using a 254 nm contact alignment deep ultraviolet lithography machine with a wavelength of 254 nm, the incompletely condensed silsesquioxane F photoresist film was exposed with 25 different doses ranging from 1 mJ / cm 2 to 20 mJ / cm 2 . After exposure, post-baking was carried out at 100 °C for 60 s, then developed with methyl ethyl ketone for 1 min, and fixed with isopropyl alcohol for 30 s. The difference between the film thickness of 25 exposed areas and the original thickness was measured with a surface profiler, and the sensitivity of the incompletely condensed silsesquioxane F photoresist under these conditions was obtained as 7.7 mJ / cm 2 , and the contrast γ = 1.84.

[0181] Subsequently, at a dose of 13 mJ / cm 2 , the photoresist film was exposed with different exposure periods, and the post-baking, development, and fixing conditions were the same as the above conditions. As Figure 19 shown, a resolution of 1.2 μm was obtained.

[0182] Example 13

[0183] Verification of the stability of the incompletely condensed silsesquioxane photoresist composition:

[0184] The photoresist composition shown in Example 7 was used for stability verification. The prepared photoresist composition was placed at room temperature in an atmospheric environment, and it was observed whether gel substances were generated in the photoresist composition. And at 1 day, 7 days, and 180 days after placement, the photoresist composition was spin-coated into a film for photolithography performance testing.

[0185] The experimental results show that no gel substance is formed after being placed in the room-temperature atmospheric environment for 180 days; the sensitivity data after being placed for 1 day, 7 days, and 180 days are 7.9, 7.8, and 8.2 μC / cm 2 , and the contrast data are 4.09, 4.02, and 3.87, showing good stability.

[0186] Example 14

[0187] To compare the performance advantages of incompletely condensed cage-type polyhedral oligomeric silsesquioxane, a random polyhedral oligomeric silsesquioxane G was prepared. The structure, synthesis route, modulation method, and imaging method are as follows:

[0188]

[0189] Dissolve 5.2 ml (30 mmol, 1 molar equivalent) of triethoxysilane and 7.6 ml (36 mmol, 1.2 molar equivalents) of trimethoxy(4-vinylphenyl)silane in 20 ml of ethylene glycol dimethyl ether to obtain a monomer mixed solution. Add 0.4 ml of hydrochloric acid aqueous solution with pH = 1 (0.04 mmol, 1.3×10 -3 molar equivalent) to 20 ml of ethylene glycol dimethyl ether, and then gradually add the above solution dropwise to the continuously stirred monomer mixed solution at 0 °C within 0.5 h. After the addition is completed, continue to stir at 0 °C for 6 h. After the reaction is completed, concentrate, replace the original reaction system solvent by adding MIBK solvent multiple times, and then configure it into a 10 wt% concentration solution. 68 g of a 10 wt% solution of random polyhedral oligomeric silsesquioxane G is prepared, with a molecular weight of 1.3 kDa and a molecular weight distribution of 1.93. The nuclear magnetic resonance silicon spectrum of random polyhedral oligomeric silsesquioxane G is as Figure 20 shown. The nuclear magnetic resonance silicon spectrum of the incompletely condensed polyhedral oligomeric silsesquioxane A in Example 1 is as Figure 21 shown.

[0190] Figure 20 and Figure 21 From the comparison, Figure 21 in, the cage-type molecular peak shape is sharp, while Figure 20 in the silicon spectrum of the random polyhedral oligomeric silsesquioxane shows a broad peak distribution, indicating that the cage-type polyhedral oligomeric silsesquioxane has higher regularity and smaller molecular volume, and the smaller molecular volume can bring higher resolution. The cage-type polyhedral oligomeric silsesquioxane also shows higher rigidity compared to the random polyhedral oligomeric silsesquioxane, which can prevent the collapse of the lithography pattern.

[0191] In a clean 20 ml glass bottle, add 10 mg of triphenylsulfonium trifluoromethanesulfonate and 1.99 g of methyl isobutyl ketone, and then ultrasonically treat for 0.5 h to fully dissolve the photoacid generator. Subsequently, in a 1 ml glass bottle, add 100 mg of a 10 wt% solution of random polyhedral oligomeric silsesquioxane G and 100 mg of the above photoacid generator solution, and ultrasonically treat the above photoresist solution for 0.5 h to fully mix it. Then filter the photoresist solution through a 0.1 micron filter. Spin-coat the above photoresist solution onto a silicon wafer at a speed of 3000 revolutions per minute to obtain a 108 nm thick film. After completion, perform a photolithography test.

[0192] Using a FEI NovaNano SEM field emission scanning electron microscope and an NPGS electron beam exposure system, at a voltage of 20 kV, expose the random polyhedral oligomeric silsesquioxane E photoresist film with 50 different doses ranging from 1 μC / cm 2 to 100 μC / cm 2 . After exposure, develop with a 10% (mass fraction) tetramethylammonium hydroxide (TMAH) solution for 1 min and fix with water for 30 s. Measure the difference between the film thickness of 50 exposed areas and the original thickness with a surface profiler, and obtain the sensitivity of the random polyhedral oligomeric silsesquioxane G photoresist under this condition as 18.9 μC / cm 2 , and the contrast γ = 2.13.

[0193] Subsequently, at a voltage of 20 kV and a dose of 37 μC / cm 2 , expose the photoresist film with different exposure periods and develop with a 25% (mass fraction) tetramethylammonium hydroxide (TMAH) solution. Obtain its resolution of 56 nm.

[0194] The elemental compositions of the incompletely condensed cage-type polyhedral oligomeric silsesquioxane A and random polyhedral oligomeric silsesquioxane G are close. The experimental results show that the photoresist prepared from random polyhedral oligomeric silsesquioxane G is weaker than cage-type polyhedral oligomeric silsesquioxane A in terms of sensitivity, contrast, and resolution performance, indicating that the cage structure is beneficial to the improvement of photolithography performance. Table 1 gives the performance comparison data of Example 1 and Example 14.

[0195] Table 1 Performance comparison of cage-type silsesquioxane photoresist and random silsesquioxane photoresist

[0196]

[0197] Example 15

[0198] In order to characterize the effect of the content of organic groups on the performance, the ratio of triethoxysilane and trimethoxy (4-vinylphenyl) silane monomers was changed according to the method described in Example 1 to prepare incompletely condensed polysilsesquioxane H with a styrene group content of 9% and incompletely condensed polysilsesquioxane I with a styrene group content of 100%. The stability, sensitivity and contrast of the incompletely condensed cage-type polysilsesquioxanes A, H and I were characterized.

[0199]

[0200] In a 10 ml glass bottle, add 0.5 g of incompletely condensed polysilsesquioxane A and 4.5 g of methyl isobutyl ketone, and treat the above solution by ultrasonic treatment for 0.5 h to make it fully mixed. Then filter the solution with a 0.1 micron filter. The same method is used to prepare solutions of incompletely condensed polysilsesquioxanes H and I. The three groups of solutions are placed under the same environmental conditions and the gel time is observed. Table 2 shows the gel time data of solutions A, H, and I.

[0201] Table 2 Gel time of incompletely condensed polysilsesquioxane A, H, and I solutions under ambient conditions

[0202]

[0203] In a clean 20ml glass bottle, add 10mg triphenylsulfonium trifluoromethanesulfonate and 1.99g methyl isobutyl ketone, and then ultrasonicate for 0.5h to fully dissolve the photoacid generator. Then in a 1ml glass bottle, add 25mg incompletely condensed polysilsesquioxane H, 250mg of the above photoacid generator solution, and 225mg methyl isobutyl ketone, and ultrasonicate the above photoresist solution for 0.5h to fully mix it. Then filter the photoresist solution with a 0.1 micron filter. Spin-coat the above photoresist solution onto a silicon wafer at a speed of 3000 rpm to obtain a 97nm thick film. After completion, use a FEI Nova NanoSEM field emission scanning electron microscope and an NPGS electron beam exposure system at a voltage of 20kV, using a 1μC / cm 2 To 100μC / cm 2 The incompletely condensed polysilsesquioxane H photoresist film was exposed to 50 different doses. After exposure, 10% (mass fraction) tetramethylammonium hydroxide (TMAH) solution was used for development. The difference between the film thickness of 50 exposed areas and the original thickness was measured using a surface profiler to obtain the sensitivity and contrast data of the incompletely condensed polysilsesquioxane H photoresist under this condition. The same method was used to prepare the I photoresist film and perform photolithography testing. Table 3 shows the sensitivity and contrast data of A, H, and I photoresists.

[0204] Table 3 Sensitivity contrast of incompletely condensed polysilsesquioxane A, H, and I photoresists

[0205]

[0206] Experimental results show that increasing the organic group content of incompletely condensed polysilsesquioxane can effectively improve the stability of the material; sensitivity and contrast data show that the addition of organic groups significantly improves the sensitivity of the photoresist, while the contrast performance is slightly reduced.

[0207] Example 16

[0208] In order to characterize the effect of the content of Si-OH groups on the performance, incompletely condensed polysilsesquioxanes J and K with different Si-OH contents were prepared in turn according to the method described in Example 4, except that the stirring time was changed to 5 h and 3 h. The stability, sensitivity and contrast data of incompletely condensed cage polysilsesquioxanes D, J and K were compared.

[0209]

[0210] In a 10 ml glass bottle, add 0.5 g of incompletely condensed polysilsesquioxane D and 4.5 g of methyl isobutyl ketone, and treat the above solution by ultrasonic treatment for 0.5 h to make it fully mixed. Then filter the solution with a 0.1 micron filter. The same method is used to prepare solutions of incompletely condensed polysilsesquioxanes J and K. The three groups of solutions are placed under the same environmental conditions and the gel time is observed. Table 4 shows the gel time data of D, J, and K solutions.

[0211] Table 4 Gel time of incompletely condensed polysilsesquioxane D, J, K solutions under ambient conditions

[0212]

[0213] a: Si-OH content is expressed as the ratio of the number of Si-OH to the number of Si elements

[0214] In a clean 20 ml glass bottle, add 10 mg of triphenylsulfonium trifluoromethanesulfonate and 1.99 g of methyl isobutyl ketone, and then ultrasonically treat for 0.5 h to fully dissolve the photoacid generator. Subsequently, in a 1 ml glass bottle, add 25 mg of incompletely condensed poly(silsesquioxane) J, 250 mg of the above photoacid generator solution, and 225 mg of methyl isobutyl ketone, and ultrasonically treat the above photoresist solution for 0.5 h to fully mix it. Then filter the photoresist solution through a 0.1 μm filter. Spin-coat the above photoresist solution onto a silicon wafer at a speed of 3000 revolutions per minute to obtain a 101 nm thick film. After completion, use a FEI NovaNano SEM field emission scanning electron microscope and an NPGS electron beam exposure system, at a voltage of 20 kV, with 50 different doses from 1 μC / cm 2 to 100 μC / cm 2 to expose the incompletely condensed silsesquioxane J photoresist film. After exposure, develop it using a 10% (mass fraction) tetramethylammonium hydroxide (TMAH) solution. Measure the difference between the film thickness of 50 exposed areas and the original thickness with a surface profiler to obtain the sensitivity and contrast data of the incompletely condensed poly(silsesquioxane) J photoresist under this condition. Prepare a K photoresist film using the same method and conduct photolithography tests. Table 5 gives the sensitivity and contrast data of D, J, and K photoresists.

[0215] Table 5 Sensitivity and contrast of incompletely condensed poly(silsesquioxane) D, J, and K photoresists

[0216]

[0217] a: The Si-OH content is expressed as the ratio of the number of Si-OH to the number of Si elements

[0218] The experimental results show that increasing the Si-OH group content of the incompletely condensed poly(silsesquioxane) will lead to a significant decrease in the stability of the material; the sensitivity and contrast data show that the addition of Si-OH groups significantly improves the sensitivity of the photoresist, while the contrast performance decreases. The Si-OH group content should be within a suitable range to have good stability and good sensitivity at the same time. The Si-OH group content cannot be too high, otherwise it will lead to a decrease in stability, and the Si-OH group content cannot be too low, otherwise it will lead to a decrease in sensitivity.

[0219] Example 17

[0220] The synthesis routes, key reaction parameters, and key properties of a series of incompletely condensed polyhedral oligomeric silsesquioxanes are shown in Table 6-9, where the same serial numbers represent the same incompletely condensed polyhedral oligomeric silsesquioxanes. The incompletely condensed polyhedral oligomeric silsesquioxanes shown in Table 6 do not contain the group shown in Formula B, and the preparation method is the same as that of Examples 1-4, only changing the monomer type, monomer feeding ratio, amount of concentrated hydrochloric acid used, and dropping / stirring time; the performance parameters of the photoresist prepared from the incompletely condensed polyhedral oligomeric silsesquioxanes in Table 6 are shown in Table 7. The incompletely condensed polyhedral oligomeric silsesquioxanes shown in Table 8 contain the group shown in Formula B, and the preparation method is the same as that of Examples 5-6, only changing the monomer type, monomer feeding ratio, amount of concentrated hydrochloric acid used, and dropping / stirring time. The performance parameters of the photoresist prepared from the incompletely condensed polyhedral oligomeric silsesquioxanes in Table 8 are shown in Table 9. The characterization methods of the photoresists and lithography performance in Tables 7 and 9 are the same as those of Example 7, only changing the type of incompletely condensed polyhedral oligomeric silsesquioxanes.

[0221]

[0222] Table 6 Key reaction parameters of a series of incompletely condensed polyhedral oligomeric silsesquioxanes (without the group shown in Formula B)

[0223]

[0224]

[0225] a: This molar amount represents the molar amount of the monomer with the substituent R a of.

[0226] b: This molar amount represents the molar amount of the monomer with the substituent R b of.

[0227] c: This molar amount represents the molar amount of the monomer with the substituent R c of.

[0228] Table 7 Key performance parameters of a series of incompletely condensed polyhedral oligomeric silsesquioxanes (without the group shown in Formula B)

[0229]

[0230]

[0231] a: For some photoresists, due to their too high sensitivity, when exposed with the minimum exposure dose of the lithography machine, there is still a photoresist film remaining, so the contrast data cannot be obtained.

[0232]

[0233] Table 8 Key reaction parameters of a series of incompletely condensed polyhedral oligomeric silsesquioxanes (containing the group shown in Formula B) a

[0234]

[0235] a: The dosage of Karstedt catalyst used in the hydrosilylation reaction is 20 ppm, and the dosage of the hydrosilylation reaction solvent (toluene) is 1.3 ml / g based on the total mass of the reactants.

[0236] b: TES is the abbreviation of triethoxysilane.

[0237] c: This molar amount represents the molar amount of the trialkoxysilane monomer with substituent R d .

[0238] d: This molar amount represents the molar amount of the vinyl epoxy monomer with substituent R e .

[0239] Table 9 Key performance parameters of a series of incompletely condensed polyhedral oligomeric silsesquioxanes (containing the group shown in Formula B)

[0240]

[0241]

[0242] a: Due to the too high sensitivity, when using the minimum exposure dose of the lithography machine for exposure, there is still a photoresist film remaining, so the contrast data cannot be obtained.

[0243] The specific embodiments described above have elaborated on the technical solutions and beneficial effects of the present invention. It should be understood that the above is only the most preferred embodiment of the present invention and is not used to limit the present invention. Any modifications, supplements, equivalent replacements, etc. made within the scope of the principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. A silsesquioxane-based chemical amplification photoresist, characterized in that The photoresist comprises an incompletely condensed polysilsesquioxane, a photoacid generator and an organic solvent, wherein the incompletely condensed polysilsesquioxane is a cage-type polysilsesquioxane; the incompletely condensed polysilsesquioxane is one or more compounds represented by formula (1); (R1SiO 1.5 ) l (R2SiO 1.5 ) m (R3SiO 1.5 ) n-k-m (H2O) 1.5n-x (1) In the formula (1), R1 and R2 are each independently H, a group represented by formula A, a group represented by formula B, or the following groups which are unsubstituted or substituted by one or more substituents A: C1-C 20 Alkyl, C3-C 30 Cycloalkyl, C4-C 30 Silane, C6-C 30 Aromatic, C3-C 30 Heterocyclic or C5-C 30 heteroaromatic group, or the above group containing one or more of O, S, N, Si, P atoms in the carbon chain, the substituent A includes halogen atoms, hydroxyl, mercapto, trifluoromethyl, C1-C 20 branched or straight chain alkyl, C1-C 20 Branched or straight chain alkoxy, C3-C 20 branched or straight chain cycloalkyl, C6-C 30 Aromatic groups, C5-C 30 One or more of the heteroaromatic groups; the C3-C 30 The cycloalkyl group includes a monocyclic or polycyclic structure; In the formula (1), R3 is a group represented by formula A or a group represented by formula B; Indicates the connection key; In formula A or formula B, K1 is 0, or is the following group which is unsubstituted or substituted by one or more substituents B: C1-C 20 Alkylene, C3-C 30 Cycloalkylene, C6-C 30 Arylene, or the above group containing oxygen or silicon atoms in the carbon chain, the substituent B is C1-C 10 Alkyl or C1-C 10 The alkoxy group, the C3-C 30 The cycloalkylene group includes a monocyclic or polycyclic structure; K2 is O, an ester group, a carbonate group or an amide group; R4 is C1-C 20 Olefin, C5-C 30 Cycloalkene or C1-C 20 Alkyne group, wherein the cycloalkene group includes a cycloalkene group having a monocyclic or polycyclic structure; R5 is C2-C 20 Epoxy group; the epoxy group includes an epoxy group of a monocyclic or polycyclic structure; In the formula (1), l represents the number of R1 in the incompletely condensed polysilsesquioxane, and l is an integer of 0-20; m represents the number of R2 in the incompletely condensed polysilsesquioxane, and m is an integer of 0-20; n represents the total number of R1, R2, and R3 in the incompletely condensed polysilsesquioxane, and n is an integer of 7 to 20; x represents the number of water molecules generated during the preparation of the incompletely condensed polysilsesquioxane, and x is an integer of 9 to 29; nlm is an integer greater than 1; 3n-2x represents the number of silicon-hydroxyl groups Si-OH in the incompletely condensed polysilsesquioxane, and 3n-2x is an integer greater than or equal to 1.

2. The silsesquioxane-based chemically amplified photoresist according to claim 1, characterized in that In the formula (1), R1 is H, a group represented by formula A, a group represented by formula B, or the following groups which are unsubstituted or substituted by one or more substituents A: C1-C8 alkyl, C3-C 12 Cycloalkyl, C6-C 12 An aromatic group, or the above group containing O, S, N or Si atoms in the carbon chain, wherein the C3-C 12 The cycloalkyl group includes a monocyclic or polycyclic cycloalkyl group, and the substituent A is a halogen atom, a C1-C5 alkyl group, a trifluoromethyl group, a hydroxyl group or a mercapto group; R2 is H, a group represented by formula A, a group represented by formula B, or the following groups which are unsubstituted or substituted by one or more substituents A: C1-C8 alkyl, C3-C 12 Cycloalkyl, C6-C 12 An aromatic group, or the above group containing O, S, N or Si atoms in the carbon chain, wherein the C3-C 12 The cycloalkyl group includes a monocyclic or polycyclic cycloalkyl group, and the substituent A is a halogen atom, a C1-C5 alkyl group, a trifluoromethyl group, a hydroxyl group or a mercapto group; K1 is 0, C1-C8 alkylene, C3-C 12 Cycloalkylene, phenylene, or any of the above groups containing oxygen or silicon atoms in the carbon chain; K2 is 0 or an ester group; R4 is C1-C 10 Olefin, C5-C 12 Cycloalkene or C1-C 10 Alkyne group; R5 is a C2-C9 epoxy group; l is an integer from 0 to 14; m is an integer from 0 to 14; n is an integer from 7 to 14; x is an integer from 9 to 20; 3n-2x is an integer from 2 to 6.

3. The silsesquioxane-based chemically amplified photoresist according to claim 1, characterized in that In the incompletely condensed polysilsesquioxane, the ratio of the amount of Si-OH to the amount of Si element is 5 to 45%.

4. The silsesquioxane-based chemically amplified photoresist according to claim 1, characterized in that In the incompletely condensed polysilsesquioxane, the content of organic groups in the incompletely condensed polysilsesquioxane is 30% to 100%; the content of organic groups refers to the ratio of the number of silicon-organic groups to the total number of silicon-organic groups and silicon-hydrogen bonds.

5. The silsesquioxane-based chemically amplified photoresist according to claim 1, characterized in that The chemical formula of the incompletely condensed polysilsesquioxane is one or more of the following cage structure formulas: wherein the R6 group is selected from any one of the R1, R2, and R3 groups, and for any cage structure, at least one of the R6 groups is R3, and not all R6 groups are R1 or R2; 6. The silsesquioxane-based chemically amplified photoresist as claimed in claim 5, characterized in that The R1 and R2 are each independently one of the following groups: H, C1-C8 alkyl, C6-C 10 Aromatic group, R3 is selected from one of the following groups:

7. The silsesquioxane-based chemically amplified photoresist according to any one of claims 1 to 6, characterized in that The incompletely condensed polysilsesquioxane is prepared by one of the following methods: (i) When R1, R2 and R3 are not the groups represented by formula B, the method is as follows: silane raw materials represented by formula (2) to formula (4) are mixed in a molar ratio of 1:m:(nlm), and slowly added dropwise to concentrated acid, and a hydrolysis condensation reaction is carried out under the action of concentrated acid to obtain an incompletely condensed polysilsesquioxane represented by formula (1); The concentrated acid is concentrated sulfuric acid, oleum, concentrated hydrochloric acid or concentrated nitric acid; In formula (2) to formula (4), R 10 Select one of the following groups: (ii) When any of R1, R2 and R3 is a group represented by formula B, taking R3 as a group represented by formula B as an example, the method is as follows: mixing the silane raw materials represented by formula (2), formula (3) and formula (5) in a molar ratio of 1:m:(nlm), and slowly dropping them into concentrated acid, performing a hydrolysis condensation reaction under the action of concentrated acid, washing with water to neutrality after the reaction, then concentrating and crystallizing, removing the crystalline material by centrifugation and evaporating the solvent to obtain an intermediate product, and then performing a hydrosilylation reaction on the intermediate product and the vinyl compound represented by formula (6) under the catalytic action of a Karstedt catalyst to prepare the incompletely condensed polysilsesquioxane represented by formula (1); The concentrated acid is concentrated sulfuric acid, oleum, concentrated hydrochloric acid or concentrated nitric acid; In formula (5), R 10 Select one of the following groups:

8. The silsesquioxane-based chemically amplified photoresist according to any one of claims 1 to 6, characterized in that In the photoresist, the content of the incompletely condensed polysilsesquioxane is 1-20% by mass, the content of the photoacid generator is 0.01-4% by mass, and the balance is an organic solvent.

9. The silsesquioxane-based chemically amplified photoresist according to claim 8, characterized in that The photoacid generator is a sulfonium salt or an iodonium salt, which is composed of a cation and an anion, wherein the anion is selected from one of the following structures: The cation is selected from one of the following structures:

10. Use of the silsesquioxane-based chemically amplified photoresist according to any one of claims 1 to 6 in electron beam lithography, deep ultraviolet lithography or extreme ultraviolet lithography.

11. Use of incompletely condensed polysilsesquioxane in the preparation of chemically amplified photoresist, characterized in that The incompletely condensed polysilsesquioxane is a cage-type polysilsesquioxane; the incompletely condensed polysilsesquioxane is one or more compounds represented by formula (1); (R1SiO 1.5 ) l (R2SiO 1.5 ) m (R3SiO 1.5 ) n-l-m (H2O) 1.5n-x (1) In the formula (1), R1 and R2 are each independently H, a group represented by formula A, a group represented by formula B, or the following groups which are unsubstituted or substituted by one or more substituents A: C1-C 20 Alkyl, C3-C 30 Cycloalkyl, C4-C 30 Silane, C6-C 30 Aromatic, C3-C 30 Heterocyclic or C5-C 30 heteroaromatic group, or the above group containing one or more of O, S, N, Si, P atoms in the carbon chain, the substituent A includes halogen atoms, hydroxyl, mercapto, trifluoromethyl, C1-C 20 branched or straight chain alkyl, C1-C 20 Branched or straight chain alkoxy, C3-C 20 branched or straight chain cycloalkyl, C6-C 30 Aromatic groups, C5-C 30 One or more of the heteroaromatic groups; the C3-C 30 The cycloalkyl group includes a monocyclic or polycyclic structure; In the formula (1), R3 is a group represented by formula A or a group represented by formula B; Indicates the connection key; In formula A or formula B, K1 is 0, or is the following group which is unsubstituted or substituted by one or more substituents B: C1-C 20 Alkylene, C3-C 30 Cycloalkylene, C6-C 30 Arylene, or the above group containing oxygen or silicon atoms in the carbon chain, the substituent B is C1-C 10 Alkyl or C1-C 10 The alkoxy group, the C3-C 30 The cycloalkylene group includes a monocyclic or polycyclic structure; K2 is O, an ester group, a carbonate group or an amide group; R4 is C1-C 20 Olefin, C5-C 30 Cycloolefin, C1-C 20 Alkyne group, wherein the cycloalkene group includes a cycloalkene group having a monocyclic or polycyclic structure; R5 is C2-C 20 Epoxy groups, or the above groups containing oxygen or sulfur atoms in the carbon chain; the epoxy groups include epoxy groups with monocyclic or polycyclic structures; In the formula (1), l represents the number of R1 in the incompletely condensed polysilsesquioxane, and l is an integer of 0-20; m represents the number of R2 in the incompletely condensed polysilsesquioxane, and m is an integer of 0-20; n represents the total number of R1, R2, and R3 in the incompletely condensed polysilsesquioxane, and n is an integer of 7 to 20; x represents the number of water molecules generated during the preparation of the incompletely condensed polysilsesquioxane, and x is an integer of 9 to 29; nlm is an integer greater than 1; 3n-2x represents the number of silicon-hydroxyl groups Si-OH in the incompletely condensed polysilsesquioxane, and 3n-2x is an integer greater than or equal to 1.

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