Single molecular weight photoresist as well as preparation method and application thereof

Abstract

The invention provides a preparation method of a single-molecular-weight photoresist, which comprises the following steps: reacting a compound containing hydroxyl and an end-capping group with a compound of which the end groups are respectively TBS-protected hydroxyl and an acyl azide group to prepare a single-molecular-weight compound, connecting one end of the single-molecular-weight compound with the end-capping group, and connecting the other end of the single-molecular-weight compound with a TBS protecting group. When chain growth needs to be carried out on a single molecular weight compound, a deprotection reaction is carried out on the single molecular weight compound, then the single molecular weight compound reacts with a group with acyl azide, and a deprotection-chain growth iteration reaction is carried out on the single molecular weight compound, so that a target compound is prepared. According to the single-molecular-weight photoresist prepared by the preparation method provided by the invention, under the action of an electron beam or EUV, a macromolecular main chain in an exposure region is broken or further polymerized, so that the dissolution rates of the exposure region and a non-exposure region are remarkably different, and therefore, the development time is expected to be shortened, and the development efficiency is improved. Overexposure is avoided; and cooperative improvement of resolution and sensitivity is realized.

Description

Technical Field

[0001] The present disclosure relates to the field of semiconductor technology, and in particular to a single molecular weight photoresist and a preparation method and application thereof. Background Art

[0002] Large-scale integrated circuits and semiconductor chip technology have developed into the core foundation of advanced manufacturing and information technology, and the integrated circuit industry involves a number of core processes, such as lithography, etching, ion implantation, etc. Among them, lithography is the prerequisite for subsequent etching and ion implantation. In addition to professional lithography equipment, the key to the success of lithography is highly dependent on the quality and performance of photoresist materials. Simply optimizing process parameters and processing conditions can no longer meet the current demand for photoresist materials. However, the shorter the wavelength of the light beam, the more demanding the performance of the photoresist material.

[0003] Traditional photoresists only involve the reaction of polymer side chain functional groups, which makes the difference in dissolution rate between the exposed area and the non-exposed area less obvious, requiring a longer development time, which has an adverse effect on the synergistic improvement of photoresist resolution and sensitivity. In addition, traditional photoresists are usually multi-component systems, which often have uneven dispersion and interactions between different components, affecting the development effect. Summary of the invention

[0004] In view of this, in order to solve at least one of the above-mentioned and other technical problems in the related art and to achieve the above-mentioned purpose, the technical solution of the present disclosure is as follows:

[0005] The present disclosure provides a method for preparing a single molecular weight photoresist, comprising:

[0006] The compound represented by formula G and the compound represented by formula H are used as raw materials to prepare the compound represented by formula J,

[0007]

[0008] Wherein, 0≤m≤2, R1, R2 and R3 are independently selected from -F, -Cl, -Br, -I, -NO2, -H, Cl~C 20 Alkyl, C2~C 20 Olefin groups, C2~C 20 Alkyne group, C1~C 20 Alkoxy, C2~C 20 Alkenyloxy or C2~C 20 One of the alkynyloxy groups, R is a functional group used to regulate the film-forming properties of a single molecular weight photoresist;

[0009] Compound and a compound represented by formula H or formula J as a raw material to prepare a compound represented by formula K, wherein i is 1 or 2, and T is a capping group;

[0010]

[0011] Performing a deprotection reaction on the compound represented by formula K to obtain a compound represented by formula L;

[0012]

[0013] Iterate the compound represented by formula L to form a new compound The rearrangement reaction and the deprotection reaction are repeated until a single molecular weight photoresist having a target molecular weight is obtained.

[0014] According to an embodiment of the present disclosure, the method further includes: preparing a compound of formula G, wherein the preparation of the compound of formula G includes:

[0015] Using sodium borohydride as a reducing agent to carry out a reduction reaction on the compound represented by formula D to obtain a compound represented by formula E;

[0016]

[0017] The compound represented by formula E is used as a raw material to react to obtain a compound represented by formula F;

[0018]

[0019] The compound represented by formula F is used as a raw material to react to obtain a compound represented by formula G;

[0020]

[0021] According to an embodiment of the present disclosure, the method further includes: preparing a compound represented by formula H, wherein the method comprises:

[0022] Using the compound represented by formula G as a raw material, protecting the hydroxyl group in the compound represented by formula G, to prepare the compound represented by formula H;

[0023]

[0024] According to an embodiment of the present disclosure, the method further comprises: preparing a compound of formula D, wherein the preparation of the compound of formula D comprises:

[0025] The compound represented by formula A and the compound RBr are used as raw materials to react to obtain the compound represented by formula B;

[0026]

[0027] The compound represented by formula B is used as a raw material to react to obtain a compound represented by formula C;

[0028]

[0029] The compound represented by formula C is used as a raw material to react to obtain a compound represented by formula D;

[0030]

[0031] According to an embodiment of the present disclosure, R is any one of the following structures:

[0032]

[0033] Among them, 1≤a≤20.

[0034] According to an embodiment of the present disclosure, Any of the following structures:

[0035]

[0036] Wherein, R4, R5 and R6 are independently selected from -F, -Cl, -Br, -I, -NO2, -H, Cl~C 20 Alkyl, C2~C 20 Olefin group, C2~C 20 Alkyne group, C1~C 20 Alkoxy, C2~C 20 Alkenyloxy or C2~C 20 One of the alkynyloxy groups.

[0037] According to an embodiment of the present disclosure,

[0038] After the rearrangement reaction, column chromatography is required to obtain the compound.

[0039] According to an embodiment of the present disclosure,

[0040] The compound represented by formula J is obtained by purification by column chromatography;

[0041] The compound represented by formula K is obtained by purification by column chromatography.

[0042] In another aspect of the present disclosure, a single molecular weight photoresist is disclosed, having a structure shown in the following formula (I):

[0043]

[0044] Among them, n is 0 to 20.

[0045] In another aspect of the present disclosure, a method for preparing a film layer using a photoresist is disclosed, comprising:

[0046] Adding the photoresist into the solvent, shaking, dissolving and filtering to obtain a photoresist solution;

[0047] The photoresist solution is coated on the substrate and dried to obtain a film layer.

[0048] According to an embodiment of the present disclosure,

[0049] The concentration of the photoresist solution is 4 mg / mL to 80 mg / mL;

[0050] The thickness of the film layer is 10nm-5000nm.

[0051] In another aspect of the present disclosure, a single molecular weight photoresist is used in an electron beam photoresist or an extreme ultraviolet photoresist.

[0052] Based on the above technical solution, the beneficial effects of the present disclosure are:

[0053] The single molecular weight photoresist disclosed in the present invention, under the action of electron beam or EUV, causes the polymer main chain in the exposed area to grow or break, resulting in a significant difference in the dissolution rate between the exposed and non-exposed areas. Therefore, it is expected to shorten the development time, avoid overexposure and achieve a synergistic improvement in resolution and sensitivity.

[0054] The single molecular weight photoresist disclosed in the present invention has a definite chain structure and chain length, and therefore has a precise molecular weight. Each molecular chain is identical, and the monomer can be precisely regulated, so that it exhibits superb stability in steps such as exposure and development, and is convenient for improving development resolution. The photoresist controlled by development parameters can be used as both positive and negative photoresists. The developer does not involve acid or alkali and is substrate-friendly. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Figure 1 is the H NMR spectrum of the compound shown in B-1 prepared according to Example 1;

[0056] Figure 2 is the H NMR spectrum of the compound shown in D-1 prepared according to Example 1;

[0057] Figure 3 is the H NMR spectrum of the compound shown in E-1 prepared according to Example 1;

[0058] Figure 4 is the H NMR spectrum of the compound shown in F-1 prepared according to Example 1;

[0059] Figure 5 is the H NMR spectrum of the compound shown in G-1 prepared according to Example 1;

[0060] Figure 6is the H NMR spectrum of the compound shown in H-1 prepared according to Example 1;

[0061] Figure 7 is the H NMR spectrum of the compound shown in J-1 prepared according to Example 1;

[0062] Figure 8 is the H NMR spectrum of the compound shown in L-1 prepared according to Example 1;

[0063] Fig. 9 is the H NMR spectrum of the compound shown in M-1 prepared according to Example 1;

[0064] Fig.10a The positive photoresist atomic force microscope characterization pattern after electron beam exposure and development obtained in Application Example 1;

[0065] Fig.10b The negative photoresist atomic force microscope characterization pattern after electron beam exposure and development obtained in Application Example 1;

[0066] Fig.11a The AFM characterization pattern of the positive photoresist after EUV exposure and development obtained in Application Example 2;

[0067] Fig.11b This is the negative photoresist atomic force microscope characterization pattern after EUV exposure and development obtained according to Application Example 2. DETAILED DESCRIPTION

[0068] In order to make the objectives, technical solutions and advantages of the present disclosure more clearly understood, the present disclosure is further described in detail below in combination with specific embodiments and with reference to the accompanying drawings.

[0069] The endpoints and any values ​​of the ranges disclosed in this disclosure are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be regarded as specifically disclosed in this disclosure.

[0070] The terms used herein are only for describing specific embodiments and are not intended to limit the present disclosure. The terms "comprise", "include", etc. used herein indicate the existence of the features, steps, operations and / or components, but do not exclude the existence or addition of one or more other features, steps, operations or components.

[0071] All terms (including technical and scientific terms) used herein have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein should be interpreted as having a meaning consistent with the context of this specification, and should not be interpreted in an idealized or overly rigid manner.

[0072] Conventional photoresists generally use resin and photoacid as raw materials. When receiving electron beams or light, the photoacid breaks the functional group chain. The present invention provides a single molecular weight photoresist, whose single component avoids the unbalanced relationship between resolution, line edge roughness and sensitivity caused by the reaction between multi-component organic substances. In terms of the use of the photoresist, since it does not contain photoacid, it will not cause corrosion and other damage to the substrate.

[0073] On this basis, the preparation method of the single molecular weight photoresist provided by the present disclosure effectively controls the chain length of the photoresist, and uses a capping group and a compound with a TBS group as raw materials to react to form a functional group with a capping group at one end and a TBS-protected functional group at the other end. In the preparation process, the molecular weight of the obtained compound is controllable by utilizing a chain growth-deprotection cyclic iteration process, so that the photoresist has stronger stability and controllability during exposure and development.

[0074] The present disclosure provides a method for preparing a single molecular weight photoresist, comprising:

[0075] Step 1: Using the compound represented by formula G and the compound represented by formula H as raw materials to prepare the compound represented by formula J,

[0076]

[0077] Wherein, 0≤m≤2 (for example, it can be 0, 1 or 2), R1, R2 and R3 are independently selected from -F, -Cl, -Br, -I, -NO2, -H, Cl~C 20 Alkyl, C2~C 20 Olefin groups, C2~C 20 Alkyne group, C1~C 20 Alkoxy, C2~C 20 Alkenyloxy or C2~C 20 One of the alkynyloxy groups, R is a functional group used to regulate the film-forming properties of a single molecular weight photoresist;

[0078] Step 2: Compound With the compound represented by formula H or formula J as a raw material, a rearrangement reaction is carried out to prepare a compound represented by formula K, wherein i is 1 or 2, and T is a capping group;

[0079]

[0080] Step 3: performing a deprotection reaction on the compound represented by formula K to obtain a compound represented by formula L;

[0081]

[0082] Step 4: Iterate the compound represented by formula L to generate a new compound The rearrangement reaction and the deprotection reaction are repeated until a single molecular weight photoresist having a target molecular weight is obtained.

[0083] According to the embodiment of the present disclosure, a capping group and a compound with a TBS group are reacted as raw materials to form a functional group with a capping group at one end and TBS protection at the other end. Based on the protection and deprotection strategy, during the preparation process, a single molecular weight photoresist with controllable molecular weight and structure is formed by a cyclic iterative process of chain growth-deprotection. The photoresist provided by the present disclosure has a precise structure of a single molecular weight, which makes it show super stability in the steps of exposure and development, and synergistically improves the development resolution and sensitivity.

[0084] According to the embodiment of the present disclosure, step one specifically includes sub-step (one) to sub-step (two):

[0085] Sub-step (i): dissolve the compound represented by formula H in anhydrous toluene, remove water by azeotropic method, then add anhydrous toluene as solvent to react at 60-110°C for 3-8h, and return to room temperature; wherein the reaction temperature can be 60°C, 80°C, 100°C, 110°C; the reaction time can be 3h, 5h, 6h, 8h.

[0086] Sub-step (ii): Add the compound of formula G and 0.5% DBTL (dibutyltin dilaurate) to another reaction vessel, use anhydrous toluene to azeotropically remove water, add anhydrous THF (tetrahydrofuran) to dissolve, transfer the solution to the reaction vessel containing the compound of formula H, and react at room temperature for 5 to 15 hours. The reaction time can be 5 hours, 7 hours, 9 hours, 12 hours, or 15 hours. After the reaction is completed, use petroleum ether-ethyl acetate as the eluent for column chromatography to obtain a single compound of formula J.

[0087] According to the embodiments of the present disclosure, THF can be replaced by 2-methyltetrahydrofuran, chloroform, etc.

[0088] According to an embodiment of the present disclosure, the hydroxyl group in the compound shown in formula G reacts with the azide group in the compound shown in formula H to generate a compound shown in formula J, wherein the compound shown in formula J is connected to an azide group at one end and to TBS at the other end, forming a compound whose one end can be used for a step-growth reaction.

[0089] According to the embodiment of the present disclosure, step 2 specifically includes:

[0090] Hydroxyl raw materials without repeating units The compound represented by formula H or formula J and 0.5% DBTL are dissolved in anhydrous toluene, and after azeotropic removal of water, NMP (N-methylpyrrolidone) is added as a solvent and the reaction is carried out at 60-110° C. for 3-8 hours to complete the reaction; wherein the reaction temperature can be 60° C., 80° C., 100° C., 110° C.; the reaction time can be 3 hours, 5 hours, 6 hours, 8 hours.

[0091] According to the embodiment of the present disclosure, step three specifically includes:

[0092] Methanol is added to the reaction solution obtained in step 2 for dilution, and p-toluenesulfonic acid is added to remove TBS protection; after the protection is removed, O is connected to H to form an exposed hydroxyl group, which can be polymerized. After the reaction is completed, EA (ethyl acrylate) and deionized water are added to the system for extraction, and the organic phase is washed three times with saturated brine. After the organic phase is dried and concentrated, the compound shown in L is obtained, and petroleum ether-ethyl acetate is used as an eluent for column chromatography to obtain a single molecular weight compound shown in formula L.

[0093] According to an embodiment of the present disclosure, methanol may be replaced by water or saturated brine.

[0094] According to the embodiment of the present disclosure, in step 4,

[0095] If the compound reacts with the compound represented by formula H, and the resulting compound increases by one repeating unit; if the compound The compound represented by formula J is reacted to increase the number of repeating units by two, thereby obtaining a compound represented by formula K with a capping group connected at one end and OTBS connected at the other end, so that the compound cannot undergo polymerization reaction.

[0096] The single molecular weight photoresist prepared by this method has a definite chain structure and chain length, and therefore has a precise molecular weight. Each molecular chain is identical, which enables it to exhibit super stability in steps such as exposure and development, making it easier to improve development resolution and adjust sensitivity. At the same time, a single component or single molecular weight photoresist can reduce the dispersion unevenness and phase separation of a multi-component system, and avoid mutual influence between different components.

[0097] It should be noted that the above expression of Ca to Cb represents that the number of carbon atoms in the group is a to b.

[0098] As C1~C 20 Examples of the alkane group include methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, pentyl, isopentyl, hexyl, heptyl, octyl, nonyl, decyl, undecane, dodecane and the like, among which methyl is preferred.

[0099] As C1~C20 Examples of alkoxy groups include methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, sec-butoxy, isobutoxy, tert-butoxy, pentyloxy, isopentyloxy, hexyloxy, heptyloxy, octyloxy, nonyloxy, decyloxy, undecyloxy, dodecyloxy and the like, among which methoxy, ethoxy, n-propoxy, isopropoxy, tert-butoxy, sec-butoxy, isobutoxy and isopentyloxy are preferred, and methoxy is more preferred.

[0100] As C2~C 20 Examples of the olefin group include vinyl, allyl, and 2-methylprop-2-enyl, among which allyl is preferred.

[0101] As C2~C 20 Examples of the alkynyl group include ethynyl, propargyl, and 2-methylprop-2-ynyl.

[0102] As C2~C 20 Examples of the alkenyloxy group include vinyloxy, allyloxy, and 2-methylprop-2-enyloxy.

[0103] As C2~C 20 Examples of the alkynyloxy group include ethynyloxy, propargyloxy, and 2-methylprop-2-ynyloxy.

[0104] According to an embodiment of the present disclosure, the above preparation method further includes: preparing the compound represented by formula G, wherein the preparation of the compound represented by formula G includes:

[0105] Step 101: using sodium borohydride as a reducing agent to perform a reduction reaction on the compound represented by formula D to obtain a compound represented by formula E;

[0106]

[0107] Step 102: using the compound represented by formula E as a raw material to react to obtain a compound represented by formula F;

[0108]

[0109] Step 103: using the compound represented by formula F as a raw material to react to obtain a compound represented by formula G;

[0110]

[0111] According to the embodiment of the present disclosure, step 101 specifically includes:

[0112] The compound represented by formula D is dissolved in THF, sodium borohydride is added in batches at 0-30°C, and the reaction is carried out at room temperature for 2-12 hours; wherein the reaction temperature can be 0°C, 10°C, 20°C, 30°C; the reaction time can be 2h, 5h, 8h, 10h, 12h;

[0113] The THF in the system was removed by rotation, EA and deionized water were added for extraction, the organic phase was washed three times with saturated brine, and the organic phase was dried and concentrated to obtain the compound represented by formula E.

[0114] According to the embodiment of the present disclosure, step 102 specifically includes:

[0115] The compound represented by formula E is dissolved in methanol, potassium hydroxide is added to the system, and reflux reaction is carried out for 6 to 10 hours; wherein the reaction time can be 6 hours, 8 hours, or 10 hours;

[0116] Remove the methanol, add deionized water, adjust the pH to about 3 with hydrochloric acid, add EA for extraction, wash the organic phase with saturated brine three times, dry and concentrate the organic phase to obtain the compound shown in formula F

[0117] According to the embodiment of the present disclosure, step 103 specifically includes:

[0118] The compound represented by formula F is dissolved in THF, triethylamine is added to the system at 0-30°C, and after stirring for 10 minutes, DPPA (azidation reagent) is gradually added dropwise to the system, and the reaction is carried out at room temperature for 6-10 hours; wherein the reaction temperature can be 0°C, 10°C, 20°C, 30°C, and the reaction time can be 6 hours, 8 hours, or 10 hours;

[0119] THF was removed by rotary evaporation, and the compound represented by formula G was obtained by column chromatography using petroleum ether-ethyl acetate as eluent.

[0120] According to an embodiment of the present disclosure, the above preparation method further includes: preparing a compound represented by formula H, wherein preparing the compound represented by formula H includes:

[0121] Using the compound represented by formula G as a raw material, protecting the hydroxyl group in the compound represented by formula G, to prepare the compound represented by formula H;

[0122]

[0123] According to the embodiment of the present disclosure, the steps of preparing the compound represented by formula H specifically include:

[0124] The compound represented by formula G is dissolved in DCM (dichloromethane), imidazole is added to the system at 0-30°C, and after stirring for 10 minutes, TBSCl (tert-butyldimethylsilyl chloride) is added to the system, and the reaction is carried out at room temperature for 5-8 hours; wherein the reaction temperature can be 0°C, 10°C, 20°C, 30°C, and the reaction time can be 5h, 6h, 7h, 8h;

[0125] DCM (dichloromethane) was added to the system for dilution and deionized water was added for extraction. The organic phase was washed three times with saturated brine. The organic phase was dried and concentrated to obtain the compound represented by formula H.

[0126] According to an embodiment of the present disclosure, the above preparation method further includes: preparing the compound represented by formula D, wherein the preparation of the compound represented by formula D includes:

[0127] Step 201: reacting the compound represented by formula A and the compound RBr as raw materials to obtain the compound represented by formula B;

[0128]

[0129] Step 202: using the compound represented by formula B as a raw material to react to obtain a compound represented by formula C;

[0130]

[0131] Step 203: using the compound represented by formula C as a raw material to react to obtain the compound represented by formula D;

[0132]

[0133] According to the embodiment of the present disclosure, step 201 further includes:

[0134] The compound represented by formula A, compound R-Br and potassium carbonate are dissolved in DMF, and reacted at 50-85°C for 6-15h under nitrogen protection; wherein the reaction temperature can be 50°C, 60°C, 75°C, 85°C; and the reaction time can be 6h, 8h, 10h, 12h, 15h.

[0135] The solvent DMF was removed by vortexing, ethyl acetate was added to dissolve, the organic phase was washed with saturated brine, the organic phase was dried and concentrated, and then column chromatography was performed using petroleum ether-ethyl acetate as the eluent to obtain the compound represented by formula B;

[0136] According to the embodiments of the present disclosure, Br in R-Br can be replaced by F, I, OTs, etc., which can achieve the same effect (forming ether with phenolic hydroxyl group).

[0137] According to the embodiment of the present disclosure, step 202 further includes:

[0138] The compound represented by formula B, NBS (N-bromosuccinimide) and AIBN (azobisisobutyronitrile) are dissolved in CCl4, and refluxed for 8 to 24 hours under nitrogen protection; wherein the reaction time can be 8 hours, 10 hours, 15 hours, 20 hours, 22 hours, or 24 hours.

[0139] After the reaction is completed, the insoluble solid is removed by filtration, the filtrate is washed three times with saturated brine, and the organic phase is dried and concentrated to obtain the compound represented by formula C;

[0140] According to the embodiment of the present disclosure, step 203 further includes:

[0141] Slowly add the compound represented by formula C to morpholine, use morpholine as reaction solvent and reactant, and react at 30-60°C for 8-16h; wherein the reaction temperature can be 30°C, 40°C, 50°C, 60°C; the reaction time can be 8h, 10h, 12h, 14h, 16h.

[0142] The excess morpholine was removed by rotation, and a large amount of ethyl acetate and water were added for extraction. The organic phase was washed several times with 1 mol / L hydrochloric acid and then washed three times with saturated brine. The organic phase was dried and concentrated, and then column chromatography was performed using petroleum ether-ethyl acetate as the eluent to obtain the compound shown in formula D.

[0143] According to an embodiment of the present disclosure,

[0144] R is any of the following structures:

[0145]

[0146] Among them, 1≤a≤20, for example, a can be 1, 2, 4, 6, 8, 12, 16, 20, etc.

[0147] According to the embodiments of the present disclosure, the above-mentioned R group in the single molecular weight photoresist can adjust the physical properties and chemical properties of the photoresist, for example: improving the coating effect; promoting microphase separation during patterning, etc., and can also cause the photoresist to undergo further cross-linking or provide space for post-modification.

[0148] According to an embodiment of the present disclosure,

[0149] Any of the following structures:

[0150]

[0151] Wherein, R4, R5 and R6 are independently selected from -F, -Cl, -Br, -I, -NO2, -H, Cl~C 20 Alkyl, C2~C 20 Olefin group, C2~C 20Alkyne group, C1~C 20 Alkoxy, C2~C 20 Alkenyloxy or C2~C 20 According to an embodiment of the present disclosure, wherein,

[0152] After the rearrangement reaction, column chromatography operation is required to obtain the compound.

[0153] According to an embodiment of the present disclosure,

[0154] The compound represented by formula J is obtained by purification by column chromatography;

[0155] The compound represented by formula K is obtained by purification by column chromatography.

[0156] Another aspect of the present disclosure also discloses a single molecular weight photoresist having a structure shown in the following formula (I):

[0157]

[0158] Wherein, n is 0 to 20, and m, R1 to R3 and R have the same meanings as above. The single molecular weight photoresist has a certain chain structure and chain length, and thus has a precise molecular weight, and each molecular chain is the same, so that it exhibits super stability in the steps of exposure and development, and is convenient for improving development resolution and adjusting sensitivity; at the same time, the single component or single molecular weight photoresist can reduce the dispersion inhomogeneity and phase separation of the multi-component system, and avoid mutual influence between different components.

[0159] According to the embodiment of the present disclosure, m can be 0, 1, or 2. An increase in the value of m will increase the difficulty of preparation and make the raw materials more expensive.

[0160] According to an embodiment of the present disclosure,

[0161] n can be 1, 5, 6, 8, 10, 12, 15, or 20. If the value of N is too small or too large, the physical properties of the photoresist will be greatly changed, thereby deteriorating the coating and other process effects.

[0162] Another aspect of the present disclosure also discloses a method for preparing a film layer using a photoresist, comprising:

[0163] Adding the photoresist solvent into the solvent, shaking, dissolving and filtering to obtain a photoresist solution;

[0164] The photoresist solution is coated on a substrate and dried to obtain the film layer.

[0165] The solvent may be THF, ethylene glycol dimethyl ether, NMP (N-methylpyrrolidone), DMF, acetone, butanone, methyl isobutyl ketone; the organic filter membrane is used to filter insoluble impurities such as dust and is ≤450nm; the oscillation operation time may be 30s-30mins, for example: 30s, 1min, 5mins, 15mins, 20mins, 30mins; the oscillation operation temperature may be 12-45°C, for example: 12°C, 25°C, 28°C, 35°C, 45°C;

[0166] The photoresist can be coated by spin coating, wherein the spin coating speed can be 500r / min-8000r / min, for example: 500r / min, 2000r / min, 5000r / min, 8000r / min; the substrate must be hydrophobic before coating; the drying temperature can be 40-120℃, for example: 40℃, 60℃, 80℃, 120℃; the drying time can be 1-30mins, for example: 1min, 5mins, 10mins, 20mins, 30mins.

[0167] According to the embodiment of the present disclosure, the substrate is a silicon wafer, but may also be other materials with a smooth surface such as glass or metal.

[0168] According to an embodiment of the present disclosure,

[0169] The concentration of the photoresist solution is 4 mg / mL to 80 mg / mL;

[0170] The thickness of the film layer is 10nm-5000nm.

[0171] Among them, the concentration of the photoresist solution is 4mg / mL to 80mg / mL, for example: 4mg / mL, 15mg / mL, 35mg / mL, 55mg / mL, 70mg / mL, 80mg / mL; the thickness of the film layer is 10nm-5000nm, for example: 10nm, 100nm, 1000nm, 3000nm, 5000nm.

[0172] In another aspect of the present disclosure, a single molecular weight photoresist is used in electron beam photoresist or extreme ultraviolet photoresist. When the electron beam or extreme ultraviolet light is irradiated and reaches a certain intensity, it self-degrades to form a positive photoresist; when the electron beam or extreme ultraviolet light continues to irradiate and reaches another intensity range, it is further polymerized and cross-linked to form a negative photoresist, and then developed. Wherein, when the voltage is 100kV and the electron beam dose is ≤200μC / cm 2 When the voltage is 100kV and the electron beam dose is ≥4000μC / cm 2 When EUV energy density is ≤5mJ / cm 2When EUV energy density is ≥35mJ / cm 2 When the negative photoresist is formed, the developing time is 20s-300s. Preferably, in the compound represented by formula (I), m=0; n=8 or n=10 or n=12.

[0173] The technical solution of the present disclosure is further described below in conjunction with specific examples, but it should be noted that the following examples are only used to illustrate the technical solution of the present disclosure, but the present disclosure is not limited thereto. The raw materials used in the examples are described as follows:

[0174] Isooctane bromide, NBS, AIBN, morpholine, sodium borohydride, DPPA and N-methylpyrrolidone (NMP) were purchased from Sigma-Aldrich and used without further purification. Tetrahydrofuran was dried with sodium wire and refluxed and used after distillation. Petroleum ether, ethyl acetate, dibutyltin laurate, potassium carbonate, zinc powder, acetic acid, methanol, triethylamine, potassium hydroxide and other reagents were all analytically pure and purchased from Sinopharm Chemical Reagent Co., Ltd. They were used directly without further purification. The ultrapure water used in the experiment was prepared by the Milli-QSP intelligent ultrapure water system with a resistivity of 18.4 MΩ·cm.

[0175] Example 1: Synthesis of single molecular weight self-degradable photoresist

[0176] Step 1: Preparation of compound shown in B-1

[0177]

[0178] Figure 1 The H NMR spectrum of the compound shown in B-1 is shown. 5.0 g, 30.09 mmol of the compound shown in formula A-1, 6.97 g, 36.11 mmol of isobutyl bromide and 12.48 g, 390.27 mmol of potassium carbonate were dissolved in 50 mL of DMF, and reacted at 50-85°C for 6-15 hours under nitrogen protection; the solvent DMF was removed by vortexing, 100 mL of ethyl acetate was added to dissolve, the organic phase was washed with saturated brine, the organic phase was dried and concentrated, and column chromatography was performed using petroleum ether-ethyl acetate as the eluent to obtain the compound shown in B-1, and the yield was 88%.

[0179] Step 2: Preparation of the compound shown in C-1

[0180]

[0181] 5.0 g, 17.96 mmol of the compound shown in B-1, 3.2 g, 17.96 mmol of NBS (N-bromosuccinimide) and 0.03 g, 0.18 mmol of AIBN were dissolved in 50 mL of CCl4 and refluxed for 8 to 24 hours under nitrogen protection. After the reaction, the insoluble solid was removed by filtration, and the filtrate was washed three times with saturated brine. The organic phase was dried and concentrated to obtain the compound shown in C-1. The yield was 92%, and it was directly used in the next step without additional purification.

[0182] Step 3: Preparation of the compound shown in D-1

[0183]

[0184] Figure 2 The NMR hydrogen spectrum of the compound shown in D-1 is shown. 5g of the compound shown in C-1 is slowly added to 50mL of morpholine, with morpholine as the reaction solvent and reactant, and the reaction is carried out at 30-60°C for 8-16h; the excess morpholine is removed by rotation, a large amount of ethyl acetate and water are added for extraction, the organic phase is washed with 1mol / L hydrochloric acid for several times, and then washed with saturated brine for three times, the organic phase is dried and concentrated, and column chromatography is performed using petroleum ether-ethyl acetate as the eluent to obtain the compound shown in D-1; the yield is 85%.

[0185] Step 4: Preparation of the compound shown in E-1

[0186]

[0187] Figure 3 The following is the H NMR spectrum of the compound shown in E-1. 5.0 g, 17.10 mmol of the compound shown in D-1 was dissolved in 50 mL of THF, 0.65 g, 17.10 mmol of sodium borohydride was added in batches at 0-30°C, and the mixture was reacted at room temperature for 2-12 hours; THF in the system was removed by rotation, 100 mL of EA and 100 mL of deionized water were added, and the organic phase was washed three times with saturated brine, and the organic phase was dried and concentrated to obtain the compound shown in E-1; the yield was 95%.

[0188] Step 5: Preparation of the compound shown in F-1

[0189]

[0190] Figure 4The following is the H NMR spectrum of the compound shown in F-1. 5.0 g, 16.98 mmol of the compound shown in E-1 was dissolved in 50 mL of methanol, 2.86 g, 50.95 mmol of potassium hydroxide was added to the system, and the reaction was refluxed for 6 to 10 hours; after the reaction, the methanol was removed by rotation, 100 mL of deionized water was added, and the pH was adjusted to about 3 with hydrochloric acid, 100 mL of EA was added for extraction, and the organic phase was washed three times with saturated brine, and the organic phase was dried and concentrated to obtain the compound shown in formula F-1, and the yield was 95%.

[0191] Step 6: Preparation of the compound shown in G-1

[0192]

[0193] Figure 5 The following is the H NMR spectrum of the compound shown in G-1. 5.0 g, 17.83 mmol of the compound shown in F-1 was dissolved in 50 mL of THF, 1.99 g, 19.62 mmol of triethylamine was added to the system at 0-30°C, and after stirring for 10 minutes, 5.4 g, 19.62 mmol of DPPA was gradually added dropwise to the system, and the reaction was carried out at room temperature for 6-10 hours; after the reaction was completed, THF was removed by rotation, and the compound shown in G-1 was obtained by column chromatography using petroleum ether-ethyl acetate as the eluent; the yield was 88%.

[0194] Step 7: Preparation of the compound shown in H-1

[0195]

[0196] Figure 6 The H NMR spectrum of the compound shown in H-1 is shown. 5.0 g, 16.37 mmol of the compound shown in G-1 was dissolved in 50 mL of DCM, 1.23 g, 18.01 mmol of imidazole was added to the system at 0-30°C, and after stirring for 10 minutes, 2.71 g, 18.01 mmol of TBSCl was added to the system, and the reaction was carried out at room temperature for 5-8 hours; after the reaction was completed, DCM was added to the system to dilute and deionized water was added, and the organic phase was extracted, and the organic phase was washed three times with saturated brine, and the organic phase was dried and concentrated to obtain compound H; its yield was 88%.

[0197] Step 8: Preparation of the compound shown in J-1

[0198]

[0199] Figure 7The NMR hydrogen spectrum of the compound shown in J-1 is shown. 5.0g, 11.91mmol of the compound shown in H-1 was dissolved in 50mL of anhydrous toluene, and after azeotropic removal of water, 50mL of anhydrous toluene was added as solvent to react at 60-110°C for 3-8h, and then returned to room temperature; 3.64g, 11.91mmol of the compound shown in G-1 and 0.5% DBTL were added to another reaction bottle, and after azeotropic removal of water with 30mL of anhydrous toluene, 40mL of anhydrous THF was added to dissolve, and the solution was transferred to the reaction bottle containing the compound shown in H-1 before, and reacted at room temperature for 5-15h. After the reaction was completed, petroleum ether-ethyl acetate was used as the eluent for column chromatography to obtain compound J; its yield was 85%.

[0200] Step 9: Preparation of the compound shown in K-1

[0201]

[0202] 1.15 g, 10.63 mmol of hydroxyl raw material T-OH without repeating unit, 5.0 g, 10.63 mmol of compound J-1 and 0.5% of DBTL were dissolved in 50 mL of anhydrous toluene, and after azeotropic removal of water, 50 mL of NMP was added as solvent and reacted at 60°C for 8 h. After the reaction was completed, compound K-1 was obtained. No additional purification was performed and the next step of deprotection was directly carried out.

[0203] Step 10: Deprotection reaction of compound K-1

[0204]

[0205] Figure 8 The NMR hydrogen spectrum of the compound shown in L-1 is shown. 30 mL of methanol was added to the compound shown in K-1 for dilution, and 0.2 g, 1.063 mmol of p-toluenesulfonic acid was added to remove the TBS protection. After the reaction was completed, 100 mL of EA and 100 mL of deionized water were added to the system for extraction. The organic phase was washed three times with saturated brine. After the organic phase was dried and concentrated, petroleum ether-ethyl acetate was used as the eluent for column chromatography to obtain the compound shown in L-1;

[0206] Step 11: Using the compound represented by formula L-1 and the compound represented by formula H or formula J as raw materials, a rearrangement reaction is carried out to obtain a compound represented by formula M-1;

[0207] The above growth-deprotection iteration cycle is continuously performed until the target precise molecule M-1 with a polymerization degree of 10 is reached; Fig. 9 Shown is the H NMR spectrum of the compound represented by M-1.

[0208]

[0209] in,

[0210] Application Example 1: Electron beam exposure and development of single molecular weight self-degradable photoresist

[0211]

[0212] The compound shown in M-1 was dissolved in an organic solvent, ethylene glycol dimethyl ether, and spin-coated on a silicon wafer to form a film layer of about 50 nm. The voltage was 100 kV and the electron beam dose was 150 μC / cm 2 The voltage is 100 kV and the electron beam dose is 4000 μC / cm 2 After the lower exposure, toluene and ethylene glycol dimethyl ether were used for development to obtain positive and negative photoresist patterns, respectively. Fig.10a In order to characterize the positive photoresist pattern after electron beam exposure and development obtained in Application Example 1, lines with line widths of 45 nm, 90 nm, 120 nm and 220 nm were obtained, and the development time was 60 s. Fig.10b In order to characterize the pattern of the negative photoresist after electron beam exposure and development obtained in Application Example 1, lines with line widths of 30nm, 80nm, 120nm and 200nm were obtained, and the development time was 60s. Application Example 1 proves that this type of polymer can be used as positive and negative photoresist under electron beam.

[0213] Application Example 2: EUV Exposure and Development of Single Molecular Weight Self-degradable Photoresist

[0214]

[0215] The compound shown in M-1 was dissolved in an organic solvent, ethylene glycol dimethyl ether, and spin-coated on a silicon wafer to form a film layer of about 50 nm. 2 and EUV energy density of 45mJ / cm 2 After the lower exposure, toluene and ethylene glycol dimethyl ether were used for development to obtain positive and negative photoresist patterns, respectively. Fig.11a The positive photoresist characterization pattern after EUV exposure and development obtained in Application Example 2 obtained a line with a line width of about 60 nm and a development time of 60 s. Fig.11b The negative photoresist pattern after EUV exposure and development obtained in Application Example 2 was characterized, and a line width of about 33 nm was obtained, and the development time was 60 s. Application Example 2 proves that this type of polymer can be used as positive and negative photoresist under EUV.

[0216] The specific embodiments described above further illustrate the purpose, technical solutions and beneficial effects of the present disclosure. It should be understood that the above description is only a specific embodiment of the present disclosure and is not intended to limit the present disclosure. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present disclosure should be included in the protection scope of the present disclosure.

Claims

1. A method for preparing a single molecular weight photoresist, comprising: The compound represented by formula G and the compound represented by formula H are used as raw materials to prepare the compound represented by formula J, Wherein, 0≤m≤2, R1, R2 and R3 are independently selected from -F, -Cl, -Br, -I, -NO2, -H, Cl~C 20 Alkyl, C2~C 20 Olefin groups, C2~C 20 Alkyne group, C1~C 20 Alkoxy, C2~C 20 Alkenyloxy or C2~C 20 One of the alkynyloxy groups, R is a functional group used to regulate the film-forming properties of a single molecular weight photoresist; Compound With the compound represented by formula H or formula J as a raw material, a rearrangement reaction is carried out to prepare a compound represented by formula K, wherein i is 1 or 2, and T is a capping group; Performing a deprotection reaction on the compound represented by formula K to obtain a compound represented by formula L; Iterate the compound represented by the formula L to form a new compound The rearrangement reaction and the deprotection reaction are repeated until a single molecular weight photoresist with a target molecular weight is obtained.

2. The preparation method according to claim 1, further comprising: Prepare the compound represented by formula G, wherein the preparation of the compound represented by formula G comprises: Using sodium borohydride as a reducing agent to carry out a reduction reaction on the compound represented by formula D to obtain a compound represented by formula E; Using the compound represented by formula E as a raw material to react, to obtain a compound represented by formula F; Using the compound represented by the formula F as a raw material to carry out a reaction to obtain the compound represented by the formula G; 3. The preparation method according to claim 2, further comprising: Prepare the compound represented by formula H, wherein the preparation of the compound represented by formula H comprises: Using the compound represented by the formula G as a raw material, protecting the hydroxyl group in the compound represented by the formula G, to prepare the compound represented by the formula H; 4. The preparation method according to claim 2, further comprising: Prepare the compound represented by formula D, wherein the preparation of the compound represented by formula D comprises: The compound represented by formula A and the compound RBr are used as raw materials to react to obtain the compound represented by formula B; Using the compound represented by formula B as a raw material to react, to obtain a compound represented by formula C; Using the compound represented by the formula C as a raw material to carry out a reaction to obtain the compound represented by the formula D; 5. The preparation method according to any one of claims 1 to 4, wherein R is any of the following structures: Among them, 1≤a≤20.

6. The preparation method according to any one of claims 1 to 4, wherein Any of the following structures: Wherein, R4, R5 and R6 are independently selected from -F, -Cl, -Br, -I, -NO2, -H, Cl~C 20 Alkyl, C2~C 20 Olefin group, C2~C 20 Alkyne group, C1~C 20 Alkoxy, C2~C 20 Alkenyloxy or C2~C 20 One of the alkynyloxy groups.

7. The preparation method according to any one of claims 1, wherein After the rearrangement reaction, column chromatography operation is required to obtain the compound.

8. The preparation method according to any one of claims 7, wherein The compound represented by formula J is obtained by column chromatography; The compound represented by formula K is obtained by column chromatography.

9. A single molecular weight photoresist prepared by the preparation method according to any one of claims 1 to 8, having a structure shown in the following formula (I): in, n is 0 to 20.

10. A method for preparing a film layer using a photoresist according to claim 9, comprising: Adding the photoresist into a solvent, shaking, dissolving and filtering to obtain a photoresist solution; The photoresist solution is coated on a substrate and dried to obtain the film layer.

11. The method according to claim 10, wherein: The concentration of the photoresist solution is 4 mg / mL to 80 mg / mL; The thickness of the film layer is 10nm-5000nm.

12. Use of the single molecular weight photoresist according to claim 9 as electron beam photoresist or extreme ultraviolet photoresist.

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