A method and system for non-destructive direct detection of photoresist critical dimensions

Abstract

The application belongs to the technical field of photoresist critical dimension detection, and more particularly relates to a method and system for non-destructive direct detection of photoresist critical dimension. The application utilizes the behavior of AIE molecules that emit almost no light in dilute solution but emit strong fluorescence when combined with target objects to perform super-resolution positioning imaging on photoresist containing target objects, thereby obtaining a high-resolution image. Compared with the traditional CD-SEM technology, the method has the following advantages: first, it does not cause damage to the sample because the use of AIE probes does not depend on the electron beam; second, combined with the super-resolution imaging technology, high-resolution imaging of the photoresist is realized, and the accuracy and reliability of the detection are improved. Therefore, the method proposed by the application provides an effective and non-destructive solution for photoresist critical dimension detection, and has wide application prospect and market potential.

Description

Technical Field

[0001] This application belongs to the field of photoresist critical dimension inspection technology, and more specifically, relates to a method and system for non-destructive direct inspection of photoresist critical dimensions. Background Technology

[0002] Currently, the photoresist industry commonly uses CD-SEM to inspect the critical dimensions of photoresists. A single device can cost tens of millions of yuan, and electron beams can cause significant damage to the measured samples, especially after photolithography, which can lead to photoresist shrinkage. During photoresist inspection, it is necessary to balance the electron beam irradiation intensity with the image quality required for inspection to minimize adverse effects on the photoresist. As photolithography technology becomes increasingly smaller, the impact of CD-SEM inspection losses on measurement accuracy can no longer be ignored, and the industry is continuously striving to develop better measurement methods. Summary of the Invention

[0003] To address the shortcomings of existing technologies, the purpose of this application is to provide a method and system for non-destructive direct detection of critical dimensions of photoresist, aiming to solve the technical problems of high equipment cost and significant electron-induced damage to the measured sample when using CD-SEM for critical dimension detection of photoresist in existing technologies.

[0004] To achieve the above objectives, in a first aspect, this application provides a system for non-destructive direct detection of critical dimensions of photoresist, including developed photoresist, a solution containing dissolved AIE fluorescent probe molecules, and a super-resolution imaging device; The developed photoresist contains a polymer capable of reversibly targeting and binding with the AIE fluorescent probe molecules; The AIE fluorescent probe molecule does not emit fluorescence in the solution, but when it comes into contact with the developed photoresist, it can reversibly target and bind to the AIE fluorescent probe molecule, causing it to exhibit random "on" and "off" states under laser irradiation. During detection, the developed photoresist is brought into contact with a solution containing dissolved AIE fluorescent probe molecules. The contact area is defined as the target area, allowing the polymer to reversibly target and bind to the AIE fluorescent probe molecules. The target area is continuously irradiated with laser, and several images are acquired using a super-resolution imaging device. A super-resolution algorithm is then used to reconstruct the super-resolution image, thereby obtaining the key dimensions of the photoresist within the target area.

[0005] Preferably, the reversible targeted binding is one or more of hydrophilic-hydrophobic interactions, electrostatic interactions, and specific binding.

[0006] Preferably, the polymer structure contains hydroxyl or phenolic hydroxyl groups; The structure of the AIE fluorescent probe molecule contains hydroxyl groups; The AIE fluorescent probe molecules containing hydroxyl groups can continuously bind and dissociate with the polymers containing hydroxyl or phenolic hydroxyl groups through hydrophilic-hydrophobic interactions, thereby causing the AIE fluorescent probe molecules to exhibit random "on" and "off" states under laser irradiation.

[0007] Preferably, the polymer is a polymer containing p-hydroxystyrene, and the solubility of the polymer in the developer can be altered by the action of acid.

[0008] Preferably, the AIE fluorescent probe molecule is one or more of the following: a non-ionic tetraphenylethylene compound containing hydroxyl groups, a non-ionic triphenylamine compound containing hydroxyl groups, a non-ionic diarylethylene compound containing hydroxyl groups, a non-ionic cyanodiarylethylene compound containing hydroxyl groups, a non-ionic thiophene compound containing hydroxyl groups, a non-ionic anthracene compound containing hydroxyl groups, a non-ionic benzothiadiazole compound containing hydroxyl groups, an ionic tetraphenylethylene compound containing hydroxyl groups, an ionic triphenylamine compound containing hydroxyl groups, an ionic diarylethylene compound containing hydroxyl groups, an ionic cyanodiarylethylene compound containing hydroxyl groups, an ionic thiophene compound containing hydroxyl groups, an ionic anthracene compound containing hydroxyl groups, and an ionic benzothiadiazole compound containing hydroxyl groups.

[0009] Preferably, the concentration of AIE fluorescent probe molecules in the solution containing the dissolved AIE fluorescent probe molecules is 2 × 10⁻⁶. - 5 mol / L-7×10 -5 The solvent used to dissolve the AIE fluorescent probe molecules is one or more of deionized water, petroleum ether, dichloromethane, chloroform, and toluene, at a concentration of mol / L.

[0010] Preferably, the wavelength of the laser is 248-561 nm; A super-resolution imaging device was used to record 5,000-30,000 frames at a speed of 10-40 milliseconds, and a super-resolution algorithm was used to reconstruct the super-resolution image. The super-resolution algorithm is QC-STORM, PALMER, or MaLing.

[0011] According to another aspect of the present invention, a method for detecting critical dimensions of photoresist using the aforementioned system is provided, comprising the following steps: (1) The photoresist composition is coated onto the wafer, and then exposed and developed sequentially to obtain the developed photoresist; the developed photoresist contains a polymer that can reversibly target and bind to the AIE probe molecules; (2) The developed photoresist is brought into contact with a solution containing AIE fluorescent probe molecules, so that the polymer and the AIE fluorescent probe molecules undergo reversible targeted binding. The contact area is defined as the target area. The AIE fluorescent probe molecules do not emit fluorescence in the solution, but after they come into contact with the developed photoresist, they can reversibly target and bind, so that the AIE probe molecules exhibit random "on" and "off" states under laser irradiation. (3) The target area is continuously irradiated with laser, and several images are acquired using a super-resolution imaging device. The super-resolution image is reconstructed using a super-resolution algorithm, thereby obtaining the key dimensions of the photoresist in the target area.

[0012] Preferably, the photoresist composition is a chemically amplified photoresist; the photoresist composition further contains a solvent, an acid-generating agent, an acid diffusion inhibitor, and a photoswitch; the solvent is used to dissolve the acid-generating agent, the acid diffusion inhibitor, and the polymer.

[0013] Overall, the technical solutions conceived in this application have the following beneficial effects compared with the prior art: (1) This invention utilizes the behavior of AIE fluorescent probe molecules, which emit almost no light in dilute solutions but emit strong fluorescence when bound to the target, to perform super-resolution localization imaging of photoresist containing the target, thereby obtaining high-resolution images and realizing the detection of key dimensions of the photoresist. Compared with the traditional CD-SEM technique, this method has significant advantages: First, it does not damage the sample because the use of AIE probes does not depend on an electron beam; second, combined with super-resolution imaging technology, it achieves high-resolution imaging of the photoresist, improving the accuracy and reliability of detection.

[0014] (2) In the preferred embodiment of the present invention, the AIE probe molecule with hydroxyl group is used to bind with the target object with hydroxyl or phenolic hydroxyl group in the photoresist through hydrophilic-hydrophobic interaction and emit strong fluorescence. For the first time, a photoresist key size detection method based on AIE (aggregation-induced emission) probe and super-resolution imaging technology is proposed. This is a non-destructive and direct detection method.

[0015] (3) The photoresist key dimension detection method proposed in this invention can detect without introducing new substances into the photoresist, and does not affect the performance of the photoresist itself.

[0016] (4) Compared with CD-SEM, the detection method of the present invention does not damage the sample while having higher resolution and better imaging effect, and is simple and easy to implement.

[0017] (5) The non-destructive direct detection method of the present invention has a wide range of applications and does not limit the specific type of photoresist. As long as the polymer contained in the photoresist can reversibly target and bind with the AIE fluorescent probe molecules, it is acceptable. Attached Figure Description

[0018] Figure 1 This is a photograph of the critical dimensions of the photoresist measured using CD-SEM, which is Comparative Example 1 of this application; Figure 2 It is a super-resolution image reconstructed from Embodiment 1 of this application; Figure 3 The results are line size measurements from a super-resolution image reconstructed according to Example 1. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0020] The embodiments of the present invention are implemented under the premise of the technical solution of the present invention, and detailed implementation methods and processes are given. However, the protection scope of the present invention is not limited to the following embodiments. The process parameters in the following embodiments that do not specify specific conditions are generally in accordance with conventional conditions.

[0021] The endpoints and any values ​​of the ranges disclosed in this invention 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 the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this invention.

[0022] The process parameters in the following examples, unless otherwise specified, are generally performed under conventional conditions.

[0023] To address the numerous shortcomings of the current method of using CD-SEM for critical dimension detection of photoresists, which is commonly used in the photoresist industry, this invention proposes a method and system for critical dimension detection of photoresists based on AIE (aggregation-induced emission) probes and super-resolution imaging technology. This invention utilizes the behavior of AIE molecules, which are almost non-luminescent in dilute solutions but emit strong fluorescence when bound to target materials in the photoresist, to perform super-resolution localization imaging of the photoresist, thereby obtaining high-resolution images. Compared with traditional CD-SEM technology, this method has significant advantages: firstly, it does not damage the sample because the use of AIE probes is independent of the electron beam; secondly, the combination with super-resolution imaging technology achieves high-resolution imaging of the photoresist, improving the accuracy and reliability of detection. Therefore, the method proposed in this invention provides an effective and non-destructive solution for critical dimension detection of photoresists, with broad application prospects and market potential.

[0024] The present invention provides a system for non-destructive direct detection of key dimensions of photoresist, comprising developed photoresist, a solution containing dissolved AIE fluorescent probe molecules, and a super-resolution imaging device; The developed photoresist contains a polymer capable of reversibly targeting and binding with the AIE probe molecules; The AIE fluorescent probe molecule does not emit fluorescence in the solution, but when it comes into contact with the developed photoresist, it can reversibly target and bind, causing the AIE probe molecule to exhibit random "on" and "off" states under laser irradiation. During detection, the developed photoresist is brought into contact with a solution containing dissolved AIE fluorescent probe molecules, allowing the developed photoresist to come into contact with the AIE fluorescent probe molecules, enabling the polymer to reversibly target and bind to the AIE fluorescent probe molecules. The contact area is defined as the target area. The target area is continuously irradiated with laser, and several images are acquired using a super-resolution imaging device. A super-resolution algorithm is then used to reconstruct a super-resolution image, thereby obtaining the key dimensions of the photoresist within the target area.

[0025] In some embodiments, the reversible targeted binding is one or more of hydrophilic-hydrophobic interactions, electrostatic interactions, and specific binding.

[0026] In some embodiments, the developed photoresist contains a polymer, the polymer structure containing hydroxyl or phenolic hydroxyl groups; the AIE fluorescent probe molecule structure contains hydroxyl groups; the AIE fluorescent probe molecule containing hydroxyl groups and the polymer containing hydroxyl or phenolic hydroxyl groups can continuously bind and dissociate through hydrophilic-hydrophobic interactions, thereby causing the AIE fluorescent probe molecule to exhibit random "on" and "off" states under laser irradiation. Accordingly, the present invention provides a system for non-destructive direct detection of key dimensions of photoresist, including developed photoresist, a solution containing dissolved AIE fluorescent probe molecules, and a super-resolution imaging device; The photoresist contains a polymer, and the polymer has a structure containing hydroxyl or phenolic hydroxyl groups; The structure of the AIE fluorescent probe molecule contains hydroxyl groups; The AIE fluorescent probe molecule does not emit fluorescence in the solution, but when it comes into contact with a polymer containing hydroxyl or phenolic hydroxyl groups in the developed photoresist, the AIE fluorescent probe molecule containing hydroxyl groups and the polymer containing hydroxyl or phenolic hydroxyl groups can continuously bind and dissociate through hydrophilic-hydrophobic interactions, thereby exhibiting random "on" and "off" of the fluorescent molecules. During detection, the developed photoresist is immersed in a solution containing AIE fluorescent probe molecules, so that the polymer in the developed photoresist comes into contact with the AIE fluorescent probe molecules, and the contact area is defined as the target area. The target area is continuously irradiated with laser, and several images are acquired using a super-resolution imaging device. A super-resolution image is reconstructed using a super-resolution algorithm, thereby obtaining the key dimensions of the photoresist within the target area.

[0027] This invention also provides a method for non-destructive direct inspection of critical dimensions of photoresist, comprising the following steps: (1) The photoresist composition is coated onto the wafer, and then exposed and developed sequentially to obtain the developed photoresist; the photoresist composition contains a polymer, and the polymer contains hydroxyl or phenolic hydroxyl groups; (2) The developed photoresist is brought into contact with a solution containing AIE fluorescent probe molecules, so that the polymer and the AIE fluorescent probe molecules undergo reversible targeted binding. The contact area is defined as the target area, and the AIE fluorescent probe molecules contain hydroxyl groups. The AIE fluorescent probe molecules do not emit fluorescence in the solution, but after they come into contact with the polymer containing hydroxyl or phenolic hydroxyl groups in the developed photoresist, the AIE fluorescent probe molecules containing hydroxyl groups and the polymer containing hydroxyl or phenolic hydroxyl groups can continuously bind and dissociate through hydrophilic-hydrophobic interactions, thereby exhibiting random "on" and "off" of fluorescent molecules. (3) The target area is continuously irradiated with laser, and several images are acquired using a super-resolution imaging device. The super-resolution image is reconstructed using a super-resolution algorithm, thereby obtaining the key dimensions of the photoresist in the target area.

[0028] In a preferred embodiment, the photoresist composition is a chemically amplified photoresist. The composition comprises a solvent, a polymer whose solubility in the developer is altered by the action of acid, an acid-generating agent, an acid diffusion inhibitor, and a photo-switching molecule. Chemically amplified photoresists are photoresist materials that utilize the amplification effect of chemical reactions to improve photolithography sensitivity and resolution, and are widely used in photolithography processes in semiconductor manufacturing. The core principle of chemically amplified photoresists is to utilize the acid generated by the photoacid generator (PAG) during exposure to catalyze the chemical reaction in the photoresist film, thereby achieving an amplification effect of the chemical reaction. The specific process is as follows: S1: Exposure stage: The photoacid generator decomposes under the irradiation of light of a specific wavelength (such as deep ultraviolet light) to produce acid.

[0029] S2: Post-baking stage: The acid produced during the post-baking process catalyzes the chemical reaction in the resist film, causing changes in the chemical properties of the resist, thereby achieving polarity reversal or solubility change.

[0030] S3: Development stage: After chemical reaction, the resist film exhibits different solubilities in the developer, forming the desired pattern.

[0031] The solvent used in the photoresist composition of the present invention is a substance capable of dissolving the resist in the composition to form a homogeneous solution. It can be a single solvent or a mixture of solvents, such as one or more of propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, tetrahydrofuran, cyclohexanone, toluene, dimethyl sulfoxide, ethyl lactate, n-heptane, butyl acetate, and γ-butyrolactone. Preferably, it is one or more of propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, γ-butyrolactone, and ethyl lactate.

[0032] The polymer can be selected from polymers commonly used as chemically amplified resists. This includes, but is not limited to, polymers containing p-hydroxystyrene in their monomers. Examples include p-hydroxystyrene-tert-butyl acrylate copolymers, p-hydroxystyrene-tert-butyl methacrylate copolymers, p-hydroxystyrene-styrene-tert-butyl acrylate copolymers, p-hydroxystyrene-styrene-tert-butyl methacrylate copolymers, p-hydroxystyrene-tert-butoxystyrene copolymers, p-hydroxystyrene-styrene-tert-butoxystyrene copolymers, p-hydroxystyrene-adamantyl acrylate, p-hydroxystyrene-styrene-adamantyl acrylate, etc.

[0033] The acid-generating agent can be one or more of the acid-generating agents used in chemically amplified resists, including but not limited to iodonium salts, sulfonium salts such as sulfonium salts, triazines, sulfonyl diazomethanes, N-sulfonyl dicarboximides, oxime esters, disulfones, and o-nitrobenzyl sulfonates. Among these, iodonium salts are preferred. For example, triphenylsulfonium trifluoromethanesulfonate, triphenylsulfonium perfluorobutyl sulfonate, and bis[4-(1,1-dimethylethyl)phenyl]trifluoromethanesulfonate iodonium salt can be used alone or in combination of two or more.

[0034] The acid diffusion inhibitor can be one or more of the acid diffusion inhibitors used in chemically amplified resists. For example, it can be various amines or ammonium salts in organic bases, preferably primary, secondary, or tertiary alkylamines or hydroxyalkylamines. Tertiary alkylamines and tertiary hydroxyalkylamines are particularly preferred, such as trimethylamine, triethylamine, tripropylamine, tributylamine, tripentylamine, trihexylamine, triheptylamine, trioctylamine, etc.

[0035] The AIE probe can be a non-ionic tetraphenylethylene compound with hydroxyl groups, a non-ionic triphenylamine compound with hydroxyl groups, a non-ionic diarylethylene compound with hydroxyl groups, a non-ionic cyanodiarylethylene compound with hydroxyl groups, a non-ionic thiophene compound with hydroxyl groups, a non-ionic anthracene compound with hydroxyl groups, a non-ionic benzothiadiazole compound with hydroxyl groups, etc., or it can be an ionic tetraphenylethylene compound with hydroxyl groups, an ionic triphenylamine compound with hydroxyl groups, an ionic diarylethylene compound with hydroxyl groups, an ionic cyanodiarylethylene compound with hydroxyl groups, an ionic thiophene compound with hydroxyl groups, an ionic anthracene compound with hydroxyl groups, an ionic benzothiadiazole compound with hydroxyl groups, etc., with non-ionic tetraphenylethylene compounds with hydroxyl groups being preferred.

[0036] In some embodiments, when the AIE probe used in this invention is a nonionic tetraphenylethylene compound with hydroxyl groups, it has the general formula shown in formula (I):

[0037] Formula (1) In formula (a), n1 is an integer from 1 to 6, preferably an integer from 1 to 3, and more preferably 1 or 2; n2 is an integer from 1 to 6, preferably an integer from 1 to 3, and more preferably 1 or 2.

[0038] Nonionic tetraphenylethylene compounds with hydroxyl groups exhibit almost no fluorescence emission in dilute solutions, but they emit strong fluorescence after binding with target polymers containing hydroxyl or phenolic hydroxyl groups through hydrophilic-hydrophobic interactions. The random "on" and "off" switching of fluorescent molecules as these nonionic tetraphenylethylene compounds continuously bind and dissociate with target polymers containing hydroxyl or phenolic hydroxyl groups can be used for super-resolution localization imaging.

[0039] In some embodiments, the concentration of AIE fluorescent probe molecules in the solution containing dissolved AIE fluorescent probe molecules is 2 × 10⁻⁶. -5 mol / L-7×10 -5 The concentration is mol / L, and the solvent is one or more of deionized water, petroleum ether, dichloromethane, chloroform, and toluene. The wavelength of the laser is 248-561 nm. A super-resolution imaging device is used to record 5000-30000 frames at a rate of 10-40 milliseconds, and the number of photons in the acquired images is between 200-20000. The super-resolution image is reconstructed using super-resolution algorithms QC-STORM, PALMER, or Maling.

[0040] In some embodiments, a solution containing AIE fluorescent probe molecules can be dropped onto the surface of the developed photoresist, so that the developed photoresist comes into contact with the solution containing AIE fluorescent probe molecules; or the developed photoresist can be immersed in a solution containing AIE fluorescent probe molecules, so that the developed photoresist comes into contact with the solution containing AIE fluorescent probe molecules, so that the polymer in the photoresist and the AIE fluorescent probe molecules undergo reversible targeted binding through hydrophilic-hydrophobic interactions, electrostatic interactions, specific binding, etc.; then it is placed on the stage of the super-resolution imaging device, covered with a coverslip, and in step (3), the target area is continuously irradiated with laser through the coverslip. The laser irradiation excites the AIE fluorescent probe molecules to emit fluorescence, so that the AIE fluorescent probe molecules exhibit random "on" and "off" under laser irradiation.

[0041] Since silicon wafers are opaque, in some preferred embodiments, the developed photoresist placed on the silicon wafer is inverted onto a transparent container containing an AIE fluorescent probe molecular solution. The transparent container is, for example, a cover glass, so that the photoresist is in direct contact with the AIE fluorescent probe molecular solution. Then, a super-resolution imaging device equipped with a nanofilter is used for imaging. A laser is continuously passed through the transparent container to irradiate the target area and acquire multiple images. Finally, a super-resolution image is reconstructed using a super-resolution algorithm.

[0042] In some embodiments, the present invention provides a method for detecting critical dimensions of photoresist based on AIE (aggregation-induced emission) probes and super-resolution imaging technology, comprising the following steps: (1) The photoresist composition was mixed in proportion and stirred for 48 hours. Then, it was filtered twice with a 0.1-micron filter and spin-coated onto a silicon wafer. After a photolithography process of soft baking, exposure, post-exposure baking and development, a pattern with a critical line size of 150 nm was obtained.

[0043] (2) Cut the photolithographically etched silicon wafer into a suitable size or place it upside down on a coverslip with a diluted AIE probe solution added, and conduct experiments in a super-resolution imaging system equipped with a 555-705 nm filter. Hydroxyl-containing nonionic tetraphenylethylene compounds emit almost no fluorescence in dilute solutions, but they emit strong fluorescence after binding with polymers containing hydroxyl or phenolic hydroxyl groups in the photoresist through hydrophilic-hydrophobic interactions. The random "on" and "off" of fluorescent molecules exhibited by the hydroxyl-containing nonionic tetraphenylethylene compounds as they continuously bind and dissociate with the hydroxyl or phenolic hydroxyl-containing target polymers satisfies the basic principle of single-molecule localization super-resolution imaging. That is, at different times, the fluorescent dye is randomly lit on the sample surface, causing a series of overlapping fluorescent images in space to be separated into many sub-images. Each sub-image contains only a few luminescent fluorophores. By collecting thousands of images, the center positions of the fluorescent points in all images are superimposed to reconstruct a super-resolution image.

[0044] (3) The target area is continuously irradiated with a 405 nm laser and 10,000 frames are recorded at a speed of 20 milliseconds per frame. The 10,000 collected images are superimposed to obtain a fluorescence image. Finally, the super-resolution image is reconstructed using the super-resolution algorithm QC-STORM.

[0045] Super-resolution imaging (SMI) is an imaging technique that overcomes the diffraction limit of traditional optical microscopes, achieving higher resolution imaging. SMI systems are commonly used for biological samples such as cells. The resolution of traditional optical microscopes is limited by the diffraction limit of light, typically around 200 nanometers, while SMI technology can improve the resolution to the nanometer level. In a preferred embodiment of this invention, the polymer contained in the photoresist can reversibly target and bind to the AIE probe through hydrophilic-hydrophobic interactions, electrostatic interactions, and specific binding. The random "on" and "off" of fluorescent molecules as the probe and polymer continuously bind and dissociate satisfies the basic principle of single-molecule localization SMI. That is, at different times, fluorescent dyes are randomly illuminated on the sample surface, causing a series of overlapping fluorescent images in space to be separated into many sub-images. Each sub-image contains only a few luminescent fluorophores. By collecting thousands of images and superimposing the center positions of the fluorescent dots in all images, a super-resolution image is reconstructed. This cleverly enables non-destructive direct detection of key dimensions of the photoresist.

[0046] The photoresist critical dimension detection method of the present invention is not limited to the type of photoresist, as long as it contains a substance capable of reversibly targeting and binding with AIE probe molecules after photolithography and development. This reversible targeting and binding causes the AIE probe molecules to exhibit random "on" and "off" states under laser irradiation, which satisfies the basic principle of single-molecule localization super-resolution imaging, thereby achieving super-resolution imaging detection. Here, reversible targeting and binding includes, but is not limited to, mechanisms such as hydrophilic-hydrophobic interactions, electrostatic interactions, and specific binding.

[0047] The resist composition of the present invention may further contain, as desired and as needed, compounds commonly used as additives for resists, such as organic carboxylic acids and oxyphosphoric acids for the purpose of preventing degradation of the sensitivity of acid-producing agents and improving the shape of the resist pattern, additional resins for improving the performance of the resist film, surfactants for improving coatability, dissolution inhibitors, plasticizers, stabilizers, colorants, anti-halo agents, dyes, etc.

[0048] The embodiments of this application are described below with reference to the accompanying drawings.

[0049] Comparative Example 1 The photoresist composition includes: Solvent: Propylene glycol monomethyl ether acetate; Polymer: Poly(hydroxystyrene / styrene / t-BOC protected hydroxystyrene), wherein the molar ratio of hydroxystyrene / styrene / t-BOC protected hydroxystyrene is 70:20:10, the molecular weight of the polymer is 16000, and the mass of the polymer is 5% of the solvent mass; Acid-generating agent: bis(4-tert-butylphenyl)iodonium perfluoro-1-butanolate, the mass of which is 5% of the polymer mass; Acid diffusion inhibitor: Tetramethylammonium hydroxide, the mass of which is 0.15% of the polymer mass.

[0050] The above photoresist composition was mixed in proportion and stirred for 48 hours. Then, it was filtered twice through a 0.1-micron filter. The photoresist composition was spin-coated onto a silicon wafer with an anti-reflective coating, baked at 100 °C for 1 min, and exposed using a KrF lithography machine at a focal length of 0.3 and an exposure dose of 500 mJ / cm². 2 After exposure, bake at 120 °C for 60 s, develop in 2.38 wt% TMAH aqueous solution for 30 s, wash with deionized water for 30 s, and purge with nitrogen to remove residual water.

[0051] The dimensions of the lines were characterized using CD-SEM.

[0052] Example 1 The structure of the nonionic tetraphenylethylene compound TPE-NI-AOH is as follows:

[0053] The nonionic tetraphenylethylene compound was dissolved in deionized water to prepare a solution of 5×10 -5 A mol / L solution was used. The wafer from Comparative Example 1, after photolithography, was cut to a suitable size and inverted onto a coverslip containing a dilute TPE-NI-AOH solution. Experiments were conducted using a super-resolution imaging system. The target area was continuously illuminated with a 380 nm laser, and 10,000 frames were recorded at a rate of 20 milliseconds per frame. These 10,000 images were combined to obtain a fluorescence image. Finally, the super-resolution image was reconstructed using the QC-STORM algorithm, and the number of photons collected was 5154.

[0054] Figure 1 This is a CD-SEM image of scale 1. Figure 1 This indicates that the line size measured by CD-SEM is approximately 150 nm. Figure 2 The super-resolution image is reconstructed from Example 2. Figure 3 Yes Figure 2 The results of the line size measurement show that the line size measured by super-resolution imaging is also about 150 nm, which is consistent with CD-SEM. This indicates that after TPE-NI-AOH is combined with photoresist, super-resolution positioning imaging of the photoresist can be used to detect the key dimensions of the photoresist.

[0055] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A system for non-destructive direct inspection of critical dimensions of photoresist, characterized in that, This includes the developed photoresist, the solution containing AIE fluorescent probe molecules, and the super-resolution imaging device; The developed photoresist contains a polymer capable of reversibly targeting and binding with the AIE fluorescent probe molecules; the polymer is a polymer containing p-hydroxystyrene, and the solubility of the polymer in the developer can be altered by the action of acid; the polymer structure contains hydroxyl or phenolic hydroxyl groups; the structure of the AIE fluorescent probe molecules contains hydroxyl groups; the reversible targeting and binding is a hydrophilic-hydrophobic interaction; the AIE fluorescent probe molecules containing hydroxyl groups and the polymer containing hydroxyl or phenolic hydroxyl groups can continuously bind and dissociate through hydrophilic-hydrophobic interactions, thereby causing the AIE fluorescent probe molecules to exhibit random "on" and "off" states under laser irradiation; The AIE fluorescent probe molecule does not emit fluorescence in the solution, but when it comes into contact with the developed photoresist, it can cause the AIE fluorescent probe molecule to exhibit random "on" and "off" behavior under laser irradiation through the hydrophilic-hydrophobic interaction. During detection, the developed photoresist is brought into contact with a solution containing dissolved AIE fluorescent probe molecules. The contact area is defined as the target area, allowing the polymer to reversibly target and bind to the AIE fluorescent probe molecules. The target area is continuously irradiated with laser, and several images are acquired using a super-resolution imaging device. A super-resolution algorithm is then used to reconstruct the super-resolution image, thereby obtaining the key dimensions of the photoresist within the target area.

2. The system as described in claim 1, characterized in that, The AIE fluorescent probe molecule is one or more of the following: a non-ionic tetraphenylethylene compound containing hydroxyl groups, a non-ionic triphenylamine compound containing hydroxyl groups, a non-ionic diarylethylene compound containing hydroxyl groups, a non-ionic cyanodiarylethylene compound containing hydroxyl groups, a non-ionic thiophene compound containing hydroxyl groups, a non-ionic anthracene compound containing hydroxyl groups, a non-ionic benzothiadiazole compound containing hydroxyl groups, an ionic tetraphenylethylene compound containing hydroxyl groups, an ionic triphenylamine compound containing hydroxyl groups, an ionic diarylethylene compound containing hydroxyl groups, an ionic cyanodiarylethylene compound containing hydroxyl groups, an ionic thiophene compound containing hydroxyl groups, an ionic anthracene compound containing hydroxyl groups, and an ionic benzothiadiazole compound containing hydroxyl groups.

3. The system as described in claim 1, characterized in that, The concentration of AIE fluorescent probe molecules in the solution containing dissolved AIE fluorescent probe molecules is 2 × 10⁻⁶. -5 mol / L-7×10 -5 The solvent used to dissolve the AIE fluorescent probe molecules is one or more of deionized water, petroleum ether, dichloromethane, chloroform, and toluene, at a concentration of mol / L.

4. The system as described in claim 1, characterized in that, The wavelength of the laser is 248-561nm; A super-resolution imaging device was used to record 5,000-30,000 frames at a speed of 10-40 milliseconds, and a super-resolution algorithm was used to reconstruct the super-resolution image. The super-resolution algorithm is QC-STORM, PALMER, or MaLing.

5. A method for detecting critical dimensions of photoresist using the system described in any one of claims 1 to 4, characterized in that, Includes the following steps: (1) The photoresist composition is coated onto the wafer, and then exposed and developed sequentially to obtain the developed photoresist; the developed photoresist contains a polymer that can reversibly target and bind to the AIE probe molecules; (2) The developed photoresist is brought into contact with a solution containing AIE fluorescent probe molecules, so that the polymer and the AIE fluorescent probe molecules undergo reversible targeted binding, and the contact area is defined as the target area; the AIE fluorescent probe molecules do not emit fluorescence in the solution, but after they come into contact with the developed photoresist, they can reversibly target and bind, so that the AIE probe molecules exhibit random "on" and "off" under laser irradiation; (3) The target area is continuously irradiated with laser, and several images are acquired using a super-resolution imaging device. A super-resolution image is reconstructed using a super-resolution algorithm, thereby obtaining the key dimensions of the photoresist in the target area.

6. The method as described in claim 5, characterized in that, The photoresist composition is a chemically amplified photoresist; the photoresist composition also contains a solvent, an acid-generating agent, an acid diffusion inhibitor, and a photoswitch; the solvent is used to dissolve the acid-generating agent, the acid diffusion inhibitor, and the polymer.

Images