Method and system for nondestructively and directly detecting key size of photoresist

Abstract

The invention belongs to the technical field of photoresist critical dimension detection, and particularly relates to a method and a system for nondestructively and directly detecting a photoresist critical dimension. According to the invention, the behavior that AIE molecules almost do not emit light in a dilute solution state but can emit strong fluorescence when being combined with the target object is utilized to carry out super-resolution positioning imaging on the photoresist containing the target object, so that a high-resolution image is obtained. Compared with a traditional CD-SEM technology, the method has the remarkable advantages that firstly, the method does not damage a sample because the use of an AIE probe does not depend on electron beams; and secondly, in combination with a super-resolution imaging technology, high-resolution imaging of the photoresist is realized, and the accuracy and reliability of detection are improved. Therefore, the method provided by the invention provides an effective and non-destructive solution for detecting the key size of the photoresist, and has wide application prospect and market potential.

Description

Technical Field

[0001] The present application belongs to the technical field of photoresist critical dimension detection, and more specifically, relates to a method and system for non-destructive direct detection of photoresist critical dimensions. Background Art

[0002] At present, the photoresist industry generally uses CD-SEM to detect the key dimensions of photoresist. The price of a device is as high as tens of thousands of yuan, and the electrons cause great damage to the measured samples, especially the test after lithography will cause the photoresist to shrink. During the photoresist inspection process, it is necessary to balance the electron beam irradiation intensity and the image quality required for detection to minimize the adverse effects on the photoresist. As the lithography technology nodes become smaller and smaller, the impact of CD-SEM detection loss on measurement accuracy can no longer be ignored, and the industry has been working hard to develop better measurement methods. Summary of the invention

[0003] In view of the defects of the prior art, the purpose of this application is to provide a method and system for non-destructive direct detection of the critical dimensions of photoresist, aiming to solve the technical problems that the prior art uses CD-SEM to detect the critical dimensions of photoresist, the equipment price is high, and the electrons cause great damage to the measured samples.

[0004] To achieve the above-mentioned objectives, in a first aspect, the present application provides a system for non-destructively and directly detecting the critical dimensions of a photoresist, comprising a developed photoresist, a solution in which AIE fluorescent probe molecules are dissolved, and a super-resolution imaging device; The developed photoresist contains a polymer capable of reversibly targeting and binding with the AIE fluorescent probe molecule; The AIE fluorescent probe molecule has no fluorescence emission in the solution, but after contacting with the developed photoresist, the AIE fluorescent probe molecule can be reversibly targeted to make the AIE fluorescent probe molecule randomly "on" and "off" under laser irradiation; During detection, the developed photoresist is brought into contact with a solution in which AIE fluorescent probe molecules are dissolved, and the contact area is defined as a target area, so that the polymer and the AIE fluorescent probe molecules undergo reversible targeted binding; the target area is continuously irradiated with a laser, and a super-resolution imaging device is used to collect a number of images, and a super-resolution image is reconstructed using a super-resolution algorithm, thereby obtaining the critical size of the photoresist in the target area.

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

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

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

[0008] Preferably, the AIE fluorescent probe molecule is one or more of a non-ionic tetraphenylene compound containing a hydroxyl group, a non-ionic triphenylamine compound containing a hydroxyl group, a non-ionic diarylethene compound containing a hydroxyl group, a non-ionic cyanodiarylethene compound containing a hydroxyl group, a non-ionic thiole compound containing a hydroxyl group, a non-ionic anthracene compound containing a hydroxyl group, a non-ionic benzothiadiazole compound containing a hydroxyl group, an ionic tetraphenylene compound containing a hydroxyl group, an ionic triphenylamine compound containing a hydroxyl group, an ionic diarylethene compound containing a hydroxyl group, an ionic cyanodiarylethene compound containing a hydroxyl group, an ionic thiole compound containing a hydroxyl group, an ionic anthracene compound containing a hydroxyl group, and an ionic benzothiadiazole compound containing a hydroxyl group.

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

[0010] Preferably, the wavelength of the laser is 248-561 nm; A super-resolution imaging device is used to record 5000-30000 frames at a speed of 10-40 milliseconds, and a super-resolution algorithm is used to reconstruct a super-resolution image; The super-resolution algorithm is QC-STORM, PALMER or MaLing.

[0011] According to another aspect of the present invention, there is provided a method for detecting a critical dimension of a photoresist using the system, comprising the following steps: (1) coating a photoresist composition onto a wafer, and sequentially performing exposure and development to obtain a developed photoresist; the developed photoresist contains a polymer capable of reversibly targeting and binding with the AIE probe molecule; (2) contacting the developed photoresist 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 contacting the developed photoresist, they can undergo reversible targeted binding, so that the AIE probe molecules exhibit random "on" and "off" under laser irradiation; (3) Continuously irradiating the target area with laser, collecting a plurality of images using a super-resolution imaging device, reconstructing the super-resolution image using a super-resolution algorithm, and then obtaining the critical size of the photoresist in the target area.

[0012] Preferably, the photoresist composition is a chemically amplified resist; the photoresist composition further comprises a solvent, an acid generator, an acid diffusion inhibitor and a light switch; the solvent is used to dissolve the acid generator, the acid diffusion inhibitor and the polymer.

[0013] In general, the above technical solutions conceived by this application have the following beneficial effects compared with the prior art: (1) The present invention utilizes the behavior of AIE fluorescent probe molecules that emit almost no light in a dilute solution state but emit strong fluorescence when combined with a targeted object, and performs super-resolution positioning imaging on the photoresist containing the targeted object, thereby obtaining a high-resolution image and realizing the detection of the key dimensions of the photoresist. Compared with the traditional CD-SEM technology, this method has significant advantages: first, it does not cause damage to the sample because the use of AIE probes does not rely on electron beams; second, combined with super-resolution imaging technology, high-resolution imaging of the photoresist is achieved, improving the accuracy and reliability of detection.

[0014] (2) In the preferred embodiment of the present invention, the characteristic that the AIE probe molecule with hydroxyl group emits strong fluorescence after binding with the target object with hydroxyl group or phenolic hydroxyl group in the photoresist through hydrophilic-hydrophobic interaction is utilized. For the first time, a method for detecting the critical size of photoresist 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 critical dimension detection method proposed in the present invention can be detected 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 cause damage to the sample and has higher resolution and better imaging effect, and is simple and easy to use.

[0017] (5) The nondestructive direct detection method of the present invention has a wide range of applications and is not limited to the specific type of photoresist, as long as the polymer contained in the photoresist can undergo reversible targeted binding with the AIE fluorescent probe molecule. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a photo of the critical dimensions of the photoresist tested using CD-SEM in Comparative Example 1 of the present application; Figure 2 is the super-resolution image reconstructed in Example 1 of the present application; Figure 3 This is the line size result of the super-resolution image test reconstructed according to Example 1. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0020] The embodiments of the present invention are implemented on the premise of the technical solution of the present invention, and detailed implementation methods and processes are given, but the protection scope of the present invention is not limited to the following embodiments. The process parameters of the following embodiments that do not specify specific conditions are usually based on conventional conditions.

[0021] The endpoints and any values ​​of the ranges disclosed in the present 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 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, which should be regarded as specifically disclosed in the present invention.

[0022] The process parameters without specific conditions in the following examples are usually based on conventional conditions.

[0023] In view of the many defects of the current photoresist industry's common use of CD-SEM to detect the critical dimensions of photoresists, the present invention proposes a photoresist critical dimension detection method and system based on AIE (aggregation-induced emission) probes and super-resolution imaging technology. The present invention utilizes the behavior of AIE molecules that hardly emit light in a dilute solution state but emit strong fluorescence when combined with targeted objects in the photoresist to perform super-resolution positioning imaging on the photoresist, thereby obtaining a high-resolution image. Compared with traditional CD-SEM technology, this method has significant advantages: first, it does not cause damage to the sample because the use of AIE probes does not rely on electron beams; second, combined with super-resolution imaging technology, high-resolution imaging of photoresists is achieved, improving the accuracy and reliability of detection. Therefore, the method proposed by the present invention provides an effective and non-destructive solution for photoresist critical dimension detection, and has broad application prospects and market potential.

[0024] The present invention provides a system for non-destructively and directly detecting the critical dimensions of a photoresist, comprising a developed photoresist, a solution in which AIE fluorescent probe molecules are dissolved, and a super-resolution imaging device; The developed photoresist contains a polymer capable of reversibly targeting and binding with the AIE probe molecule; The AIE fluorescent probe molecule has no fluorescence emission in the solution, but after contacting with the developed photoresist, the AIE probe molecule can be reversibly targeted to make the AIE probe molecule exhibit random "on" and "off" under laser irradiation; During detection, the developed photoresist is contacted with a solution in which AIE fluorescent probe molecules are dissolved, so that the developed photoresist is in contact with the AIE fluorescent probe molecules, and the polymer and the AIE fluorescent probe molecules undergo reversible targeted binding, and the contact area is defined as the target area; the target area is continuously irradiated with laser, and a super-resolution imaging device is used to collect several images, and a super-resolution image is reconstructed using a super-resolution algorithm, thereby obtaining the critical size of the photoresist in the target area.

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

[0026] In some embodiments, the developed photoresist contains a polymer, and the polymer structure contains a hydroxyl group or a phenolic hydroxyl group; the structure of the AIE fluorescent probe molecule contains a hydroxyl group; the AIE fluorescent probe molecule containing a hydroxyl group and the polymer containing a hydroxyl group or a phenolic hydroxyl group can continuously combine and dissociate through hydrophilic-hydrophobic interactions, thereby making the AIE fluorescent probe molecule exhibit random "on" and "off" under laser irradiation. Accordingly, the present invention provides a system for non-destructive direct detection of the critical dimensions of a photoresist, comprising a developed photoresist, a solution containing AIE fluorescent probe molecules, and a super-resolution imaging device; The photoresist comprises a polymer, and the structure of the polymer contains a hydroxyl group or a phenolic hydroxyl group; The structure of the AIE fluorescent probe molecule contains a hydroxyl group; The AIE fluorescent probe molecule has no fluorescence emission in the solution, but after it contacts with the polymer containing hydroxyl or phenolic hydroxyl in the developed photoresist, the AIE fluorescent probe molecule containing hydroxyl and the polymer containing hydroxyl or phenolic hydroxyl can continuously combine and dissociate through hydrophilic-hydrophobic interaction, thereby showing that the fluorescent molecule is randomly "on" and "off"; During detection, the developed photoresist is immersed in a solution in which AIE fluorescent probe molecules are dissolved, so that the polymer in the developed photoresist contacts the AIE fluorescent probe molecules, and the contact area is defined as the target area; the target area is continuously irradiated with laser, and a super-resolution imaging device is used to collect several images, and a super-resolution image is reconstructed using a super-resolution algorithm, thereby obtaining the critical size of the photoresist in the target area.

[0027] The present invention also provides a method for non-destructively and directly detecting the critical dimension of a photoresist, comprising the following steps: (1) coating a photoresist composition onto a wafer, and sequentially performing exposure and development to obtain a developed photoresist; the photoresist composition comprises a polymer, and the polymer comprises a hydroxyl group or a phenolic hydroxyl group; (2) contacting the developed photoresist 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 contacting with the polymer containing hydroxyl groups or phenolic hydroxyl groups in the developed photoresist, the AIE fluorescent probe molecules containing hydroxyl groups and the polymer containing hydroxyl groups or phenolic hydroxyl groups can continuously bind and dissociate through hydrophilic-hydrophobic interactions, thereby showing that the fluorescent molecules are randomly "on" and "off"; (3) Continuously irradiating the target area with laser, collecting a plurality of images using a super-resolution imaging device, reconstructing the super-resolution image using a super-resolution algorithm, and then obtaining the critical size of the photoresist in the target area.

[0028] In a preferred embodiment, the photoresist composition is a chemically amplified resist. The composition comprises a solvent, a polymer whose solubility in a developer is changed by the action of an acid, an acid generator, an acid diffusion inhibitor, and a light switch molecule. A chemically amplified resist is a photoresist material that uses a chemical reaction amplification effect to improve photolithography sensitivity and resolution, and is widely used in photolithography processes in semiconductor manufacturing. The core principle of a chemically amplified resist is to use the acid generated by a photoacid generator (PAG) during the exposure process to catalyze the chemical reaction in the resist film, thereby achieving the 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 generated catalyzes the chemical reaction in the resist film during the post-baking process, causing the chemical properties of the resist to change, thereby achieving polarity reversal or solubility change.

[0030] S3: Development stage: After chemical reaction, the resist film shows different solubility in the developer to form the desired pattern.

[0031] The solvent used in the photolithography resist composition of the present invention is a substance that can dissolve the components of the resist composition to form a uniform solution, and can be a single solvent or a mixed solvent, for example, one or more of propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, tetrahydrofuran, cyclohexanone, toluene, dimethyl sulfoxide, ethyl lactate, n-heptane, butyl acetate, γ-butyrolactone, etc. Preferably, one or more of propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, γ-butyrolactone, and ethyl lactate are used.

[0032] The polymer can be arbitrarily selected from polymers commonly used for chemically amplified resists. Including but not limited to polymers containing p-hydroxystyrene in the monomers. For example, p-hydroxystyrene-tert-butyl acrylate copolymer, p-hydroxystyrene-tert-butyl methacrylate copolymer, p-hydroxystyrene-styrene-tert-butyl acrylate copolymer, p-hydroxystyrene-styrene-tert-butyl methylmethacrylate copolymer, p-hydroxystyrene-tert-butoxystyrene copolymer, p-hydroxystyrene-styrene-tert-butoxystyrene copolymer, p-hydroxystyrene-adamantyl acrylate, p-hydroxystyrene-styrene-adamantyl acrylate, etc.

[0033] The acid generator can be selected from one or more of the acid generators used in chemically amplified resists, including but not limited to onium salts such as iodonium salts, sulfonium salts, triazines, sulfonyldiazomethanes, N-sulfonyldiformimides, oxime esters, disulfones, o-nitrobenzyl sulfonates, etc. Among these, onium salts are preferred. For example, triphenylsulfonium trifluoromethanesulfonic acid sulfonium salt, triphenylsulfonium perfluorobutanesulfonic acid sulfonium salt, bis[4-(1,1-dimethylethyl)phenyl]trifluoromethanesulfonic acid iodonium salt, etc., which can be used alone or in combination of two or more.

[0034] The acid diffusion inhibitor can be selected from one or more of the acid diffusion inhibitors used in chemically amplified resists. For example, it can be various amines or ammonium salts of 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 a hydroxyl group, a non-ionic triphenylamine compound with a hydroxyl group, a non-ionic diarylethylene compound with a hydroxyl group, a non-ionic cyanodiarylethylene compound with a hydroxyl group, a non-ionic thiole compound with a hydroxyl group, a non-ionic anthracene compound with a hydroxyl group, a non-ionic benzothiadiazole compound with a hydroxyl group, etc. It can also be an ionic tetraphenylethylene compound with a hydroxyl group, an ionic triphenylamine compound with a hydroxyl group, an ionic diarylethylene compound with a hydroxyl group, an ionic cyanodiarylethylene compound with a hydroxyl group, an ionic thiole compound with a hydroxyl group, an ionic anthracene compound with a hydroxyl group, an ionic benzothiadiazole compound with a hydroxyl group, etc., preferably a non-ionic tetraphenylethylene compound with a hydroxyl group.

[0036] In some embodiments, when the AIE probe used in the present invention is a non-ionic tetraphenylethylene compound with a hydroxyl group, it has the general formula shown in formula (1):

[0037] Formula (I) In formula (1), n 1 is an integer of 1 to 6, preferably an integer of 1 to 3, more preferably 1 or 2, n 2 It is an integer of 1 to 6, preferably an integer of 1 to 3, and more preferably 1 or 2.

[0038] The nonionic tetraphenylethylene compounds with hydroxyl groups have almost no fluorescence emission in dilute solution, but they will emit strong fluorescence after binding to the target polymer with hydroxyl groups or phenolic hydroxyl groups through hydrophilic-hydrophobic interactions. The nonionic tetraphenylethylene compounds with hydroxyl groups and the target polymer with hydroxyl groups or phenolic hydroxyl groups continuously bind and dissociate, and the fluorescent molecules randomly "turn on" and "off" when they are continuously bound and dissociated can be used for super-resolution localization imaging.

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

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

[0041] Since silicon wafers are opaque, in some preferred embodiments, the developed photoresist placed on the silicon wafer is placed upside down on a light-transmitting container containing an AIE fluorescent probe molecule solution, such as a cover glass, that is, the photoresist is in direct contact with the AIE fluorescent probe molecule solution, and then imaging is performed using a super-resolution imaging device equipped with a nanofilter. The laser is continuously passed through the light-transmitting container to irradiate the target area, and multiple pictures are collected. 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) probe and super-resolution imaging technology, comprising the following steps: (1) The photoresist composition was mixed in proportion and stirred for 48 hours. It was then filtered twice with a 0.1 μm 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 photolithographic silicon wafer into appropriate sizes or directly invert it on a coverslip dripped with a dilute solution of the AIE probe, and conduct experiments under a super-resolution imaging system equipped with a 555-705 nm filter. The non-ionic tetraphenylethylene compound with hydroxyl groups has almost no fluorescence emission in a dilute solution state, but it will emit strong fluorescence after combining with the polymer containing hydroxyl groups or phenolic hydroxyl groups in the photoresist through hydrophilic-hydrophobic interactions. The fluorescent molecules exhibited by the non-ionic tetraphenylethylene compound with hydroxyl groups and the targeted polymer with hydroxyl groups or phenolic hydroxyl groups are randomly "on" and "off" when they continuously combine and dissociate. This meets the basic principle of single-molecule localization super-resolution imaging, that is, at different times, the fluorescent dye is randomly illuminated on the sample surface, so that a series of overlapping fluorescence images in space are separated into many sub-images, each of which contains only a few luminescent fluorophores. In this way, thousands of images are collected, and the center positions of the fluorescent points in all images are superimposed to reconstruct a super-resolution image.

[0044] (3) Continuously illuminate the target area with a 405 nm laser and record 10,000 frames at a rate of 20 milliseconds per frame. Overlay these 10,000 captured images to obtain a fluorescence image, and finally reconstruct a super-resolution image using the super-resolution algorithm QC-STORM.

[0045] Super-resolution imaging system is an imaging technology that can break through the diffraction limit of traditional optical microscopes, thereby achieving higher resolution imaging. Super-resolution imaging system is usually applied to biological samples such as cells. The resolution of traditional optical microscopes is limited by the diffraction limit of light, usually around 200 nanometers, while super-resolution imaging technology can improve the resolution to the nanometer level. In the preferred embodiment of the present invention, the polymer contained in the photoresist can be reversibly targeted and bound to the AIE probe through hydrophilic-hydrophobic interaction, electrostatic interaction, specific binding, etc., and the fluorescent molecules exhibited when the probe and the polymer are continuously bound and dissociated are randomly "on" and "off", which meets 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, so that a series of overlapping fluorescent images in space are separated into many sub-images, each sub-image has only a few luminous fluorophores, so that thousands of pictures are collected, and the center positions of the fluorescent points of all pictures are superimposed to reconstruct a super-resolution image, so that the non-destructive direct detection of the key size of the photoresist can be cleverly achieved.

[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 that can reversibly target and bind to the AIE probe molecule after photolithography and development, and the reversible targeted binding makes the AIE probe molecule show random "on" and "off" under laser irradiation, which meets the basic principle of single-molecule localization super-resolution imaging, thereby realizing super-resolution imaging detection. Here, reversible targeted binding includes but is not limited to hydrophilic-hydrophobic interaction, electrostatic interaction, specific binding and the like.

[0047] The resist composition of the present invention may further contain appropriate compounds commonly used as resist additives, such as organic carboxylic acids and phosphorus oxygen acids for the purpose of preventing the sensitivity of the acid generator from deteriorating and improving the shape of the resist pattern, additional resins for improving the properties of the resist film, surfactants for improving coating properties, dissolution inhibitors, plasticizers, stabilizers, colorants, antihalation agents, dyes, etc., as desired and as needed.

[0048] The embodiments of the present application are described below in conjunction with the drawings in the embodiments of the present application.

[0049] Comparative Example 1 The photoresist composition comprises: 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 mass of the solvent; Acid generator: bis(4-tert-butylphenyl)iodonium perfluoro-1-butanesulfonate, the mass of the acid generator is 5% of the mass of the polymer; Acid diffusion inhibitor: tetramethylammonium hydroxide, the mass of the acid diffusion inhibitor is 0.15% of the mass of the polymer.

[0050] The above photoresist composition was mixed in proportion and stirred for 48 hours, then filtered twice with a 0.1 μm filter head, and the photoresist composition was spin-coated on a silicon wafer with an anti-reflective coating, baked at 100 °C for 1 min, and exposed with a KrF photolithography machine with a focal length of 0.3 and an exposure dose of 500 mJ / cm 2 After exposure, the film was baked at 120 °C for 60 s, developed in a 2.38 wt% TMAH aqueous solution for 30 s, washed with deionized water for 30 s, and purged with nitrogen to remove residual water.

[0051] The size of the lines was characterized by CD-SEM.

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

[0053] The nonionic tetraphenylethylene compound was dissolved in deionized water to prepare 5×10 -5 mol / L solution. The wafer after photolithography in comparative example 1 was cut into suitable sizes and placed upside down on a cover glass with a dilute TPE-NI-AOH solution added, and the experiment was carried out under a super-resolution imaging system. The target area was continuously irradiated with a 380 nm laser, and 10,000 frames were recorded at a rate of 20 milliseconds per frame. The 10,000 captured images were combined to obtain a fluorescence image, and finally the super-resolution image was reconstructed using the super-resolution algorithm QC-STORM, with a collected photon number of 5154.

[0054] Figure 1 This is the CD-SEM photograph of Comparative Example 1. Figure 1 It shows that the line size measured by CD-SEM is about 150 nm. Figure 2 The super-resolution image is reconstructed in Example 2. Figure 3 Yes Figure 2 The line size was measured and the results showed that the line size measured by super-resolution imaging was also about 150 nm, which was consistent with that of CD-SEM. This shows that after TPE-NI-AOH was combined with photoresist, super-resolution positioning imaging of the photoresist was performed, and the super-resolution image obtained can be used to detect the key size of the photoresist.

[0055] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A system for non-destructive direct detection of critical dimensions of photoresist, characterized in that: It includes a developed photoresist, a solution in which AIE fluorescent probe molecules are dissolved, and a super-resolution imaging device; The developed photoresist contains a polymer capable of reversibly targeting and binding with the AIE fluorescent probe molecule; The AIE fluorescent probe molecule has no fluorescence emission in the solution, but after contacting with the developed photoresist, the AIE fluorescent probe molecule can be reversibly targeted to make the AIE fluorescent probe molecule randomly "on" and "off" under laser irradiation; During detection, the developed photoresist is brought into contact with a solution in which AIE fluorescent probe molecules are dissolved, and the contact area is defined as a target area, so that the polymer and the AIE fluorescent probe molecules undergo reversible targeted binding; the target area is continuously irradiated with a laser, and a super-resolution imaging device is used to collect a number of images, and a super-resolution image is reconstructed using a super-resolution algorithm, thereby obtaining the critical size of the photoresist in the target area.

2. The system according to claim 1, characterized in that The reversible targeted binding is one or more of hydrophilic-hydrophobic interaction, electrostatic interaction, and specific binding.

3. The system according to claim 1, characterized in that The polymer structure contains hydroxyl groups or phenolic hydroxyl groups; The structure of the AIE fluorescent probe molecule contains a hydroxyl group; The AIE fluorescent probe molecule containing hydroxyl groups and the polymer containing hydroxyl groups or phenolic hydroxyl groups can continuously combine and dissociate through hydrophilic-hydrophobic interactions, thereby causing the AIE fluorescent probe molecule to exhibit random "on" and "off" behavior under laser irradiation.

4. The system according to claim 3, characterized in that The polymer is a polymer containing p-hydroxystyrene, and the solubility of the polymer in a developer can be changed by the action of an acid.

5. The system according to claim 1, wherein: The AIE fluorescent probe molecule is one or more of a non-ionic tetraphenylene compound containing a hydroxyl group, a non-ionic triphenylamine compound containing a hydroxyl group, a non-ionic diarylethene compound containing a hydroxyl group, a non-ionic cyanodiarylethene compound containing a hydroxyl group, a non-ionic thiole compound containing a hydroxyl group, a non-ionic anthracene compound containing a hydroxyl group, a non-ionic benzothiadiazole compound containing a hydroxyl group, an ionic tetraphenylene compound containing a hydroxyl group, an ionic triphenylamine compound containing a hydroxyl group, an ionic diarylethene compound containing a hydroxyl group, an ionic cyanodiarylethene compound containing a hydroxyl group, an ionic thiole compound containing a hydroxyl group, an ionic anthracene compound containing a hydroxyl group, and an ionic benzothiadiazole compound containing a hydroxyl group.

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

7. The system according to claim 1, characterized in that The wavelength of the laser is 248-561nm; A super-resolution imaging device is used to record 5000-30000 frames at a speed of 10-40 milliseconds, and a super-resolution algorithm is used to reconstruct a super-resolution image; The super-resolution algorithm is QC-STORM, PALMER or MaLing.

8. A method for detecting a critical dimension of a photoresist using a system as claimed in any one of claims 1 to 7, characterized in that: The steps include: (1) coating a photoresist composition onto a wafer, and sequentially performing exposure and development to obtain a developed photoresist; the developed photoresist contains a polymer capable of reversibly targeting and binding with the AIE probe molecule; (2) contacting the developed photoresist 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 contacting the developed photoresist, they can undergo reversible targeted binding, so that the AIE probe molecules exhibit random "on" and "off" under laser irradiation; (3) Continuously irradiating the target area with laser, collecting a plurality of images using a super-resolution imaging device, reconstructing the super-resolution image using a super-resolution algorithm, and then obtaining the critical size of the photoresist in the target area.

9. The method according to claim 8, characterized in that The photoresist composition is a chemically amplified resist; the photoresist composition also contains a solvent, an acid generator, an acid diffusion inhibitor and a light switch; the solvent is used to dissolve the acid generator, the acid diffusion inhibitor and the polymer.

Images