WO2023108999A1 - 光刻胶层的处理方法及光刻胶层 - Google Patents

光刻胶层的处理方法及光刻胶层 Download PDF

Info

Publication number
WO2023108999A1
WO2023108999A1 PCT/CN2022/092033 CN2022092033W WO2023108999A1 WO 2023108999 A1 WO2023108999 A1 WO 2023108999A1 CN 2022092033 W CN2022092033 W CN 2022092033W WO 2023108999 A1 WO2023108999 A1 WO 2023108999A1
Authority
WO
WIPO (PCT)
Prior art keywords
photoresist layer
processing
exposure
photoresist
layer
Prior art date
Application number
PCT/CN2022/092033
Other languages
English (en)
French (fr)
Inventor
曹堪宇
Original Assignee
长鑫存储技术有限公司
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 长鑫存储技术有限公司 filed Critical 长鑫存储技术有限公司
Priority to US17/814,025 priority Critical patent/US20230185194A1/en
Publication of WO2023108999A1 publication Critical patent/WO2023108999A1/zh

Links

Images

Classifications

    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
    • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
    • G03F7/16—Coating processes; Apparatus therefor
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
    • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
    • G03F7/20—Exposure; Apparatus therefor
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
    • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
    • G03F7/70—Microphotolithographic exposure; Apparatus therefor
    • G03F7/70058—Mask illumination systems
    • G03F7/70191—Optical correction elements, filters or phase plates for controlling intensity, wavelength, polarisation, phase or the like

Definitions

  • the present disclosure relates to but not limited to a photoresist layer processing method and the photoresist layer.
  • Photolithography Process is one of the most important process steps for making integrated circuits (Integrated Circuit referred to as IC). Photolithography process is used to form desired patterns on semiconductor substrates. With the continuous shrinking of the critical dimension, the requirements for the precision of the photolithography process are getting higher and higher.
  • the disclosure provides a photoresist layer processing method and the photoresist layer.
  • a first aspect of the present disclosure provides a method for processing a photoresist layer, the method for processing the photoresist layer comprising:
  • the photoresist layer including a first portion away from the target layer and a second portion close to the target layer;
  • a second aspect of the present disclosure provides a photoresist layer covering a target layer, the photoresist layer comprising a first portion away from the target layer and a second portion close to the target layer, the first portion
  • the light absorptivity of a part is smaller than the light absorptivity of the second part.
  • Fig. 1 is a flowchart showing a method for processing a photoresist layer according to an exemplary embodiment.
  • Fig. 2 is a flow chart of stripping a first part in a method for processing a photoresist layer according to an exemplary embodiment.
  • Fig. 3 is a flowchart showing a method for processing a photoresist layer according to an exemplary embodiment.
  • Fig. 4 is a schematic structural diagram of a photoresist layer according to an exemplary embodiment.
  • Fig. 5 is a schematic diagram showing an exposure image formed by a first exposure process according to an exemplary embodiment.
  • Fig. 6 is a schematic diagram showing a second process for treating the first part according to an exemplary embodiment.
  • Fig. 7 is a schematic diagram of peeling off the first part according to an exemplary embodiment.
  • Fig. 8 is a schematic diagram showing a first developing process according to an exemplary embodiment.
  • Fig. 9 is a schematic diagram of exposing a photoresist layer by an exposure device according to an exemplary embodiment.
  • FIG. 10 is a schematic diagram of the focal plane of the exposure device shown in FIG. 9 .
  • Fig. 11 is a schematic diagram showing a first exposure process according to an exemplary embodiment.
  • Fig. 12 is a schematic diagram of forming an exposure image in the second part according to an exemplary embodiment.
  • Fig. 13 is a schematic diagram of a second exposure process according to an exemplary embodiment.
  • Photoresist layer 11. First part; 12. Second part; 2. Target layer; 3. First medium; 4. Exposure device; 41. Exposure light source; 42. Projection lens; 5. First incident light beam ; 6, the second incident light beam; 7, the third incident light beam; 8, the photoresist pattern; 9, the mask plate; 10, the exposure image; F-F, the focal plane.
  • FIG. 1 shows a process flow of a method for processing a photoresist layer according to an exemplary embodiment of the present disclosure.
  • Figures 4-13 are schematic diagrams of various stages of the photoresist layer processing method, and the photoresist layer processing method will be introduced below in conjunction with Fig. 4-13.
  • a method for processing a photoresist layer includes the following steps:
  • Step S110 forming a photoresist layer on the target layer, the photoresist layer including a first portion away from the target layer and a second portion close to the target layer.
  • a photoresist solution is coated on the target layer 2, and the photoresist solution includes a photoacid generator (photo acid generator, PAG), a polymer resin and an organic solvent.
  • the target layer 2 coated with the photoresist solution is pre-baked (i.e. soft baked), part of the solution in the photoresist solution is heated and escapes, and the content of the organic solvent in the photoresist solution is reduced, as shown in Figure 4 , forming a photoresist layer 1 .
  • the target layer refers to the material layer to be etched that needs to be patterned.
  • the target layer can be a semiconductor substrate, or a semiconductor material layer used to form semiconductor elements, such as a dielectric layer or a metal layer.
  • the material of the semiconductor substrate can be silicon (Si), germanium (Ge), or silicon germanium (GeSi), silicon carbide (SiC); it can also be silicon on insulator (SOI), germanium on insulator (GOI); or it can also be Other materials, such as III-V group compounds such as gallium arsenide.
  • the semiconductor substrate can be doped with certain impurity ions as required, and the impurity ions can be N-type impurity ions or P-type impurity ions.
  • the semiconductor material layer may be an amorphous carbon layer, an oxide layer, a nitride layer, a copper layer, a tungsten layer, an aluminum layer, etc., but is not limited thereto.
  • the target layer 2 coated with the photoresist solution may be baked in an environment at a temperature of 80° C. to 110° C. for 50 seconds to 80 seconds.
  • the formed photoresist layer 1 is a positive photoresist layer, and the positive photoresist layer does not dissolve in the developer before photochemical reaction occurs, and the positive photoresist layer undergoes photochemical reaction. After the reaction, the solubility characteristics change and can be dissolved by the developer.
  • Step S120 Process the photoresist layer by using the first process, so that the light absorption rate of the first part is smaller than the light absorption rate of the second part.
  • the photoresist layer 1 is treated with the first process to reduce the light absorptivity of the first part 11 and/or increase the light absorptivity of the second part 12. After the first process, the light absorptivity of the first part 11 less than the light absorptivity of the second portion 12.
  • the light absorptivity of the first part 11 and the light absorptivity of the second part 12 may refer to the relative light absorptivity of the two parts, that is, the light absorptivity of the first part 11 and the light absorptivity of the second part 12
  • the rate can also refer to the light absorption rate of the two parts.
  • the light absorptivity of the photoresist layer can be increased in incremental ways such as gradual increase, step increase or jump increase.
  • Step S130 performing a first exposure treatment on the photoresist layer, and forming an exposure image on the second part.
  • the incident light beam is emitted to the photoresist layer 1, and the incident light beam passes through the first part 11 to form an exposure image in the second part 12, and the first part 11 is also exposed by the incident light beam simultaneously, because the first part 11 and the second part 12 have different light absorptivity, the light absorptivity of the first part 11 is smaller than the light absorptivity of the second part 12, during the first exposure process, the exposed area of the first part 11 absorbs less light, and the photochemical reaction is not Completely, the solubility of the first part 11 and the second part 12 to the developer is different, and the resolution of the exposed image in the first part 11 is lower than that of the exposed image in the second part 12 .
  • Step S140 Peel off the first part.
  • the first part 11 is removed from the second part 12 as a whole, and the exposure area formed in the first part 11 by the first exposure process is removed thereupon, only the second part 12 and the second part remain. Exposure image in section 12.
  • the photoresist layer 1 after the first exposure treatment can be directly subjected to the first development treatment, and based on the different solubility of the first part 11 and the second part 12 to the developer, the development time is controlled to remove the first part 12 , while retaining the second part 12.
  • Step S150 performing a first development process on the photoresist layer to pattern the second part as a photoresist pattern.
  • the first developer is sprayed to the second part 12, so that the first developer is covered with the second part 12, so that the second part 12 is completely soaked by the first developer, and the second part 12 is removed by the first developer.
  • a developer dissolves the second part 12 , and the retained second part 12 forms the photoresist pattern 8 .
  • the concentration of the photoacid generator at the top of the photoresist layer is relatively low, which causes the top shape of the formed photoresist pattern to deviate from the expected one and affects the photolithography resolution.
  • the first part is removed after the exposure image is formed in the second part, so as to avoid the problem that the top shape of the photoresist pattern caused by the first part does not meet expectations.
  • the second part is processed by the first process to increase the light absorption rate of the second part, thereby improving the image quality of the exposed image formed in the second part, and improving the second part. Part of the lithographic resolution.
  • metal oxide can be added to the photoresist layer to enhance the light absorption rate of the photoresist layer, such as adding metal oxide nanoparticles with titanium dioxide and hafnium dioxide nanoparticle structures to the photoresist layer , and can also be processed by the first process, so that the concentration of the metal oxide contained in the second part 12 is greater than the concentration of the metal oxide contained in the first part 11 .
  • the lithographic resolution and etching resistance of the photoresist layer can also be improved by adding metal oxides in the photoresist layer.
  • the photoresist layer is processed by the first process, so that the light absorption rate of the first part is smaller than the light absorption rate of the second part , including: using the first process to process the first part, the photoacid generator in the first part reacts to form a photoacid generator, and the concentration of the photoacid generator in the first part after treatment is higher than that of the photoacid generator in the second part The agent concentration is low.
  • the photoacid generator in the photoresist solution decomposes to produce acid under light, and the hydrogen ion H of the acid can be used as a catalyst to promote the destabilization of the polymer resin in the photoresist solution.
  • the polymer resin has enough After the pendant group falls off, the polarity of the polymer resin changes, and the photoresist can be dissolved in the developer.
  • the first process is used to process the first part, including: implanting amino ions from the top surface of the photoresist layer to the first part, the implantation depth of the amino ions is a first depth, and the first depth and the thickness of the first part equal.
  • the photoacid generator in the first part undergoes a neutralization reaction with the amino ion to generate a photoacid generator, the concentration of the photoacid generator in the first part decreases, and the light absorption rate of the first part decreases.
  • the reaction speed with the photoacid generator is fast, and the concentration of the photoacid generator in the first part 11 can be quickly reduced.
  • the chemical properties of the photoacid generator generated by the reaction with the photoacid generator are unstable, so that the photoacid generator in the first part 11 is subsequently reduced to the photoacid generator, reducing the subsequent treatment of the second process. Difficulty, so that the first part 11 is completely peeled off from the second part 12.
  • using the first process to process the first part includes: spraying an alkaline gas on the top surface of the photoresist layer, so that the photoacid generator in the first part reacts with the alkaline gas to form a photosensitive acid generator. acid generator.
  • an alkaline gas is sprayed on the top surface of the photoresist layer 1, the alkaline gas penetrates into the first part 11, and the alkaline gas neutralizes the photoacid generator in the first part 11. reaction, the concentration of the photoacid generator in the first part 11 decreases, and the light absorptivity of the first part 11 decreases.
  • the basic gas may be ammonia (NH 3 ) or methylamine, dimethylamine, trimethylamine or ethylamine, and the like.
  • the difficulty of controlling the first process is reduced, the control accuracy of the first process is ensured, and the treatment area of the first process can be precisely controlled in the first part 11, avoiding the first process A process range involves the second part 12, ensuring that the light absorptivity of the second part 12 is greater than the light absorptivity of the first part 11, the second part 12 has good photosensitivity, and ensuring that the first exposure treatment can be carried out in the second part 12 A high-precision, high-resolution exposure image 10 is formed.
  • the first part is treated by the first process, and the concentration of the photoacid generator in the first part is reduced, so that when the incident light beam irradiates the first part, the photoacid generator in the first part decomposes to generate less acid, and the first part
  • the unstable group of the polymer resin falls off slowly, thereby reducing the light absorption rate of the first part, and more incident light beams can pass through the first part and enter the second part, forming an exposure image in the second part, improving the light absorption rate. utilization rate.
  • this embodiment is an illustration of the implementation of the above step S120.
  • the photoresist layer is processed by the first process, so that the light absorption rate of the first part is smaller than that of the second part
  • the light absorption rate includes: heating the target layer, heating the photoresist layer through the target layer, so that the temperature of the second part is higher than the temperature of the first part.
  • a heat source can be placed at the bottom of the target layer 2 to radiate thermal energy to the target layer 2, and the target layer 2 conducts the thermal energy into the photoresist layer 1, and by controlling the time for heating the target layer 2, the second part 12
  • the temperature of the second part 12 is higher than the temperature of the first part 11, the chemical activity of the photoacid generator in the second part 12 increases, and the chemical reaction speed is faster, so that the light absorption rate of the second part 12 is greater than that of the first part 11 light absorption rate.
  • the incident light beam is incident on the second part, and the photoacid generator in the second part decomposes to generate acid faster, and the acid in the second part
  • the concentration the clearer the exposure image formed by the incident light beam in the second part, and the higher dimensional accuracy of the formed photoresist pattern.
  • this embodiment is an illustration of the implementation of the above step S140.
  • stripping the first part includes:
  • Step S141 Process the first part by using the second process.
  • the second process is a process capable of improving the light sensitivity of the first part 11 , and after the second process, the light sensitivity of the first part 11 is higher than that of the second part 12 .
  • the second process can be a process that can increase the concentration of the photoacid generator in the first part 11 or a process that can increase the concentration of other photoradiation-sensitive components in the first part 11 .
  • the second process is a process of reducing the photoacid generator in the first part 11 to a photogenerator; or, a process of increasing the H + concentration in the first part 11 .
  • the second process is used to process the first part, including: implanting hydrogen ions into the photoresist layer from the top surface of the photoresist layer, the implantation depth of the hydrogen ions is the second depth, and the second depth is the same as the first Parts are of equal thickness.
  • the second depth of implanting hydrogen ions into the photoresist layer 1 from the top surface of the photoresist layer 1 may also be greater than the thickness of the first portion 11 .
  • the concentration of hydrogen ions in the first portion 11 is higher than that in the second portion 12 .
  • the concentration of H + in the first part 11 can be much higher than the concentration of H + in the second part 12 by injecting H + , and the concentration of H + is positively correlated with the time when the polarity of the polymer resin changes.
  • the detachment speed of the suspension group of the polymer resin of the first part 11 is faster than the detachment speed of the suspension group of the polymer resin of the second part 12, and the dissolution characteristics of the first part 11
  • the time required for the change is shorter than the time required for the second part 12 .
  • the concentration of H + in the first part 11 is more than twice the concentration of H + in the second part 12 .
  • the concentration of H + in the first portion 11 may be 2 times, 2.5 times, 3 times, etc. of the concentration of H + in the second portion 12 .
  • the first part after the second process treatment, has a high concentration of H + , and when the first part is irradiated by light, the high concentration of H + acts on the polymer resin, which can accelerate the catalysis of the polymer resin in the first part.
  • the stable group falls off, shortens the time required for the polarity change of the polymer resin, and shortens the time required for the dissolution characteristics of the first part to change, so that the first part can be exposed to the first part by controlling the exposure intensity and exposure time, and then the first part can be removed by developing treatment .
  • the second process is used to treat the first part, including: spraying an acid gas on the top surface of the photoresist layer, and the acid gas reduces the photoacid generator in the first part to a photoacid generator .
  • the top surface of the photoresist layer 1 will be sprayed with acid gas, and the acid gas will penetrate into the first part 11, and the unstable photoacid generator in the first part 11 will be acidified.
  • the gas is reduced to the photoacid generator and the concentration of the photoacid generator in the first part 11 is increased.
  • the dissolution properties of the first part 11 are changed in a shorter time than that of the second part 12 during the light treatment.
  • part of the acidic gas sprayed on the top surface of the photoresist layer 1 will dissociate to generate H + , increasing the H + concentration of the first part 11, and under the condition of light, it can further promote the photochemical reaction of the first part 11 and shorten the life of the polymer resin.
  • the time required for the polarity change enables a faster change in the dissolution properties of the first part 11 .
  • the acidic gas sprayed onto the top surface of the photoresist layer 1 diffuses around the photoresist layer 1 to provide acidic process conditions for processing the photoresist layer 1.
  • the activity of the photoacid reactant Higher so that the photoacid generator is more easily decomposed to generate acid when it is photosensitive, improves the catalytic activity of the photoacid generator, and accelerates the unstable group of the polymer resin to come off, so that the second part 12 can be peeled off to remove the second part.
  • the process operation of part 11 is easier.
  • the acid gas for spraying may be hydrogen chloride (HCL) gas or hydrofluoric acid (HF) gas.
  • reducing the photoacid generator by acid gas reduces the difficulty of process control and high control accuracy, and can precisely control the treatment area of the second process in the first part, avoiding the treatment range of the second process from involving the first part; and
  • the gas by-products generated by the reaction of photoacid products and acid gases escape into the process space, which will not pollute the process environment, ensure the cleanliness of the process environment, and prevent the reduction reaction by-products from polluting the process environment. Circumstances affecting the process of the process occur.
  • Step S142 performing a second exposure treatment on the photoresist layer to expose the first part treated by the second process.
  • the difference in the light absorptivity between the first part 11 and the second part 12 is used to control the exposure intensity and exposure time of the first exposure treatment, so that the first part 11 is fully exposed, and the second part 12 is not exposed at all, so that the treated first part 11 and second part 12 have different dissolution characteristics.
  • Step S143 performing a second developing treatment on the photoresist layer, and peeling off the exposed first part.
  • the first part 11 is treated by the second developing solution, and the first part 11 is dissolved in the second developing solution to completely remove the first part 11 .
  • the concentration of the second developer is lower than the concentration of the first developer.
  • the first part is processed by the second process to increase the light absorption rate of the first part, so that during the light treatment, the photochemical reaction of the first part is faster than that of the second part.
  • the time required to change the dissolution characteristics of the first part is short.
  • first and second used in the “first developing process” and “second developing process” in some embodiments do not limit the sequence in the process, these terms Used only to distinguish one process from another.
  • a method for processing a photoresist layer includes the following steps:
  • S210 forming a photoresist layer on the target layer, the photoresist layer including a first portion away from the target layer and a second portion close to the target layer.
  • forming a photoresist layer 1 on the target layer 2 includes: coating a photoresist solution on the target layer 2, the photoresist solution includes two different photoresist compositions, During the prebaking process, the two photoresist compositions are layered on the top surface of the target layer 2 to form the first part 11 and the second part 12 of the photoresist layer 1 respectively.
  • the photoresist layer 1 formed in some embodiments is a positive photoresist layer, and the photorefractive power of the first part 11 and the second part 12 of the photoresist layer 1 is different.
  • the light refractive index of the second portion 12 is greater than that of the first portion 11 .
  • S220 Process the photoresist layer by using the first process, so that the light absorptivity of the first part is smaller than the light absorptivity of the second part.
  • the processing method of this embodiment is the same as step S120 in the above embodiment. Treat the first part 11 through the first process to reduce the concentration of the photoacid generator in the first part 11, reduce the light absorption rate of the first part 11, and reduce the photosensitivity of the first part 11. During the first exposure process, the treatment The last first part 11 acts as a propagation medium for the incident beam to enter the second part 12 .
  • Step S230 performing a first exposure treatment on the photoresist layer, and forming an exposure image on the second part.
  • the first exposure treatment is performed in the exposure device 4, and the first exposure treatment is performed on the photoresist layer 1, including:
  • Step S231 Adjust the exposure device so that the focal plane of the exposure device imaging is located in the second part.
  • an exposure device 4 is provided, the exposure device 4 includes an exposure light source 41 and a projection lens 42, a reticle 9 is provided, and the reticle 9 includes a mask pattern, and the reticle 9 is arranged between the exposure light source 41 and the projection lens 42. between projection lenses 42 .
  • the photoresist layer 1 is placed under the projection lens 42 of the exposure device 4 , and the exposure device 4 is adjusted so that the projection lens 42 is aligned with the photoresist layer 1 .
  • the imaging focal plane F-F of the exposure device 4 is adjusted to ensure that the incident light beam passing through the first part 11 can enter the second part 12 to form an exposure image 10 in the second part 12 .
  • the first medium 3 can be gas or liquid.
  • the projection lens 42 and the photoresist layer 1 are immersed in the first medium 3 .
  • the first medium 3 can be air and water.
  • Step S232 emit a first incident light beam with a first wavelength to the photoresist layer in the first medium, and the first incident light beam is refracted by the first part into a second incident light beam with a second wavelength, wherein the second wavelength is smaller than the first incident light beam one wavelength.
  • the refractive index of the first medium 3 is n1
  • the refractive index of the first portion 11 of the photoresist layer 1 is n2
  • the refractive index of the second portion 12 is n3, n1 ⁇ n2 ⁇ n3.
  • the exposure device 4 emits a first incident light beam 5 to the photoresist layer 1, the first incident light beam 5 enters the first part 11 from the first medium 3, and the first incident light beam 5 is refracted by the first part 11 Afterwards, the wavelength is reduced to form the second incident beam 6 .
  • the wavelength of the first incident light beam 5 is ⁇ 1
  • the wavelength of the second incident light beam 6 is ⁇ 2, and ⁇ 2 ⁇ 1.
  • Step S233 the second incident light beam is incident on the second part, and an exposure image is formed on the second part.
  • the second incident light beam 6 forms an exposure image 10 in the second portion 12 .
  • Lithographic resolution affects the quality of the exposure image, and the higher the lithography resolution, the higher the precision of the exposure image formed.
  • Lithographic resolution follows the Rayleigh formula:
  • R is the lithography resolution
  • k1 is the process constant
  • ⁇ is the exposure wavelength
  • NA is the numerical aperture (numerical aperture, NA) of the projection lens emitting the incident beam.
  • Photolithography resolution is used to represent the minimum linewidth achievable in the lithography process.
  • the wavelength of the incident light wave and the smaller the process constant the smaller the linewidth can be obtained, that is, the higher the lithography accuracy. high.
  • the wavelength of the incident light beam entering the second part 12 is reduced through the first part 11 to improve the precision of the exposure image 10 formed on the second part 12 .
  • Step S240 Process the first part by using the second process.
  • the processing method of this embodiment is the same as the processing method of step S140 in the above embodiment.
  • the first part 11 is processed through the second process to improve the photosensitivity of the first part 11.
  • the polymer resin in the first part 11 The detaching speed of the unstable group is faster, which accelerates the polarity change of the polymer resin of the first part 11, so as to shorten the time for the first part 11 to undergo a photochemical reaction and be able to dissolve in the developing solution.
  • Step S250 performing a second exposure treatment on the photoresist layer to expose the first part treated by the second process.
  • the second exposure treatment is performed on the photoresist layer 1, including: emitting a third incident beam 7 to the photoresist layer 1, and the third incident beam 7 irradiates the surface of the first part 11, so that The entire layer of the first part 11 is exposed by the third incident light beam 7, and the polarity of the polymer resin of the first part 11 is changed, so that the first part 11 is soluble in the developer.
  • the light intensity of the third incident light beam 6 is less than the light intensity of the first incident light beam 5, and the time of the second exposure treatment is shorter than the time of the first exposure treatment, so that the first part 11 is covered by the third incident light beam 7 fully exposed, while the second portion 12 is not affected by the third incident light beam 7 .
  • Step S260 Developing the photoresist layer to pattern the second part as a photoresist pattern.
  • Developing the photoresist layer 1, referring to Fig. 8 and Fig. 13, includes: spraying a developing solution on the photoresist layer 1, so that the whole photoresist layer 1 is soaked in the developing solution, and the first part 11 is completely dissolved in the developing solution.
  • the area where the exposed image 10 of the second portion 12 is located is dissolved in the developer solution.
  • Cleaning and removing the developer that dissolved the photoresist layer 1 and the excess developer, the second part 12 that is not dissolved by the developer forms a photoresist pattern 8,
  • post-baking the retained second portion 12 after developing the photoresist layer, post-baking the retained second portion 12: hard-baking the unremoved second portion 12 at a temperature of 130° C. to 200° C., post-baking The time is 20-40 minutes, so that the solvent in the second part 12 is completely released, and at the same time, the second part 12 is further polymerized, thereby enhancing the etching resistance of the formed photoresist pattern 8 .
  • the focal plane of imaging is adjusted to the second part so that the formed exposure image is located in the second part, which improves the exposure efficiency; and, this embodiment
  • the wavelength of light incident to the second part is reduced by the first part, and the lithography resolution of the second part is improved. Complex and diverse exposure process.
  • An exemplary embodiment of the present disclosure provides a photoresist layer covering the target layer 2.
  • the photoresist layer 1 includes a first portion 11 away from the target layer 2 and a second portion 12 close to the target layer 2.
  • the light absorptivity of the part 11 is smaller than the light absorptivity of the second part 12 .
  • the photoresist layer of this embodiment reduces the light absorptivity of the first part 11, improves the transmittance of the incident light beam that passes through the first part 11 and enters the second part 12, and improves the exposure of the incident light beam in the second part 12. s efficiency.
  • the first portion 11 of the photoresist layer 1 is used to reduce the wavelength of light waves incident from the first medium 3 to the second portion 12 of the photoresist layer 1 .
  • the first part 11 is used as the propagating medium of the incident light beam incident on the second part 12, and the wavelength of the incident light beam incident on the second part 12 is reduced through the first part 11, thereby improving the second part 12. Lithographic resolution.
  • the refractive index n2 of the first part 11 of the photoresist layer 1 is greater than the refractive index n1 of the first medium 3; the refractive index n2 of the first part 11 of the photoresist layer 1 is smaller than the photoresist The refractive index n3 of the second portion 11 of the glue layer 1 .
  • the refractive index n2 of the first part 11 is greater than 1
  • the refractive index n2 of the first part 11 is greater than 1.44.
  • the photoresist layer of this embodiment forms a propagation medium layer whose refractive index gradually increases from the first medium 3 to the second part 12 in the light propagation path of the incident light beam incident on the second part 12, which further improves the photolithography performance.
  • the photolithography resolution of the glue layer, the photoresist pattern formed in the second part 12 has higher precision and better quality.
  • the photoresist layer 1 is a positive photoresist layer.
  • the photoresist layer 1 of this embodiment is a positive photoresist layer, the photosensitivity of the first part 11 can be improved by processing the first part 11, and then the first part 11 can be removed by exposing and developing, leaving only the second part 12 to form The photoresist pattern prevents the first portion 11 from affecting the top shape of the photoresist pattern.
  • the thickness of the first portion 11 is larger than one-tenth of the wavelength of the incident light beam from the first medium 3 to the photoresist layer 1 .
  • light wavelengths of lithographic equipment include, but are not limited to, G-line (436nm), I-line (365nm), KrF (248nm), ArF (193nm) and extreme ultraviolet (EUV) (13.5nm).
  • the thickness of the first portion 11 when using KrF lithography equipment, can be set to be greater than 24.8nm; when using ArF lithography equipment, the thickness of the first portion 11 can be set to be greater than 19.3nm; when using EUV lithography During equipment, the thickness of the first part 11 can be set to be greater than 1.35 nm.
  • the thickness of the first portion 11 is less than one-fifth of the thickness of the second portion 12 , which reduces the difficulty of peeling off the first portion 11 while ensuring that the thickness of the second portion 12 meets the etching requirements.
  • steps in the flowcharts of FIGS. 1-3 are connected sequentially, these steps are not necessarily executed sequentially in the sequence of connection. Unless otherwise specified herein, there is no strict order restriction on the execution of these steps, and these steps can be executed in other orders. Moreover, at least some of the steps in Figures 1-3 may include a plurality of sub-steps or stages, these sub-steps or stages are not necessarily executed at the same time, but may be executed at different times, these sub-steps or stages The order of execution is not necessarily performed sequentially, but may be performed alternately or alternately with at least a part of other steps or sub-steps or stages of other steps.
  • the first part is removed after the exposure image is formed in the second part, so as to avoid that the top shape of the photoresist pattern does not conform to the existence of the first part. expected problems.

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Photosensitive Polymer And Photoresist Processing (AREA)
  • Exposure Of Semiconductors, Excluding Electron Or Ion Beam Exposure (AREA)

Abstract

本公开提供了一种光刻胶层的处理方法及光刻胶层，涉及半导体技术领域，光刻胶层的处理方法包括：在目标层上形成光刻胶层，光刻胶层包括远离目标层的第一部分和靠近目标层的第二部分；采用第一工艺对光刻胶层进行处理，以使第一部分的光吸收率小于第二部分的光吸收率；对光刻胶层进行第一曝光处理，在第二部分形成曝光图像；剥离第一部分并对光刻胶层进行第一显影处理，以图案化第二部分为光刻胶图案。

Description

光刻胶层的处理方法及光刻胶层
本公开基于申请号为202111516517.2、申请日为2021年12月13日、申请名称为“光刻胶层的处理方法及光刻胶层”的中国专利申请提出，并要求该中国专利申请的优先权，该中国专利申请的全部内容在此引入本公开作为参考。
技术领域
本公开涉及但不限于一种光刻胶层的处理方法及光刻胶层。
背景技术
光刻工艺(Photolithography Process)是制作集成电路(Integrated Circuit简称IC)最重要的工艺步骤之一，光刻工艺用于在半导体衬底上形成期望的图案，随着集成电路工艺的发展以及半导体元件的特征尺寸(Critical Dimension)的不断缩小，对光刻工艺的精度的要求越来越高。
发明内容
以下是对本公开详细描述的主题的概述。本概述并非是为了限制权利要求的保护范围。
本公开提供了一种光刻胶层的处理方法及光刻胶层。
本公开的第一方面提供了一种光刻胶层的处理方法，所述光刻胶层的处理方法包括：
在目标层上形成光刻胶层，所述光刻胶层包括远离所述目标层的第一部分和靠近所述目标层的第二部分；
采用第一工艺对所述光刻胶层进行处理，以使所述第一部分的光吸收率小于所述第二部分的光吸收率；
对所述光刻胶层进行第一曝光处理，在所述第二部分形成曝光图像；
剥离所述第一部分并对所述光刻胶层进行第一显影处理，以图案化所述第二部分为光刻胶图案。
本公开的第二方面提供了一种光刻胶层，覆盖在目标层上，所述光刻胶层包括远离所述目标层的第一部分以及靠近所述目标层的第二部分，所述第一部分的光吸收率小于所述第二部分的光吸收率。
在阅读并理解了附图和详细描述后，可以明白其他方面。
附图说明
并入到说明书中并且构成说明书的一部分的附图示出了本公开的实施例，并且与描述一起用于解释本公开实施例的原理。在这些附图中，类似的附图标记用于表示类似的要素。下面描述中的附图是本公开的一些实施例，而不是全部实施例。对于本领域技术人员来讲，在不付出创造性劳动的前提下，可以根据这些附图获得其他的附图。
图1是根据一示例性实施例示出的一种光刻胶层的处理方法的流程图。
图2是根据一示例性实施例示出的光刻胶层的处理方法中剥离第一部分的流程图。
图3是根据一示例性实施例示出的一种光刻胶层的处理方法的流程图。
图4是根据一示例性实施例示出的一种光刻胶层的结构示意图。
图5是根据一示例性实施例示出的第一曝光处理形成曝光图像的示意图。
图6是根据一示例性实施例示出的第二工艺处理第一部分的示意图。
图7是根据一示例性实施例示出的剥离第一部分的示意图。
图8是根据一示例性实施例示出的第一显影处理的示意图。
图9是根据一示例性实施例示出的通过曝光装置对光刻胶层进行曝光处理的示意图。
图10是如图9所示的曝光装置的焦平面的示意图。
图11是根据一示例性实施例示出的第一曝光处理的示意图。
图12是根据一示例性实施例示出的在第二部分中形成曝光图像的示意图。
图13是根据一示例性实施例示出的第二曝光处理的示意图。
附图标记：
1、光刻胶层；11、第一部分；12、第二部分；2、目标层；3、第一介质；4、曝光装置；41、曝光光源；42、投影透镜；5、第一入射光束；6、第二入射光束；7、第三入射光束；8、光刻胶图案；9、掩膜版；10、曝光图像；F-F、焦平面。
具体实施方式
下面将结合本公开实施例中的附图，对公开实施例中的技术方案进行清楚、完整地描述，显然，所描述的实施例是本公开一部分实施例，而不是全部的实施例。基于本公开中的实施例，本领域技术人员在没有做出创造性劳动前提下所获得的所有其他实施例，都属于本公开保护的范围。需要说明的是，在不冲突的情况下，本公开中的实施例及实施例中的特征可以相互任意组合。
本公开示例性的实施例中提供一种光刻胶层的处理方法，如图1所示，图1示出了根据本公开一示例性的实施例提供的光刻胶层的处理方法的流程图，图4-图13为光刻胶层的处理方法的各个阶段的示意图，下面结合图4-图13对光刻胶层的处理方法进行介绍。
如图1所示，本公开一示例性的实施例提供的一种光刻胶层的处理方法，包括如下的步骤：
步骤S110：在目标层上形成光刻胶层，光刻胶层包括远离目标层的第一部分和靠近目标层的第二部分。
形成光刻胶层1的过程中，在目标层2上涂覆光刻胶溶液，光刻胶溶液包括光致酸产生剂(photo acid generator，PAG)、聚合物树脂以及有机溶剂。对涂覆了光刻胶溶液的目标层2进行前烘处理(即软烘焙)，光刻胶溶液中的部分溶液受热逸出，光刻胶溶液的有机溶剂的含量降低，如图4所示，形成光刻胶层1。
目标层是指需要进行图案化的待刻蚀材料层，目标层可以是半导体衬底，也可以是用于形成半导体元件的半导体材料层，如介质层或金属层。半导体衬底的材料可以为硅(Si)、锗(Ge)、或硅锗(GeSi)、碳化硅(SiC)；也可以是绝缘体上硅(SOI)，绝缘体上锗(GOI)；或者还可以为其它的材料，例如砷化镓等Ⅲ-Ⅴ族化合物。半导体衬底中根据需要可以掺杂一定的杂质离子，杂质离子可以为N型杂质离子或P型杂质离子。半导体材料层可以为无定形碳层、氧化物层、氮化物层、铜层、钨层、铝层等，不限于此。
在一些实施例中，前烘处理时，可以将涂覆了光刻胶溶液的目标层2置于80℃～110℃温度环境中烘烤50秒～80秒。
一些实施例中，参照图4，形成的光刻胶层1为正性光刻胶层，正性光刻胶层没有发生光化学反应之前在显影剂中不溶解，正性光刻胶层发生光化学反应之后溶解特性改变，可被显影液溶解。
步骤S120：采用第一工艺对光刻胶层进行处理，以使第一部分的光吸收率小于第二部分的光吸收率。
参照图4，采用第一工艺处理光刻胶层1，降低第一部分11的光吸收率和/或提高第二部分12的光吸收率，经过第一工艺处理后，第一部分11的光吸收率小于第二部分12的光吸收率。
可以理解的是，第一部分11的光吸收率和第二部分12的光吸收率可以指代两部 分相对而言的光吸收率，即第一部分11的光吸收率和第二部分12的光吸收率也可以指代两部分各自综合具备的光吸收率。例如，可以是按照光入射方向，光刻胶层的光吸收率按照逐渐递增式、阶梯递增式或跳变递增式等递增方式进行递增。
步骤S130：对光刻胶层进行第一曝光处理，在第二部分形成曝光图像。
如图5所示，参照图9，向光刻胶层1发射入射光束，入射光束穿过第一部分11在第二部分12中形成曝光图像，同时第一部分11也被入射光束曝光，由于第一部分11和第二部分12的光吸收率不同，第一部分11的光吸收率小于第二部分12的光吸收率，在第一曝光处理时，第一部分11的被曝光区域吸收光线少，光化学反应不完全，导致第一部分11和第二部分12对显影液的溶解度不同，第一部分11中被曝光图像的分辨率比第二部分12的曝光图像的分辨率低。
步骤S140：剥离第一部分。
如图7所示，参照图5，将第一部分11整体从第二部分12上去除，第一曝光处理在第一部分11中形成的曝光区域随之被去除，仅保留第二部分12及第二部分12中的曝光图像。
在一些实施例中，可以直接对第一曝光处理后的光刻胶层1进行第一显影处理，基于第一部分11和第二部分12对显影液的不同溶解度，控制显影时间以去除第一部分12，而保留第二部分12。
步骤S150：对光刻胶层进行第一显影处理，以图案化第二部分为光刻胶图案。
如图8所示，参照图7，向第二部分12喷洒第一显影液，使第一显影液布满第二部分12，以使第二部分12被第一显影液完全浸润，去除被第一显影液溶解的第二部分12，被保留的第二部分12形成光刻胶图案8。
在光刻过程中，受到工艺环境影响，光刻胶层的顶部的光致酸产生剂的浓度偏低，导致形成的光刻胶图案的顶端的形貌偏离预期，影响光刻分辨率。一些实施例中，在第二部分中形成曝光图像后去除第一部分，避免了第一部分造成的光刻胶图案的顶端形貌不符合预期的问题。
一些实施例中，在第一曝光处理前，通过第一工艺处理第二部分，以提高第二部分的光吸收率，提高了在第二部分中形成的曝光图像的图像质量，提高了第二部分的光刻分辨率。
根据一个示例性实施例，可以在光刻胶层中添加金属氧化物增强光刻胶层的光吸收率，如添加二氧化钛与二氧化铪纳米颗粒结构的金属氧化物纳米颗粒至光刻胶层中，且还可以通过第一工艺处理，使得第二部分12包含的金属氧化物浓度大于所述第一部分11包含的金属氧化物浓度。通过在光刻胶层中添加金属氧化物还能够提高光刻胶层的光刻分辨率以及抗刻蚀性。
根据一个示例性实施例，对上述步骤S120的实现方式的说明，在实施过程中，采用第一工艺对光刻胶层进行处理，以使第一部分的光吸收率小于第二部分的光吸收率，包括：采用第一工艺对第一部分进行处理，第一部分的光致酸产生剂反应形成光致酸生成物，处理后的第一部分的光致酸产生剂浓度比第二部分的光致酸产生剂浓度低。
光刻胶溶液中的光致酸产生剂在光照下分解产生酸，酸的氢离子H +能够作为催化剂促进光刻胶溶液中的聚合物树脂的不稳定基团脱落，聚合物树脂有足够多的悬挂基团脱落后，聚合物树脂的极性改变，光刻胶就能溶于显影液。
在一实施例中，采用第一工艺对第一部分进行处理，包括：自光刻胶层的顶面向第一部分注入氨基离子，氨基离子的注入深度为第一深度，第一深度与第一部分的厚度相等。第一部分中的光致酸产生剂与氨基离子发生中和反应生成光致酸生成物，第一部分中光致酸生成物的浓度降低，第一部分的光吸收率降低。
参照图4，通过向第一部分11直接注入氨基离子，与光致酸生成剂的反应速度快，能够快速降低第一部分11中的光致酸产生剂的浓度。而且，与光致酸产生剂反应生成的光致酸生成物的化学性质不稳定，以便后续将第一部分11中的光致酸生成物还原成光致酸产生物，降低后续第二工艺的处理难度，以便将第一部分11从第二部分12上完整剥离。
在另一实施例中，采用第一工艺对第一部分进行处理，包括：向光刻胶层的顶面喷涂碱性气体，以使第一部分的光致酸产生剂与碱性气体反应成为光致酸生成物。
一些实施例中，参照图4，向光刻胶层1的顶面喷涂碱性气体，碱性气体渗透到第一部分11中，碱性气体与第一部分11中的光致酸产生剂发生中和反应，第一部分11中光致酸生成物的浓度降低，第一部分11的光吸收率降低。
示例性的，碱性气体可以为氨气(NH 3)或甲胺、二甲胺、三甲胺或乙胺等等。
一些实施例中，通过碱性气体中和光致酸产生剂，降低了第一工艺的控制难度，确保第一工艺的控制精度，能够将第一工艺的处理区域精确控制在第一部分11，避免第一工艺处理范围涉及第二部分12，保证第二部分12的光吸收率大于第一部分11的光吸收率，第二部分12具有良好的感光能力，确保第一曝光处理能够在第二部分12中形成高精度、高分辨率的曝光图像10。
本实施例通过第一工艺处理第一部分，降低了第一部分的光致酸产生剂的浓度，以使入射光束照射第一部分时，第一部分中的光致酸产生剂分解产生的酸少，第一部分的聚合物树脂的不稳定基团脱落速度慢，进而减少第一部分对光的吸收率，更多的入射光束能够穿过第一部分入射至第二部分，在第二部分中形成曝光图像，提高光利用率。
根据一个示例性实施例，本实施例是对上述步骤S120的实现方式的说明，在实施过程中，采用第一工艺对光刻胶层进行处理，以使第一部分的光吸收率小于第二部分的光吸收率，包括：加热目标层，通过目标层加热光刻胶层，以使第二部分的温度比第一部分的温度高。
一些实施例中，可以将热源置于目标层2底部向目标层2辐射热能，目标层2将热能传导至光刻胶层1中，通过控制加热目标层2的时间，以使第二部分12的温度高于第一部分11的温度，第二部分12温度升高其中的光致酸产生剂的化学活跃度上升，化学反应速度越快，以使第二部分12的光吸收率大于第一部分11的光吸收率。
一些实施例中处理后的光刻胶层，第一曝光处理过程中，入射光束入射至第二部分中，第二部分中光致酸产生剂分解产生酸的速度更快，第二部分中酸浓度更高，入射光束在第二部分中形成的曝光图像更清晰，形成的光刻胶图案的尺寸精度更高。
根据一个示例性实施例，本实施例是对上述步骤S140的实现方式的说明，在实施过程中，剥离第一部分，包括：
步骤S141：采用第二工艺对第一部分进行处理。
在一些实施例中，参照图5、图6，第二工艺为能够提高第一部分11的光敏感度的工艺，第二工艺处理后，第一部分11的光敏感度比第二部分12的光敏感度高。其中，第二工艺可以为能够提高第一部分11中的光致酸产生剂浓度的工艺或提高第一部分11中其它光辐射性敏感成分的浓度的工艺。
示例性的，第二工艺为将第一部分11中的光致酸生成物还原为光致生成剂的工艺；或者，增加第一部分11中H +浓度的工艺。
在一实施例中，采用第二工艺对第一部分进行处理，包括：自光刻胶层的顶面向光刻胶层中注入氢离子，氢离子的注入深度为第二深度，第二深度与第一部分的厚度相等。自光刻胶层1的顶面向光刻胶层1中注入氢离子的第二深度还可以大于第一部分11的厚度。
在一些实施例中，向第一部分11注入氢离子后，第一部分11的氢离子浓度比第二部分12的氢离子浓度高。参照图5、图6，通过注入H +能够使第一部分11的H +浓度远高于第二部分12的H +浓度，H +的浓度与聚合物树脂极性改变的时间呈正相关。因此，在光刻胶层1被光照时，第一部分11的聚合物树脂的悬挂基团的脱离速度比第二部分12的聚合物树脂的悬挂基团的脱离速度快，第一部分11的溶解特性改变所需时间比第二部分12所需时间短。
示例性的，注入H +后，第一部分11的H +的浓度为第二部分12的H +的浓度的2倍以上。例如，第一部分11的H +的浓度可以为第二部分12的H +的浓度的2倍、2.5倍、3倍等。
一些实施例中经过第二工艺处理后，第一部分具有高浓度的H +，在第一部分受到光线照射时，高浓度的H +作用于聚合物树脂，能够加速催化第一部分中聚合物树脂的不稳定基团脱落，缩短聚合物树脂的极性改变所需时间，缩短第一部分的溶解特性改变所需时间，以便于后续通过控制曝光强度和曝光时间对第一部分曝光，再通过显影处理去除第一部分。
在另一实施例中，采用第二工艺对第一部分进行处理，包括：向光刻胶层的顶面喷涂酸性气体，酸性气体将第一部分中的光致酸生成物还原为光致酸产生剂。
一些实施例中，参照图5、图6，将向光刻胶层1的顶面喷涂酸性气体，酸性气体渗透到第一部分11中，第一部分11中性质不稳定的光致酸生成物被酸性气体还原成光致酸产生剂，第一部分11中光致酸产生剂浓度提高。在光照处理时，第一部分11的溶解特性被改变所需时间比第二部分12所需时间短。
同时，喷涂到光刻胶层1顶面的部分酸性气体会解离生成H +，增加第一部分11的H+浓度，在光照条件下，能够进一步促进第一部分11发生光化学反应，缩短聚合物树脂的极性改变所需时间，能够更快改变第一部分11溶解特性。
一些实施例中，喷涂到光刻胶层1顶面的酸性气体向光刻胶层1周围扩散，为处理光刻胶层1提供酸性工艺条件，在酸性条件下，光致酸反应剂的活性更高，以使光致酸产生剂感光更易分解产生酸，提高了光致酸产生剂的催化活性，加速聚合物树脂的不稳定基团脱落，以使后续从第二部分12上剥离去除第一部分11的工艺操作更加容易。
其中，喷涂的酸性气体可以为氯化氢(HCL)气体或氢氟酸(HF)气体。
一些实施例中，通过酸性气体还原光致酸产生剂，降低了工艺控制难度，控制精度高，能够将第二工艺的处理区域精确控制在第一部分，避免第二工艺处理范围涉及第一部分；而且，一些实施例中光致酸生成物与酸性气体反应生成的气体副产物逸散到工艺空间中，不会污染工艺环境，保证了工艺环境的洁净度，杜绝了还原反应副产物污染制程环境、影响工艺进程的情况发生。
步骤S142：对光刻胶层进行第二曝光处理，以曝光被第二工艺处理后的第一部分。
参照图6，对光刻胶层1进行第二曝光处理时，利用第一部分11和第二部分12的光吸收率的差异，通过控制第一曝光处理的曝光强度和曝光时间，以使第一部分11完全曝光，第二部分12完全不曝光，以使处理后的第一部分11和第二部分12具有不同的溶解特性。
步骤S143：对光刻胶层进行第二显影处理，剥离被曝光后的第一部分。
如图7所示，参照图6，通过第二显影液处理第一部分11，第一部分11溶解在第二显影液中，以将第一部分11整体去除。在一些实施例中，第二显影液的浓度比第一显影液的浓度低。
本实施例的处理方式，在第一曝光处理后，通过第二工艺处理第一部分，提高第一部分的光吸收率，以在光照处理时，第一部分发生光化学反应的速度比第二部分速 度快，第一部分溶解特性改变所需时间短，通过控制第二曝光处理的曝光强度和曝光时间，能够实现第一部分被完全曝光，而第二部分完全不被曝光，降低了从第二部分上剥离去除第一部分的工艺难度。
需要说明的是，一些实施例中的“第一显影处理”、“第二显影处理”中所使用的术语“第一”、“第二”，并不限制处理过程中的先后顺序，这些术语仅用于将一个工艺与另一个工艺进行区分。
如图3所示，本公开一示例性的实施例提供的一种光刻胶层的处理方法，包括如下的步骤：
S210：在目标层上形成光刻胶层，光刻胶层包括远离目标层的第一部分和靠近目标层的第二部分。
一些实施例中，参照图4，在目标层2上形成光刻胶层1，包括：在目标层2上涂覆光刻胶溶液，光刻胶溶液包括两种不同的光刻胶组合物，在前烘过程中，两种光刻胶组合物在目标层2顶面分层，分别形成光刻胶层1的第一部分11和第二部分12。
一些实施例中形成的光刻胶层1为正性光刻胶层，且光刻胶层1的第一部分11和第二部分12的光折射能力不同。在一些实施例中，第二部分12的光折射率大于第一部分11的光折射率。
S220：采用第一工艺对光刻胶层进行处理，以使第一部分的光吸收率小于第二部分的光吸收率。
本实施例的处理方式和上述实施例的步骤S120相同。通过第一工艺处理第一部分11以降低第一部分11中的光致酸产生剂的浓度，减小第一部分11的光吸收率，降低第一部分11的感光能力，在第一曝光处理过程中，处理后的第一部分11作为入射光束入射至第二部分12中的传播介质。
步骤S230：对光刻胶层进行第一曝光处理，在第二部分形成曝光图像。
在一些实施例中，如图9所示，第一曝光处理在曝光装置4中进行，对光刻胶层1进行第一曝光处理，包括：
步骤S231：调整曝光装置，使曝光装置成像的焦平面位于第二部分。
如图9所示，提供曝光装置4，曝光装置4包括曝光光源41和投影透镜42，提供掩膜版9，掩膜版9上包括掩膜图案，将掩膜版9设置在曝光光源41和投影透镜42之间。将光刻胶层1置于曝光装置4的投影透镜42的下方，调整曝光装置4使投影透镜42对准光刻胶层1。如图10所示，调整曝光装置4成像的焦平面F-F，以确保穿过第一部分11的入射光束能够入射至第二部分12中，在第二部分12中形成曝光图像10。
其中，参照图9，投影透镜42和光刻胶层1之间为第一介质3，第一介质3可以为气体或液体。第一介质3为液体时，投影透镜42和光刻胶层1浸没在第一介质3中。示例性的，第一介质3可以为空气和水。
步骤S232：在第一介质中向光刻胶层发射具有第一波长的第一入射光束，第一入射光束被第一部分折射为具有第二波长的第二入射光束，其中，第二波长小于第一波长。
在一些实施例中，第一介质3的折射率为n1，光刻胶层1的第一部分11的折射率为n2，第二部分12的折射率n3，n1＜n2＜n3。
光在两种不同折射率的传播介质层传播，光波和折射率之间关系为：
Figure PCTCN2022092033-appb-000001
如图9、图11所示，曝光装置4向光刻胶层1发射第一入射光束5，第一入射光束5从第一介质3进入第一部分11，第一入射光束5被第一部分11折射后波长减小， 形成为第二入射光束6。第一入射光束5的波长为λ1，第二入射光束6的波长为λ2，λ2＜λ1。
步骤S233：第二入射光束入射至第二部分，在第二部分形成曝光图像。
如图12所示，第二入射光束6在第二部分12中形成曝光图像10。
光刻工艺中光刻分辨率影响曝光图像质量，光刻分辨率越高则形成的曝光图像精度越高。光刻分辨率遵循瑞利公式：
Figure PCTCN2022092033-appb-000002
其中，R为光刻分辨率；k1是工艺常数；λ是曝光波长；NA是发射入射光束的投影透镜的数值孔径(numerical aperture，NA)。
光刻分辨率用于表征光刻工艺中可达到的最小线宽，根据瑞利公式可知，入射光波的波长越小，工艺常数越小，则可以得到更小的线宽，即光刻精度越高。一些实施例中，通过第一部分11减小入射第二部分12的入射光束的波长，提高在第二部分12形成的曝光图像10的精度。
步骤S240：采用第二工艺对第一部分进行处理。
本实施例的处理方式和上述实施例中的步骤S140的处理方式相同，通过第二工艺处理第一部分11以提高第一部分11的光敏感性，在光照条件下，第一部分11中的聚合物树脂的不稳定基团脱落速度更快，加速了第一部分11的聚合物树脂极性改变，以缩短第一部分11发生光化学反应能够溶解于显影液的时间。
步骤S250：对光刻胶层进行第二曝光处理，以曝光被第二工艺处理后的第一部分。
如图13所示，参照图12，对光刻胶层1进行第二曝光处理，包括：向光刻胶层1发射第三入射光束7，第三入射光束7照射第一部分11表面，以使第一部分11整层被第三入射光束7曝光，第一部分11的聚合物树脂的极性改变，使得第一部分11可溶解于显影剂。
一些实施例中，第三入射光束6的光强小于第一入射光束5的光强，且第二曝光处理的时间比第一曝光处理的时间短，以使第一部分11被第三入射光束7完全曝光，而第二部分12不受第三入射光束7影响。
步骤S260：对光刻胶层进行显影处理，以图案化第二部分为光刻胶图案。
对光刻胶层1进行显影处理，参照图8、图13，包括：对光刻胶层1喷洒显影液，以使整个光刻胶层1浸润在显影液中，第一部分11完全溶解于显影液中，第二部分12的曝光图像10所在区域溶解于显影液中。清洗去除溶解了光刻胶层1的显影液和多余的显影液，未被显影液溶解的第二部分12形成光刻胶图案8，
在一些实施例中，对光刻胶层进行显影处理后，对被保留的第二部分12进行后烘处理：在130℃～200℃温度硬烘焙处理未被去除的第二部分12，后烘时间为20～40分钟，以使第二部分12中的溶剂完全逸出，同时使第二部分12进一步聚合，从而增强了形成的光刻胶图案8的耐刻蚀性。
本实施例的光刻胶层的处理方法，在第一曝光处理时，将成像的焦平面调整到第二部分中以使形成的曝光图像位于第二部分中，提高了曝光效率；并且，本实施例通过第一部分减小入射至第二部分的光波波长，提高了第二部分的光刻分辨率，本实施例的光刻胶层的处理方法能够用于光刻特征尺寸更小、结构更加复杂多样的曝光过程。
本公开一示例性的实施例提供的一种光刻胶层，覆盖在目标层2上，光刻胶层1包括远离目标层2的第一部分11以及靠近目标层2的第二部分12，第一部分11的光吸收率小于第二部分12的光吸收率。
本实施例的光刻胶层，减小了第一部分11的光吸收率，提高了穿过第一部分11 入射至第二部分12的入射光束透过率，提高入射光束在第二部分12中曝光的效率。
根据一个示例性实施例，参照图4，光刻胶层1的第一部分11用于减小从第一介质3入射至光刻胶层1的第二部分12的光波的波长。
本实施例的光刻胶层，将第一部分11作为入射光束入射在第二部分12的传播介质，通过第一部分11减小入射至第二部分12的入射光束的波长，提高第二部分12的光刻分辨率。
根据一个示例性实施例，参照图4，光刻胶层1的第一部分11的折射率n2大于第一介质3的折射率n1；光刻胶层1的第一部分11的折射率n2小于光刻胶层1的第二部分11的折射率n3。例如，当第一介质3为空气时，第一部分11的折射率n2大于1，当第一介质3为水时，第一部分11的折射率n2大于1.44。
本实施例的光刻胶层，在入射光束入射第二部分12的光传播路径中，形成了自第一介质3到第二部分12折射率逐渐增大的传播介质层，进一步提高了光刻胶层的光刻分辨率，在第二部分12形成的光刻胶图案精度更高、质量更好。
根据一个示例性实施例，参照图4光刻胶层1为正性光刻胶层。
本实施例的光刻胶层1为正性光刻胶层，可以通过处理第一部分11提高第一部分11的光敏感性，再通过曝光、显影处理去除第一部分11，仅保留第二部分12形成光刻胶图案，避免第一部分11影响光刻胶图案的顶端形貌。
根据一个示例性实施例，第一部分11的厚度大于从第一介质3入射至光刻胶层1的入射光束的波长的十分之一。例如，光刻设备的光波波长包括但不限于G线(436nm)、I线(365nm)、KrF(248nm)、ArF(193nm)和极紫外光(EUV)(13.5nm)。相应的，举例来说，当采用KrF光刻设备时，可设置第一部分11的厚度大于24.8nm，当采用ArF光刻设备时，可设置第一部分11的厚度大于19.3nm，当采用EUV光刻设备时，可设置第一部分11的厚度大于1.35nm。
在一些实施例中，第一部分11的厚度小于第二部分12的厚度为的五分之一，在保证第二部分12的厚度满足刻蚀要求的情况下，降低剥离第一部分11的难度。
本说明书中各实施例或实施方式采用递进的方式描述，每个实施例重点说明的都是与其他实施例的不同之处，各个实施例之间相同相似部分相互参见即可。
在本说明书的描述中，参考术语“实施例”、“示例性的实施例”、“一些实施方式”、“示意性实施方式”、“示例”等的描述意指结合实施方式或示例描述的具体特征、结构、材料或者特点包含于本公开的至少一个实施方式或示例中。
在本说明书中，对上述术语的示意性表述不一定指的是相同的实施方式或示例。而且，描述的具体特征、结构、材料或者特点可以在任何的一个或多个实施方式或示例中以合适的方式结合。
在本公开的描述中，需要说明的是，术语“中心”、“上”、“下”、“左”、“右”、“竖直”、“水平”、“内”、“外”等指示的方位或位置关系为基于附图所示的方位或位置关系，仅是为了便于描述本公开和简化描述，而不是指示或暗示所指的装置或元件必须具有特定的方位、以特定的方位构造和操作，因此不能理解为对本公开的限制。
可以理解的是，本公开所使用的术语“第一”、“第二”等可在本公开中用于描述各种结构，但这些结构不受这些术语的限制。这些术语仅用于将第一个结构与另一个结构区分。
在一个或多个附图中，相同的元件采用类似的附图标记来表示。为了清楚起见，附图中的多个部分没有按比例绘制。此外，可能未示出某些公知的部分。为了简明起见，可以在一幅图中描述经过数个步骤后获得的结构。在下文中描述了本公开的许多特定的细节，例如器件的结构、材料、尺寸、处理工艺和技术，以便更清楚地理解本 公开。但正如本领域技术人员能够理解的那样，可以不按照这些特定的细节来实现本公开。
虽然图1-3流程图中的各个步骤依次连接，但是这些步骤并不是必然按照连接的顺序依次执行。除非本文中有明确的说明，这些步骤的执行并没有严格的顺序限制，这些步骤可以以其它的顺序执行。而且，图1-3中的至少一部分步骤可以包括多个子步骤或者多个阶段，这些子步骤或者阶段并不必然是在同一时刻执行完成，而是可以在不同的时刻执行，这些子步骤或者阶段的执行顺序也不必然是依次进行，而是可以与其它步骤或者其它步骤的子步骤或者阶段的至少一部分轮流或者交替地执行。
最后应说明的是：以上各实施例仅用以说明本公开的技术方案，而非对其限制；尽管参照前述各实施例对本公开进行了详细的说明，本领域技术人员应当理解：其依然可以对前述各实施例所记载的技术方案进行修改，或者对其中部分或者全部技术特征进行等同替换；而这些修改或者替换，并不使相应技术方案的本质脱离本公开各实施例技术方案的范围。
工业实用性
本公开实施例所提供的光刻胶层的处理方法及光刻胶层中，在第二部分中形成曝光图像后去除第一部分，避免第一部分的存在导致光刻胶图案的顶端形貌不符合预期的问题。

Claims (16)

  1. 一种光刻胶层的处理方法，其中，所述光刻胶层的处理方法包括：
    在目标层上形成光刻胶层，所述光刻胶层包括远离所述目标层的第一部分和靠近所述目标层的第二部分；
    采用第一工艺对所述光刻胶层进行处理，以使所述第一部分的光吸收率小于所述第二部分的光吸收率；
    对所述光刻胶层进行第一曝光处理，在所述第二部分形成曝光图像；
    剥离所述第一部分并对所述光刻胶层进行第一显影处理，以图案化所述第二部分为光刻胶图案。
  2. 根据权利要求1所述的光刻胶层的处理方法，其中，所述采用第一工艺对所述光刻胶层进行处理，以使所述第一部分的光吸收率小于所述第二部分的光吸收率，包括：
    采用第一工艺对所述第一部分进行处理，所述第一部分的光致酸产生剂反应形成光致酸生成物，处理后的所述第一部分的光致酸产生剂浓度比所述第二部分的光致酸产生剂浓度低。
  3. 根据权利要求2所述的光刻胶层的处理方法，其中，所述采用第一工艺对所述第一部分进行处理，包括：
    自所述光刻胶层的顶面向所述第一部分注入氨基离子，所述氨基离子的注入深度为第一深度，所述第一深度与所述第一部分的厚度相等。
  4. 根据权利要求2所述的光刻胶层的处理方法，其中，所述采用第一工艺对所述第一部分进行处理，包括：
    向所述光刻胶层的顶面喷涂碱性气体，以使所述第一部分的光致酸产生剂与所述碱性气体反应成为光致酸生成物。
  5. 根据权利要求1所述的光刻胶层的处理方法，其中，所述采用第一工艺对所述光刻胶层进行处理，以使所述第一部分的光吸收率小于所述第二部分的光吸收率，包括：
    加热所述目标层，通过所述目标层加热所述光刻胶层，以使所述第二部分的温度比所述第一部分的温度高。
  6. 根据权利要求2或5所述的光刻胶层的处理方法，其中，所述剥离所述第一部分，包括：
    采用第二工艺对所述第一部分进行处理，并剥离被第二工艺处理后的所述第一部分。
  7. 根据权利要求6所述的光刻胶层的处理方法，其中，所述采用第二工艺对所述第一部分进行处理，包括：
    自所述光刻胶层的顶面向所述光刻胶层中注入氢离子，所述氢离子的注入深度为第二深度，所述第二深度与所述第一部分的厚度相等。
  8. 根据权利要求6所述的光刻胶层的处理方法，其中，所述采用第二工艺对所述第一部分进行处理，包括：
    向所述光刻胶层的顶面喷涂酸性气体，所述酸性气体将所述第一部分中的光致酸生成物还原为光致酸产生剂。
  9. 根据权利要求6所述的光刻胶层的处理方法，其中，所述剥离被第二工艺处理后的所述第一部分，包括：
    对所述光刻胶层进行第二曝光处理，以曝光被第二工艺处理后的所述第一部分；
    对所述光刻胶层进行第二显影处理，剥离被曝光后的所述第一部分。
  10. 根据权利要求1所述的光刻胶层的处理方法，其中，所述第一曝光处理在曝光装置中进行，所述对所述光刻胶层进行第一曝光处理，包括：
    调整所述曝光装置，使所述曝光装置成像的焦平面位于所述第二部分。
  11. 根据权利要求1所述的光刻胶层的处理方法，其中，所述对所述光刻胶层进行第一曝光处理，包括：
    在第一介质中向所述光刻胶层发射具有第一波长的第一入射光束，所述第一入射光束被所述第一部分折射为具有第二波长的第二入射光束，其中，所述第二波长小于所述第一波长；
    所述第二入射光束入射至所述第二部分，在所述第二部分形成所述曝光图像。
  12. 一种光刻胶层，覆盖在目标层上，其中，所述光刻胶层包括远离所述目标层的第一部分以及靠近所述目标层的第二部分，所述第一部分的光吸收率小于所述第二部分的光吸收率。
  13. 根据权利要求12所述的光刻胶层，其中，所述光刻胶层的第一部分用于减小从第一介质入射至所述光刻胶层的第二部分的光波的波长。
  14. 根据权利要求13所述的光刻胶层，其中，所述光刻胶层的第一部分的折射率大于所述第一介质的折射率；所述光刻胶层的第一部分的折射率小于所述光刻胶层的第二部分的折射率。
  15. 根据权利要求12所述的光刻胶层，其中，所述光刻胶层为正性光刻胶层。
  16. 根据权利要求12所述的光刻胶层，其中，所述第二部分包含的金属氧化物浓度大于所述第一部分包含的金属氧化物浓度。
PCT/CN2022/092033 2021-12-13 2022-05-10 光刻胶层的处理方法及光刻胶层 WO2023108999A1 (zh)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US17/814,025 US20230185194A1 (en) 2021-12-13 2022-07-21 Method of processing photoresist layer, and photoresist layer

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN202111516517.2 2021-12-13
CN202111516517.2A CN116263566A (zh) 2021-12-13 2021-12-13 光刻胶层的处理方法及光刻胶层

Related Child Applications (1)

Application Number Title Priority Date Filing Date
US17/814,025 Continuation US20230185194A1 (en) 2021-12-13 2022-07-21 Method of processing photoresist layer, and photoresist layer

Publications (1)

Publication Number Publication Date
WO2023108999A1 true WO2023108999A1 (zh) 2023-06-22

Family

ID=86723287

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2022/092033 WO2023108999A1 (zh) 2021-12-13 2022-05-10 光刻胶层的处理方法及光刻胶层

Country Status (2)

Country Link
CN (1) CN116263566A (zh)
WO (1) WO2023108999A1 (zh)

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6797456B1 (en) * 2002-08-01 2004-09-28 Integrated Device Technology, Inc. Dual-layer deep ultraviolet photoresist process and structure
CN101206407A (zh) * 2006-12-19 2008-06-25 财团法人工业技术研究院 光刻曝光方法
US20100178619A1 (en) * 2009-01-15 2010-07-15 International Business Machines Corporation Method for enhancing lithographic imaging of isolated and semi-isolated features
CN103365092A (zh) * 2012-03-31 2013-10-23 中芯国际集成电路制造(上海)有限公司 双重光刻胶及其处理方法

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6797456B1 (en) * 2002-08-01 2004-09-28 Integrated Device Technology, Inc. Dual-layer deep ultraviolet photoresist process and structure
CN101206407A (zh) * 2006-12-19 2008-06-25 财团法人工业技术研究院 光刻曝光方法
US20100178619A1 (en) * 2009-01-15 2010-07-15 International Business Machines Corporation Method for enhancing lithographic imaging of isolated and semi-isolated features
CN103365092A (zh) * 2012-03-31 2013-10-23 中芯国际集成电路制造(上海)有限公司 双重光刻胶及其处理方法

Also Published As

Publication number Publication date
CN116263566A (zh) 2023-06-16

Similar Documents

Publication Publication Date Title
KR100639680B1 (ko) 반도체 소자의 미세 패턴 형성방법
US8283111B2 (en) Method for creating gray-scale features for dual tone development processes
CN103547968B (zh) 在光刻应用中细化辐射敏感材料线的方法
TWI483079B (zh) Pattern formation method
KR100913005B1 (ko) 마스크 패턴 형성 방법
US8158332B2 (en) Method of manufacturing a semiconductor device
US20100221672A1 (en) Pattern forming method
US20100273107A1 (en) Dual tone development with a photo-activated acid enhancement component in lithographic applications
JP4679997B2 (ja) 微細パターン形成方法
JP2013524517A (ja) リソグラフィ用途において放射線感受性を有する材料のラインを細くする方法
KR20200021897A (ko) 마스크 형성 방법
KR20040078867A (ko) 미세 패턴 형성 방법
US9075313B2 (en) Multiple exposures in extreme ultraviolet lithography
US20060189147A1 (en) Pattern forming method and semiconductor device manufacturing method
KR20130039124A (ko) 반도체 소자의 패턴 형성방법
KR101853253B1 (ko) 듀얼 현상 공정을 포함한 포토리소그래피 방법
US9651870B2 (en) Method and tool of lithography
WO2023108999A1 (zh) 光刻胶层的处理方法及光刻胶层
US8546069B2 (en) Method for enhancing lithographic imaging of isolated and semi-isolated features
WO2023108998A1 (zh) 光刻胶层的处理方法及光刻胶层
WO2023108997A1 (zh) 光刻胶图案的形成方法和光刻胶结构
JP2013057877A (ja) パターン形成方法
KR19990003857A (ko) 감광막 형성 방법
US20230187207A1 (en) Method of processing photoresist layer, and photoresist layer
TWI597588B (zh) 圖案化光阻劑的去除

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 22905767

Country of ref document: EP

Kind code of ref document: A1