EUV-sensitive metal oxide materials as underlayers for thin CARs to improve pattern transfer

Abstract

Embodiments disclosed herein include methods for patterning a substrate. In one embodiment, the method includes depositing a metal oxo layer on a substrate and coating a chemically amplified resist (CAR) on the metal oxo layer. In one embodiment, the method further includes exposing the CAR and developing the CAR to form a pattern on the CAR. In one embodiment, the method further includes transferring the pattern to the metal oxo layer and transferring the pattern to a substrate.

Description

Technical Field

[0001] [Cross - Reference to Related Applications] This application claims priority to U.S. Patent Application No. 18 / 581,290, filed on February 19, 2024, which claims the benefit of U.S. Patent Application No. 63 / 466,897, filed on May 16, 2023, and U.S. Patent Application No. 63 / 453,410, filed on March 20, 2023, the entire contents of which are incorporated herein by reference.

[0002] Embodiments of the present disclosure relate to the field of semiconductor processing, and more particularly, to chemically amplified resists (CARs) provided on metal oxide (i.e., metal oxo) underlayers for improving pattern transfer.

Background Art

[0003] Lithography has been used in the semiconductor industry for decades to create 2D and 3D patterns of microelectronic devices. The lithography process involves spin - on deposition of a film (photoresist), irradiation (exposure) of the film with a selected pattern by an energy source, and removal (development) of the exposed (positive - tone) or unexposed (negative - tone) regions of the film by dissolving in a solvent. A bake is performed to remove the remaining solvent.

[0004] The photoresist should be a material sensitive to irradiation, and a chemical conversion occurs within the exposed portion of the film after irradiation, which enables a change in solubility between the exposed and unexposed regions. This change in solubility is used to remove either the exposed or unexposed regions of the photoresist. Here, the photoresist is developed, and the pattern can be transferred to the underlying thin film or substrate by etching. After the pattern is transferred, the residual photoresist is removed, and by repeating this process multiple times, 2D and 3D structures used in microelectronic devices can be obtained.

[0005] Several properties are important in the lithography process. These important properties include sensitivity, resolution, lower LER (line-edge roughness), etching resistance, and the ability to form thin layers. Higher sensitivity means less energy is required to change the solubility of the deposited film, which increases the efficiency of the lithography process. The degree to which a feature can be realized by the lithography process is determined by the resolution and LER. Pattern transfer to form deep structures requires materials with higher etching resistance. Materials with higher etching resistance also enable thinner films. Thinner films improve the efficiency of the lithography process. [Overview of the project]

[0006] Embodiments disclosed herein include methods for patterning a substrate. In one embodiment, the method includes depositing a metal oxo layer on a substrate and coating a chemically amplified resist (CAR) on the metal oxo layer. In one embodiment, the method further includes exposing the CAR and developing the CAR to form a pattern on the CAR. In one embodiment, the method further includes transferring the pattern to the metal oxo layer and transferring the pattern to a substrate.

[0007] Embodiments disclosed herein further include photoresist stacks. In one embodiment, the photoresist stack includes an extreme ultraviolet (EUV) radiation-sensitive substrate and a chemically amplified resist (CAR) on the substrate. In one embodiment, the CAR is EUV radiation-sensitive.

[0008] Embodiments disclosed herein further include methods for patterning a substrate, the method comprising: providing an extreme ultraviolet (EUV) radiation-sensitive underlayer on a substrate; and arranging a chemically amplified resist (CAR) on the underlayer, the CAR being applied by a spin-coating process. In one embodiment, the method comprises: exposing and developing the CAR to form a pattern on the CAR; transferring the pattern to the underlayer; and transferring the pattern to a substrate. It also includes. [Brief explanation of the drawing]

[0009] [Figure 1] This is a cross-sectional view of a substrate on which one chemically amplified resist (CAR) is placed. [Figure 2] This is a cross-sectional view of a substrate having a metal oxide (i.e., metal oxo) underlayer and a CAR on the underlayer, according to one embodiment. [Figure 3A] This is a cross-sectional view of a substrate on which a metal oxo underlayer is placed, according to one embodiment. [Figure 3B] This is a cross-sectional view of a substrate after CAR has been applied to a metal oxo underlayer according to one embodiment. [Figure 3C] This is a cross-sectional view of a substrate after patterning has been applied to a CAR according to one embodiment. [Figure 3D] This is a cross-sectional view of a substrate after a CAR pattern has been transferred to a metal oxo substrate using a dry developing process according to one embodiment. [Figure 3E] This is a cross-sectional view of a substrate after a pattern has been transferred to it, according to one embodiment. [Figure 4A] This is a cross-sectional view of a substrate having a metal oxo underlayer and a CAR on the underlayer according to one embodiment. [Figure 4B] This is a cross-sectional view of a substrate after the CAR and metal oxo underlayers have been developed, according to one embodiment. [Figure 4C] This is a cross-sectional view of a substrate after a pattern has been transferred to it, according to one embodiment. [Figure 5] This is a processing flow diagram of a process for patterning a substrate using a metal oxo layer and CAR according to one embodiment. [Figure 6] This is a schematic diagram of a cluster tool that can be used to process a substrate having a metal oxo underlayer and CAR, according to one embodiment. [Figure 7] A block diagram of an exemplary computer system according to one embodiment of the present disclosure is shown. [Modes for carrying out the invention]

[0010] This specification describes chemically amplified resists (CARs) provided on a metal oxide (i.e., metal oxo) underlayer for improved pattern transfer. The following description of the specification includes numerous specific details for developing the photoresist (e.g., hot vapor phase processes and material regimes) to provide a comprehensive understanding of the embodiments of the disclosure. It will be apparent to those skilled in the art that the embodiments of the disclosure can be practiced without these specific details. In other instances, well-known aspects such as the manufacture of integrated circuits are not described in detail to avoid unnecessarily complicating the embodiments of the disclosure. Furthermore, it should be understood that the various embodiments shown in the figures are illustrative and not necessarily drawn to scale.

[0011] To further aid understanding, photoresist systems used in extreme ultraviolet (EUV) lithography have a problem with low efficiency. That is, existing photoresist material systems for EUV lithography require high doses to provide the necessary solubility switch that enables the development of the photoresist material. Chemically amplified resists (CARs) contain chemicals that are sensitive to EUV radiation.

[0012] An example of a structure 100 containing a standard CAR system is shown in Figure 1. As shown, CAR 120 can be deposited on the surface of a substrate 101. The substrate 101 can be any type of layer (or more layers) that is patterned by an etching process. For example, the substrate 101 may contain semiconductor materials (e.g., silicon), oxides, nitrides, or metals. In one embodiment, the substrate 101 may also contain a hard mask material (e.g., a carbon-containing hard mask) provided on top of the patterned layer. Typically, CAR 120 is applied by a spin coating process. That is, a solvent containing CAR 120 is dispensed onto the substrate 101, and the substrate 101 is rotated at a high revolutions per minute (RPM) to disperse a thin layer of CAR 120 on the surface of the substrate 101. Subsequently, the solvent may be removed (or partially removed) using a bake process.

[0013] In the chemical amplification concept of CAR, a photochemically generated acid is used as a catalyst. The catalyst triggers a series of chemical transformations in the resist film, providing a gain mechanism that completely transforms the exposed regions of the photoresist. The transformed regions of the CAR then exhibit etching selectivity relative to the unexposed regions. Thus, using a development process, it is possible to remove the exposed regions while leaving the unexposed regions intact, or to remove the unexposed regions while leaving the exposed regions intact.

[0014] Traditionally, resist structures may contain thick resist material to provide the necessary etching resistance for transferring patterns to the underlying substrate. However, thicker resists can lead to pattern breakdown when dense patterning (e.g., fine pitch structures) is required. Furthermore, the thicker the resist layer, the greater the dose of EUV radiation required to induce solubility switching throughout the entire thickness of the resist. These issues can lead to increased LWR and ultimately a decrease in pattern transfer performance.

[0015] Organic-inorganic hybrid materials (e.g., metal oxo material systems) have been proposed as material systems for EUV lithography due to their improved sensitivity to EUV radiation. Such material systems typically contain a metal (e.g., Sn, Hf, Zr, etc.), oxygen, and carbon. For example, the metal element may be bonded to a butyl group, a hydroxyl group, or a phenyl group, etc. In metal oxo photoresist systems, exposure to EUV radiation results in cross-linking and carbon removal. The difference in the carbon ratio between the exposed and unexposed regions is used as a solubility switch during development. In particular, during negative tone development, the unexposed regions with a higher carbon content are preferentially etched by the developer. However, it should be understood that in some embodiments, positive tone development can also be used.

[0016] Therefore, in the embodiments disclosed herein, a combination of a CAR material and a metal oxo underlayer can be used to leverage the advantages of various resist systems. A combination of a thin CAR and a metal oxo underlayer can result in an improvement in LWR and overall pattern transfer. In one embodiment, the metal oxo underlayer provides improved resistance to etching chemicals and thus sets the LWR for patterning. Additionally, the presence of the metal oxo underlayer can help reduce the dose of the resist system and improve adhesion properties.

[0017] Previously, combinations of CAR systems and metal oxo systems were not attempted because the solvents used for CAR deposition typically dissolve the metal oxo film. However, post-deposition treatment of the metal oxo layer can provide resistance to solvents. Examples of such treatment include heat treatment, ultraviolet (UV) radiation treatment, or chemical treatment, etc. Such treatment can change the cross-linking characteristics of the metal oxo layer to make the surface of the metal oxo layer more resistant to the solvents of the CAR.

[0018] Furthermore, it is also possible to improve the resistance by modifying the deposition parameters of the metal oxo film. This is because the metal oxo film can be deposited by a dry deposition process (e.g., atomic layer deposition (ALD), chemical vapor deposition (CVD), physical vapor deposition (PVD), etc.) that enables adjustment of the resist characteristics through the thickness of the resist. In a further embodiment, the combination of the metal oxo system and the CAR system can also improve the bonding with the underlying substrate. For example, the metal oxo material may have an organic ligand that is likely to adhere to the CAR-type material having a -CH3 end. Thus, the adhesion problem of the existing CAR system is reduced.

[0019] In this specification, the metal oxo underlayer and the CAR photoresist are mentioned as an example of suitable materials. However, it should be understood that any material sensitive to EUV radiation can be used as the underlayer. Similarly, any EUV-sensitive material can be used as the photoresist on top of the underlayer. That is, in some embodiments, the photoresist does not need to be CAR. In a particular embodiment, the underlayer is a metal oxo underlayer and the photoresist thereon is an EUV-sensitive photoresist material. Both the underlayer and the above photoresist can be developed by a dry development process similar to the embodiments described herein.

[0020] Referring now to FIG. 2, a cross-sectional view of a structure including a hybrid resist system according to an embodiment is shown. In one embodiment, the structure 200 may include a substrate 201. The substrate 201 can be any type of layer (or layers) patterned by an etching process. For example, the substrate 201 can include a semiconductor material (e.g., silicon), an oxide, a nitride, or a metal, etc. In one embodiment, the substrate 201 can also include a hard mask material (e.g., a carbon-containing hard mask) provided on the layer to be patterned.

[0021] In one embodiment, a first sensitive resist layer 210 may be provided on a substrate 201, and a second sensitive resist layer 220 may be provided on the first sensitive resist layer 210. The first resist layer 210 may be a different class of resist than the second resist layer 220. For example, as used throughout the remainder of this disclosure, the first resist layer 210 may be a metal oxo resist 210, and the second resist layer 220 may be a CAR 220. In one embodiment, the thickness of the metal oxo resist 210 may be greater than the thickness of the CAR 220. However, in other embodiments, the metal oxo resist 210 and the CAR 220 may have similar thicknesses, or the CAR 220 may be thicker than the metal oxo resist 210. More generally, the combined thickness of the CAR 220 and the metal oxo resist 210 may be less than the thickness required for the CAR 220 excluding the underlying layer of the metal oxo resist 210.

[0022] In one embodiment, the metal oxo-resist 210 can be coated by any suitable deposition process. In one embodiment, the metal oxo-resist 210 can be coated by a spin-coating process. In other embodiments, the metal oxo-resist 210 can be coated by a dry deposition process. For example, the metal oxo-resist 210 can be deposited using ALD, CVD, or PVD processes. Dry deposition processes allow for improved tuning of the properties of the metal oxo-resist 210. By adjusting various deposition parameters (e.g., temperature, gas flow rate, pressure, etc.), a metal oxo-resist 210 with non-uniform properties throughout its thickness can be provided. For example, the lower part of the metal oxo-resist 210 can be adjusted to improve adhesion strength, and the upper region of the metal oxo-resist 210 can be adjusted for dose improvement, improved adhesion to CAR220, or etching resistance. Furthermore, the metal oxo-resist 210 can be processed after deposition is complete. For example, heat treatment, UV treatment, or chemical treatment can be used to improve the performance of the hybrid resist system shown in structure 200.

[0023] In one embodiment, the metal oxoresist 210 may have any suitable formulation. In one embodiment, the metal component may include tin. However, other metal elements may be used instead of or in combination with tin. The organic ligand used may also be any suitable ligand, as described in more detail above. In one embodiment, the composition of the metal oxoresist 210 may also be non-uniform throughout the thickness of the metal oxoresist 210. Such embodiments may be made possible by using a dry deposition process.

[0024] After the metal oxo-resist 210 is deposited, CAR220 may be applied. In one embodiment, CAR220 may be applied by a typical spin-coating process. As described above, the treatment of the metal oxo-resist 210 can protect it from the adverse effects of the solvent used to deposit CAR220. That is, CAR220 can be applied in its original state (i.e., without any change in formulation) while maintaining compatibility with the metal oxo-resist 210.

[0025] Next, referring to Figures 3A to 3E, a series of cross-sectional views are shown illustrating the process and structure 300 for patterning the substrate. In one embodiment, the process shown in Figures 3A to 3E can utilize a dry developing process for the metal oxo layer 310.

[0026] Referring now to Figure 3A, a cross-sectional view of a structure 300 including a substrate 301 and a metal oxoresist 310 according to one embodiment is shown. In one embodiment, the substrate 301 can be any suitable substrate patterned with a hybrid resist system. Although shown as a single layer, the substrate 301 may include multiple layers, one or more of which may be hard mask layers.

[0027] In one embodiment, the metal oxoresist 310 may be coated onto the surface of the substrate 301. In one embodiment, the metal oxoresist 310 may be coated by a spin coating process. In other embodiments, a dry deposition process (e.g., ALD, CVD, PVD, etc.) may be used to deposit the metal oxoresist 310 on the substrate 301. The dry deposition process may provide greater flexibility in the design of the metal oxoresist 310. For example, deposition parameters such as temperature, pressure, and gas flow rate may be adjusted to tailor the metal oxoresist 310 through its thickness. Furthermore, the dry deposition process may be used to tailor the composition through the thickness of the metal oxoresist 310. For example, various metal atoms may be provided at various thicknesses. In one embodiment, the metal oxoresist 310 may contain tin or any other suitable metal centers. Ligands may also be tailored through the thickness of the metal oxoresist 310.

[0028] In one embodiment, the metal oxoresist 310 may be treated after deposition on the substrate 301. Treatment (or a combination of treatments) may be used to improve compatibility with subsequently deposited CARs. For example, the treatment can alter the cross-linking percentage to withstand dissolution by the solvent used to deposit the CARs. In one embodiment, heat treatment is applied to the metal oxoresist 310. Heat treatment may involve exposing the metal oxoresist 310 to a high temperature for a predetermined period. For example, temperatures between 50°C and 250°C may be used, and the period may be between 1 second and 1 hour or longer. In one embodiment, the treatment may include UV treatment. UV treatment may be performed under any suitable atmosphere. For example, an atmosphere containing one or more of nitrogen, oxygen, and argon may be used. In yet another embodiment, the treatment may include chemical treatment. Chemical treatment may be used to alter the polarity of the surface. An example of a suitable chemical treatment is the application of hexamethyldisilane (HMDS).

[0029] Referring to Figure 3B, a cross-sectional view of structure 300 after CAR320 has been applied according to one embodiment is shown. In one embodiment, CAR320 may be applied by a spin coating process. However, the solvent used for spin coating does not adversely affect the metal oxo-resist 310 due to the treatment of the metal oxo-resist 310. This makes it possible to use existing CAR320 without requiring any change in composition.

[0030] Referring here to Figure 3C, a cross-sectional view of structure 300 after exposure of CAR320 according to one embodiment is shown. In one embodiment, CAR320 can be exposed by EUV radiation. EUV radiation causes a solubility switch within CAR320, and subsequently CAR320 can be developed to form a patterned CAR321. For example, an opening 322 may be provided that penetrates the thickness of the patterned CAR321. The underlying metal oxoresist 310, which is not developed at this point, can also be exposed by the exposure process used to pattern the patterned CAR321. That is, a latent image of the pattern can be provided in the metal oxoresist 310. CAR321 can be developed by wet developing chemicals (e.g., wet etching) or dry etching.

[0031] Referring here to Figure 3D, a cross-sectional view of the structure 300 after the metal oxo-resist 310 has been patterned is shown according to one embodiment. In the particular embodiment shown in Figure 3D, the metal oxo-resist 310 may be developed by a dry development process. For example, but not limited to, etchants such as HCl, HBr, and HI can be used in a dry etching environment to form the patterned metal oxo-resist 311. The etchant used to develop the metal oxo-resist 310 has only a slight (if any) effect on the patterned CAR 321. Furthermore, the existing pattern on the patterned CAR 321 can act as an etchant mask, thereby assisting in the development of the underlying metal oxo-resist 310. This may result in a lower dose being required on the metal oxo-resist 310 to enable good pattern transfer. In one embodiment, the dry development process for forming the patterned metal oxo-resist 311 may be a thermal etching process. For example, the temperature of structure 301 during etching can range from -100°C to 350°C. The thermal process can also function as a post-development bake for the patterned CAR321 above.

[0032] Referring now to Figure 3E, a cross-sectional view of structure 300 after a pattern has been transferred to the substrate below, according to one embodiment. As shown, the opening 322 can be transferred to the substrate 301. The pattern transfer process can use any suitable etching process (e.g., wet etching or dry etching) selective to the substrate 301 for the patterned resist layers 311 and 321. In one embodiment, the resistance of the patterned metal oxoresist 311 to etching chemicals may be higher than that of the patterned CAR 321 to etching chemicals. However, because the patterned metal oxoresist 311 remains, the LWR and other pattern transfer characteristics may be better than in embodiments using only a thin CAR.

[0033] Next, referring to Figures 4A to 4C, a structure 400 including an alternative hybrid resist and patterning process according to one embodiment is shown.

[0034] Referring here to Figure 4A, a cross-sectional view of a structure 400 comprising a substrate 401 and a metal oxoresist 410 on the substrate 401 is shown according to one embodiment. In one embodiment, CAR 420 may be coated on top of the metal oxoresist 410. In one embodiment, structure 400 may be similar to structure 300 shown in Figure 3A. That is, the metal oxoresist 410 may be deposited by a dry deposition process to provide an improved ability to modify the metal oxoresist 410. The metal oxoresist 410 may also be treated (e.g., by heat treatment, UV treatment, and / or chemical treatment). After that, CAR 420 is coated.

[0035] In one embodiment, CAR420 may include any suitable CAR material. CAR420 may be applied by a spin-coating process. Because the metal oxo-resist 410 is treated, the solvent used to extrude CAR420 cannot adversely affect the performance or structure of the underlying metal oxo-resist 410. In one embodiment, CAR420 is thinner than the thickness of the metal oxo-resist 410. However, in some embodiments, thicker CAR420 may also be used. More generally, the combined thickness of CAR420 and the metal oxo-resist 410 may be less than the thickness of CAR420 when the underlying metal oxo-resist 410 is not provided.

[0036] Next, referring to Figure 4B, a cross-sectional view of structure 400 is shown after pattern 422 has been formed on CAR 420 and metal oxoresist 410, and patterned CAR 421 and patterned metal oxoresist 411 have been formed. In contrast to the embodiments described earlier with respect to Figures 3A to 3E, the development process may be carried out using a single developer. For example, EUV exposure may be performed on structure 400, and after exposure, a single development process is performed to remove both portions of CAR 420 and the underlying metal oxoresist 410. In one embodiment, the developer may be a wet etching chemical or a dry etching chemical.

[0037] Referring now to Figure 4C, a cross-sectional view of the structure 400 after the pattern has been transferred to the substrate 401 below, according to one embodiment. As shown, the openings 422 of the pattern can be transferred to the substrate 401. The pattern transfer process may use any suitable etching process (e.g., wet etching or dry etching) selective to the substrate 401 for the patterned resist layers 411 and 421. In one embodiment, the resistance of the patterned metal oxoresist 411 to etching chemicals may be higher than that of the patterned CAR 421 to etching chemicals. However, because the patterned metal oxoresist 411 remains, the LWR and other pattern transfer characteristics may be better than in embodiments using only a thin CAR.

[0038] Referring now to Figure 5, a process flow diagram is shown illustrating a process 550 for patterning a substrate using a hybrid resist stack according to one embodiment. In one embodiment, process 550 may be similar to any of the process flows previously illustrated in Figures 3A to 3E or Figures 4A to 4C.

[0039] In one embodiment, process 550 may be initiated by depositing a metal oxoresist layer on a substrate. The metal oxoresist can be deposited by either a wet deposition process (e.g., spin coating) or a dry deposition process (e.g., ALD, CVD, PVD, etc.). In the case of a dry deposition process, processing parameters may be adjusted to provide a metal oxoresist with non-uniform thickness composition and / or non-uniform material properties (e.g., adhesive strength, dose, etc.). In one embodiment, the substrate may be any material patterned using a hybrid resist stack, which may include a hard mask layer. The metal oxoresist layer is described in detail with respect to process 550. It should be understood that any EUV-sensitive material may be used as the underlayer for process 550.

[0040] In one embodiment, process 550 may proceed to step 552, which includes treating a metal oxoresist. In one embodiment, the above treatment may be performed after the metal oxoresist has been deposited. The above treatment may include one or more heat treatments, UV treatments, or chemical treatments. Details of such treatments may be similar to those described in more detail above. In one embodiment, the treatment process may modify the crosslinking of the metal oxoresist to provide improved protection of the subsequently deposited CAR from the solvent. In one embodiment, the above treatment may also modify interfacial chemical properties, polarity, etc. For example, surface treatment may improve adhesion with the subsequently deposited CAR.

[0041] In one embodiment, process 550 may proceed to step 553, which includes coating CAR onto a metal oxo resist. In one embodiment, CAR may be coated by a spin coating process or the like. In some embodiments, the thickness of CAR may be less than the thickness of the metal oxo resist. However, in other embodiments, the metal oxo resist may be thinner or thicker than the CAR, or the same thickness as the CAR. More generally, the combined thickness of CAR and metal oxo resist may be thinner than when CAR alone is used.

[0042] CAR is provided as an example of a photoresist layer in process 550, but embodiments are not limited to such material systems. More generally, step 553 may be used to deposit any EUV-sensitive resist material on a metal oxo resist. In some embodiments, the photoresist layer may be other metal oxo materials or any other EUV-sensitive material.

[0043] In one embodiment, process 550 may proceed to step 554, which includes exposing the CAR with EUV radiation. In one embodiment, the EUV radiation may provide a latent image in the CAR. For example, the area of ​​the CAR exposed to EUV radiation is subjected to a solubility switch. In one embodiment, the exposure used to expose the CAR may also result in the exposure of the underlying metal oxoresist. That is, a latent image from the solubility switch may also occur in the metal oxoresist.

[0044] In one embodiment, process 550 may proceed to step 555, which includes developing the CAR to form a pattern within the CAR layer. In one embodiment, the development may be performed using a wet etching chemical. In some embodiments, the developer develops only the CAR, leaving the metal oxoresist unchanged. The CAR can also be developed by a dry development process, such as thermal dry development.

[0045] In one embodiment, process 550 may proceed to step 556, which includes developing a metal oxo-resist to form a pattern on the metal resist layer. In some embodiments, the development of the metal oxo-resist may be a dry development process, such as thermal development. In other embodiments, the developer used to develop the CAR may also be used to develop the metal oxo-resist.

[0046] In one embodiment, process 550 may proceed to step 557, which includes transferring the pattern to a substrate. The resist layer pattern can be transferred to the substrate using an etching process, such as a wet etching process or a dry etching process. In the embodiments described in more detail above, the tools used to perform the various processing steps have been omitted. More generally, it should be understood that separate processing tools may be used to perform each of the various processing steps. However, in other embodiments, two or more individual processing steps may be performed within a single cluster tool. An example of one such cluster tool is shown in Figure 6.

[0047] Referring now to Figure 6, a plan view of a cluster tool 600 according to one embodiment is shown. In one embodiment, the processing tool 600 may include an EFEM (equipment front end module) 621. The EFEM 621 may receive a front-opening unified pod (FOUP) or a cassette as an entry point for substrates into the cluster tool 600. The substrates processed in the cluster tool 600 may include wafers (e.g., silicon wafers or other semiconductor wafers) of any standard form factor (e.g., 200 mm, 300 mm, 450 mm, etc.). In one embodiment, the EFEM 621 may be coupled to the rest of the cluster tool 600 via a load lock 622. The load lock 622 can separate the atmospheric conditions within the EFEM from the vacuum conditions within the rest of the cluster tool 600. However, in some embodiments, the EFEM may also be held at a pressure below atmospheric pressure (e.g., a pressure higher than the other side of the load lock 622 but lower than atmospheric pressure).

[0048] In one embodiment, the measuring tool 625 may be located after the load lock 622. The measuring tool 625 may be a scatterometry tool or any other measuring tool useful for after-develop inspection (ADI) or after-etch inspection (AEI) applications. In one embodiment, the measuring tool 625 may be communicatively connected to a transfer chamber 627. The transfer chamber 627 may include a robotic arm, track, or any suitable structure for transferring a substrate between the measuring tool 625 and the rest of the cluster tool 600.

[0049] In one embodiment, one or more developing chambers 610 and one or more etching chambers 612 may be connected to a transfer chamber 627. For example, a cluster tool 600 may contain six developing chambers 610 and four etching chambers 612. One or more deposition chambers 615 may also be provided within the cluster tool 600. The above chambers 610, 612, and 615 may be located on two sides of the transfer chamber 627 to optimize space saving. In one embodiment, the developing chamber 610 may be a dry developing chamber. A plasma source may be used in combination with the developing chamber 610 to develop the resist layer without using wet chemicals. Furthermore, the etching chamber 612 may be a dry etching chamber 612 that uses plasma to etch the substrate through the resist layer. The deposition chamber 615 may be a dry deposition chamber (e.g., ALD, CVD, etc.) used to deposit a photoresist layer. One or more of the deposition chambers 615 may also include a spin coating chamber.

[0050] In one embodiment, a substrate may enter the EFEM, pass through the load lock 622 and the measuring tool 625, and be sent to one of the deposition chambers 615. In one or more of the deposition chambers 615, a hybrid resist system containing a metal oxo resist and CAR is applied. In one embodiment, the hybrid resist and substrate may be sent to an exposure tool (which may be a different tool from the cluster tool 600). After development, the substrate may be sent to the measuring tool 625 for ADI. After ADI, the substrate may be sent via the transfer chamber 627 to one of the etching chambers 612. There, the substrate may be etched through the developed resist layer. The substrate may then be transferred back to the measuring tool 625 for AEI. Thus, the processing of resist development, ADI, substrate etching, and AEI can be performed within a single cluster tool 600 without leaving the vacuum environment.

[0051] Figure 7 shows a schematic diagram of an exemplary form of machine, computer system 700, in which a set of instructions for causing the machine to perform any one or more of the methods described herein can be executed internally. In alternative embodiments, the machine may be connected to other machines on a local area network (LAN), intranet, extranet, or internet (e.g., it may be networked). The machine may operate as a server or client machine in a client-server network environment, or as a peer machine in a peer-to-peer (or distributed) network environment. The machine may be a personal computer (PC), tablet PC, set-top box (STB), portable information terminal (PDA), mobile phone, web device, server, network router, switch or bridge, or any machine capable of executing (sequentially or otherwise) a set of instructions specifying the actions to be performed by the machine. Furthermore, although a single machine is shown, the term “machine” should also be interpreted to include any set of machines (e.g., computers) that individually or in conjunction execute one or more sets of instructions for performing any one or more of the methods described herein.

[0052] An exemplary computer system 700 includes a processor 702, main memory 704 (e.g., read-only memory (ROM), flash memory, dynamic random access memory (DRAM) (synchronous DRAM (SDRAM) or rhombus DRAM (RDRAM), etc.)), static memory 706 (e.g., flash memory, static random access memory (SRAM), MRAM, etc.), and secondary memory 718 (e.g., data storage devices), all communicating with each other via a bus 730.

[0053] The processor 702 represents one or more general-purpose processing devices, such as a microprocessor or a central processing unit. More specifically, the processor 702 may be a composite instruction set arithmetic (CISC) microprocessor, a reduced instruction set arithmetic (RISC) microprocessor, a very long instruction word (VLIW) microprocessor, a processor implementing another instruction set, or a processor implementing a combination of instruction sets. Furthermore, the processor 702 may be one or more special-purpose processing devices, such as an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), a digital signal processor (DSP), or a network processor. The processor 702 is configured to execute processing logic 726 for performing the steps described herein.

[0054] The computer system 700 may further include a network interface device 708. The computer system 700 may also include a video display unit 710 (e.g., a liquid crystal display (LCD), a light-emitting diode display (LED), or a cathode ray tube (CRT)), an alphanumeric input device 712 (e.g., a keyboard), a cursor control device 714 (e.g., a mouse), and a signal generating device 716 (e.g., a speaker).

[0055] The secondary memory 718 may include a machine-accessible storage medium (or, specifically, a computer-readable storage medium) 732 containing one or more sets of instructions (e.g., software 722) that embody any one or more of the methods or functions described herein. The software 722 may also reside entirely or at least partially in the main memory 704 and / or in the processor 702 while being executed by the computer system 700, and the main memory 704 and the processor 702 also constitute a machine-readable storage medium. The software 722 may further be transmitted or received over the network 760 via a network interface device 708.

[0056] In one exemplary embodiment, the machine-accessible storage medium 732 is shown as a single medium, but the term “machine-readable storage medium” should be interpreted to include a single or multiple mediums (e.g., a centralized or distributed database, and / or associated caches and servers) that store one or more instruction sets. The term “machine-readable storage medium” should also be interpreted to include any medium capable of storing or recording a set of instructions executed by a machine, which causes the machine to execute any one or more of the methods of the Disclosure. Accordingly, the term “machine-readable storage medium” should be interpreted to include, but not be limited to, solid-state memory, optical media, and magnetic media.

[0057] According to one embodiment of the present disclosure, a mechanically accessible storage medium stores instructions for a data processing system to perform a method of forming a hybrid resist system including a metal oxo underlayer and CAR, exposing the hybrid resist system, developing the hybrid resist system, and etching the underlying substrate. This process can be performed at least partially using a cluster tool. The cluster tool may include a measurement tool, a developing chamber, a deposition chamber, and an etching chamber. In one embodiment, the method disclosed herein makes it possible to improve etching performance compared to conventional methods.

[0058] Thus, a method for processing a substrate using a hybrid resist system containing a metal oxo underlayer and CAR is described. In one embodiment, the substrate containing the hybrid resist system may be processed in a cluster tool comprising a measurement tool, a dry developing chamber, a deposition chamber, and an etching chamber.

Claims

1. A method for patterning a circuit board, Depositing a sublayer on the aforementioned substrate, Applying an extreme ultraviolet (EUV) sensitive resist on the aforementioned underlayer, Exposing the aforementioned substrate to light, Developing the EUV-sensitive resist to form a pattern on the EUV-sensitive resist, Transferring the aforementioned pattern to the aforementioned underlayer, Transferring the aforementioned pattern to the substrate, A method for patterning a circuit board, including [specific details omitted].

2. The method according to claim 1, further comprising treating the underlayer by a processing step before the EUV-sensitive resist is applied.

3. The method according to claim 2, wherein the processing step includes heat treatment.

4. The method according to claim 3, wherein the heat treatment is performed at a temperature between approximately 70 degrees Celsius and approximately 250 degrees Celsius.

5. The method according to claim 2, wherein the processing process includes ultraviolet (UV) radiation treatment.

6. The method according to claim 5, wherein the UV radiation treatment is carried out in an atmosphere containing one or more of nitrogen, oxygen, and argon.

7. The method according to claim 2, wherein the process includes a chemical process.

8. The method according to claim 7, wherein the chemical treatment comprises hexamethyldisilane (HMDS).

9. The method according to claim 1, wherein the transfer of the pattern to the underlayer is performed by a dry developing process.

10. The method according to claim 1, wherein developing the EUV-sensitive resist to form a pattern on the EUV-sensitive resist and transferring the pattern to the underlayer is performed in a single wet development process or a dry development process.

11. The method according to claim 1, wherein the combined thickness of the EUV-sensitive resist and the underlayer is smaller than the thickness required for the EUV-sensitive resist alone.

12. The method according to claim 1, wherein two or more steps are performed within a single cluster tool.

13. The method according to claim 1, wherein the substrate is a hard mask layer.

14. A photoresist stack, A base layer that is sensitive to extreme ultraviolet (EUV) radiation, The EUV-sensitive resist on the aforementioned underlayer, A photoresist stack, including the photoresist.

15. The photoresist stack according to claim 14, wherein the underlying layer comprises a metal oxo material.

16. The photoresist stack according to claim 15, wherein the metal oxo material contains tin.

17. A method for patterning a circuit board, A substrate that is sensitive to extreme ultraviolet (EUV) radiation is provided on the substrate, The process involves placing a photoresist that is sensitive to EUV radiation on the aforementioned underlayer, wherein the photoresist is applied by a spin coating process. The substrate is exposed to the EUV radiation, and the photoresist is developed to form a pattern on the photoresist. Transferring the aforementioned pattern to the aforementioned underlayer, Transferring the aforementioned pattern to the substrate, A method for patterning a circuit board, including [specific details omitted].

18. The method according to claim 17, wherein the underlayer is treated before the photoresist is applied, and the treatment includes heat treatment, ultraviolet (UV) radiation treatment, or chemical treatment.

19. The method according to claim 17, wherein the transfer of the pattern to the underlayer is performed by a dry developing process.

20. The method according to claim 17, wherein two or more steps are performed within a single cluster tool.

Images