Method of patterning substrate and photoresist stack

Abstract

The embodiments disclosed herein include a method for patterning a substrate. In an embodiment, the method includes depositing a metal oxide layer on the substrate and coating a chemically amplified resist (CAR) on the metal oxide layer. In an embodiment, the method further includes exposing the CAR and developing the CAR to form a pattern in the CAR. In an embodiment, the method further includes transferring the pattern to the metal oxide layer and transferring the pattern to the substrate.

Description

Technical Field

[0001] This application claims the benefits of U.S. Patent Application No. 63 / 466,897, filed May 16, 2023, and U.S. Patent Application No. 63 / 453,410, filed March 20, 2023, the entire contents of which are incorporated herein by reference.

[0002] The embodiments disclosed herein relate to the field of semiconductor processing, and more specifically to a chemical amplification resist (CAR) disposed on a metal oxide (i.e., metal oxide) substrate for improving pattern transfer. Prior Technology

[0003] Lithography has been used in the semiconductor industry for decades to create 2D and 3D patterns in microelectronic components. The lithography process involves spin-coating a film (photoresist), irradiating the film with a selected pattern using energy (exposure), and removing (developing) the exposed (positive-tone) or unexposed (negative-tone) areas of the film by dissolving it in a solvent. Baking is then performed to remove the remaining solvent.

[0004] The photoresist should be a radiation-sensitive material, undergoing a chemical transformation in the exposed portions of the film upon irradiation. This transformation alters the solubility between the exposed and unexposed areas. This solubility change is used to remove the photoresist from either the exposed or unexposed areas. The photoresist is then developed, and the pattern can be transferred to the underlying thin film or substrate via etching. After pattern transfer, residual photoresist is removed, and this process is repeated multiple times to obtain 2D and 3D structures for use in microelectronic devices.

[0005] In lithography, several properties are crucial. These include sensitivity, resolution, low line edge roughness (LER), etch resistance, and the ability to form thinner layers. Higher sensitivity requires less energy to alter the solubility of the deposited film, enabling greater efficiency in lithography. Resolution and LER determine the narrowest features achievable in lithography. Pattern transfer requires materials with higher etch resistance to form deeper structures. Higher etch resistance also allows for thinner films. Thinner films improve the efficiency of lithography. Summary of the Invention

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

[0007] The embodiments disclosed herein further include a photoresist stack. In an embodiment, the photoresist stack includes a substrate sensitive to extreme ultraviolet (EUV) radiation and a chemically amplified resist (CAR) layer on top of the substrate. In an embodiment, the CAR is sensitive to EUV radiation.

[0008] The embodiments disclosed herein also include a method for patterning a substrate, comprising providing an underlayer on the substrate, wherein the underlayer is sensitive to extreme ultraviolet (EUV) radiation, and depositing a chemically amplified resist (CAR) on the underlayer, wherein the CAR is coated by a spin-coating process. In embodiments, the method further includes exposing and developing the CAR to form a pattern in the CAR, transferring the pattern to the underlayer, and transferring the pattern to the substrate. Simple Explanation of the Diagram

[0009] Figure 1 is a cross-sectional view of a substrate, on which a single chemical amplification resist (CAR) is present.

[0010] Figure 2 is a cross-sectional view of a substrate according to an embodiment, the substrate having a metal oxide (i.e., metal oxide) underlayer and a CAR on the underlayer.

[0011] Figure 3A is a cross-sectional view of a substrate according to an embodiment, wherein the substrate has a metal oxide underlayer.

[0012] Figure 3B is a cross-sectional view of a substrate after CAR coating on a metal oxide substrate according to an embodiment.

[0013] Figure 3C is a cross-sectional view of the substrate after patterning of the CAR according to an embodiment.

[0014] Figure 3D is a cross-sectional view of the substrate after the pattern in the CAR has been transferred to the metal oxide underlayer using a dry developing process, according to an embodiment.

[0015] Figure 3E is a cross-sectional view of the substrate after the pattern has been transferred into the substrate according to an embodiment.

[0016] Figure 4A is a cross-sectional view of a substrate according to an embodiment, the substrate having a metal oxide underlayer and a CAR on the underlayer.

[0017] Figure 4B is a cross-sectional view of the substrate after development of the CAR and metal oxide underlayers according to the embodiment.

[0018] Figure 4C is a cross-sectional view of the substrate after the pattern has been transferred into the substrate according to an embodiment.

[0019] Figure 5 is a process flow diagram of a process for using a metal oxide underlayer and a CAR patterned substrate according to an embodiment.

[0020] Figure 6 is a schematic diagram of a clustering tool according to an embodiment, which can be used to process a substrate having a metal oxide underlayer and CAR.

[0021] Figure 7 illustrates a block diagram of an exemplary computer system according to an embodiment of this disclosure. Implementation

[0022] This document describes a chemically amplified resist (CAR) disposed on a metal oxide (i.e., metal oxide) substrate for improving pattern transfer. In the following description, numerous specific details, such as the thermal vapor phase process and material scheme for developing the photoresist, are set forth to provide a thorough understanding of embodiments of this disclosure. It will be apparent to those skilled in the art that embodiments of this disclosure can be practiced without these specific details. In other instances, well-known practices (such as integrated circuit fabrication) have not been described in detail to avoid unnecessarily obscuring embodiments of this disclosure. Furthermore, it should be understood that the various embodiments shown in the figures are illustrative and not necessarily drawn to scale.

[0023] To provide context, the photoresist systems used in extreme ultraviolet (EUV) lithography are inefficient. That is, existing photoresist material systems for EUV lithography require high doses to provide the solubility switching necessary to allow the photoresist material to develop. Chemically amplified resists (CARs) comprise chemicals sensitive to EUV radiation.

[0024] Figure 1 illustrates an example of a structure 100 with a standard CAR system. As shown, CAR 120 can be deposited on the surface of substrate 101. Substrate 101 can be any type of layer (or layers) to be patterned by an etching process. For example, substrate 101 may include a semiconductor material (e.g., silicon), oxide, nitride, metal, or the like. In embodiments, substrate 101 may also include a hard mask material (e.g., a carbon-containing hard mask) disposed over the layer to be patterned. Typically, CAR 120 is coated by a spin coating process. That is, a solvent containing CAR 120 is applied to substrate 101, and substrate 101 is rotated at a high rotational speed (RPM) to distribute a thin layer of CAR 120 on the surface of substrate 101. The solvent and the like can then be removed (or partially removed) using a baking process.

[0025] The chemical amplification concept of CAR (Carbon Activated Resistant) uses photochemically generated acids as catalysts. These catalysts induce a series of chemical transformations within the resist film, providing a gain mechanism to completely convert the exposed areas of the photoresist. The converted areas of CAR then exhibit etch selectivity relative to the unexposed areas. Thus, a development process can be used to remove the exposed areas while preserving the unexposed areas, or vice versa.

[0026] Traditionally, resist architectures may include thick resist materials to provide the necessary etch resistance for pattern transfer to the underlying substrate. However, when dense patterning is required (e.g., fine-pitch structures), thicker resist layers can suffer from pattern collapse. Additionally, thicker resist layers require larger doses of EUV radiation to induce solubility switching across the entire thickness of the resist. These issues can lead to increased LWR and ultimately poor pattern transfer performance.

[0027] In other cases, due to increased sensitivity to EUV radiation, organic-inorganic hybrid materials (e.g., metal oxometallic material systems) have been proposed as material systems for EUV lithography. Such material systems typically comprise metals (e.g., Sn, Hf, Zr, etc.), oxygen, and carbon. For example, the metal element can be bonded to butyl, hydroxy, phenyl, or the like. In metal oxometallic photoresist systems, exposure to EUV radiation leads to cross-linking and carbon removal. The difference in carbon percentage between exposed and unexposed areas is used for solubility switching during development. Specifically, unexposed areas with higher carbon content are preferentially etched in negative-tone development using the developer solution. However, it should be understood that positive-tone development can also be used in some embodiments.

[0028] Therefore, the embodiments disclosed herein may utilize a combination of CAR material and a metal oxide underlayer to take advantage of the benefits of each type of resist system. The combination of a thin CAR and a metal oxide underlayer provides improved LWR and overall pattern transfer improvement. In the embodiments, the metal oxide underlayer provides improved resistance to etching chemicals, thus setting the LWR for patterning. Additionally, the presence of the metal oxide underlayer can contribute to a reduction in resist system dosage and provide improved adhesion properties.

[0029] Previously, the combination of CAR and metal oxide systems had not been explored because solvents used for CAR deposition typically dissolve metal oxide films. However, resistance to solvents can be provided through post-deposition treatment of the metal oxide layer. For example, treatments may include thermal treatment, ultraviolet (UV) radiation treatment, or chemical treatment. These treatments can alter the crosslinking properties of the metal oxide layer, making its surface more resistant to CAR solvents.

[0030] Furthermore, the deposition parameters of the metal oxide film can be modified to improve resistance. This is because metal oxide films can be deposited using dry deposition processes (e.g., atomic layer deposition (ALD), chemical vapor deposition (CVD), physical vapor deposition (PVD), etc.), which allow the properties of the resist to be tuned through the resist thickness. In an additional embodiment, the combination of the metal oxide system and the CAR system can also improve adhesion to the underlying substrate. For example, the metal oxide material can have organic ligands that readily adhere to CAR-type materials with -CH3 ends. Therefore, the adhesion challenges of existing CAR systems are alleviated.

[0031] As used herein, references to metal oxide substrates and CAR photoresist are provided as examples of suitable materials. However, it should be understood that any material sensitive to EUV radiation can be used as the substrate. Similarly, any EUV-sensitive material can be used as the photoresist over the substrate. That is, in some embodiments, the photoresist is not necessarily CAR. In certain embodiments, the substrate is a metal oxide substrate, and the overlying photoresist is an EUV-sensitive photoresist material. Both the substrate and the photoresist can be developed using a dry development process similar to the embodiments described herein.

[0032] Referring now to Figure 2, a cross-sectional view of a structure 200 having a hybrid resist system is shown according to one embodiment. In this embodiment, structure 200 may include a substrate 201. The substrate 201 may be any type of layer (or layers) to be patterned by an etching process. For example, the substrate 201 may include a semiconductor material (e.g., silicon), oxide, nitride, metal, or the like. In this embodiment, the substrate 201 may also include a hard masking material (e.g., a carbon-containing hard mask) provided over the layer to be patterned.

[0033] In an embodiment, a first photoresist layer 210 may be provided on the substrate 201, and a second photoresist layer 220 may be provided on the first photoresist layer 210. The first resist layer 210 may be a different type of resist than the second resist layer 220. For example, and as used throughout the remainder of this disclosure, the first resist layer 210 may be a metal oxide resist 210, and the second resist layer 220 may be CAR 220. In an embodiment, the thickness of the metal oxide resist 210 may be greater than the thickness of the CAR 220. However, in other embodiments, the metal oxide resist 210 and the CAR 220 may have similar thicknesses, or the CAR 220 may be thicker than the metal oxide resist 210. More generally, the total thickness of the CAR 220 and the metal oxide resist 210 may be thinner than the required thickness of the CAR 220 without the metal oxide resist 210 substrate.

[0034] In embodiments, the metal oxide resist 210 can be coated using any suitable deposition process. In one embodiment, the metal oxide resist 210 can be coated using a spin-coating process. In another embodiment, the metal oxide resist 210 can be coated using a dry deposition process. For example, ALD, CVD, or PVD processes can be used to deposit the metal oxide resist 210. Dry deposition processes allow for enhanced tuning of the properties of the metal oxide resist 210. Variation of various deposition parameters (e.g., temperature, gas flow rate, pressure, etc.) can be used to provide the metal oxide resist 210 with non-uniform properties within its thickness. For example, the bottom of the metal oxide resist 210 can be tuned to achieve improved adhesion strength, and the upper region of the metal oxide resist 210 can be tuned to achieve improved dosage, improved adhesion properties to CAR 220, or improved etch resistance. Additionally, the metal oxide resist 210 can be treated after deposition. For example, heat treatment, UV treatment, or chemical treatment can be used to improve the performance of the hybrid inhibitor system shown in structure 200.

[0035] In embodiments, the metal oxide inhibitor 210 may have any suitable formulation. In one embodiment, the metal component may include tin. However, other metal elements may be used instead of tin, or in combination with tin. The organic ligands used may also be any suitable ligands, such as those described in more detail above. In embodiments, the composition of the metal oxide inhibitor 210 may also be non-uniform within the thickness of the metal oxide inhibitor 210. These embodiments may be achieved by using a dry deposition process.

[0036] After depositing the metal oxide inhibitor 210, CAR 220 can be coated. In this embodiment, CAR 220 can be coated using a typical spin-coating process. As described above, the treatment of the metal oxide inhibitor 210 protects it from the negative effects of the solvent used to deposit CAR 220. That is, CAR 220 can be coated as is (i.e., without any formulation changes) while remaining compatible with the metal oxide inhibitor 210.

[0037] Referring now to Figures 3A through 3E, a series of cross-sectional views depicting the process and structure 300 for patterning a substrate are shown. In an embodiment, the process shown in Figures 3A through 3E may employ a dry development process for the metal oxide layer 310.

[0038] Referring now to Figure 3A, a cross-sectional view of a structure 300 having a substrate 301 and a metal oxide resist 310 according to an embodiment is shown. In the embodiment, the substrate 301 may be any suitable substrate to be patterned by the hybrid resist system. Although shown as a single layer, it should be understood that the substrate 301 may comprise multiple layers, one or more of which may be hard masking layers.

[0039] In one embodiment, the metal oxide resist 310 may be coated onto the surface of the substrate 301. In one embodiment, the metal oxide resist 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 oxide resist 310 onto the substrate 301. The dry deposition process provides greater flexibility in the design of the metal oxide resist 310. For example, deposition parameters (such as temperature, pressure, gas flow rate, etc.) may be modulated to tune the metal oxide resist 310 via its thickness. Additionally, the dry deposition process may be used to modulate the composition via the thickness of the metal oxide resist 310. For example, different metal atoms may be provided at different thicknesses. In one embodiment, the metal oxide resist 310 may include tin or any other suitable metal center. The ligands may also be modulated via the thickness of the metal oxide resist 310.

[0040] In an embodiment, the metal oxide inhibitor 310 may be treated after deposition on the substrate 301. This treatment (or multiple treatments) may be used to enhance compatibility with the subsequently deposited CAR. For example, the treatment may vary the crosslinking percentage to resist dissolution by the solvent used to deposit the CAR. In one embodiment, a heat treatment is applied to the metal oxide inhibitor 310. The heat treatment may include exposing the metal oxide inhibitor 310 to a high temperature for a given duration. For example, a temperature between 50°C and 250°C may be used, and the duration may be between one second and one hour or longer. In another embodiment, the treatment may include a UV treatment. The UV treatment may be carried out in 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 a chemical treatment. A chemical treatment may be used to change the polarity of the surface. An example of a suitable chemical treatment is the application of hexamethyldisilane (HMDS).

[0041] Referring now to Figure 3B, a cross-sectional view of structure 300 after coating with CAR 320 is shown according to an embodiment. In this embodiment, CAR 320 can be coated by spin coating. However, due to the treatment of metal oxide inhibitor 310, the solvent used for spin coating does not negatively affect the metal oxide inhibitor 310. This allows the use of existing CAR 320 without the need for reconstruction.

[0042] Referring now to Figure 3C, a cross-sectional view of structure 300 after CAR 320 has been exposed and developed, according to an embodiment, is shown. In this embodiment, CAR 320 may be exposed to EUV radiation. EUV radiation causes a solubility switch in CAR 320, which may then be developed to form a patterned CAR 321. For example, an opening 322 may be provided through the thickness of the patterned CAR 321. Although not developed at this time, the underlying metal oxide resist 310 may also be exposed to the exposure process used to pattern the patterned CAR 321. That is, a latent image of the pattern may be provided in the metal oxide resist 310. CAR 321 may be developed by wet development chemicals (e.g., wet etching) or dry etching.

[0043] Referring now to Figure 3D, a cross-sectional view of structure 300 after patterning of metal oxide resist 310 is shown according to an embodiment. In the specific embodiment shown in Figure 3D, metal oxide resist 310 can be developed by a dry etching process. For example, an etchant such as, but not limited to, HCl, HBr, HI, and the like can be used in a dry etching environment to form the patterned metal oxide resist 311. The etchant used to develop the metal oxide resist 310 may have little effect (if any) on the patterned CAR 321. Alternatively, the existing pattern of the patterned CAR 321 can assist in the development of the underlying metal oxide resist 310 by acting as an etchant mask. This allows for a lower required dosage of metal oxide resist 310 to enable good pattern transfer. In an embodiment, the dry etching process used to form the patterned metal oxide resist 311 can also be a thermal etching process. For example, the temperature of structure 301 during etching can be between -100°C and 350°C. The thermal process can also be used for post-development baking of patterned CAR 321 overlays.

[0044] Referring now to Figure 3E, a cross-sectional view of structure 300 is shown according to an embodiment after the pattern has been transferred to the underlying substrate 301. As shown, opening 322 can be transferred into substrate 301. The pattern transfer process can use any suitable etching process (e.g., wet or dry etching) that is selective to the substrate 301 relative to the patterned photoresist layers 311 and 321. In an embodiment, the patterned metal oxide resist 311 may have higher resistance to etching chemicals than the patterned CAR 321. However, since the patterned metal oxide resist 311 is retained, LWR and other pattern transfer properties may be superior to embodiments with only a single thin CAR.

[0045] Referring now to Figures 4A to 4C, a structure 400 having an alternative mixed resist and a patterning process is shown according to an embodiment.

[0046] Referring now to Figure 4A, a cross-sectional view of structure 400 is shown according to an embodiment, the structure having a substrate 401 and a metal oxide resist 410 on the substrate 401. In an embodiment, CAR 420 may be coated on the metal oxide resist 410. In an embodiment, structure 400 may be similar to structure 300 shown in Figure 3A. That is, the metal oxide resist 410 may be deposited by a dry deposition process to provide the ability to tune the enhanced metal oxide resist 410. The metal oxide resist 410 may also be treated (e.g., by heat treatment, UV treatment, and / or chemical treatment). Thereafter, CAR 420 is coated.

[0047] In embodiments, CAR 420 may comprise any suitable CAR material. CAR 420 may be coated by a spin coating process. Since the metal oxide inhibitor 410 has been treated, the solvent used to apply CAR 420 will not negatively affect the performance or structure of the underlying metal oxide inhibitor 410. In embodiments, CAR 420 may have a thickness less than that of the metal oxide inhibitor 410. However, in some embodiments, a thicker CAR 420 may also be used. More generally, the combined thickness of CAR 420 and metal oxide inhibitor 410 may be less than the thickness of CAR 420 without the metal oxide inhibitor 410 underlayer.

[0048] Referring now to Figure 4B, which is a cross-sectional view of structure 400 formed in pattern 422 to CAR 420 and metal oxide resist 410 to form patterned CAR 421 and patterned metal oxide resist 411. In contrast to the embodiments described above with respect to Figures 3A to 3E, the development process can be performed by a single developing solution. For example, EUV exposure can be performed on structure 400, followed by a single developing process that removes portions of CAR 420 and the underlying metal oxide resist 410. In embodiments, the developer can be a wet etching chemical or a dry etching chemical.

[0049] Referring now to Figure 4C, a cross-sectional view of structure 400 is shown according to an embodiment after the pattern has been transferred to the underlying substrate 401. As shown, the opening of pattern 422 can be transferred into substrate 401. The pattern transfer process can use any suitable etching process (e.g., wet or dry etching) that is selective to substrate 401 relative to the patterned resist layers 411 and 421. In an embodiment, the patterned metal oxide resist 411 may have higher resistance to etching chemicals than the patterned CAR 421. However, since the patterned metal oxide resist 411 is retained, LWR and other pattern transfer properties may be superior to embodiments with only a single thin CAR.

[0050] Referring now to Figure 5, a process flow diagram depicting a process 550 of stacking patterned substrates using mixed resists is shown according to an embodiment. In this embodiment, process 550 may be similar to any of the processing flows depicted above in Figures 3A to 3E or Figures 4A to 4C.

[0051] In an embodiment, process 550 may begin by depositing a metal oxide resist layer on a substrate. The metal oxide resist can be deposited using a wet (e.g., spin coating) or dry (e.g., ALD, CVD, PVD, etc.) deposition process. In the case of a dry deposition process, processing parameters can be modulated to provide a metal oxide resist with a non-uniform thickness composition and / or non-uniform material properties (e.g., adhesion strength, dosage, etc.). In an embodiment, the substrate can be any material to be patterned by stacking mixed resists, and may include a hard mask layer. While the metal oxide resist layer has been described in detail with respect to process 550, it should be understood that any EUV-sensitive material can be used as the underlayer in process 550.

[0052] In an embodiment, process 550 may proceed to operation 552, which includes treating the metal oxide inhibitor. In an embodiment, the treatment may be performed after the deposition of the metal oxide inhibitor. This treatment may include one or more of thermal treatment, UV treatment, or chemical treatment. Details of these treatments may be similar to those described in more detail above. In an embodiment, the treatment process may modify the crosslinking of the metal oxide inhibitor to provide enhanced protection against the solvent effects of the subsequently deposited CAR. In an embodiment, the treatment may also modify surface chemistry, polarity, and the like. For example, surface treatment may improve adhesion to the subsequently deposited CAR.

[0053] In one embodiment, process 550 can proceed to operation 553, which includes coating the CAR over the metal oxide resist. In another embodiment, the CAR can be coated by spin coating or a similar process. In some embodiments, the thickness of the CAR is thinner than the thickness of the metal oxide resist. However, in other embodiments, the metal oxide resist can be thinner, thicker, or the same thickness as the CAR. More generally, the combined thickness of the CAR and the metal oxide resist can be thinner than when only the CAR is used.

[0054] While CAR is provided as one example of a photoresist layer in process 550, the embodiments are not limited to these material systems. More generally, operation 553 can be used to deposit any EUV-sensitive resist material on top of a metal oxide resist. In some embodiments, the photoresist layer may be another metal oxide material or any other EUV-sensitive material.

[0055] In one embodiment, process 550 can proceed to operation 554, which includes exposing the CAR to EUV radiation. In this embodiment, EUV radiation can provide a latent image in the CAR. For example, regions of the CAR exposed to EUV radiation undergo a solubility switch. In this embodiment, the exposure of the CAR can also result in the exposure of the underlying metal oxide inhibitor. That is, a latent image arising from a solubility switch can also be generated in the metal oxide inhibitor.

[0056] In one embodiment, process 550 can continue to operation 555, which includes developing the CAR to form a pattern in the CAR layer. In one embodiment, development can be performed using wet etching chemicals. In some embodiments, the developer solution develops only the CAR, leaving the metal oxide resist unchanged. The CAR can also be developed using a dry development process, such as thermal dry development.

[0057] In one embodiment, process 550 may continue to operation 556, which includes developing the metal oxide resist to form a pattern in the metal oxide resist. In some embodiments, the development of the metal oxide resist may be a dry development process, such as thermal development. In other embodiments, the developing solution used for developing CAR may also be used to develop the metal oxide resist.

[0058] In one embodiment, process 550 may continue to operation 557, which includes transferring a pattern to the substrate. The pattern of the resist layer can be transferred to the substrate using an etching process (such as a wet etching process or a dry etching process).

[0059] In the embodiments described in more detail above, the tools used to perform the various processing operations have been omitted. More generally, it should be understood that individual processing tools can be used to perform each of the various processing operations. However, in other embodiments, two or more of the individual processing operations may be implemented in a single cluster tool. An example of such a cluster tool is shown in Figure 6.

[0060] Referring now to Figure 6, a plan view of a clustering tool 600 according to an embodiment is shown. In this embodiment, the clustering tool 600 may include a device front-end module (EFEM) 621. The EFEM 621 may receive a front-open wafer transfer cassette (FOUP), a box, or the like as an entry point for a substrate into the clustering tool 600. The substrate processed in the clustering tool 600 may include a wafer (e.g., a silicon wafer or other semiconductor wafer) having any standard form factor (e.g., 200 mm, 300 mm, 450 mm, etc.). In this embodiment, the EFEM 621 may be coupled to the remainder of the clustering tool 600 via a loading gate 622. The loading gate 622 separates the atmospheric conditions in the EFEM from the vacuum conditions in the remainder of the clustering tool 600. However, in some embodiments, the EFEM may also be maintained at sub-atmospheric pressure (e.g., a pressure higher than the pressure on the other side of the loading gate 622, but lower than atmospheric pressure).

[0061] In one embodiment, the metrology tool 625 may be positioned after the loading gate 622. The metrology tool 625 may be a scattering measurement tool or any other metrology tool used for post-development inspection (ADI) or post-etching inspection (AEI) applications. In another embodiment, the metrology tool 625 may be communicatively coupled to a transfer chamber 627. The transfer chamber 627 may include a robotic arm, rails, or any suitable architecture for transporting substrates between the metrology tool 625 and the remainder of the cluster tool 600.

[0062] In embodiments, one or more developing chambers 610 and one or more etching chambers 612 may be coupled to transfer chamber 627. For example, six developing chambers 610 and four etching chambers 612 are provided in cluster tool 600. One or more deposition chambers 615 may also be provided in cluster tool 600. Chambers 610, 612, and 615 may be located on both sides of transfer chamber 627 to optimize space saving. In embodiments, developing chamber 610 may be a dry developing chamber. A plasma source may be used in conjunction with developing chamber 610 to develop the resist layer without any wet chemicals. Additionally, etching chamber 612 may be a dry etching chamber 612, which uses plasma to etch the substrate through the resist layer. Deposition chamber 615 may be a dry deposition chamber for depositing photoresist layers (e.g., ALD, CVD, etc.). One or more deposition chambers 615 may also include spin-coating chambers.

[0063] In one embodiment, the substrate enters the EFEM, passes through a loading gate 622 and a metering tool 625, and is conveyed to one of the deposition chambers 615. In one or more of the deposition chambers 615, a mixed resist system comprising a metal oxide resist and CAR is applied. In another embodiment, the mixed resist and the substrate can be conveyed to an exposure tool (which may be different from the clustering tool 600). After development, the substrate can be conveyed to the metering tool 625 for ADI. After ADI, the substrate can be conveyed via a transfer chamber 627 to one of the etching chambers 612. There, the substrate can be etched over the developed resist layer. The substrate can then be transferred back to the metering tool 625 for AEI. Thus, resist development, ADI, substrate etching, and AEI operations can occur within a single clustering tool 600 without leaving the vacuum environment.

[0064] Figure 7 illustrates a schematic representation of a machine in an exemplary form of a computer system 700, within which a set of instructions is executable to cause the machine to perform any or more of the methods described herein. In alternative embodiments, the machine may be connected (e.g., networked) to other machines in a local area network (LAN), intranet, extranet, or internet. The machine may operate as a server or client machine in a client-server network environment, or as a peer machine in a peer (or distributed) network environment. The machine may be a personal computer (PC), tablet PC, set-top box (STB), personal digital assistant (PDA), cellular phone, web facility, server, network router, switch, or bridge, or any machine capable of executing a set of instructions (sequentially or otherwise) specifying the actions to be performed by another machine. Furthermore, although only a single machine is depicted, the term "machine" should also be considered as any collection of machines (e.g., computers) that individually or jointly execute a set (or more) of instructions to perform any one or more of the methods described herein.

[0065] 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) such as synchronous DRAM (SDRAM) or Rambus DRAM (RDRAM), static memory 706 (e.g., flash memory, static random access memory (SRAM), MRAM, etc.), and secondary memory 718 (e.g., data storage device), which communicate with each other via bus 730.

[0066] Processor 702 represents one or more general-purpose processing devices, such as microprocessors, central processing units, or the like. More specifically, processor 702 may be a Complex Instruction Set Computing (CISC) microprocessor, a Reduced Instruction Set Computing (RISC) microprocessor, a Very Long Instruction Word (VLIW) microprocessor, a processor implementing other instruction sets, or a processor implementing combinations of instruction sets. Processor 702 may also be one or more special-purpose processing devices, such as application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), digital signal processors (DSPs), network processors, or the like. Processor 702 is configured to execute processing logic 726 for performing the operations described herein.

[0067] 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)), a digit input device 712 (e.g., a keyboard), a cursor control device 714 (e.g., a mouse), and a signal generation device 716 (e.g., a speaker).

[0068] Secondary memory 718 may include machine-accessible storage medium 732 (or more specifically, computer-readable storage medium) storing one or more sets of instructions (e.g., software 722) that embody any or more of the methods or functions described herein. During execution of software 722 by computer system 700, software 722 may also reside wholly or at least partially in main memory 704 and / or processor 702, which also constitute machine-readable storage media. Software 722 may further be transmitted or received on network 760 via network interface device 708.

[0069] Although machine-accessible storage medium 732 is shown as a single medium in the exemplary embodiments, the term "machine-readable storage medium" should be considered to include a single medium or multiple media (e.g., a centralized or distributed database, and / or associated cache and server) that store one or more sets of instructions. The term "machine-readable storage medium" should also be considered to include any medium capable of storing or encoding a set of instructions for machine execution and causing the machine to perform any one or more of the methods of this disclosure. Therefore, the term "machine-readable storage medium" should be considered to include, but is not limited to, solid-state memory, as well as optical and magnetic media.

[0070] According to embodiments of this disclosure, a machine can access a storage medium having instructions stored thereon, which cause a data processing system to execute a method for forming a mixed resist system having a metal oxide underlayer and CAR, exposing the mixed resist system, developing the mixed resist system, and etching the underlayer substrate. This process can be implemented at least in part using clustered tools. Clustered tools may include metering tools, a developing chamber, a deposition chamber, and an etching chamber. In embodiments, the method disclosed herein allows for improved etching performance compared to conventional methods.

[0071] Therefore, a method for processing a substrate using a hybrid resist system having a metal oxide underlayer and CAR is described. In an embodiment, the substrate having the hybrid resist system can be processed in a cluster of tools having a metering tool, a dry developing chamber, a deposition chamber, and an etching chamber.

[0072] 100: Structure 101:Substrate 120:CAR 200: Structure 201:Substrate 210: Metal oxide inhibitor 220:CAR 300: Structure 301:Substrate 310: Metal oxide inhibitor 311: Patterned metal oxide inhibitor 320:CAR 321: Patterned CAR 322: Opening 400: Structure 401:Substrate 410: Metal oxide inhibitor 411: Patterned metal oxide inhibitor 420:CAR 421: Patterned CAR 422: Pattern 550: Process 551: Operation 552: Operation 553: Operation 554: Operation 555: Operation 556: Operation 557: Operation 600: Cluster Tools 610: Development Chamber 612: Etching Chamber 615: Deposition Chamber 621: Equipment front-end module 622: Loading gate 625: Measuring Tools 627: Transfer Chamber 700: Computer System 702: Processor 704: Main Memory 706: Static Memory 708: Network Interface Device 710: Video display unit 712: Digital Input Device 714: Vernier control device 716: Signal generating device 718: Secondary Memory 722: Software 726: Processing Logic 730: Busbar 732: Machine-accessible storage media 760: Internet

[0073] Domestic storage information (please note in order of storage institution, date, and number) none Overseas storage information (please note in the order of storage country, institution, date, and number) none

Claims

1. A method for patterning a substrate, comprising: A metal-oxo substrate is deposited on a substrate; an extreme ultraviolet (EUV) sensitive resist is coated on the metal-oxo substrate, wherein the EUV sensitive resist is a chemical amplification resist (CAR); the substrate is exposed; the EUV sensitive resist is developed to form a pattern in the EUV sensitive resist; the pattern is transferred to the metal-oxo substrate; and the pattern is transferred to the substrate.

2. The method as described in claim 1, further comprising: Before coating the EUV-sensitive resist, the metal oxide underlayer is treated by a processing step.

3. The method as described in claim 2, wherein the processing procedure includes a heat treatment.

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

5. The method as described in claim 2, wherein the processing procedure includes an ultraviolet (UV) radiation treatment.

6. The method as described in claim 5, wherein the UV radiation treatment is performed in an atmosphere comprising one or more of nitrogen, oxygen and argon.

7. The method as described in claim 2, wherein the process includes a chemical treatment.

8. The method as described in claim 7, wherein the chemical treatment comprises hexamethyldisilane (HMDS).

9. The method as described in claim 1, wherein the pattern is transferred to the metal oxide underlayer by a dry development process.

10. The method as claimed in claim 1, wherein developing the EUV sensitive resist to form a pattern in the EUV sensitive resist and transferring the pattern to the metal oxide underlayer is accomplished by a single wet development process or dry development process.

11. The method as described in claim 1, wherein the combined thickness of the EUV sensitive resist and the metal oxide substrate is less than the required thickness of a single EUV sensitive resist.

12. The method as described in claim 1, wherein two or more of the processes are implemented in a single cluster tool.

13. The method as described in claim 1, wherein the substrate is a hard mask layer.

14. A photoresist stack, comprising: A metal oxide substrate, wherein the metal oxide substrate is sensitive to extreme ultraviolet (EUV) radiation; And an EUV sensitive resist on the metal oxide substrate, wherein the EUV sensitive resist is a chemical amplification resist (CAR).

15. The photoresist stack as described in claim 14, wherein the metal oxide underlayer comprises a metal oxide material.

16. The photoresist stack as described in claim 15, wherein the metal oxide material comprises tin.

17. A method for patterning a substrate, comprising: A metal oxide underlayer is provided on the substrate, wherein the metal oxide underlayer is sensitive to extreme ultraviolet (EUV) radiation; A photoresist is disposed on the metal oxide substrate, wherein the photoresist is sensitive to EUV radiation, wherein the photoresist is a chemical amplification resist (CAR), and wherein the photoresist is coated by a spin coating process; the substrate is exposed to EUV radiation and the photoresist is developed to form a pattern in the photoresist; the pattern is transferred to the metal oxide substrate; and the pattern is transferred to the substrate.

18. The method as described in claim 17, wherein the metal oxide underlayer is treated prior to coating the photoresist, wherein the treatment includes a heat treatment, an ultraviolet (UV) radiation treatment, or a chemical treatment.

19. The method as described in claim 17, wherein the transfer of the pattern to the metal oxide underlayer is accomplished by a dry development process.

20. The method as described in claim 17, wherein two or more of the processes are implemented in a single cluster tool.

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