Method for forming patterns on a substrate
By using the O2/H2 environment to perform EUV radiation on the film surface in the EUV lithography system, selectively forming patterned exposed and unexposed areas, the problem of limited resolution in the manufacturing of small-sized semiconductor devices is solved, and higher resolution and fewer manufacturing steps are achieved.
Patent Information
- Application Number
- CN202411348256.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2023-09-29
- Filing Date
- 2024-09-26
- Publication Date
- 2025-04-01
AI Technical Summary
The prior lithography technology has limited resolution and is unable to use a solid resist in a single exposure to define such small features when manufacturing semiconductor devices with a critical size below 20 nm, resulting in the need of multiple lithography steps.
By EUV radiation on the film surface using an O2/H2 environment in an extreme ultraviolet (EUV) lithography system, the patterned exposed and unexposed areas are selectively formed, and the hard mask is selectively deposited in the exposed areas.
The lithography steps are simplified, resolution is improved, smaller features can be formed in a single exposure, and the number of steps in the manufacturing process is reduced.
Smart Images
Figure CN119739006A_ABST
Abstract
Description
Technical Field
[0001] The present disclosure relates to a method for forming a pattern on a substrate, and more particularly, to a method for selectively patterning exposed portions by subjecting portions of a film surface to EUV radiation using an O2 / H2 environment. Background Art
[0002] Devices in integrated circuits (ICs) are shrinking rapidly. The manufacture of such devices requires multiple steps, and one of the main bottlenecks in manufacturing is the photolithography step.
[0003] Extreme ultraviolet (EUV) lithography is becoming one of the mainstream methods for manufacturing semiconductor devices with critical dimensions below 20nm, which helps solve the resolution problem of lithography tools.
[0004] However, multiple lithography steps are still required to achieve smaller dimensions. This is primarily due to the limited resolution of lithography tools and secondly because such small features cannot be defined in a single exposure using strong resists.
[0005] The present disclosure proposes a solution to the second problem by using EUV radiation to expose the surface of a thin film (<5 nm thick).
[0006] After surface modification, a hard mask can be selectively deposited on the exposed / non-exposed surfaces of the film. Summary of the invention
[0007] This summary is provided to introduce some concepts in a simplified form. These concepts are further described in detail in the detailed description of the example embodiments disclosed below. This summary is not intended to identify the key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.
[0008] According to one embodiment, a method for forming a pattern on a substrate may be provided, the method comprising: providing an extreme ultraviolet (EUV) lithography system having an exposure chamber, providing a substrate to the exposure chamber, the substrate comprising a patternable layer, the patternable layer comprising a photosensitive surface termination, and exposing the substrate to EUV radiation while exposing the patternable layer to a reactive gas, thereby forming a pattern on the patternable layer comprising exposed areas and unexposed areas, the unexposed areas comprising the photosensitive surface terminations, and the exposed areas comprising altered surface terminations.
[0009] In at least one aspect, the patternable layer comprises a silicon-containing anti-reflective coating (SiARC) film.
[0010] In at least one aspect, the SiARC film is deposited using plasma enhanced atomic layer deposition (PEALD) or thermal atomic layer deposition (ALD).
[0011] In at least one aspect, the SiARC film is deposited at a temperature between 50°C and 200°C.
[0012] In at least one aspect, the reactive gas comprises O2 / H2.
[0013] In at least one aspect, the photosensitive surface termination comprises a methyl group (CH3).
[0014] In at least one aspect, the altered surface termination comprises hydroxide (OH).
[0015] In at least one aspect, the altered surface termination is hydrophilic.
[0016] In at least one aspect, the partial pressures of O2 and H2 are respectively 1×10 -6 and 1×10 -4 Between millibars.
[0017] In at least one aspect, the total pressure of O2 and H2 is 1×10 -6 and 1×10 -4 Between millibars.
[0018] In at least one aspect, the photosensitive surface termination is hydrophobic. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] It should be understood that the elements in the drawings are shown for simplicity and clarity and are not necessarily drawn to scale. For example, the size of some elements in the drawings may be exaggerated relative to other elements to help improve the understanding of the illustrated embodiments of the present disclosure.
[0020] Figure 1 An EUV lithography system with a SiARC film on a substrate according to an embodiment of the present disclosure is shown.
[0021] Figure 2 EUV radiation on a SiARC film with a reactant gas environment according to an embodiment of the disclosure is shown.
[0022] Figure 3 An example using the present disclosure is shown where, after EUV exposure, a hard mask is selectively deposited on the EUV exposed areas.
[0023] Figure 4 A flow chart showing the sequence of the present disclosure. DETAILED DESCRIPTION
[0024] Although certain embodiments and examples are disclosed below, those skilled in the art will appreciate that the invention extends beyond the specifically disclosed embodiments and / or uses of the invention and their obvious modifications and equivalents. Therefore, it is intended that the scope of the disclosed invention should not be limited by the specifically disclosed embodiments described below.
[0025] As used herein, the term "substrate" may refer to any one or more underlying materials, including any one or more underlying materials that may be modified or on which a device, circuit, or film may be formed. A "substrate" may be continuous or non-continuous; rigid or flexible; solid or porous; and combinations thereof. A substrate may be in any form, such as a powder, a plate, or a workpiece. A plate-like substrate may include wafers of various shapes and sizes. A substrate may be made of semiconductor materials, including, for example, silicon, silicon germanium, silicon oxide, gallium arsenide, gallium nitride, and silicon carbide.
[0026] For example, a substrate in powder form can be used in drug manufacturing. The porous substrate can include a polymer. Examples of workpieces can include medical devices (such as stents and syringes), jewelry, tool equipment, components for battery manufacturing (such as anodes, cathodes, or separators), or components of photovoltaic cells, etc.
[0027] The continuous substrate may extend beyond the boundaries of the processing chamber in which the deposition process occurs. In some processes, the continuous substrate may be moved through the processing chamber so that the process continues until the end of the substrate is reached. The continuous substrate may be provided from a continuous substrate feed system to allow the continuous substrate to be manufactured and output in any suitable form.
[0028] Non-limiting examples of continuous substrates may include sheets, nonwoven films, rolls, foils, meshes, flexible materials, bundles of continuous filaments or fibers (eg, ceramic fibers or polymer fibers).The continuous substrate may also include a carrier or sheet on which a discontinuous substrate is mounted.
[0029] The illustrations presented herein are not meant to be actual views of any particular material, structure, or device but are merely idealized representations used to describe embodiments of the present disclosure.
[0030] The specific embodiments shown and described are illustrations of the present invention and its best mode and are not intended to limit the scope of these aspects and embodiments in any way. In fact, for the sake of brevity, the traditional manufacturing, connection, preparation and other functional aspects of the system may not be described in detail. In addition, the connecting lines shown in the various figures are intended to represent exemplary functional relationships and / or physical connections between various elements. Many alternative or additional functional relationships or physical connections may exist in actual systems, and / or may not exist in some embodiments.
[0031] It should be understood that the configuration and / or method described herein are exemplary in nature, and these specific embodiments or examples should not be considered restrictive, because many variations are possible. The specific routine or method described herein can represent one or more of any number of processing strategies. Therefore, the various actions shown can be performed in the order shown, in other orders, or omitted in some cases.
[0032] The subject matter of the present disclosure includes all novel and nonobvious combinations and subcombinations of the various processes, systems and configurations, and other features, functions, acts and / or properties disclosed herein, and any and all equivalents thereof.
[0033] Reference Figure 1 , a photopolymer layer 120 is formed on a top surface of a substrate 110 , and the substrate 110 is placed on top of the base 100 .
[0034] The EUV lithography system 150 includes a photosensitive polymer layer 120 , a substrate 110 , and a susceptor 100 therein.
[0035] The EUV lithography system 150 may include an EUV chamber 140 generating EUV light and an exposure chamber 145 exposing the substrate 110 to the generated EUV light.
[0036] The photosensitive polymer layer 120 may include a silicon-containing anti-reflective coating (SiARC) film, and this may be formed on top of the substrate 110 by plasma enhanced atomic layer deposition (PEALD) or thermal atomic layer deposition (thermal ALD).
[0037] The SiARC film can be Figure 1 The silicon oxycarbide (SiOC) film shown terminated with a methyl group (CH3) 121 attached to Si and the SiARC film can be deposited at a temperature between 50°C and 200°C.
[0038] The patterning method disclosed in the present invention is Figure 4 The flowchart shown is disclosed.
[0039] First, an EUV lithography system 150 including an EUV lamp chamber 140 and an exposure (reaction) chamber 145 may be prepared. Figure 4 of 400).
[0040] The EUV chamber 140 may include one or more EUV lamps for generating EUV light and an exposure chamber 145 that may include the substrate 110 .
[0041] Once the EUV lithography system is ready, the substrate 110 may be placed in the exposure chamber 145. The substrate 110 may include a patternable layer 120 ( Figure 4 410 in the above).
[0042] The patternable layer 120 may include a photosensitive surface termination, and the photosensitive surface termination may include a methyl group (CH3) 121. The patternable layer 120 may be a SiARC film.
[0043] The substrate 110 will be inherently hydrophobic due to the methyl groups 121 in the substrate 110. This hydrophobicity of the substrate 110 from the photosensitive surface terminations (methyl groups) 121 of the patternable layer 120 may need to be altered in order to pattern the substrate 110.
[0044] Changes for patterning can come from Figure 2 EUV exposure is shown. Figure 2 In the embodiment, the substrate 210 may be placed on the base 200, and the substrate 210 may include a patternable layer 220 including a photosensitive surface terminal 221. The EUV lamp chamber 140 ( Figure 1 ) can selectively emit EUV radiation toward the substrate 210.
[0045] In substrate 210 , portion 232 may be exposed to EUV radiation, while portion 231 may not be exposed to EUV, and the EUV radiation occurs in an O 2 / H 2 environment ( 420 ).
[0046] Using EUV radiation with an O2 / H2 environment, the photosensitive surface terminations 221 of the patternable layer 220 are replaced by other terminations.
[0047] For example, the photosensitive surface terminal 221, i.e., the methyl group (CH3), can be replaced by a hydroxide (OH), such as Figure 2 This replacement of the surface termination will change the surface of the patternable layer (SiARC film) from hydrophobic to hydrophilic.
[0048] As described above, the present disclosure provides a method of changing the surface of a target layer (patternable layer) from hydrophobic to hydrophilic by using an oxidizing or reducing environment during EUV exposure of the target.
[0049] In order to create a suitable environment for oxidation or reduction, the partial pressure of O2 gas and the partial pressure of H2 gas in the chamber can be respectively 1×10 -6 and 1×10 -4 mbar. In other cases, the total pressure of O2 and H2 gases can be between 1×10 -6 and 1×10 -4 Between millibars.
[0050] The EUV exposed area 232 and the unexposed area 231 may have different surface terminations in the patternable layer 220. Figure 2 In the embodiment, the unexposed area 231 remains hydrophobic, while the exposed area 232 may become hydrophilic.
[0051] Figure 3 It shows that Figure 2A hard mask 321 is shown deposited on a substrate 310 after EUV exposure. The unexposed regions 331 may remain unchanged, but the hard mask 321 may be selectively deposited on the exposed regions 332 using a water-based thermal oxidation process at a low temperature of less than 150°C.
[0052] The above arrangement of the method is only an illustration of the application of the principles of the present invention, and many other embodiments and modifications may be made without departing from the spirit and scope of the present invention as defined by the claims. Therefore, the scope of the present invention should not be determined with reference to the above description, but with reference to the full scope of the appended claims and their equivalents.
Claims
1. A method for forming a pattern on a substrate, the method comprising: Providing an extreme ultraviolet (EUV) lithography system having an exposure chamber; providing a substrate to an exposure chamber, the substrate comprising a patternable layer, the patternable layer comprising a photosensitive surface termination; as well as The substrate is exposed to EUV radiation while the patternable layer is exposed to a reactive gas, thereby forming a pattern on the patternable layer including exposed areas including photosensitive surface terminations and unexposed areas including altered surface terminations.
2. The method according to claim 1, wherein: The patternable layer includes a silicon-containing anti-reflective coating (SiARC) film.
3. The method according to claim 2, wherein: The SiARC film is deposited using plasma enhanced atomic layer deposition (PEALD) or thermal atomic layer deposition (ALD).
4. The method according to claim 3, wherein: The SiARC film is deposited at a temperature between 50°C and 200°C.
5. The method according to claim 1, wherein: The reactive gas includes O2 / H2.
6. The method according to claim 1, wherein: The photosensitive surface terminations contain methyl groups (CH3).
7. The method according to claim 1, wherein: The altered surface termination comprises hydroxide (OH).
8. The method according to claim 1, wherein: The altered surface terminology is hydrophilic.
9. The method according to claim 5, wherein: The partial pressures of O2 and H2 are 1×10 -6 and 1×10 -4 Between millibars.
10. The method according to claim 5, wherein: The total pressure of O2 and H2 is 1×10 -6 and 1×10 -4 Between millibars.
11. The method according to claim 1, wherein: The photosensitive surface terminal is hydrophobic.