Multiple patterning process method

Abstract

The disclosure provides a multi-pattern structure processing method, comprising: providing a substrate, a surface of the substrate is divided into a pattern region and a non-pattern region, and the pattern region is provided with a first pattern structure; preparing a sacrificial layer on the substrate, performing back etching on the sacrificial layer to thin the sacrificial layer, and the surface of the thinned sacrificial layer is lower than the surface of the first pattern structure; sequentially preparing a second hard mask layer and a second photoresist layer on the substrate, exposing the non-pattern region of the second photoresist layer, and removing the second photoresist layer in the non-pattern region after development; etching and stripping the second hard mask layer above the non-pattern region by taking the second photoresist layer as a mask layer, and removing the second photoresist layer; sequentially preparing a third hard mask layer and a third photoresist layer on the substrate and the second hard mask layer, exposing the pattern region of the third photoresist layer, and forming a second pattern structure on the third photoresist layer after development; transferring the second pattern structure to the substrate, stripping the remaining sacrificial layer and the second hard mask layer, and obtaining a multi-pattern structure.

Description

Technical Field

[0001] This disclosure relates to the field of photolithography, and in particular to a method for processing multiple patterned structures. Background Technology

[0002] As manufacturing processes shrink, to prevent the exposed pattern from collapsing during development due to its high aspect ratio, the photoresist thickness must be reduced as the feature size decreases. Simultaneously, a single layer of photoresist cannot meet the etching requirements for high aspect ratio trenches, vias, and other structures on the substrate. Therefore, a multi-layer hard mask structure is required to achieve the processing of high aspect ratio structures. The processing method involves first transferring the photoresist layer pattern to the hard mask layer, and then transferring the hard mask layer pattern to the substrate. Hard masks typically include SiO2, SiN, TiN, etc., grown by chemical vapor deposition (CVD), as well as Si-based hard mask compositions prepared by spin coating and spin-coated carbon hard masks.

[0003] In photolithography processes at 65nm and below, achieving high resolution requires the fabrication of multiple patterned structures. Taking the process of creating vias and trenches in the latter half of semiconductor manufacturing as an example, firstly, the first patterned structure is exposed and etched to fill it. Then, the second patterned structure is exposed and etched again. However, the surface after filling the first patterned structure is usually not flat enough, with depressions above the first patterned area, which affects the etching rate and may even lead to exposure failure. Summary of the Invention

[0004] This disclosure provides a method for processing multiple graphic structures, which solves the technical problems of flattening the graphic structure in the previous processing stage and flattening the boundary between the graphic area and the non-graphic area in the existing processing of multiple graphic structures.

[0005] The first aspect of this disclosure provides a method for fabricating a multiple patterned structure, comprising: providing a substrate, the surface of which is divided into patterned regions and non-patterned regions, the patterned regions having a first patterned structure; preparing a sacrificial layer on the substrate, performing back etching on the sacrificial layer to thin it, the surface of the thinned sacrificial layer being lower than the surface of the first patterned structure; sequentially preparing a second hard mask layer and a second photoresist layer on the substrate with the sacrificial layer, exposing the non-patterned regions of the second photoresist layer, developing and removing the second photoresist layer in the non-patterned regions; using the second photoresist layer above the patterned regions as a masking layer, etching and peeling off the second hard mask layer above the non-patterned regions, removing the second photoresist layer above the patterned regions; sequentially preparing a third hard mask layer and a third photoresist layer on the substrate and the second hard mask layer, exposing the patterned regions of the third photoresist layer, developing and forming a second patterned structure on the third photoresist layer; transferring the second patterned structure to the substrate, peeling off the remaining sacrificial layer and the second hard mask layer, to obtain a multiple patterned structure.

[0006] According to embodiments of this disclosure, preparing a sacrificial layer on a substrate includes: using spin-coated carbon material or spin-coated glass material as raw materials and preparing the sacrificial layer on the substrate using a spin-coating-curing method; or, using amorphous carbon material or silane material as raw materials and preparing the sacrificial layer on the substrate using a chemical vapor deposition method; preparing a second hard mask layer on the substrate with the prepared sacrificial layer includes: using spin-coated carbon material or spin-coated glass material as raw materials and preparing the second hard mask layer on the substrate with the prepared sacrificial layer using a spin-coating-curing method, wherein the carbon content of the spin-coated carbon material used in the second hard mask layer is higher than 90%; wherein the curing method includes high-temperature curing or ultraviolet curing, and the curing temperature is 250°C to 600°C.

[0007] According to embodiments of this disclosure, when the raw material of the sacrificial layer is spin-coated carbon material or spin-coated glass material, the spin-coating thickness of the sacrificial layer is 1.5 to 2 times the feature size of the first pattern structure, the feature size of the first pattern structure is 10 nm to 500 nm, and the aspect ratio is 1 to 50; when the raw material of the sacrificial layer is amorphous carbon material or silane material, the deposition thickness of the sacrificial layer is sufficient to cover the first pattern structure; the spin-coating thickness of the second hard mask layer is 50 nm to 500 nm, and the thickness of the second photoresist layer is 2 to 3 times the thickness of the second hard mask layer.

[0008] According to embodiments of this disclosure, re-etching the sacrificial layer to thin it includes: re-etching the sacrificial layer using dry etching, wet etching, or chemical mechanical polishing; wherein, dry etching includes reactive ion beam etching or inductively coupled ion beam etching, and the etching gas includes O2 or CHF3; the etching solution for wet etching includes a mixture of hydrogen peroxide and sulfuric acid or a diluted hydrofluoric acid solution; the polishing slurry for chemical mechanical polishing includes an acidic polishing slurry or an alkaline polishing slurry, the abrasive particles include cerium oxide or silicon oxide, and the polishing pad includes polyester fiber.

[0009] According to embodiments of this disclosure, exposing the second photoresist layer above the non-patterned area includes: exposing the non-patterned area of ​​the second photoresist layer using laser direct writing lithography, projection exposure, or proximity contact exposure.

[0010] According to an embodiment of this disclosure, etching and stripping the second hard mask layer above the non-patterned area using the second photoresist layer above the patterned area as a mask layer includes: dry etching the second hard mask layer above the non-patterned area, wherein the dry etching includes reactive ion beam etching or inductively coupled ion beam etching, and the etching gas includes O2 or CHF3.

[0011] According to embodiments of this disclosure, the third hard mask layer and the third photoresist layer are sequentially stacked on the substrate and the second hard mask layer, comprising: preparing the third hard mask layer and the third photoresist layer by spin coating; the third hard mask layer comprises a silicon-containing bottom anti-reflection hard mask coating or a spin-coated metal hard mask coating, with a thickness of 10 nm to 100 nm; the third photoresist layer comprises high-resolution photoresist, with a thickness of 30 nm to 100 nm.

[0012] According to an embodiment of this disclosure, the third photoresist layer above the exposed patterned area includes: exposing the patterned area of ​​the third photoresist layer using a proximity contact exposure method.

[0013] According to embodiments of this disclosure, transferring the second patterned structure onto a substrate includes: using a third photoresist layer as a masking layer, etching a third hard mask layer to transfer the second patterned structure on the third photoresist layer onto the third hard mask layer; using the third hard mask layer as a masking layer, etching a second hard mask layer to transfer the second patterned structure on the third hard mask layer onto the second hard mask layer; and using the second hard mask layer as a masking layer, etching a substrate to transfer the second patterned structure on the second hard mask layer onto the substrate.

[0014] According to embodiments of this disclosure, a third hard mask layer is etched using a dry etching method, which includes reactive ion beam etching or inductively coupled ion beam etching, and the etching gas includes CHF3 or Cl2; a second hard mask layer is etched using a dry etching method, which includes reactive ion beam etching or inductively coupled ion beam etching, and the etching gas includes O2 or CHF3; a substrate is etched using a dry etching method, which includes ion beam etching, reactive ion beam etching, or inductively coupled ion beam etching, and the etching gas includes CHF3, SF6, O2, and Cl2.

[0015] According to embodiments of this disclosure, the removal of the remaining sacrificial layer and the second hard mask layer includes: when the raw material of the sacrificial layer is spin-coated carbon material or amorphous carbon material, and the material of the second hard mask layer is spin-coated carbon material, the remaining sacrificial layer and the second hard mask layer on the surface are removed in one step by dry etching or wet etching; when the raw material of the sacrificial layer is spin-coated glass material or silane material, and the material of the second hard mask layer is spin-coated glass material, the remaining sacrificial layer and the second hard mask layer on the surface are also removed in one step by dry etching or wet etching.

[0016] Dry etching includes reactive ion beam etching or inductively coupled ion beam etching, and the etching gas includes O2 or CHF3; wet etching uses a solution of hydrogen peroxide and sulfuric acid or a diluted hydrofluoric acid solution.

[0017] The multi-graphic structure processing method provided according to the embodiments of this disclosure has at least the following beneficial effects:

[0018] The second hard mask layer is prepared by spin coating after thinning the micro-undulations of the sacrificial layer using the back etching method. On the one hand, it can simplify the photolithography process. On the other hand, by utilizing the gap-filling ability and planarization properties of spin-coated carbon materials, the undulations on the first pattern structure can be effectively covered, increasing the planarization of the first pattern structure. In near-contact exposure, the gap between the mask and the substrate is made uniform, thereby improving the exposure uniformity of the second pattern structure.

[0019] By using exposure etching to remove the second hard mask layer in the non-patterned area, the height difference between the patterned and non-patterned areas can be eliminated, reducing the gap between the wafer and the mask in near-contact lithography, thereby improving exposure resolution.

[0020] By using the same material as the sacrificial layer and the second hard mask layer, the remaining sacrificial layer and the second hard mask layer can be removed in one go by etching process or wet etching after the etching transfer is completed, which further simplifies the process and improves the process efficiency. Attached Figure Description

[0021] The above and other objects, features and advantages of this disclosure will become clearer from the following description of embodiments with reference to the accompanying drawings, in which:

[0022] Figure 1 The diagram schematically shows a cross-sectional view of traditional multi-pattern structure processing before the photolithography process.

[0023] Figure 2 A flowchart illustrating a multi-graphic structure processing method according to an embodiment of the present disclosure is shown.

[0024] Figure 3 The diagram schematically illustrates the extent of patterned and non-patterned regions on a substrate according to an embodiment of the present disclosure.

[0025] Figure 4 The diagram illustrates the structure at each stage of the processing of the multi-graphic structure according to the embodiments of this disclosure.

[0026] Figure 5 The following is a schematic diagram of the exposure scanning electron microscope image of the second pattern structure after the processing method of thinning the sacrificial layer and peeling off the second hard mask layer of the non-pattern area in Example 1.

[0027] Figure 6 The exposure scanning electron microscope image of the second patterned structure obtained by the processing method in Comparative Example 1 without stripping the second hard mask layer of the non-patterned region is shown schematically.

[0028] Figure 7 An exposure scanning electron microscope image of the second patterned structure obtained by the processing method without thinning the sacrificial layer in Comparative Example 2 is shown schematically.

[0029] [Attached image labels]

[0030] 1-Substrate, 1-1First patterned structure, 1-2-Second patterned structure, 2-1-Patterned region, 2-2-Non-patterned region, 3-Sacrificial layer, 4-First hard mask layer, 5-First photoresist layer, 6-Second hard mask layer, 7-Third hard mask layer, 8-Third photoresist layer, 9-Second photoresist layer. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of this disclosure clearer, the following detailed description is provided in conjunction with specific embodiments and accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this disclosure. All other embodiments obtained by those skilled in the art based on the embodiments of this disclosure without inventive effort are within the scope of protection of this disclosure.

[0032] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this disclosure. The terms “comprising,” “including,” etc., as used herein indicate the presence of the stated features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.

[0033] In this disclosure, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this disclosure according to the specific circumstances.

[0034] In the description of this disclosure, it should be understood that the terms "longitudinal", "length", "circumferential", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this disclosure and simplifying the description, and do not indicate or imply that the subsystem or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this disclosure.

[0035] Throughout the accompanying drawings, identical elements are represented by the same or similar reference numerals. Conventional structures or constructions have been omitted where they may cause confusion in understanding this disclosure. Furthermore, the shapes, dimensions, and positional relationships of the components in the drawings do not reflect actual size, scale, or actual positional relationships. Additionally, any reference numerals placed between parentheses in the claims should not be construed as limiting the claims.

[0036] Similarly, to simplify this disclosure and aid in understanding one or more of the various aspects of the disclosure, in the above description of exemplary embodiments of the present disclosure, various features of the present disclosure are sometimes grouped together in a single embodiment, figure, or description thereof. The use of terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refers to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the present disclosure. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0037] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this disclosure, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0038] Figure 1 The diagram schematically shows a cross-sectional view of traditional multi-pattern structure processing before the photolithography process.

[0039] like Figure 1 As shown, substrate 1 contains a first patterned structure 1-1, which is filled with a sacrificial layer 3. A first hard mask layer 4 and a first photoresist layer 5 are formed on substrate 1 and sacrificial layer 3. During processing, the surface of the first patterned structure 1-1 on substrate 1 is not flat enough, with depressions above the patterned areas. The thickness of the multilayer hard mask for the second patterned structure prepared on this basis is also uneven. This not only affects the etching rate but also causes the second patterned structure near the first patterned structure to fail to be exposed directly. At the same time, the film layer prepared by deposition or spin coating is "absorbed" in the patterned areas, while the thickness remains unchanged in the non-patterned areas, resulting in obvious "steps" at the boundary between the patterned and non-patterned areas. This is especially true for large-area dense patterns, where the patterned areas are significantly lower than the surrounding non-patterned areas. Furthermore, as the multilayer hard mask and photoresist layers are stacked, the height difference of the "steps" gradually increases. This gap also reduces the exposure resolution, especially in near-contact exposure.

[0040] In view of this, embodiments of the present disclosure provide a method for fabricating a multiple patterned structure, comprising: providing a substrate, the surface of which is divided into patterned regions and non-patterned regions, the patterned regions having a first patterned structure; fabricating a sacrificial layer on the substrate, and performing back etching on the sacrificial layer to thin it, the surface of the thinned sacrificial layer being lower than the surface of the first patterned structure; sequentially fabricating a second hard mask layer and a second photoresist layer on the substrate with the sacrificial layer, exposing the non-patterned regions of the second photoresist layer, and removing the second photoresist layer in the non-patterned regions after development; etching and peeling off the second hard mask layer above the non-patterned regions using the second photoresist layer above the patterned regions as a mask layer, and removing the second photoresist layer above the patterned regions; sequentially fabricating a third hard mask layer and a third photoresist layer on the substrate and the second hard mask layer, exposing the patterned regions of the third photoresist layer, and forming a second patterned structure on the third photoresist layer after development; transferring the second patterned structure to the substrate, and peeling off the remaining sacrificial layer and the second hard mask layer to obtain a multiple patterned structure.

[0041] The method for processing multiple graphic structures provided in this disclosure will be described in detail below with reference to the specific accompanying drawings.

[0042] Figure 2 A flowchart illustrating a multi-graphic structure processing method according to an embodiment of the present disclosure is shown.

[0043] Figure 3 The diagram schematically illustrates the extent of patterned and non-patterned regions on a substrate according to an embodiment of the present disclosure.

[0044] Figure 4 The diagram illustrates the structure at each stage of the processing of the multi-graphic structure according to the embodiments of this disclosure.

[0045] like Figure 2 As shown, the multi-graphic structure processing method may include operations S210 to S260.

[0046] In operation S210, a substrate is provided, the surface of which is divided into patterned areas and non-patterned areas, and the patterned areas are provided with a first patterned structure.

[0047] In some embodiments, substrate 1 may be a silicon substrate, silicon carbide substrate, sapphire substrate, etc., or a dielectric layer substrate, including SiO2, doped SiO2, low-K dielectric, high-K dielectric, etc. The specific type of substrate can be selected according to the actual application scenario, and this disclosure does not impose any restrictions.

[0048] like Figure 3 and Figure 4As shown in (1), for example, the patterned region 2-1 can be a square region, and the other positions on the substrate 1 excluding the patterned region are non-patterned regions 2-2. The first patterned structure 1-1 is located in the patterned region 2-1, and the second patterned structure 1-2 prepared subsequently is also located in the patterned region 2-1. That is, the patterned region covers all the patterned structures but does not cover the non-patterned structures.

[0049] The first pattern structure feature size can be 10nm to 500nm, and the aspect ratio can be 1 to 50, which can be adjusted according to actual needs.

[0050] In operation S220, a sacrificial layer is prepared on the substrate, and the sacrificial layer is etched back to thin it, so that the surface of the thinned sacrificial layer is lower than the surface of the first patterned structure.

[0051] In some embodiments, a sacrificial layer 3 can be prepared on substrate 1 using spin-coated carbon material or spin-coated glass material as raw material and a spin-coating-curing method. In this case, the spin-coating thickness of the sacrificial layer 3 can be 1.5 to 2 times the feature size of the first patterned structure 1-1. In other embodiments, amorphous carbon material or silane material can be used as raw material, and a sacrificial layer 3 can be prepared on substrate 1 using a CVD method. In this case, the deposition thickness of the sacrificial layer 3 is sufficient to cover the first patterned structure 1-1. The curing method can include high-temperature curing or ultraviolet curing, and the curing temperature can be 250°C to 600°C. The prepared structure can be as follows: Figure 4 As shown in (2).

[0052] In some embodiments, the sacrificial layer can be etched back using dry etching, wet etching, or chemical mechanical polishing (CMP). Dry etching can include reactive ion beam etching or inductively coupled ion beam etching, and the etching gas can include O2 or CHF3. The etching solution for wet etching can include a mixture of hydrogen peroxide and sulfuric acid or a diluted hydrofluoric acid solution. The polishing slurry for chemical mechanical polishing includes acidic or alkaline polishing slurries, the abrasive particles can include cerium oxide or silicon oxide, and the polishing pad can include polyester fibers. After thinning, the surface of the sacrificial layer 3 is lower than the surface of the first patterned structure 1-1, and the resulting structure can be as follows: Figure 4 As shown in (3).

[0053] In operation S230, a second hard mask layer and a second photoresist layer are sequentially stacked on a substrate with a sacrificial layer. The non-patterned area of ​​the second photoresist layer is exposed, and the second photoresist layer in the non-patterned area is stripped after development.

[0054] In some embodiments, a second hard mask layer 6 can be prepared on a substrate 1 with a sacrificial layer 3 using spin-coated carbon material or spin-coated glass material as raw materials and a spin-coating-curing method. The carbon content of the spin-coated carbon material used in the second hard mask layer 6 is higher than 90%, the spin-coating thickness of the second hard mask layer 6 is 50 nm to 500 nm, and the thickness of the second photoresist layer 9 is 2 to 3 times the thickness of the second hard mask layer 6, with a thickness of 100 to 1500 nm. The curing method can include high-temperature curing or ultraviolet curing, and the curing temperature can be 250°C to 600°C. The resulting structure can be as follows: Figure 4 As shown in (4).

[0055] In some embodiments, the non-patterned areas of the second photoresist layer 9 can be exposed using laser direct writing lithography, projection exposure, or proximity contact exposure. The developer can be a 300-series solution. After development, the non-patterned areas of the second photoresist layer are removed, and the resulting structure can be as follows. Figure 4 As shown in (5).

[0056] In operation S240, the second hard mask layer above the non-pattern area is etched and stripped using the second photoresist layer above the patterned area as a mask layer, and the second photoresist layer above the patterned area is removed.

[0057] In some embodiments, the second hard mask layer 6 above the non-patterned region 2-2 can be dry-etched. Dry etching can include reactive ion beam etching or inductively coupled ion beam etching, and the etching gas can include O2 or CHF3. The remaining second photoresist layer 9 above the patterned region 2-1 can be removed using wet etching, and the etching solution can be a solution such as NMP or acetone. The prepared structure can be as follows: Figure 4 As shown in (6).

[0058] In operation S250, a third hard mask layer and a third photoresist layer are sequentially stacked on the substrate and the second hard mask layer. The patterned area of ​​the third photoresist layer is exposed, and after development, a second patterned structure is formed on the third photoresist layer.

[0059] In some embodiments, the third hard mask layer 7 and the third photoresist layer 8 can be prepared by spin coating. The third hard mask layer 7 may include a silicon-based bottom anti-reflective hard mask coating or a spin-coated metal hard mask coating, with a thickness of 10 nm to 100 nm. The third photoresist layer 8 may include a high-resolution photoresist with a thickness of 30 nm to 100 nm. The resulting structure can be as follows: Figure 4 As shown in (7).

[0060] In some embodiments, the patterned region 2-1 of the third photoresist layer 8 can be exposed using a proximity contact exposure method, and the resulting structure can be as follows: Figure 4 As shown in (8).

[0061] In some embodiments, a 300-series developer can be used to develop the exposed third photoresist layer 8, forming a second patterned structure 1-2 on the third photoresist layer 8. The resulting structure can be as follows: Figure 4 As shown in (9).

[0062] In operation S260, the second patterned structure is transferred onto the substrate, and the remaining sacrificial layer and the second hard mask layer are stripped to obtain a multi-patterned structure.

[0063] In some embodiments, the transfer process can be divided into the following three steps:

[0064] First, using the third photoresist layer 8 as a masking layer, the third hard mask layer 7 is etched to transfer the second patterned structure 1-2 on the third photoresist layer 8 onto the third hard mask layer 8. The third hard mask layer 7 can be etched using a dry etching process, which may include reactive ion beam etching or inductively coupled ion beam etching. The etching gas may include CHF3 or Cl2. The resulting structure can be as follows... Figure 4 As shown in (10).

[0065] Then, using the third hard mask layer 7 as a masking layer, the second hard mask layer 6 is etched to transfer the second patterned structure 1-2 on the third hard mask layer 7 onto the second hard mask layer 6. Dry etching of the second hard mask layer 6 can be used, including reactive ion beam etching or inductively coupled ion beam etching, and the etching gas can include O2 or CHF3. The resulting structure can be as follows... Figure 4 As shown in (11).

[0066] Finally, using the second hard mask layer 6 as a masking layer, the substrate 1 is etched to transfer the second patterned structure 1-2 on the second hard mask layer 3 onto the substrate 1. Dry etching of the second hard mask layer can be used, including ion beam etching, reactive ion beam etching, or inductively coupled ion beam etching. Etching gases include CHF3, SF6, O2, and Cl2. The resulting structure can be... Figure 4 As shown in (12).

[0067] In some embodiments, the materials of the sacrificial layer 3 and the second hard mask layer 6 must be the same to allow for a one-time stripping process. This one-time stripping of the remaining sacrificial layer and second hard mask layer further simplifies the process and improves efficiency. Specifically, when the raw material of the sacrificial layer 3 is spin-coated carbon or amorphous carbon, the material of the second hard mask layer 6 is spin-coated carbon, and the remaining sacrificial layer and second hard mask layer are stripped from the surface in one step using dry etching or wet etching. When the raw material of the sacrificial layer 3 is spin-coated glass or silane, the material of the second hard mask layer 6 is spin-coated glass, and the remaining sacrificial layer and second hard mask layer are also stripped from the surface in one step using dry etching or wet etching. The resulting structure can be as follows: Figure 4 As shown in (13). Dry etching can include reactive ion beam etching or inductively coupled ion beam etching, and the etching gas includes O2 or CHF3, etc. Wet etching solutions include a mixture of hydrogen peroxide and sulfuric acid or a diluted hydrofluoric acid solution, etc.

[0068] By employing a process that involves stripping the remaining sacrificial layer and the second hard mask layer in a single step, the substrate cleaning effect can be enhanced simply by increasing the dry etching or wet etching time, while improving process efficiency.

[0069] To further illustrate the multi-graphic structure processing method provided in the embodiments of this disclosure more clearly, several specific embodiments and comparative examples are given below.

[0070] Example 1:

[0071] The specific implementation steps of this embodiment can be as follows:

[0072] The substrate 1 is a SiO2 dielectric layer material. The first pattern structure 1-1 already exists on the substrate 1, with a feature size of 100nm and a structure depth of 50nm.

[0073] The first patterned structure 1-1 is filled. The sacrificial layer 3 is a spin-coated carbon material, model SOC-200nm, prepared by spin coating at a speed of 2000 r / min and thermally cured at 300℃ for 10 min. The sacrificial layer 3 is thinned by reactive ion beam dry etching to make it lower than the surface of the first patterned structure 1-1. The etching gas is O2, the gas flow rate is 20 sccm, the cavity pressure is 0.1 Pa, and the etching time is 5 min. The second hard mask layer 6 is prepared by spin coating with SOC-100nm material at a speed of 2000 r / min and thermally cured at 250℃. The second photoresist layer 9 is prepared by spin coating with AZ1500 photoresist at a speed of 2000 r / min and a spin coating thickness of 500 nm.

[0074] The non-patterned area 2-2 of the second photoresist layer 9 was exposed by laser direct writing. After development, the second photoresist layer 9 above the non-patterned area 2-2 was removed. Using the second photoresist layer 9 as a masking layer, the second hard mask layer 6 above the non-patterned area 2-2 was etched and stripped by reactive ion beam dry etching. The etching gas was O2, the gas flow rate was 20 sccm, the cavity pressure was 0.1 Pa, and the etching time was 2.5 min. The remaining second photoresist layer 9 was removed by IPA immersion.

[0075] The third hard mask layer 7 was prepared by spin-coating SiBarc onto substrate 1 at a speed of 2000 r / min with a thickness of 50 nm and curing at 200 °C for 5 min. The third photoresist layer 8 was prepared by spin-coating AR-P3170 photoresist at a speed of 4000 r / min with a thickness of 50 nm and pre-baking at 100 °C for 5 min.

[0076] A second patterned structure 1-2 with a feature size of 80 nm was formed on the third photoresist layer 8 using contact exposure. The second patterned structure 1-2 was then transferred to the third hard mask layer 7 using reactive ion beam etching (RIE), with CHF3 as the etching gas, a cavity pressure of 0.1 Pa, an RF power of 40 W, and an etching time of 30 min. The second patterned structure 1-2 was then transferred to the second hard mask layer 6 using reactive ion beam etching (RIE), with O2 as the etching gas, a gas flow rate of 40 sccm, a cavity pressure of 0.1 Pa, an RF power of 40 W, and an etching time of 8 min. Finally, the second patterned structure 1-2 was transferred to the substrate 1 using reactive ion beam etching (RIE), with an etching depth of 400 nm, CHF3 as the etching gas, a gas flow rate of 50 sccm, a cavity pressure of 0.5 Pa, an RF power of 40 W, and an etching time of 60 min.

[0077] The sacrificial layer 3 and the second hard mask layer 6 are peeled off in one step by wet etching, thereby forming a dual-pattern structure on the substrate 1. The wet etching liquid is a solution of concentrated H2SO4 and H2O2 in a ratio of 3:1, and the temperature is 120°C.

[0078] In this embodiment, the sacrificial layer 3 and the second hard mask layer 6 are made of the same spin-coated carbon material, resulting in a simpler and less expensive process compared to CVD. Utilizing the gap-filling and planarization properties of the spin-coated carbon material is equivalent to a double-layer superposition, which increases the planarization of the area above the first patterned structure 1-1. This ensures a uniform gap between the mask and the substrate during near-contact exposure, thereby improving the exposure uniformity of the second patterned structure 1-2. Simultaneously, reducing the thickness of the second hard mask layer 6 makes the non-patterned area 2-2 lower than the surface of the patterned area 2-1. This effectively increases the contact area between the mask and the substrate during near-contact exposure, thereby improving the exposure resolution and contrast of the second patterned structure 1-2.

[0079] Example 2:

[0080] The specific implementation steps of this embodiment can be as follows:

[0081] The substrate 1 is made of Si material. The first pattern structure 1-1 already exists on the substrate 1, with a feature size of 500nm, a period of 2um, and a structure depth of 100nm.

[0082] The first pattern structure 1-1 is filled. The sacrificial layer 3 is made of amorphous carbon material and is prepared by CVD deposition with a thickness of 100 nm. The sacrificial layer 3 is thinned by reactive ion beam dry etching to make it lower than the surface of the first pattern structure 1-1. The etching gas is O2 with a flow rate of 20 sccm, the cavity pressure is 0.1 Pa, and the etching time is 2 min.

[0083] The second hard mask layer 6 was prepared by spin coating. The spin coating material was SOC-200nm, the spin coating speed was 2000r / min, and the high temperature was cured at 250℃ for 10min. The second photoresist layer 9 was prepared by spin coating. The photoresist was AZ1500, the spin coating speed was 2000r / min, the spin coating thickness was 500nm, and the pre-baking was carried out at 100℃.

[0084] The non-patterned area 2-2 of the second photoresist layer 9 was exposed using a projection exposure method. After development, the second photoresist layer 9 above the non-patterned area 2-2 was removed. The developer was AR 300-26. Using the second photoresist layer 9 as a mask layer, the second hard mask layer 6 above the non-patterned area 2-2 was removed by reactive ion etching. The etching gas was O2, the gas flow rate was 40 sccm, the cavity pressure was 0.1 Pa, the RF power was 40 W, and the etching time was 15 min. The remaining second photoresist layer 9 was cleaned with acetone.

[0085] The third hard mask layer 7 was prepared by spin-coating SiBarc onto the substrate 1 at a speed of 2000 r / min with a thickness of 50 nm and curing at 200 °C for 5 min. The third photoresist layer 8 was prepared by spin-coating AR-P3170 photoresist at a speed of 4000 r / min with a thickness of 50 nm and pre-baking at 100 °C for 5 min.

[0086] A second patterned structure 1-2 with a feature size of 50 nm was formed on the third photoresist layer 8 using contact exposure. The second patterned structure 1-2 was then transferred to the third hard mask layer 7 using reactive ion beam etching (RIE), with CHF3 as the etching gas, a cavity pressure of 0.1 Pa, an RF power of 40 W, and an etching time of 30 min. The second patterned structure 1-2 was then transferred to the second hard mask layer 6 using reactive ion beam etching (RIE), with O2 as the etching gas, a gas flow rate of 40 sccm, a cavity pressure of 0.1 Pa, an RF power of 40 W, and an etching time of 10 min. Finally, the second patterned structure 1-2 was transferred to the substrate 1 using inductively coupled plasma etching (ICP-C), with an etching depth of 500 nm, using SF6 as the etching gas, a gas flow rate of 20 sccm, CHF3 as the etching gas, a gas flow rate of 5 sccm, an RF power of 100 W, a cavity pressure of 0.2 Pa, and an etching time of 30 min.

[0087] The second hard mask layer 6 and the sacrificial layer 3 were removed by reactive ion beam etching, and a dual-pattern structure was formed on the substrate 1. The etching gas was O2, the gas flow rate was 40 sccm, the cavity pressure was 0.1 Pa, the radio frequency power was 40 W, and the etching time was 30 min.

[0088] In this embodiment, firstly, the sacrificial layer 3 is thinned using reverse etching to reduce the microscopic undulations of its patterned region 2-1. Then, a second hard mask layer 6 is prepared by spin coating, which can effectively cover the microscopic undulations of the patterned region 2-1 using its fluidity, serving as an etch hard mask while also increasing planarization performance. This method replaces the CVD+CMP+CVD process, simplifying the process and reducing costs. Simultaneously, the second hard mask layer 6 above the non-patterned region 2-2 is removed using etching, making the surface of the non-patterned region 2-2 200nm lower than that of the patterned region 2-1. In near-contact exposure, this effectively increases the contact area between the mask and the substrate, thereby improving exposure resolution and contrast.

[0089] Example 3:

[0090] The specific implementation steps of this embodiment can be as follows:

[0091] Substrate 1 is made of polycrystalline silicon material. The first pattern structure 1-1 already exists on substrate 1 with a feature size of 50nm and a structure depth of 100nm.

[0092] The first patterned structure 1-1 is filled. The sacrificial layer 3 is a spin-coated glass material, model SOG-200nm, prepared by spin coating at a speed of 2000 r / min and thermally cured at 300℃ for 10 min. The sacrificial layer 3 is thinned by reactive ion beam dry etching to make it lower than the surface of the first patterned structure 1-1. The etching gas is CHF3, the gas flow rate is 40 sccm, the cavity pressure is 0.1 Pa, and the etching time is 5 min. The second hard mask layer 6 is prepared by spin coating glass, model SOG-100nm, at a speed of 2000 r / min and thermally cured at 250℃. The second photoresist layer 9 is prepared by spin coating, model AZ1500, at a speed of 2000 r / min, with a spin coating thickness of 500 nm.

[0093] The non-patterned area 2-2 of the second photoresist layer 9 was exposed using a projection exposure method. After development, the photoresist above the non-patterned area 2-2 was removed. The developer was AR 300-26. Using the second photoresist layer 9 as a masking layer, the second hard mask layer 6 above the non-patterned area was removed by reactive ion etching. The etching gas was CHF3, the gas flow rate was 40 sccm, the cavity pressure was 0.1 Pa, the RF power was 40 W, and the etching time was 30 min. The remaining second photoresist layer 9 was cleaned with acetone.

[0094] The third hard mask layer 7 was prepared by spin-coating a metal hard mask layer onto the substrate at a rotation speed of 2000 r / min and a thickness of 50 nm, followed by high-temperature curing at 200 °C for 5 min. The third photoresist layer 8 was prepared by spin-coating AR-P3170 photoresist at a rotation speed of 4000 r / min and a thickness of 50 nm, followed by pre-baking at 100 °C for 5 min.

[0095] The second patterned structure 1-2 was obtained by contact exposure with a feature size of 80 nm. Reactive ion beam etching was used to transfer the second patterned structure 1-2 to the third hard mask layer 7. The etching gas was Cl2, the cavity pressure was 0.5 Pa, the RF power was 20 W, and the etching time was 10 min. Reactive ion beam etching was then used to transfer the second patterned structure 1-2 to the second hard mask layer 6. The etching gas was CHF3, the gas flow rate was 40 sccm, the cavity pressure was 0.1 Pa, the RF power was 40 W, and the etching time was 30 min. Inductively coupled plasma etching was used to transfer the second patterned structure 1-2 to the substrate. The etching depth was 200 nm, the etching gas was SF6, the gas flow rate was 20 sccm, the etching gas was CHF3, the gas flow rate was 5 sccm, the RF power was 100 W, the cavity pressure was 0.2 Pa, and the etching time was 20 min.

[0096] The second hard mask layer 6 and the sacrificial layer 3 were removed in one step by wet etching. The solution was diluted hydrofluoric acid, and the etching time was 30 minutes.

[0097] In this embodiment, the second hard mask layer 6 above the non-patterned region 2-2 is stripped, making the surface of the non-patterned region 2-2 300nm lower than that of the patterned region 2-1. This effectively increases the contact area between the mask and the substrate in near-contact exposure, thereby improving exposure resolution and contrast. Simultaneously, since the sacrificial layer 3 and the second hard mask layer 6 can be removed in a single etching operation, process efficiency is improved.

[0098] Comparative Example 1:

[0099] Substrate 1 is made of polycrystalline silicon material. The first pattern structure 1-1 already exists on substrate 1 with a feature size of 50nm and a structure depth of 100nm.

[0100] The first pattern structure 1-1 is filled. The sacrificial layer 3 is made of spin-coated glass and is prepared by spin coating at a speed of 2000 r / min, a thickness of 100 nm, and high temperature of 250 °C for 20 min. The spin-coated glass material is etched by reactive ion beam back etching with CHF3 as the etching gas, a cavity pressure of 0.1 Pa, an RF power of 40 W, and an etching time of 30 min. The second hard mask layer 6 is prepared by spin coating carbon at a SOC of 100 nm at a speed of 2000 r / min and high temperature of 250 °C for thermal curing.

[0101] A third hard mask layer 7 was fabricated by spin-coating SiBarc onto the substrate at a rotation speed of 2000 r / min to a thickness of 50 nm, followed by high-temperature curing at 200℃ for 5 min. A third photoresist layer 8 was fabricated by spin-coating AR-P3170 photoresist at a rotation speed of 4000 r / min to a thickness of 50 nm, followed by pre-baking at 100℃ for 5 min. The second patterned structure 1-2 was exposed using contact exposure with a feature size of 80 nm. The second patterned structure 1-2 was transferred to the third hard mask layer 7 using reactive ion beam etching (RIE), with CHF3 as the etching gas, a cavity pressure of 0.1 Pa, an RF power of 40 W, and an etching time of 30 min. The second patterned structure 1-2 was then transferred to the second hard mask layer 6 using reactive ion beam etching (RIE), with O2 as the etching gas, a gas flow rate of 40 sccm, a cavity pressure of 0.1 Pa, an RF power of 40 W, and an etching time of 30 min. Finally, the second patterned structure 1-2 was transferred to the substrate 1 using inductively coupled plasma etching (ICP-P) to a depth of [insert etching depth here]. The etching process involved etching at 200 nm using SF6 as the etching gas at a flow rate of 20 sccm, and CHF3 as the etching gas at a flow rate of 5 sccm. The radio frequency (RF) power was 100 W, the cavity pressure was 0.2 Pa, and the etching time was 20 min. Reactive ion beam etching was used to remove the second hard mask layer 6 and the sacrificial layer 3. First, the spin-coated carbon material was removed: the etching gas was O2 at a flow rate of 40 sccm, the cavity pressure was 0.1 Pa, the RF power was 40 W, and the etching time was 30 min. Then, the spin-coated glass material was removed: the etching gas was CHF3 at a cavity pressure of 0.1 Pa, the RF power was 40 W, and the etching time was 40 min.

[0102] Comparative Example 2:

[0103] Substrate 1 is made of polycrystalline silicon material. The first pattern structure 1-1 already exists on substrate 1 with a feature size of 50nm and a structure depth of 100nm.

[0104] The first pattern structure 1-1 is filled with SOC material as the sacrificial layer 3, which is filled by spin coating at a speed of 2000 r / min and a thickness of 100 nm. It is then thermally cured at 250 °C for 20 min. The second hard mask layer 6 is prepared by spin coating with SOC-300 nm material at a speed of 2000 r / min and thermally cured at 300 °C. The second photoresist layer 9 is prepared by spin coating with AZ-1500 UV photoresist at a speed of 2000 r / min and a thickness of 500 nm. It is then pre-baked at 100 °C for 5 min.

[0105] The non-patterned area 2-2 of the second photoresist layer 9 was exposed using a projection exposure method with AR 300-26 as the developer. After development, the second photoresist layer 9 above the non-patterned area 2-2 was removed. Using the second photoresist layer 9 as a masking layer, the second hard mask layer 6 above the non-patterned area 2-2 was removed by reactive ion etching. The etching gas was O2 with a flow rate of 40 sccm, a cavity pressure of 0.1 Pa, an RF power of 40 W, and an etching time of 30 min. The remaining second photoresist layer 9 was cleaned with acetone.

[0106] A third hard mask layer 7 was fabricated by spin-coating SiBarc onto a substrate at a rotation speed of 2000 r / min to a thickness of 50 nm, followed by curing at 200 °C for 5 min. A second photosensitive adhesive layer 8 was fabricated by spin-coating AR-P3170 photoresist at a rotation speed of 4000 r / min to a thickness of 50 nm, followed by pre-baking at 100 °C for 5 min. The second patterned structure 1-2 was exposed using contact exposure with a feature size of 80 nm. The second patterned structure 1-2 was transferred to the third hard mask layer 7 using reactive ion beam etching (RIE), with CHF3 as the etching gas, a cavity pressure of 0.1 Pa, an RF power of 40 W, and an etching time of 30 min. The second patterned structure 1-2 was then transferred to the second hard mask using RIE. Layer 6: Etching gas is O2, gas flow rate is 40 sccm, cavity pressure is 0.1 Pa, RF power is 40 W, and etching time is 30 min. Inductively coupled plasma etching is used to transfer the second patterned structure 1-2 to substrate 1, with an etching depth of 200 nm and etching gas of SF6, gas flow rate is 20 sccm. Etching gas is CHF3, gas flow rate is 5 sccm, RF power is 100 W, cavity pressure is 0.2 Pa, and etching time is 20 min. Reactive ion beam etching is used to remove the third hard mask layer 6 and sacrificial layer 3 in one step, with etching gas of O2, gas flow rate is 40 sccm, cavity pressure is 0.1 Pa, RF power is 40 W, and etching time is 30 min.

[0107] To verify the advantages of the multi-graphic structure processing method provided in the embodiments of this disclosure, the test results of the above embodiments and comparative examples are listed below.

[0108] Figure 5 The following is a schematic diagram of the exposure scanning electron microscope image of the second pattern structure after the processing method of thinning the sacrificial layer and peeling off the second hard mask layer of the non-pattern area in Example 1.

[0109] Figure 6 The exposure scanning electron microscope image of the second patterned structure obtained by the processing method in Comparative Example 1 without stripping the second hard mask layer of the non-patterned region is shown schematically.

[0110] Figure 7An exposure scanning electron microscope image of the second patterned structure obtained by the processing method without thinning the sacrificial layer in Comparative Example 2 is shown schematically.

[0111] contrast Figure 5 and Figure 6 and Figure 7 It can be known that:

[0112] The multi-patterned structure was fabricated using the method described in Example 1. Utilizing the gap-filling and planarization properties of spin-coated carbon material, the planarization of the first patterned structure 1-1 was increased, resulting in a more uniform gap between the mask and substrate during near-contact exposure, thus improving the exposure uniformity of the second patterned structure 1-2. Because the second hard mask layer 6 above the non-patterned region 2-2 was stripped, making the non-patterned region 2-2 lower than the surface of the patterned region 2-1, the contact area between the mask and substrate was effectively increased during near-contact exposure, improving the exposure resolution and contrast of the second patterned structure 1-2. Figure 5 As shown.

[0113] Using the method described in Comparative Example 1, a multi-patterned structure was fabricated. Because the second hard mask layer 6 was not etched and removed from the non-patterned region 2-2 after fabrication, the surface of the patterned region 2-1 was significantly lower than the surface of the non-patterned region 2-2. This resulted in an increased time gap between the mask and the wafer during the exposure of the second patterned structure 2-1, leading to insufficient depth of focus during exposure of the second patterned structure 1-2 in the patterned region 2-1, and thus exposure failure. Figure 6 As shown. At the same time, the sacrificial layer 3 and the third hard mask layer 6 cannot be etched and peeled off in one go, which increases the number of process steps and process costs.

[0114] Using the method described in Comparative Example 2, a multi-pattern structure was fabricated. Since the first pattern structure 1-1 is a dense pattern, no back etching operation was performed after spin-coating the sacrificial layer material 3. As the underlying layer became uneven, microscopic undulations appeared above pattern area 2-1. Furthermore, with the stacking of multiple hard mask structures, the microscopic unevenness significantly increased. This directly led to a deterioration in the exposure uniformity of the second pattern structure 1-2 in the pattern area. Figure 7 As shown.

[0115] In summary, the multi-pattern structure processing method provided in this disclosure uses a back-etching method to thin the sacrificial layer and then spin-coating to planarize it to prepare a second hard mask layer instead of CVD+CMP. This simplifies the process and further improves the planarization degree of the hard mask patterned area, thereby ensuring the uniformity of the exposed pattern in near-contact lithography. Using an exposure etching method to remove the second hard mask layer from the non-patterned area eliminates the height difference between the patterned and non-patterned areas, reducing the gap between the wafer and the mask in near-contact lithography and thus improving exposure resolution. Since the sacrificial layer and the second hard mask layer are made of the same material, they can be removed in one step after etching transfer, thereby simplifying the processing.

[0116] The specific embodiments described above further illustrate the purpose, technical solutions, and beneficial effects of this disclosure. It should be understood that the above descriptions are merely specific embodiments of this disclosure and are not intended to limit this disclosure. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this disclosure should be included within the protection scope of this disclosure.

Claims

1. A method for processing multiple graphic structures, characterized in that, include: A substrate is provided, the surface of which is divided into a patterned region and a non-patterned region, the patterned region being provided with a first patterned structure; A sacrificial layer is prepared on the substrate, and the sacrificial layer is etched back to thin it, such that the surface of the thinned sacrificial layer is lower than the surface of the first patterned structure. A second hard mask layer and a second photoresist layer are sequentially stacked on a substrate with a sacrificial layer. The non-patterned area of ​​the second photoresist layer is exposed, and the second photoresist layer in the non-patterned area is removed after development. The preparation of the second hard mask layer on the substrate with the sacrificial layer includes: using spin-coated carbon material or spin-coated glass material as raw material, and using a spin-coating-curing method to prepare the second hard mask layer on the substrate with the sacrificial layer. Using the second photoresist layer above the patterned area as a masking layer, the second hard mask layer above the non-patterned area is etched and peeled off to remove the second photoresist layer above the patterned area; A third hard mask layer and a third photoresist layer are sequentially stacked on the substrate and the second hard mask layer. The patterned area of ​​the third photoresist layer is exposed, and a second patterned structure is formed on the third photoresist layer after development. The second patterned structure is transferred onto the substrate, and the remaining sacrificial layer and the second hard mask layer are peeled off to obtain a multi-patterned structure.

2. The multi-graphic structure processing method according to claim 1, characterized in that, The preparation of the sacrificial layer on the substrate includes: A sacrificial layer is prepared on the substrate using spin-coated carbon material or spin-coated glass material as raw material and a spin-coating-curing method; or, a sacrificial layer is prepared on the substrate using chemical vapor deposition using amorphous carbon material or silane material as raw material. The carbon content of the spin-coated carbon material used in the second hard mask layer is higher than 90%; the curing method includes high-temperature curing or ultraviolet curing, and the curing temperature is 250 ℃~600 ℃.

3. The multi-graphic structure processing method according to claim 2, characterized in that, When the raw material of the sacrificial layer is the spin-coated carbon material or the spin-coated glass material, the spin-coating thickness of the sacrificial layer is 1.5 to 2 times the feature size of the first pattern structure, the feature size of the first pattern structure is 10 nm to 500 nm, and the aspect ratio is 1 to 50; when the raw material of the sacrificial layer is amorphous carbon material or silane material, the deposition thickness of the sacrificial layer is sufficient to cover the first pattern structure. The spin-coating thickness of the second hard mask layer is 50 nm to 500 nm, and the thickness of the second photoresist layer is 2 to 3 times the thickness of the second hard mask layer.

4. The multi-graphic structure processing method according to claim 1, characterized in that, The step of etching back the sacrificial layer to thin it includes: The sacrificial layer is etched back using dry etching, wet etching, or chemical mechanical polishing. The dry etching method includes reactive ion beam etching or inductively coupled ion beam etching, and the etching gas includes O2 or CHF3; the wet etching solution includes a mixture of hydrogen peroxide and sulfuric acid or a diluted hydrofluoric acid solution; the chemical mechanical polishing solution includes an acidic polishing solution or an alkaline polishing solution, the abrasive includes cerium oxide or silicon oxide, and the polishing pad includes polyester fiber.

5. The multi-graphic structure processing method according to claim 1, characterized in that, The second photoresist layer exposed above the non-patterned area includes: The non-patterned areas of the second photoresist layer are exposed using laser direct writing lithography, projection exposure, or near-contact exposure.

6. The multi-graphic structure processing method according to claim 1, characterized in that, The step of etching and stripping the second hard mask layer above the non-patterned area using the second photoresist layer above the patterned area as a masking layer includes: The second hard mask layer above the non-patterned area is etched using a dry etching method, which includes reactive ion beam etching or inductively coupled ion beam etching, and the etching gas includes O2 or CHF3.

7. The multi-graphic structure processing method according to claim 1, characterized in that, The step of sequentially fabricating a third hard mask layer and a third photoresist layer on the substrate and the second hard mask layer includes: The third hard mask layer and the third photoresist layer are prepared by spin coating; the third hard mask layer includes a silicon-containing bottom anti-reflective hard mask coating or a spin-coated metal hard mask coating, with a thickness of 10 nm to 100 nm; the third photoresist layer includes high-resolution photoresist, with a thickness of 30 nm to 100 nm.

8. The multi-graphic structure processing method according to claim 1, characterized in that, The third photoresist layer exposed above the patterned area includes: The patterned area of ​​the third photoresist layer is exposed using a near-contact exposure method.

9. The multi-graphic structure processing method according to claim 1, characterized in that, The step of transferring the second patterned structure onto the substrate includes: Using the third photoresist layer as a masking layer, the third hard mask layer is etched to transfer the second pattern structure on the third photoresist layer onto the third hard mask layer; Using the third hard mask layer as a masking layer, the second hard mask layer is etched to transfer the second pattern structure on the third hard mask layer onto the second hard mask layer; Using the second hard mask layer as a masking layer, the substrate is etched to transfer the second patterned structure on the second hard mask layer onto the substrate.

10. The multi-graphic structure processing method according to claim 9, characterized in that, The third hard mask layer is etched using a dry etching method, which includes reactive ion beam etching or inductively coupled ion beam etching, and the etching gas includes CHF3 or Cl2. The second hard mask layer is etched using a dry etching method, which includes reactive ion beam etching or inductively coupled ion beam etching, and the etching gas includes O2 or CHF3. The substrate is etched using a dry etching method, which includes ion beam etching, reactive ion beam etching, or inductively coupled ion beam etching. The etching gas includes CHF3, SF6, O2, and Cl2.

11. The multi-graphic structure processing method according to claim 2, characterized in that, The stripping of the remaining sacrificial layer and the second hard mask layer includes: When the raw material of the sacrificial layer is spin-coated carbon material or amorphous carbon material, the material of the second hard mask layer is spin-coated carbon material, and the remaining sacrificial layer and the second hard mask layer on the surface are removed in one step by dry etching or wet etching. When the raw material of the sacrificial layer is spin-coated glass material or silane material, the material of the second hard mask layer is spin-coated glass material, and the remaining sacrificial layer and the second hard mask layer on the surface are removed in one step by dry etching or wet etching. The dry etching method includes reactive ion beam etching or inductively coupled ion beam etching, and the etching gas includes O2 or CHF3; the wet etching method uses a solution of hydrogen peroxide and sulfuric acid or a diluted hydrofluoric acid solution.

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