Mask and manufacturing method thereof

Abstract

The invention discloses a mask plate and a manufacturing method thereof, and the mask plate comprises a substrate which is provided with a first surface and a second surface opposite to the first surface, and a first phase shift structure and a second phase shift structure which are located on the substrate; wherein the substrate further comprises a first area and a second area, the first phase shift structure is located on the first surface of the second area, the second phase shift structure is located on the second surface of the first area, and the light transmittance of the first phase shift structure is different from that of the second phase shift structure.

Description

Technical Field

[0001] The present disclosure relates to the field of semiconductor manufacturing, and in particular to a mask and a manufacturing method thereof. Background Art

[0002] In semiconductor processing, photolithography technology is required to transfer the pattern of the mask to the wafer. Among them, the phase shift mask (PSM) has higher resolution and focus depth, and is therefore widely used.

[0003] A phase-shift mask usually includes a transparent substrate and a phase-shift layer on the transparent substrate. Different patterns often have different requirements on the transmittance of the phase-shift layer. Therefore, multiple masks are usually required to perform multiple pattern transfers to transfer different patterns to the same wafer, which increases the process cost. Summary of the invention

[0004] The present disclosure provides a mask, comprising:

[0005] A substrate, the substrate comprising a first surface and a second surface opposite to the first surface, the substrate further comprising a first region and a second region;

[0006] a first phase-shift structure, located on a first surface of the second region;

[0007] The second phase-shift structure is located on the second surface of the first region; wherein the first phase-shift structure and the second phase-shift structure have different light transmittances.

[0008] In some embodiments, the first surface of the second region is recessed relative to the first surface of the first region in a direction perpendicular to the first surface, so that the first surface of the second region and the first surface of the first region have a first preset height difference, and the surface of the first phase-shift structure away from the second region is flush with the first surface of the first region.

[0009] In some embodiments, the second surface of the first region is recessed relative to the second surface of the second region in a direction perpendicular to the second surface, so that the second surface of the first region and the second surface of the second region have a second preset height difference, and a surface of the second phase-shift structure away from the first region is flush with the second surface of the second region.

[0010] In some embodiments, the second surface of the first region is flush with the first surface of the second region.

[0011] In some embodiments, the first surface of the first region is flush with the first surface of the second region, and the second surface of the first region is flush with the second surface of the second region.

[0012] In some embodiments, the mask further includes: a first shielding structure and a second shielding structure, wherein the first shielding structure covers a portion of the first phase-shift structure and is disposed along an edge of the second region, and the second shielding structure covers a portion of the second phase-shift structure and is disposed along an edge of the first region.

[0013] In some embodiments, the transmittance of the first phase-shift structure is greater than the transmittance of the second phase-shift structure, the first phase-shift structure is used to form an array region of a memory, and the second phase-shift structure is used to form a core region of the memory.

[0014] The present disclosure also provides a method for manufacturing a mask, comprising:

[0015] Providing a substrate, the substrate comprising a first surface and a second surface opposite to the first surface, the substrate further comprising a first region and a second region;

[0016] forming a first phase-shift material layer on the first surface of the substrate, the first phase-shift material layer at least covering the second region, and forming a second phase-shift material layer on the second surface of the substrate, the second phase-shift material layer at least covering the first region; wherein the first phase-shift material layer and the second phase-shift material layer have different light transmittances;

[0017] The first phase-shift material layer is etched to form a first phase-shift structure on the first surface of the second region, and the second phase-shift material layer is etched to form a second phase-shift structure on the second surface of the first region.

[0018] In some embodiments, before forming the first phase-shift material layer on the first surface of the substrate, the method further includes:

[0019] The first surface of the second region is etched so that the first surface of the second region is recessed relative to the first surface of the first region in a direction perpendicular to the first surface, the first surface of the second region and the first surface of the first region have a first preset height difference, and a surface of the first phase-shift material layer in the second region away from the second region is flush with the first surface of the first region.

[0020] In some embodiments, before forming the second phase-shift material layer on the second surface of the substrate, the method further includes:

[0021] The second surface of the first region is etched so that the second surface of the first region is recessed relative to the second surface of the second region in a direction perpendicular to the second surface, the second surface of the first region and the second surface of the second region have a second preset height difference, and a surface of the second phase-shift material layer in the first region away from the first region is flush with the second surface of the second region.

[0022] In some embodiments, before etching the first phase-shift material layer to form the first phase-shift structure, the method further includes: forming a first shielding material layer, wherein the first shielding material layer covers the first phase-shift material layer;

[0023] Etching the first phase-shift material layer to form the first phase-shift structure includes:

[0024] forming a first patterned mask layer on a first surface of the substrate;

[0025] Using the first patterned mask layer as a mask, etching the first shielding material layer and the first phase-shift material layer until the substrate is exposed, so as to transfer the pattern of the first patterned mask layer to the first shielding material layer and the first phase-shift material layer, and respectively forming a first shielding structure and a first phase-shift structure on the first surface of the second region;

[0026] The method further includes: removing the first shielding structure located in a middle area of ​​the second area, and the remaining first shielding structure is arranged along an edge of the second area.

[0027] In some embodiments, before etching the second phase-shift material layer to form the second phase-shift structure, the method further includes: forming a second shielding material layer, wherein the second shielding material layer covers the second phase-shift material layer;

[0028] Etching the second phase-shift material layer to form the second phase-shift structure includes:

[0029] forming a second patterned mask layer on the second surface of the substrate;

[0030] Using the second patterned mask layer as a mask, etching the second shielding material layer and the second phase-shift material layer until the substrate is exposed, so as to transfer the pattern of the second patterned mask layer to the second shielding material layer and the second phase-shift material layer, and respectively forming a second shielding structure and a second phase-shift structure on the second surface of the first region;

[0031] The method further includes: removing the second shielding structure located in a middle area of ​​the first area, and the remaining second shielding structure is arranged along an edge of the first area.

[0032] The mask provided by the embodiment of the present disclosure and the manufacturing method thereof, wherein the mask includes: a substrate, the substrate includes a first surface and a second surface opposite to the first surface, the substrate also includes a first region and a second region; a first phase shift structure, located on the first surface of the second region; a second phase shift structure, located on the second surface of the first region; wherein the first phase shift structure and the second phase shift structure have different transmittances. The mask provided by the embodiment of the present disclosure includes a first phase shift structure located on the first surface of the substrate and a second phase shift structure located on the second surface of the substrate, and the transmittance of the first phase shift structure and the transmittance of the second phase shift structure are different. In this way, the embodiment of the present disclosure forms phase shift structures with different transmittances on the same mask, meeting the different requirements of different patterns on the transmittance of the phase shift structure, so that different patterns (such as dot patterns and strip patterns) can be transferred to the wafer at the same time using one mask, reducing the number of masks used, thereby reducing process steps and process costs.

[0033] The details of one or more embodiments of the present disclosure are set forth in the accompanying drawings and the description below. Other features and advantages of the present disclosure will become apparent from the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0035] Figure 1 A schematic diagram of the structure of a mask provided in an embodiment of the present disclosure;

[0036] Figure 2 A schematic structural diagram of a mask provided in another embodiment of the present disclosure;

[0037] Figure 3 A schematic structural diagram of a mask provided in yet another embodiment of the present disclosure;

[0038] Figure 4 A process flow chart of a method for manufacturing a mask provided in an embodiment of the present disclosure;

[0039] Figures 5 to 12 A process flow chart of a method for manufacturing a mask provided in an embodiment of the present disclosure;

[0040] Figures 13 to 15 A process flow chart of a method for manufacturing a mask provided in another embodiment of the present disclosure;

[0041] Fig.16 A process flow chart of a method for manufacturing a mask provided in accordance with yet another embodiment of the present disclosure. DETAILED DESCRIPTION

[0042] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the specific embodiments set forth herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0043] In the following description, a large number of specific details are given to provide a more thorough understanding of the present disclosure. However, it is obvious to those skilled in the art that the present disclosure can be implemented without one or more of these details. In other examples, in order to avoid confusion with the present disclosure, some technical features known in the art are not described; that is, all features of actual embodiments are not described here, and well-known functions and structures are not described in detail.

[0044] In the drawings, the sizes of layers, regions, elements and their relative sizes may be exaggerated for clarity. Like reference numerals denote like elements throughout.

[0045] It should be understood that when an element or layer is referred to as "on ...", "adjacent to ...", "connected to" or "coupled to" other elements or layers, it can be directly on, adjacent to, connected to or coupled to other elements or layers, or there can be intervening elements or layers. On the contrary, when an element is referred to as "directly on ...", "directly adjacent to ...", "directly connected to" or "directly coupled to" other elements or layers, there is no intervening element or layer. It should be understood that although the terms first, second, third, etc. can be used to describe various elements, components, regions, layers and / or parts, these elements, components, regions, layers and / or parts should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or part from another element, component, region, layer or part. Therefore, without departing from the teachings of the present disclosure, the first element, component, region, layer or part discussed below can be represented as the second element, component, region, layer or part. And when the second element, component, region, layer or part is discussed, it does not indicate that the present disclosure necessarily has the first element, component, region, layer or part.

[0046] Spatially relative terms such as "under", "beneath", "below", "under", "above", "above", etc., may be used here for convenience of description to describe the relationship between an element or feature shown in the figure and other elements or features. It should be understood that in addition to the orientation shown in the figure, the spatial relationship terms are intended to also include different orientations of the device in use and operation. For example, if the device in the accompanying drawings is turned over, then the elements or features described as "under other elements" or "under it" or "under it" will be oriented as "on" other elements or features. Therefore, the exemplary terms "under" and "under" may include both upper and lower orientations. The device can be oriented otherwise (rotated 90 degrees or other orientations) and the spatial descriptors used herein are interpreted accordingly.

[0047] The purpose of the terms used herein is only to describe specific embodiments and is not intended to be a limitation of the present disclosure. When used herein, the singular forms "one", "an" and "said / the" are also intended to include plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "consisting of" and / or "comprising", when used in this specification, determine the presence of the features, integers, steps, operations, elements and / or parts, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, parts and / or groups. When used herein, the term "and / or" includes any and all combinations of the relevant listed items.

[0048] In semiconductor processing, photolithography technology is required to transfer the pattern of the mask to the wafer. Among them, the phase shift mask (PSM) has higher resolution and focus depth, and is therefore widely used.

[0049] The phase-shift mask usually includes a transparent substrate and a phase-shift layer located on the transparent substrate. Different patterns often have different requirements for the transmittance of the phase-shift layer. For example, in actual operation, when forming the array area and core area of ​​the memory, it is usually necessary to use a phase-shift mask to transfer the dot pattern to the array area and the stripe pattern to the core area; among them, for the dot pattern, it is necessary to use a phase-shift structure with higher transmittance for exposure to reduce the error enhancement factor of the mask and reduce the influence of the error of the mask itself on the pattern formed after exposure; and for the stripe pattern, it is necessary to use a phase-shift structure with lower transmittance for exposure to increase the depth of focus. Therefore, it is usually necessary to use multiple masks for multiple pattern transfers to transfer different patterns to the same wafer, which increases the process cost.

[0050] Based on this, the following technical solutions of the embodiments of the present disclosure are proposed. The specific implementation methods of the present disclosure are described in detail below in conjunction with the accompanying drawings. When describing the embodiments of the present disclosure in detail, for the convenience of explanation, the schematic diagram will not be partially enlarged according to the general proportion, and the schematic diagram is only an example, which should not limit the scope of protection of the present disclosure.

[0051] Figure 1 A schematic diagram of the structure of a mask provided in an embodiment of the present disclosure, Figure 2 A schematic diagram of the structure of a mask provided by another embodiment of the present disclosure, Figure 3 A schematic diagram of the structure of a mask provided in yet another embodiment of the present disclosure. Figures 1 to 3 The mask provided in the embodiment of the present disclosure is further described.

[0052] As shown in the figure, the mask includes: a substrate 10, the substrate 10 includes a first surface S1 and a second surface S2 opposite to the first surface S1, and the substrate 10 also includes a first region 101 and a second region 102; a first phase shift structure 11, located on the first surface S1 of the second region 102; a second phase shift structure 13, located on the second surface S2 of the first region 101; wherein the first phase shift structure 11 and the second phase shift structure 13 have different light transmittances.

[0053] In actual operation, the mask provided by the embodiment of the present disclosure can be used to manufacture dynamic random access memory (DRAM), but is not limited thereto, and the mask provided by the embodiment of the present disclosure can also be used to manufacture any semiconductor structure.

[0054] In the embodiment of the present disclosure, the substrate 10 may be a transparent substrate, and the material of the transparent substrate may be quartz glass, polymer or other suitable transparent materials.

[0055] In one embodiment, when performing a photolithography process on a wafer, the first area 101 of the substrate 10 corresponds to the array area of ​​the memory, and the second area 102 corresponds to the core area of ​​the memory. The photolithography process transfers the pattern on the first area 101 to the array area, and transfers the pattern on the second area 102 to the core area.

[0056] In one embodiment, the number of the first phase shift structure 11 and the number of the second phase shift structure 13 are both plural, and the plural first phase shift structures 11 are discretely arranged on the first surface S1 of the second region 102, and the plural second phase shift structures 13 are discretely arranged on the second surface S2 of the first region 101; wherein, there is a 180° phase difference between an outgoing light beam passing through a position of the substrate 10 covered by the first phase shift structure 11 and an outgoing light beam passing through a position of the substrate 10 located between adjacent first phase shift structures 11, and there is a 180° phase difference between an outgoing light beam passing through a position of the substrate 10 covered by the second phase shift structure 13 and an outgoing light beam passing through a position of the substrate 10 located between adjacent second phase shift structures 13. Thus, in actual operation, when the photoresist on the wafer under the mask is exposed, the light intensity of the dark area is weakened and the light intensity of the bright area is enhanced due to destructive interference between adjacent patterns on the wafer surface, thereby improving the exposure resolution.

[0057] In one embodiment, the transmittance of the first phase shift structure 11 is greater than the transmittance of the second phase shift structure 13, the first phase shift structure 11 is used to form the array area of ​​the memory, and the second phase shift structure 13 is used to form the core area of ​​the memory. Further, the first phase shift structure 11 with high transmittance is used to form a dot pattern in the array area of ​​the memory, so that the mask error enhancement factor can be reduced; the second phase shift structure 13 with low transmittance is used to form a stripe pattern in the core area, so that the focus depth of exposure can be increased, thereby improving the exposure quality. Here, the dot pattern includes circular, elliptical, rectangular and other patterns.

[0058] In one embodiment, the transmittance of the first phase shift structure 11 is in the range of 15% to 50% (including the endpoint values), such as 18%, 20%, 25%, 30%, 35%, 40%, 45%, etc.; the transmittance of the second phase shift structure 13 is in the range of 3% to 15% (including the endpoint values), such as 5%, 6%, 10%, 12%, 14%, etc. In a specific embodiment, the transmittance of the first phase shift structure 11 is 30%, and the transmittance of the second phase shift structure 13 is 6%.

[0059] The materials of the first phase shift structure 11 and the second phase shift structure 13 include one or a combination of molybdenum oxysilicon nitride (MoSiON), molybdenum silicide (MoSi), zirconium silicon nitride (ZrSiN), titanium silicon nitride (TiSiN), silicon nitride (SiN), tantalum silicide (TaSi), tantalum nitride (TaN), etc. The first phase shift structure 11 and the second phase shift structure 13 can be a single-layer structure. However, the first phase shift structure 11 and the second phase shift structure 13 can also be a multi-layer structure, such as a combination of molybdenum silicide and silicon nitride. In a specific embodiment, the material of the first phase shift structure 11 is silicon nitride, and the material of the second phase shift structure 13 is molybdenum silicide.

[0060] In actual operation, the first phase-shift structure 11 and the second phase-shift structure 13 can be formed by one or more thin film deposition processes, such as chemical vapor deposition (CVD), plasma enhanced chemical vapor deposition (PECVD), physical vapor deposition (PVD), atomic layer deposition (ALD), electroplating, chemical plating, sputtering, evaporation or any combination thereof.

[0061] In one embodiment, part of the first phase-shift structure 11 covers the edge of the second region 102, and part of the second phase-shift structure 13 covers the edge of the first region 101; the mask further comprises: a first shielding structure 12 and a second shielding structure 14, the first shielding structure 12 covers part of the first phase-shift structure 11 and is arranged along the edge of the second region 102, and the second shielding structure 14 covers part of the second phase-shift structure 13 and is arranged along the edge of the first region 101. In some embodiments, the first shielding structure 12 and the second shielding structure 14 are both annular. The material of the first shielding structure 12 and the second shielding structure 14 is an opaque material, which is used to prevent the edge area of ​​the mask from transmitting light and affecting the exposure quality.

[0062] Figure 1 The first shielding structure 12 shown in the figure completely overlaps with the orthographic projection of the first phase-shifting structure 11 located at the edge of the second region 102 on the second region 102, and the second shielding structure 14 completely overlaps with the orthographic projection of the second phase-shifting structure 13 located at the edge of the first region 101 on the first region 101. However, the present invention is not limited thereto. The first shielding structure 12 may also only cover a portion of the first phase-shifting structure 11 located at the edge of the second region 102, and the second shielding structure 14 may also only cover a portion of the second phase-shifting structure 13 located at the edge of the first region 101.

[0063] The materials of the first shielding structure 12 and the second shielding structure 14 are the same or different. The materials of the first shielding structure 12 and the second shielding structure 14 include one or a combination of chromium (Cr), chromium oxide (CrO), chromium nitride (CrN), chromium carbide (CrC), chromium carbide nitride (CrCN), chromium oxycarbide (CrCO), chromium oxycarbide nitride (CrCON), molybdenum chromium (MoCr), molybdenum chromium oxide (MoCrO), molybdenum chromium nitride (MoCrN), molybdenum chromium carbide (MoCrC), or other compounds of molybdenum chromium (such as MoCrCN, MoCrCO, MoCrCON, etc.). In a specific embodiment, the materials of the first shielding structure 12 and the second shielding structure 14 are both chromium (Cr).

[0064] In actual operation, the first shielding structure 12 and the second shielding structure 14 can be formed by one or more thin film deposition processes, such as chemical vapor deposition (CVD), plasma enhanced chemical vapor deposition (PECVD), physical vapor deposition (PVD), atomic layer deposition (ALD), electroplating, chemical plating, sputtering, evaporation or any combination thereof.

[0065] like Figure 1 As shown, in one embodiment, the first surface S1 of the first region 101 of the substrate 10 is flush with the first surface S1 of the second region 102 , and the second surface S2 of the first region 101 is flush with the second surface S2 of the second region 102 .

[0066] But not limited to this, such as Figure 2 As shown, in one embodiment, the first surface S1 of the second region 102 is recessed relative to the first surface S1 of the first region 101 in a direction perpendicular to the first surface S1, so that the first surface S1 of the second region 102 and the first surface S1 of the first region 101 have a first preset height difference H1. In some embodiments, the thickness of the first phase-shift structure 11 is equal to the first preset height difference H1, so that a surface W1 of the first phase-shift structure 11 away from the second region 102 is flush with the first surface S1 of the first region 101.

[0067] In one embodiment, the second surface S2 of the first region 101 is recessed relative to the second surface S2 of the second region 102 along a direction perpendicular to the second surface S2, so that the second surface S2 of the first region 101 and the second surface S2 of the second region 102 have a second preset height difference H2. In some embodiments, the thickness of the second phase-shift structure 13 is equal to the second preset height difference H2, so that a surface W2 of the second phase-shift structure 13 away from the first region 101 is flush with the second surface S2 of the second region 102.

[0068] In the embodiment of the present disclosure, by arranging the surface W1 of the first phase-shift structure 11 away from the second region 102 to be flush with the first surface S1 of the first region 101, and the surface W2 of the second phase-shift structure 13 away from the first region 101 to be flush with the second surface S2 of the second region 102, the focal points of the outgoing light beams from the first region 101 and the second region 102 tend to fall on the same plane, thereby facilitating exposure.

[0069] like Figure 3As shown, in a specific embodiment, the second surface S2 of the first region 101 is flush with the first surface S1 of the second region 102. More specifically, the thickness of the first phase shift structure 11 is equal to the first preset height difference H1, so that the surface W1 of the first phase shift structure 11 away from the second region 102 is flush with the first surface S1 of the first region 101, and the thickness of the second phase shift structure 13 is equal to the second preset height difference H2, so that the surface W2 of the second phase shift structure 13 away from the first region 101 is flush with the second surface S2 of the second region 102. In this way, the focal points of the outgoing light beams of the first region 101 and the second region 102 are located in the same plane, which is more conducive to exposure.

[0070] It can be seen that the mask provided by the embodiment of the present disclosure includes a first phase-shift structure 11 located on the first surface S1 of the substrate 10 and a second phase-shift structure 13 located on the second surface S2 of the substrate 10, and the transmittance of the first phase-shift structure 11 is different from the transmittance of the second phase-shift structure 13. In this way, the embodiment of the present disclosure forms phase-shift structures with different transmittances on the same mask, which meets the different requirements of different patterns on the transmittance of the phase-shift structure, so that different patterns (such as dot patterns and strip patterns) can be transferred to the wafer at the same time by using one mask, thereby reducing the number of masks used, and further reducing the process steps and process costs.

[0071] The present disclosure also provides a method for manufacturing a mask. Figure 3 As shown, the manufacturing method comprises the following steps:

[0072] Step S101, providing a substrate, wherein the substrate comprises a first surface and a second surface opposite to the first surface, and the substrate further comprises a first region and a second region;

[0073] Step S102, forming a first phase-shift material layer on the first surface of the substrate, the first phase-shift material layer at least covering the second region, and forming a second phase-shift material layer on the second surface of the substrate, the second phase-shift material layer at least covering the first region; wherein the first phase-shift material layer and the second phase-shift material layer have different light transmittances;

[0074] Step S103 , etching the first phase-shift material layer to form a first phase-shift structure on the first surface of the second region, and etching the second phase-shift material layer to form a second phase-shift structure on the second surface of the first region.

[0075] Figures 5 to 12 A process flow chart of a method for manufacturing a mask provided in an embodiment of the present disclosure, Figures 13 to 15 A process flow chart of a method for manufacturing a mask provided in another embodiment of the present disclosure, Fig.16 A process flow chart of a method for manufacturing a mask provided by another embodiment of the present disclosure. Figures 5 to 16The method for manufacturing the mask according to the embodiment of the present disclosure is further described in detail.

[0076] First, execute step S101, such as Figure 5 As shown, a substrate 10 is provided. The substrate 10 includes a first surface S1 and a second surface S2 opposite to the first surface S1 . The substrate 10 also includes a first region 101 and a second region 102 .

[0077] Here, the substrate 10 may be a transparent substrate, and the material of the transparent substrate may be quartz glass, polymer or other suitable transparent materials.

[0078] In actual operation, when performing a photolithography process on a wafer, the first area 101 of the mask corresponds to the array area of ​​the memory, and the second area 102 corresponds to the core area of ​​the memory. The photolithography process transfers the pattern on the first area 101 to the array area, and transfers the pattern on the second area 102 to the core area. Here, the memory includes a dynamic random access memory (DRAM). However, it is not limited thereto, and the memory can also be any other memory.

[0079] Next, execute step S102, such as Figure 6 As shown, a first phase-shift material layer 11′ is formed on the first surface S1 of the substrate 10, and the first phase-shift material layer 11′ at least covers the second region 102, and a second phase-shift material layer 13′ is formed on the second surface S2 of the substrate 10, and the second phase-shift material layer 13′ at least covers the first region 101; wherein the first phase-shift material layer 11′ and the second phase-shift material layer 13′ have different light transmittances.

[0080] In one embodiment, after forming the first phase-shift material layer 11′ on the first surface S1 of the substrate 10, the method further includes: forming a first shielding material layer 12′, wherein the first shielding material layer 12′ covers the first phase-shift material layer 11′. In some embodiments, after forming the second phase-shift material layer 13′ on the second surface S2 of the substrate 10, the method further includes: forming a second shielding material layer 14′, wherein the second shielding material layer 14′ covers the second phase-shift material layer 13′.

[0081] Specifically, in actual operation, the first phase-shift material layer 11 ′ and the first shielding material layer 12 ′ can be formed by the following method: first, the first surface S1 of the substrate 10 is facing upward, and then the first phase-shift material layer 11 ′ and the first shielding material layer 12 ′ are sequentially deposited on the first surface S1 . Figure 6 In some embodiments, the method further includes: removing the first shielding material layer 12 ′ and the first phase-shifting material layer 11 ′ located in the first region 101 , and the remaining first shielding material layer 12 ′ and the first phase-shifting material layer 11 ′ cover the first surface S1 of the second region 102 .

[0082] The second shielding material layer 14′ and the second phase-shift material layer 13′ may be formed by the following method: first, the second surface S2 of the substrate 10 is facing upward; then, the second phase-shift material layer 13′ and the second shielding material layer 14′ are sequentially deposited on the second surface S2. In some embodiments, the method further includes: removing the second shielding material layer 14′ and the second phase-shift material layer 13′ located in the second region 102, and the remaining second shielding material layer 14′ and the second phase-shift material layer 13′ cover the second surface S2 of the first region 101.

[0083] In one embodiment, the transmittance of the first phase-shift material layer 11' is greater than the transmittance of the second phase-shift material layer 13'. In a subsequent process, the first phase-shift material layer 11' is etched to form a first phase-shift structure 11 on the first surface S1 of the second region 102 (see Figure 8 ), and etching the second phase-shift material layer 13′ to form a second phase-shift structure 13 on the second surface S2 of the first region 101 (see Fig.12 ), the first phase shift structure 11 (see Figure 8 ) is used to form an array region of a memory, and a second phase shift structure 13 (see Fig.12 ) is used to form the core area of ​​the memory. Further, the first phase shift structure 11 with high light transmittance (see Figure 8 ) is used to form a dot pattern in the array area of ​​the memory, so that the mask error enhancement factor can be reduced; a second phase shift structure 13 with low transmittance (see Fig.12 ) is used to form a stripe pattern in the core area, so that the focus depth of exposure can be increased. Here, the dot pattern includes a circular, elliptical, rectangular and other patterns.

[0084] In one embodiment, the transmittance of the first phase-shift material layer 11' is in the range of 15% to 50% (including the endpoint values), such as 18%, 20%, 25%, 30%, 35%, 40%, 45%, etc.; the transmittance of the second phase-shift material layer 13' is in the range of 3% to 15% (including the endpoint values), such as 5%, 6%, 10%, 12%, 14%, etc. In a specific embodiment, the transmittance of the first phase-shift material layer 11' is 30%, and the transmittance of the second phase-shift material layer 13' is 6%.

[0085] The materials of the first phase-shift material layer 11′ and the second phase-shift material layer 13′ include one or a combination of molybdenum oxysilicon nitride (MoSiON), molybdenum silicide (MoSi), zirconium silicon nitride (ZrSiN), titanium silicon nitride (TiSiN), silicon nitride (SiN), tantalum silicide (TaSi), tantalum nitride (TaN), etc. The first phase-shift material layer 11′ and the second phase-shift material layer 13′ can be a single-layer structure. However, it is not limited thereto. The first phase-shift material layer 11′ and the second phase-shift material layer 13′ can also be a multi-layer structure, such as a combination of molybdenum silicide and silicon nitride. In a specific embodiment, the material of the first phase-shift material layer 11′ is silicon nitride, and the material of the second phase-shift material layer 13′ is molybdenum silicide.

[0086] The materials of the first shielding material layer 12′ and the second shielding material layer 14′ are the same or different, and the materials of the first shielding structure 12 and the second shielding structure 14 are opaque materials. In one embodiment, the materials of the first shielding material layer 12′ and the second shielding material layer 14′ include one or a combination of chromium (Cr), chromium oxide (CrO), chromium nitride (CrN), chromium carbide (CrC), chromium nitride carbide (CrCN), chromium oxycarbide (CrCO), chromium oxycarbide (CrCON), molybdenum chromium (MoCr), molybdenum chromium oxide (MoCrO), molybdenum chromium nitride (MoCrN), molybdenum chromium carbide (MoCrC), or other compounds of molybdenum chromium (such as MoCrCN, MoCrCO, MoCrCON, etc.). In a specific embodiment, the materials of the first shielding material layer 12′ and the second shielding material layer 14′ are both chromium (Cr).

[0087] In actual operation, the first phase-shift material layer 11′, the second phase-shift material layer 13′, the first shielding material layer 12′ and the second shielding material layer 14′ can be formed by one or more thin film deposition processes, such as chemical vapor deposition (CVD), plasma enhanced chemical vapor deposition (PECVD), physical vapor deposition (PVD), atomic layer deposition (ALD), electroplating, chemical plating, sputtering, evaporation or any combination thereof.

[0088] Next, execute step S103, as Figures 7 and 8 , Figure 11 to Figure 12 As shown, the first phase-shift material layer 11 ′ is etched to form a first phase-shift structure 11 on the first surface S1 of the second region 102 , and the second phase-shift material layer 13 ′ is etched to form a second phase-shift structure 13 on the second surface S2 of the first region 101 .

[0089] See again Figures 7 and 8 Specifically, etching the first phase-shift material layer 11′ to form the first phase-shift structure 11 includes:

[0090] forming a first patterned mask layer 15 on the first surface S1 of the substrate 10;

[0091] The first shielding material layer 12′ and the first phase-shift material layer 11′ are etched using the first patterned mask layer 15 as a mask to expose the substrate 10, so as to transfer the pattern of the first patterned mask layer 15 to the first shielding material layer 12′ and the first phase-shift material layer 11′, and form the first shielding structure 12 and the first phase-shift structure 11 on the first surface S1 of the second region 102, respectively.

[0092] Next, if Fig. 9 As shown, after etching the first shielding material layer 12 ′ and the first phase-shifting material layer 11 ′ to form the first shielding structure 12 and the first phase-shifting structure 11 respectively, the method further includes: removing the first shielding structure 12 located in the middle area of ​​the second area 102 , and the remaining first shielding structure 12 is arranged along the edge of the second area 102 .

[0093] See again Figure 11 to Figure 12 , etching the second phase-shift material layer 13′ to form a second phase-shift structure 13, comprising:

[0094] forming a second patterned mask layer 17 on the second surface S2 of the substrate 10;

[0095] The second shielding material layer 14′ and the second phase-shift material layer 13′ are etched using the second patterned mask layer 17 as a mask to expose the substrate 10, so as to transfer the pattern of the second patterned mask layer 17 to the second shielding material layer 14′ and the second phase-shift material layer 13′, and form a second shielding structure 14 and a second phase-shift structure 13 on the second surface S2 of the first region 101, respectively.

[0096] Next, if Figure 1 As shown, after etching the second shielding material layer 14 ′ and the second phase-shifting material layer 13 ′ to form the second shielding structure 14 and the second phase-shifting structure 13 respectively, the second shielding structure 14 located in the middle area of ​​the first area 101 is removed, and the remaining second shielding structure 14 is arranged along the edge of the first area 101 .

[0097] In actual operation, the first surface S1 of the substrate 10 may be turned upward to etch the first phase-shift material layer 11′ and the first shielding material layer 12′; then, the second surface S2 of the substrate 10 may be turned upward to etch the second phase-shift material layer 13′ and the second shielding material layer 14′. Fig.10 As shown, before etching the second phase-shift material layer 13' and the second shielding material layer 14', a protective layer 16 is formed. The protective layer 16 covers the first surface S1 of the substrate 10 and fills the gap between the adjacent first phase-shift structures 11 and the first shielding structures 12. The protective layer 16 plays a protective role to prevent the first surface S1 of the substrate 10, the first phase-shift structure 11 and the first shielding structure 12 from being damaged in subsequent processes. Figure 1 As shown, the protective layer 16 can be removed in a subsequent process. The material of the protective layer 16 includes resin, such as nitrocellulose resin, fluorine-containing resin, etc.

[0098] However, the present invention is not limited thereto, and the second phase-shift material layer 13′ and the second shielding material layer 14′ may be etched first, and then the first phase-shift material layer 11′ and the first shielding material layer 12′ may be etched. Before etching the first phase-shift material layer 11′ and the first shielding material layer 12′, a protective layer 16 may be formed on the second surface S2 of the substrate 10.

[0099] In one embodiment, the number of the first phase shift structure 11 and the number of the second phase shift structure 13 are both plural, and the plural first phase shift structures 11 are discretely arranged on the first surface S1 of the second region 102, and the plural second phase shift structures 13 are discretely arranged on the second surface S2 of the first region 101, wherein an outgoing light beam at a position covered by the first phase shift structure 11 through the substrate 10 and an outgoing light beam at a position between adjacent first phase shift structures 11 through the substrate 10 have a phase difference of 180°, and an outgoing light beam at a position covered by the second phase shift structure 13 through the substrate 10 and an outgoing light beam at a position between adjacent second phase shift structures 13 through the substrate 10 have a phase difference of 180°. Thus, in actual operation, when the photoresist on the wafer under the mask is exposed, the light intensity of the dark area is weakened and the light intensity of the bright area is enhanced due to destructive interference between adjacent patterns on the wafer surface, thereby improving the exposure resolution.

[0100] In the embodiment of the present disclosure, a first phase shift structure 11 is arranged on the first surface S1 of the substrate, and a second phase shift structure 13 is arranged on the second surface S2. The transmittance of the first phase shift structure 11 and the transmittance of the second phase shift structure 13 are different, thereby meeting different requirements of different patterns on the transmittance of the phase shift structure. Therefore, different patterns (such as dot patterns and strip patterns) can be transferred to the wafer at the same time by using one mask, thereby reducing the number of masks used, and further reducing the process steps and process costs.

[0101] In one embodiment, the first shielding structure 12 and the second shielding structure 14 are both annular. The disclosed embodiment uses the opaque first shielding structure 12 and the second shielding structure 14 to cover the edge of the substrate 10, which can prevent the edge area of ​​the mask from transmitting light and affecting the exposure quality.

[0102] Figure 1The first shielding structure 12 shown in the figure completely overlaps with the orthographic projection of the first phase-shifting structure 11 located at the edge of the second region 102 on the second region 102, and the second shielding structure 14 completely overlaps with the orthographic projection of the second phase-shifting structure 13 located at the edge of the first region 101 on the first region 101. However, the present invention is not limited thereto. The first shielding structure 12 may also only cover a portion of the first phase-shifting structure 11 located at the edge of the second region 102, and the second shielding structure 14 may also only cover a portion of the second phase-shifting structure 13 located at the edge of the first region 101.

[0103] Figure 1 The first surface S1 of the first region 101 of the substrate 10 shown in FIG. 1 is flush with the first surface S1 of the second region 102, and the second surface S2 of the first region 101 is flush with the second surface S2 of the second region 102. However, this is not limited to this. Fig.13 As shown, in another embodiment of the present disclosure, before forming the first phase-shift material layer 11 ′ on the first surface S1 of the substrate 10 , the method further includes:

[0104] Etching the first surface S1 of the second region 102 so that the first surface S1 of the second region 102 is recessed relative to the first surface S1 of the first region 101 along a direction perpendicular to the first surface S1, and the first surface S1 of the second region 102 and the first surface S1 of the first region 101 have a first preset height difference H1;

[0105] Before forming the second phase-shift material layer 13 ′ on the second surface S2 of the first region 101 , the method further includes:

[0106] The second surface S2 of the first region 101 is etched to be recessed relative to the second surface S2 of the second region 102 along a direction perpendicular to the second surface S2, and the second surface S2 of the first region 101 and the second surface S2 of the second region 102 have a second preset height difference H2.

[0107] Then, if Fig.14 As shown, a first phase-shift material layer 11′ and a first shielding material layer 12′ are formed on the first surface S1 of the substrate 10, and a second phase-shift material layer 13′ and a second shielding material layer 14′ are formed on the second surface S2 of the substrate 10; wherein the thickness of the first phase-shift material layer 11′ is equal to the first preset height difference H1, and a surface W3 of the first phase-shift material layer 11′ located in the second region 102 away from the second region 102 is flush with the first surface S1 of the first region 101; the thickness of the second phase-shift material layer 13′ is equal to the second preset height difference H2, and a surface W4 of the second phase-shift material layer 13′ located in the first region 101 away from the first region 101 is flush with the second surface S2 of the second region 102.

[0108] Then, in Fig.14 Based on Figures 7 to 9 The same steps are used to form Fig.15 The structure shown is to form a first phase shift structure 11 on the first surface S1 of the second region 102 and a first shielding structure 12 arranged along the edge of the second region 102 ; wherein a surface W1 of the first phase shift structure 11 away from the second region 102 is flush with the first surface S1 of the first region 101 .

[0109] Then, in Fig.15 Based on Figures 10 to 12 , Figure 1 The same steps eventually form Figure 2 The structure shown is to form a second phase shift structure 13 on the second surface S2 of the first region 101 and a second shielding structure 14 arranged along the edge of the first region 101 ; wherein a surface W2 of the second phase shift structure 13 away from the first region 101 is flush with the second surface S2 of the second region 102 .

[0110] In the embodiment of the present disclosure, by arranging the surface W1 of the first phase shift structure 11 away from the second area 102 to be flush with the first surface S1 of the first area 101, and the surface W2 of the second phase shift structure 13 away from the first area 101 to be flush with the second surface S2 of the second area 102, the focal points of the outgoing light beams from the first area 101 and the second area 102 tend to fall on the same plane, thereby facilitating exposure.

[0111] like Fig.16 As shown, in one specific embodiment, the second surface S2 of the first region 101 is flush with the first surface S1 of the second region 102. Fig.16 Based on Figure 14 to Figure 15 as well as Figure 2 The same steps are used to form Figure 3 More specifically, the thickness of the first phase shift structure 11 is equal to the first preset height difference H1, so that the surface W1 of the first phase shift structure 11 away from the second area 102 is flush with the first surface S1 of the first area 101, and the thickness of the second phase shift structure 13 is equal to the second preset height difference H2, so that the surface W2 of the second phase shift structure 13 away from the first area 101 is flush with the second surface S2 of the second area 102, so that the focal points of the outgoing light beams of the first area 101 and the second area 102 are located in the same plane, which is more conducive to exposure.

[0112] It should be noted that the above is only a preferred embodiment of the present disclosure and is not intended to limit the scope of protection of the present disclosure. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present disclosure should be included in the scope of protection of the present disclosure.

Claims

1. A mask, characterized in that: include: A substrate, the substrate comprising a first surface and a second surface opposite to the first surface, the substrate further comprising a first region and a second region; a first phase-shift structure, located on a first surface of the second region; The second phase-shift structure is located on the second surface of the first region; wherein the first phase-shift structure and the second phase-shift structure have different light transmittances.

2. The mask according to claim 1, characterized in that: The first surface of the second region is recessed relative to the first surface of the first region in a direction perpendicular to the first surface, so that the first surface of the second region and the first surface of the first region have a first preset height difference, and the surface of the first phase-shift structure away from the second region is flush with the first surface of the first region.

3. The mask according to claim 2, characterized in that: The second surface of the first region is recessed relative to the second surface of the second region in a direction perpendicular to the second surface, so that the second surface of the first region and the second surface of the second region have a second preset height difference, and a surface of the second phase-shift structure away from the first region is flush with the second surface of the second region.

4. The mask according to claim 3, characterized in that: The second surface of the first region is flush with the first surface of the second region.

5. The mask according to claim 1, characterized in that: The first surface of the first region is flush with the first surface of the second region, and the second surface of the first region is flush with the second surface of the second region.

6. The mask according to claim 1, characterized in that: The mask further includes: a first shielding structure and a second shielding structure, wherein the first shielding structure covers a portion of the first phase-shifting structure and is disposed along an edge of the second region, and the second shielding structure covers a portion of the second phase-shifting structure and is disposed along an edge of the first region.

7. The mask according to claim 1, characterized in that: The light transmittance of the first phase shift structure is greater than that of the second phase shift structure. The first phase shift structure is used to form an array area of ​​a memory, and the second phase shift structure is used to form a core area of ​​the memory.

8. A method for manufacturing a mask, characterized in that: include: Providing a substrate, the substrate comprising a first surface and a second surface opposite to the first surface, the substrate further comprising a first region and a second region; forming a first phase-shift material layer on the first surface of the substrate, the first phase-shift material layer at least covering the second region, and forming a second phase-shift material layer on the second surface of the substrate, the second phase-shift material layer at least covering the first region; wherein the first phase-shift material layer and the second phase-shift material layer have different light transmittances; The first phase-shift material layer is etched to form a first phase-shift structure on the first surface of the second region, and the second phase-shift material layer is etched to form a second phase-shift structure on the second surface of the first region.

9. The manufacturing method according to claim 8, characterized in that: Before forming the first phase-shift material layer on the first surface of the substrate, the method further includes: The first surface of the second region is etched so that the first surface of the second region is recessed relative to the first surface of the first region in a direction perpendicular to the first surface, the first surface of the second region and the first surface of the first region have a first preset height difference, and a surface of the first phase-shift material layer in the second region away from the second region is flush with the first surface of the first region.

10. The manufacturing method according to claim 8, characterized in that: Before forming a second phase-shift material layer on the second surface of the substrate, the method further includes: The second surface of the first region is etched so that the second surface of the first region is recessed relative to the second surface of the second region in a direction perpendicular to the second surface, the second surface of the first region and the second surface of the second region have a second preset height difference, and a surface of the second phase-shift material layer in the first region away from the first region is flush with the second surface of the second region.

11. The manufacturing method according to claim 8, characterized in that: Before etching the first phase-shift material layer to form the first phase-shift structure, the method further includes: forming a first shielding material layer, wherein the first shielding material layer covers the first phase-shift material layer; Etching the first phase-shift material layer to form the first phase-shift structure includes: forming a first patterned mask layer on a first surface of the substrate; Using the first patterned mask layer as a mask, etching the first shielding material layer and the first phase-shift material layer until the substrate is exposed, so as to transfer the pattern of the first patterned mask layer to the first shielding material layer and the first phase-shift material layer, and respectively forming a first shielding structure and a first phase-shift structure on the first surface of the second region; The method further includes: removing the first shielding structure located in a middle area of ​​the second area, and the remaining first shielding structure is arranged along an edge of the second area.

12. The manufacturing method according to claim 8, characterized in that: Before etching the second phase-shift material layer to form the second phase-shift structure, the method further includes: forming a second shielding material layer, wherein the second shielding material layer covers the second phase-shift material layer; Etching the second phase-shift material layer to form the second phase-shift structure includes: forming a second patterned mask layer on the second surface of the substrate; Using the second patterned mask layer as a mask, etching the second shielding material layer and the second phase-shift material layer until the substrate is exposed, so as to transfer the pattern of the second patterned mask layer to the second shielding material layer and the second phase-shift material layer, and respectively forming a second shielding structure and a second phase-shift structure on the second surface of the first region; The method further includes: removing the second shielding structure located in a middle area of ​​the first area, and the remaining second shielding structure is arranged along an edge of the first area.

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