Attenuated phase-shift mask and manufacturing method thereof

Abstract

The present application provides an attenuated phase-shift mask and a manufacturing method thereof, and relates to the field of semiconductor manufacturing technology. The present application provides a transparent substrate including a first surface and a second surface arranged opposite to each other, then forms a light-shielding film layer on the first surface of the transparent substrate, and etches a pattern groove for representing a target mask pattern on the light-shielding film layer to obtain a mask structure to be processed, and then deposits a growth phase-shift layer on the surface of the mask structure to be processed that is opposite to the second surface, and finally etches the grown phase-shift layer so that the remaining phase-shift layer is only attached to the groove wall of the pattern groove, so that the obtained attenuated phase-shift mask is significantly different from the traditional attenuated phase-shift mask structure, and there is no need to worry that the phase-shift layer will show different thickness sizes at different positions under the etching operation, so as to ensure that the prepared attenuated phase-shift mask can achieve the expected attenuation value and improve the mask preparation yield.

Description

Technical Field

[0001] The present application relates to the field of semiconductor process technology, and in particular to an attenuated phase-shift mask and a process method thereof. Background Art

[0002] With the continuous development of science and technology, in order to meet the different needs of various industries for semiconductor devices, it is necessary to ensure that the semiconductor process has a higher lithography resolution, and various lithography resolution enhancement technologies have emerged. Among them, Phase Shift Mask (PSM) technology is a commonly used lithography resolution enhancement technology, which can make the light beams of adjacent light-transmitting areas of the mask pattern on the mask plate produce a 180-degree phase difference, ensuring that the light intensity of the dark area caused by destructive interference between adjacent patterns on the silicon wafer surface is weakened, thereby improving the observation contrast and lithography resolution.

[0003] In the actual application of PSM technology, the attenuated phase-shift mask is a commonly used phase-shift mask. The traditional attenuated phase-shift mask includes a stacked transparent glass, a phase-shift layer and a light-shielding layer. The phase-shift layer needs to be etched to form the final mask pattern. The specific attenuation value of the attenuated phase-shift mask needs to be achieved by adjusting the actual thickness of the phase-shift layer. However, in the actual process, it is usually difficult to accurately control the etching time at different positions of the phase-shift layer, resulting in uneven thickness of the phase-shift layer at different positions in the same mask, which in turn affects the specific attenuation value of the attenuated phase-shift mask and fails to achieve the expected attenuation. Summary of the invention

[0004] In view of this, the purpose of the present application is to provide an attenuated phase-shift mask and a manufacturing method thereof, which can ensure that the prepared attenuated phase-shift mask can reach the expected attenuation value and improve the mask manufacturing yield.

[0005] In order to achieve the above purpose, the technical solution adopted in the embodiment of the present application is as follows:

[0006] In a first aspect, an embodiment of the present application provides a method for manufacturing an attenuated phase shift mask, the method comprising:

[0007] Providing a transparent substrate, wherein the transparent substrate comprises a first surface and a second surface disposed opposite to each other;

[0008] Forming a light-shielding film layer on the first surface of the transparent substrate, and etching a pattern groove for representing a target mask pattern on the light-shielding film layer to obtain a mask structure to be processed;

[0009] Depositing a growth phase shift layer on a surface of the mask structure to be processed that is opposite to the second surface;

[0010] The grown phase-shift layer is etched so that the remaining phase-shift layer is only attached to the groove wall of the pattern groove to obtain the attenuated phase-shift mask.

[0011] In an optional embodiment, etching a pattern groove for representing a target mask pattern on the light shielding film layer to obtain a mask structure to be processed includes:

[0012] Spin-coating a photoresist layer on a surface of the light-shielding film layer that is opposite to the first surface;

[0013] Exposing and developing the photoresist layer according to the target mask pattern to form a pattern to be transferred corresponding to the target mask pattern on the photoresist layer;

[0014] Using the photoresist layer having the pattern to be transferred as a mask, transferring the pattern to be transferred to the light shielding film layer by etching to form the pattern groove connected to the transparent substrate;

[0015] The photoresist layer is cleaned to obtain the mask structure to be processed.

[0016] In an optional embodiment, the phase-shift layer is formed by atomic layer deposition of molybdenum silicon compound.

[0017] In an optional embodiment, the material of the light-shielding film layer includes any one of chromium metal, iron dioxide, and chromium-molybdenum compounds.

[0018] In an optional embodiment, the deposition thickness of the phase-shift layer is in the range of 10 nm to 50 nm.

[0019] In a second aspect, an embodiment of the present application provides an attenuated phase shift mask, wherein the attenuated phase shift mask comprises a transparent substrate and a light shielding film layer;

[0020] The light shielding film layer is arranged on a side surface of the transparent substrate, and a pattern groove for representing a target mask pattern is opened on the light shielding film layer;

[0021] A phase shift layer is attached to the groove wall of the pattern groove.

[0022] In an optional embodiment, a projection height of the phase-shift layer on a plane perpendicular to the bottom of the pattern groove is less than or equal to a thickness of the light-shielding film layer.

[0023] In an optional embodiment, the phase-shift layer is made of molybdenum-silicon compound.

[0024] In an optional embodiment, the material of the light-shielding film layer includes any one of chromium metal, iron dioxide, and chromium-molybdenum compounds.

[0025] In an optional embodiment, a projected thickness of the phase-shift layer on a plane parallel to the bottom of the pattern groove is in a range of 10 nm to 50 nm.

[0026] The beneficial effects of the embodiments of the present application include the following:

[0027] The present application provides a transparent substrate including a first surface and a second surface that are arranged opposite to each other, then forms a light-shielding film layer on the first surface of the transparent substrate, and etches a pattern groove for representing a target mask pattern on the light-shielding film layer to obtain a mask structure to be processed, and then deposits a growth phase-shift layer on a surface of the mask structure to be processed that is opposite to the second surface, and finally etches the grown phase-shift layer so that the remaining phase-shift layer is only attached to the groove wall of the pattern groove, so that the obtained attenuated phase-shift mask is significantly different from the traditional attenuated phase-shift mask structure, and there is no need to worry that the phase-shift layer will show different thickness sizes at different positions under the etching operation, so as to ensure that the prepared attenuated phase-shift mask can achieve the expected attenuation value and improve the mask preparation yield.

[0028] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, preferred embodiments are specifically cited below and described in detail with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0030] Figure 1 A schematic diagram of the structure of an attenuated phase-shift mask provided in an embodiment of the present application;

[0031] Figure 2 A schematic flow chart of a method for manufacturing an attenuated phase-shift mask provided in an embodiment of the present application;

[0032] Figure 3 for Figure 2 A schematic structural diagram of a device structure corresponding to step S210 in FIG.

[0033] Figure 4 for Figure 2 A schematic structural diagram of a device structure corresponding to step S220 in FIG.

[0034] Figure 5 for Figure 2 A schematic structural diagram of a device structure corresponding to step S230 in FIG.

[0035] Figure 6 for Figure 2 A schematic structural diagram of a device structure corresponding to step S240 in FIG.

[0036] Figure 7 for Figure 2 A schematic flow chart of the sub-steps included in step S220;

[0037] Figure 8 for Figure 7 A schematic structural diagram of the device structure corresponding to sub-step S221 in FIG.

[0038] Fig. 9 for Figure 7 A schematic structural diagram of the device structure corresponding to sub-step S222 in FIG.

[0039] Fig.10 for Figure 7 A schematic structural diagram of the device structure corresponding to sub-step S223 in FIG.

[0040] Fig.11 for Figure 7 A schematic structural diagram of the device structure corresponding to sub-step S224 in FIG.

[0041] Icons: 100 - attenuated phase-shift mask; 110 - transparent substrate; 111 - first surface; 112 - second surface; 120 - light-shielding film layer; 130 - pattern groove; 140 - phase-shift layer; 150 - photoresist layer; 160 - mask structure to be processed. DETAILED DESCRIPTION

[0042] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.

[0043] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for which protection is sought, but merely represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0044] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0045] In the description of the present application, it should be understood that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, or are the orientations or positional relationships in which the product of the application is conventionally placed when in use, or are the orientations or positional relationships conventionally understood by those skilled in the art. They are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0046] In the description of this application, it should also be noted that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0047] In addition, relational terms such as the terms "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or equipment. In the absence of further restrictions, the elements defined by the statement "comprise one..." do not exclude the existence of other identical elements in the process, method, article or equipment including the elements. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood by specific circumstances.

[0048] The applicant has found through hard research that the manufacturing method of the traditional attenuated phase shift mask is to sequentially arrange a phase shift layer, a light shielding layer and a photoresist layer on a transparent substrate, and then process the photoresist layer by electron beam exposure and development based on the expected mask pattern to expose the light shielding layer area to be processed, and then etch the exposed light shielding layer area, and simultaneously etch the area where the projection position overlaps on the phase shift layer, and then complete the photoresist cleaning process to obtain a structure including the overall mask pattern. Then, spin-coat the light shielding layer surface with photoresist, and use electron beam exposure and development to process the photoresist to expose the light shielding layer area within the main image area, and etch the light shielding layer area within the main image area, and finally clean the photoresist to obtain the corresponding attenuated phase shift mask. The attenuated phase shift mask prepared by this process method is usually difficult to accurately control the stop time of the secondary etching, resulting in the final phase shift layer structure being uneven in thickness due to partial etching, which in turn affects the attenuation value of the attenuated phase shift mask, and there is a problem of low yield. To this end, the applicant provides a mask manufacturing method to prepare a new attenuated phase-shift mask whose structure is significantly different from that of a traditional attenuated phase-shift mask, to ensure that the prepared attenuated phase-shift mask can achieve the expected attenuation value and improve the mask manufacturing yield.

[0049] In conjunction with the accompanying drawings, some embodiments of the present application are described in detail below. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0050] Please refer to Figure 1 , Figure 1 1 is a schematic diagram of the structure of the attenuated phase shift mask 100 provided in the embodiment of the present application. In the embodiment of the present application, the attenuated phase shift mask 100 can be prepared by a conventional preparation process, and the prepared attenuated phase shift mask 100 has a significantly different structure from a conventional attenuated phase shift mask, can normally show the expected attenuation value, and has a good mask preparation yield.

[0051] In this embodiment, the attenuated phase-shift mask 100 includes a transparent substrate 110 and a light-shielding film layer 120. The transparent substrate 110 includes a first surface 111 and a second surface 112 that are arranged opposite to each other. The light-shielding film layer 120 is arranged on one side surface (i.e., the first surface 111) of the transparent substrate 110. The light-shielding film layer 120 is provided with a pattern groove 130 for representing a target mask pattern designed by a semiconductor device developer, so that the bottom of the pattern groove 130 is directly connected to the first surface 111 of the transparent substrate 110. At this time, the pattern groove 130 is formed by the cooperation between the transparent substrate 110 and the light-shielding film layer 120, and the pattern groove 130 can represent a light-transmitting area of ​​the attenuated phase-shift mask 100 that matches the target mask pattern.

[0052] The transparent substrate 110 is used for allowing exposure light to pass through, and can be made of completely light-transmitting quartz glass; the light-shielding film layer 120 is used to prevent light from passing through and can cooperate with the transparent substrate 110 to limit the light-transmitting area, and can be made of any one of chromium metal, iron dioxide, and chromium-molybdenum compounds. In one implementation of this embodiment, the transparent substrate 110 is made of completely light-transmitting quartz glass, and the light-shielding film layer 120 is made of chromium metal.

[0053] At the same time, the attenuated phase-shift mask 100 has a phase-shift layer 140 attached to the groove wall of the pattern groove 130, that is, the phase-shift layer 140 is attached to the surface of the light-shielding film layer 120 where the pattern groove 130 is formed, so that the light passing through the phase-shift layer 140 is inverted by the phase-shift layer 140, so that the light beam that has not passed through the phase-shift layer 140 and the light beam that has passed through the phase-shift layer 140 in the exposure light passing through the pattern groove 130 have a phase difference of 180 degrees, and the light intensity attenuation value of the attenuated phase-shift mask 100 can be ensured by adjusting the projection thickness of the phase-shift layer 140 on a plane parallel to the groove bottom (that is, the first surface 111) of the pattern groove 130, and / or controlling the projection height of the phase-shift layer 140 on a plane perpendicular to the groove bottom (that is, the first surface 111) of the pattern groove 130.

[0054] The phase-shift layer 140 can be made of molybdenum silicon compound by atomic layer deposition, and the projected thickness of the phase-shift layer 140 on a plane parallel to the bottom of the pattern groove 130 is in the range of 10nm to 50nm, and the projected height of the phase-shift layer 140 on a plane perpendicular to the bottom of the pattern groove 130 can also be in the range of 10nm to 50nm. In an implementation of this embodiment, the projected height of the phase-shift layer 140 on a plane perpendicular to the bottom of the pattern groove 130 needs to be less than or equal to the film thickness of the light-shielding film layer 120, so as to reduce the difficulty of preparing the attenuated phase-shift mask 100.

[0055] In the embodiments of the present application, Figure 1 The attenuated phase-shift mask 100 shown can ensure that the phase-shift layer 140 has a consistent projection thickness and projection height through a conventional manufacturing process, thereby ensuring that the attenuated phase-shift mask 100 can normally exhibit the expected attenuation value while having a mask structure different from that of a conventional attenuated phase-shift mask, thereby improving the mask manufacturing yield.

[0056] In the present application, in order to ensure that the above-mentioned attenuated phase shift mask 100 can be successfully manufactured and can achieve the expected attenuation value, and improve the mask manufacturing yield rate, the present application accordingly provides a process method for the above-mentioned attenuated phase shift mask 100, ensuring that the finally manufactured attenuated phase shift mask 100 has the aforementioned functions. The process method for the attenuated phase shift mask 100 provided by the present application is described in detail below.

[0057] Please refer to Figure 2 , Figure 2 1 is a flow chart of a method for manufacturing an attenuated phase-shift mask 100 provided in an embodiment of the present application.

[0058] In step S210 , a transparent substrate is provided, wherein the transparent substrate includes a first surface and a second surface which are oppositely disposed.

[0059] In this embodiment, Figure 3 yes Figure 2 A schematic diagram of the structure of the device corresponding to step S210 in FIG. Figure 3 In the embodiment, the first surface 111 and the second surface 112 of the transparent substrate 110 are two surfaces of the transparent substrate 110. The transparent substrate 110 is made of completely light-transmissive quartz glass.

[0060] In step S220 , a light shielding film layer is formed on the first surface of the transparent substrate, and a pattern groove for representing a target mask pattern is etched on the light shielding film layer to obtain a mask structure to be processed.

[0061] In this embodiment, Figure 4 yes Figure 2 A schematic diagram of the structure of the device corresponding to step S220 in FIG. Figure 4 In the embodiment, the light shielding film layer 120 can be formed on the first surface 111 of the transparent substrate 110 by evaporation, coating, etc., and then a pattern groove 130 for representing a target mask pattern directly connected to the first surface 111 can be etched on the light shielding film layer 120 accordingly, thereby directly obtaining a corresponding mask structure 160 to be processed. The light shielding film layer 120 is made of any one of chromium metal, iron dioxide, and chromium-molybdenum compounds.

[0062] Step S230 , depositing a growth phase-shift layer on the surface of the mask structure to be processed that is opposite to the second surface.

[0063] In this embodiment, Figure 5 yes Figure 2 A schematic diagram of the structure of the device corresponding to step S230 in FIG. Figure 5In the embodiment, after the mask structure 160 to be processed is prepared, a complete phase-shift layer 140 can be directly formed on the surface of the mask structure 160 to be processed away from the second surface 112 by deposition. At this time, the surface of the mask structure 160 to be processed away from the second surface 112 includes the surface of the light shielding film layer 120 opposite to the second surface 112 after the pattern groove 130 is constructed, and the groove wall surface of the pattern groove 130. In this embodiment, the complete phase-shift layer 140 can be formed by atomic layer deposition of molybdenum silicon compound, and the deposition thickness of the complete phase-shift layer 140 is in the range of 10nm to 50nm.

[0064] Step S240, etching the grown phase-shift layer so that the remaining phase-shift layer is only attached to the groove wall of the pattern groove, thereby obtaining an attenuated phase-shift mask.

[0065] In this embodiment, Figure 6 yes Figure 2 A schematic diagram of the structure of the device corresponding to step S240 in FIG. Figure 6 In the embodiment, after the phase-shift layer 140 is deposited on the surface of the mask structure 160 to be processed which is away from the second surface 112, the grown phase-shift layer 140 can be etched so that the remaining phase-shift layer 140 is only attached to the groove wall of the pattern groove 130, so that the projection thickness of the residual phase-shift layer 140 on the plane parallel to the first surface 111 is kept consistent through a simple etching process, and the projection height of the residual phase-shift layer 140 on the plane perpendicular to the first surface 111 is kept consistent and is not greater than the film thickness of the light-shielding film layer 120, and there is no need to worry that the phase-shift layer 140 will show different thickness dimensions at different positions under the etching operation, so as to ensure that the attenuated phase-shift mask 100 finally prepared can reach the expected attenuation value, and improve the mask preparation yield. In one implementation of this embodiment, the projection height of the phase-shift layer 140 on the plane perpendicular to the first surface 111 can also be in the range of 10nm to 50nm.

[0066] In an embodiment of the present application, in order to ensure that the above-mentioned mask structure 160 to be processed can be successfully prepared normally, the present application elaborates on the step S220 of etching a pattern groove 130 for representing the target mask pattern on the shading film layer 120 to obtain the mask structure 160 to be processed.

[0067] Please refer to Figure 7 , Figure 7 yes Figure 2 Schematic diagram of the flow of sub-steps included in step S220 of FIG. In this embodiment, step S220 may include sub-steps S221 to S224.

[0068] Sub-step S221 , spin-coating a photoresist layer on the surface of the light-shielding film layer that is away from the first surface.

[0069] In this embodiment, Figure 8 yes Figure 7 A schematic diagram of the structure of the device corresponding to the sub-step S221 in FIG. Figure 8 In the embodiment, the light shielding film layer 120 is prepared and formed on the first surface 111 of the transparent substrate 110, and then a complete photoresist layer 150 can be formed on the surface of the light shielding film layer 120 away from the first surface 111 by spin coating photoresist. The photoresist layer 150 is used to transfer the target mask pattern to the light shielding film layer 120 to form the corresponding pattern groove 130, and the photoresist layer 150 can be formed by positive or negative photoresist material.

[0070] Sub-step S222, exposing and developing the photoresist layer according to the target mask pattern to form a pattern to be transferred corresponding to the target mask pattern on the photoresist layer.

[0071] In this embodiment, Fig. 9 yes Figure 7 A schematic diagram of the structure of the device corresponding to the sub-step S222 in FIG. Fig. 9 In the embodiment, when a complete photoresist layer 150 is formed on the surface of the light shielding film layer 120 away from the first surface 111, the photoresist layer 150 can be formed into a pattern to be transferred corresponding to the target mask pattern through operations such as exposure and development.

[0072] Sub-step S223, using the photoresist layer with the pattern to be transferred as a mask, transferring the pattern to be transferred to the light shielding film layer by etching, so as to form a pattern groove connected to the transparent substrate.

[0073] In this embodiment, Fig.10 yes Figure 7 A schematic diagram of the structure of the device corresponding to the sub-step S223 in FIG. Fig.10 In the process, after the pattern to be transferred is formed on the photoresist layer 150, the shading film layer 120 can be further etched according to the pattern to be transferred, so that the area on the shading film layer 120 overlapping with the position of the pattern to be transferred is etched to expose the first surface 111, thereby forming the pattern groove 130 connected to the transparent substrate 110.

[0074] Sub-step S224, cleaning the photoresist layer to obtain a mask structure to be processed.

[0075] In this embodiment, Fig.11In the process, after the construction operation of the pattern groove 130 is completed, the residual photoresist layer 150 can be cleaned to directly obtain the final mask structure 160 to be processed.

[0076] Therefore, by executing Figure 2 Steps S210 to S240 and Figure 7 The sub-steps S221 to S224 shown are used to prepare a new attenuated phase-shift mask 100 that is significantly different from the traditional attenuated phase-shift mask structure. There is no need to worry about the phase-shift layer showing different thicknesses at different positions during the etching operation, so as to ensure that the prepared attenuated phase-shift mask 100 can achieve the expected attenuation value and improve the mask preparation yield.

[0077] In summary, in the attenuated phase-shift mask and its manufacturing method provided in the embodiment of the present application, the present application provides a transparent substrate including a first surface and a second surface arranged opposite to each other, then forms a light-shielding film layer on the first surface of the transparent substrate, and etches a pattern groove for representing a target mask pattern on the light-shielding film layer to obtain a mask structure to be processed, and then deposits a growth phase-shift layer on the surface of the mask structure to be processed that is opposite to the second surface, and finally etches the grown phase-shift layer so that the residual phase-shift layer is only attached to the groove wall of the pattern groove, so that the obtained attenuated phase-shift mask is significantly different from the traditional attenuated phase-shift mask structure, and there is no need to worry that the phase-shift layer will show different thickness sizes at different positions under the etching operation, so as to ensure that the prepared attenuated phase-shift mask can achieve the expected attenuation value and improve the mask preparation yield.

[0078] The above are only various implementations of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A method for manufacturing an attenuated phase shift mask, characterized in that: The process method comprises: Providing a transparent substrate, wherein the transparent substrate comprises a first surface and a second surface disposed opposite to each other; Forming a light-shielding film layer on the first surface of the transparent substrate, and etching a pattern groove for representing a target mask pattern on the light-shielding film layer to obtain a mask structure to be processed, wherein the light-shielding film layer is made of chromium metal; Depositing a growth phase shift layer on a surface of the mask structure to be processed that is opposite to the second surface; The grown phase-shift layer is etched so that the remaining phase-shift layer is only attached to the groove wall of the pattern groove, thereby obtaining the attenuated phase-shift mask, wherein the phase-shift layer is formed by atomic layer deposition of molybdenum silicon compound, the projection thickness of the remaining phase-shift layer on a plane parallel to the first surface is kept consistent, and the projection height of the remaining phase-shift layer on a plane perpendicular to the first surface is ensured to be consistent and less than or equal to the film thickness of the light-shielding film layer.

2. The process method according to claim 1, characterized in that: The step of etching a pattern groove for representing a target mask pattern on the light shielding film layer to obtain a mask structure to be processed comprises: Spin-coating a photoresist layer on a surface of the light-shielding film layer that is opposite to the first surface; Exposing and developing the photoresist layer according to the target mask pattern to form a pattern to be transferred corresponding to the target mask pattern on the photoresist layer; Using the photoresist layer having the pattern to be transferred as a mask, transferring the pattern to be transferred to the light shielding film layer by etching to form the pattern groove connected to the transparent substrate; The photoresist layer is cleaned to obtain the mask structure to be processed.

3. The process method according to any one of claims 1 to 2, characterized in that: The deposition thickness of the phase-shift layer is in the range of 10 nm to 50 nm.

4. An attenuated phase shift mask, characterized in that: The attenuated phase-shift mask comprises a transparent substrate and a light-shielding film layer; The light shielding film layer is arranged on a side surface of the transparent substrate, and a pattern groove for representing a target mask pattern is opened on the light shielding film layer, wherein the light shielding film layer is made of chromium metal; A phase shift layer is attached to the groove wall of the pattern groove, wherein the material of the phase shift layer is molybdenum silicon compound, the projection thickness of the phase shift layer on a plane parallel to the groove bottom of the pattern groove remains consistent, and the projection height of the phase shift layer on a plane perpendicular to the groove bottom of the pattern groove remains consistent and is less than or equal to the film thickness of the light-shielding film layer.

5. The attenuated phase-shift mask according to claim 4, characterized in that: The projected thickness of the phase-shift layer on a plane parallel to the bottom of the pattern groove is in the range of 10 nm to 50 nm.

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