Phase shift mask plate, preparation method and film layer opening method
By forming a phase conversion layer and a second light shielding area of an annular structure around the light-transmitting area of the phase shift mask plate, the problem of the phase shift mask plate requiring more exposure dose and photoresist loss when forming holes is solved, and the problem of the phase shift mask plate requiring more exposure dose and photoresist loss is achieved. Improved exposure uniformity and process yield.
Patent Information
- Application Number
- CN202211154761.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2022-09-21
- Publication Date
- 2025-02-11
- Estimated Expiration
- 2042-09-21
AI Technical Summary
The phase shift mask plate requires more exposure dose when forming holes of the same size, resulting in a decrease in plant production capacity, and the improved Cr-rim PSM causes photoresist loss in areas outside the light transmission area, affecting subsequent process flow.
By forming a phase conversion layer of an annular structure and a second light-shielding region in the periphery of the light-shielding region, the phase shift region is positioned between the two light-shielding regions, reducing the intensity of light and protecting the photoresist.
It improves exposure uniformity, reduces photoresist losses, ensures the smooth progress of subsequent process flow, and improves process yield.
Smart Images
Figure CN115542655B_ABST
Abstract
Description
Technical Field
[0001] The present invention generally relates to the field of display technology, and in particular to a phase shift mask plate, a preparation method and a film layer opening method. Background Art
[0002] In the hole exposure process in the display technology field, the phase shift mask (PSM) is used to improve the exposure uniformity and ultimately improve the process yield. However, compared with conventional masks, phase shift masks require more exposure dose to form holes of the same size, which affects the factory's production capacity.
[0003] In order to improve the problem of increased exposure dose, an improved chrome edge phase shift mask (Cr-rimPSM) in the related art improves exposure uniformity while avoiding the waste of exposure energy in the light-transmitting area.
[0004] For the improved Cr-rim PSM, photoresist loss (PR Loss) will be caused in the area outside the light-transmitting area, affecting the subsequent process flow. Summary of the invention
[0005] In view of the above-mentioned defects or deficiencies in the prior art, it is desired to provide a phase-shift mask plate, a preparation method and a film layer opening method, by setting the phase conversion layer outside the light-transmitting area into a ring structure so that it is located between two shading areas, so as to improve the exposure uniformity while avoiding photoresist loss.
[0006] In a first aspect, an embodiment of the present application provides a phase shift mask, comprising:
[0007] A transparent substrate, wherein a light shielding area and a phase shift area are formed around a light transmission area on the transparent substrate, wherein the light transmission area is used to form an opening, and the phase shift area is used to change the phase of light passing therethrough to reduce the intensity of light passing through the phase shift area;
[0008] The shading area includes a first shading area and a second shading area. The orthographic projection of the first shading area on the transparent substrate surrounds the light-transmitting area. The orthographic projection of the phase shift area on the transparent substrate surrounds the first shading area. The orthographic projection of the second shading area on the transparent substrate surrounds the phase shift area.
[0009] Optionally, in some embodiments of the phase shift mask of the present application, a shading layer and a phase conversion layer are arranged on the same side of the transparent substrate, and the orthographic projection of the area where the shading layer is located on the transparent substrate forms the shading area, and the orthographic projection of the phase conversion layer on the transparent substrate forms the phase shift area.
[0010] Optionally, in some embodiments of the phase shift mask of the present application, a shading layer and a phase conversion layer are arranged on the same side of the transparent substrate, and the orthographic projection of the area where the shading layer is located on the transparent substrate forms the shading area, and the orthographic projection of the phase conversion layer on the transparent substrate forms the phase shift area.
[0011] Optionally, in the phase shift mask in some embodiments of the present application, the phase conversion layer is disposed close to the transparent substrate, and the light shielding layer is disposed on the phase conversion layer.
[0012] Optionally, in some embodiments of the phase-shift mask of the present application, the width of the edges in the annular structure of the first light-shielding area and the phase-shift area is 0.3 μm to 1.5 μm.
[0013] Optionally, in the phase-shift mask in some embodiments of the present application, the light-shielding layer is a metal chromium layer, and the phase conversion layer is a semi-transparent oxide film layer.
[0014] In a second aspect, an embodiment of the present application provides a method for preparing a phase shift mask plate, the method comprising:
[0015] forming a phase conversion layer and a light shielding layer on a transparent substrate;
[0016] Patterning is performed on the bit conversion layer and the light-shielding layer to form a light-shielding pattern layer including a light-shielding area and a phase conversion pattern layer in a phase-shift area. The light-shielding area includes a first light-shielding area and a second light-shielding area. The orthographic projection of the first light-shielding area on the transparent substrate surrounds the light-transmitting area; the orthographic projection of the phase-shifting area on the transparent substrate surrounds the first light-shielding area; the orthographic projection of the second light-shielding area on the transparent substrate surrounds the phase-shifting area. The light-transmitting area is used to form an opening, and the phase-shifting area is used to change the phase of light passing therethrough to reduce the intensity of light passing through the phase-shifting area.
[0017] Optionally, in some embodiments of the present application, the method for preparing a phase shift mask plate, wherein the phase conversion layer and the light shielding layer are formed on a transparent substrate, comprises:
[0018] forming the phase conversion layer on the transparent substrate;
[0019] The light shielding layer is formed on the phase conversion layer.
[0020] Optionally, in some embodiments of the present application, the method for preparing the phase shift mask plate, wherein patterning is performed on the bit conversion layer and the light shielding layer to form a light shielding pattern layer including a light shielding area and a phase conversion pattern layer including a phase shift area, comprises:
[0021] forming a first photoresist layer on the light shielding layer;
[0022] Using the light-transmitting area as a mask pattern, patterning the first photoresist layer to form a first photoresist pattern layer;
[0023] Using the first photoresist pattern layer as a mask, etching the phase conversion layer and the light shielding layer to form a light-transmitting area;
[0024] forming a second photoresist layer on the light shielding layer;
[0025] Using the annular structure of the phase shift region as a mask pattern, patterning the second photoresist layer to form a second photoresist pattern layer;
[0026] The light shielding layer is etched using the second photoresist pattern layer as a mask to form a light shielding pattern layer including a first light shielding area and a second light shielding area, and a phase conversion pattern layer including a phase shift area.
[0027] In a third aspect, an embodiment of the present application provides a method for opening a hole in a membrane layer, the method comprising:
[0028] forming a film layer on a substrate;
[0029] The phase-shift mask plate as described in the first aspect is used to perform patterning on the film layer to form openings on the film layer.
[0030] In summary, the phase-shift mask plate, preparation method and film layer opening method provided by the embodiments of the present application form two shading areas and one phase-shift area on the periphery of the light-transmitting area of the transparent substrate, and make the orthographic projection of the first shading area on the transparent substrate surround the light-transmitting area, and then make the orthographic projection of the phase-shift area on the transparent substrate surround the first shading area, and finally make the orthographic projection of the second shading area on the transparent substrate surround the phase-shift area, so that the shading area and the phase-shift area with an annular structure are formed in sequence on the transparent substrate around the light-transmitting area, and the second shading area is arranged around the phase-shift area outside the phase-shift area of the annular structure, so that the light-transmitting area is formed by using When the phase-shift mask plate forms an opening on the film layer, due to the phase-shift zone of the annular structure arranged outside the light-transmitting zone and the second shading zone outside the phase-shift zone of the annular structure, the phase-shift zone of the annular structure is utilized to realize phase modulation of the light to offset the diffraction of the light of the exposure machine and reduce the intensity of the light passing through the phase-shift zone to improve the exposure uniformity and the uniformity of the opening. At the same time, the second shading zone arranged outside the phase-shift zone can be utilized to protect the photoresist in the area outside the opening corresponding to the light-transmitting zone, avoid the loss of the photoresist, ensure the smooth progress of the subsequent process flow, and ultimately improve the process yield. BRIEF DESCRIPTION OF THE DRAWINGS
[0031] Other features, objects and advantages of the present application will become more apparent by reading the detailed description of non-limiting embodiments made with reference to the following drawings:
[0032] Figure 1 This is a schematic structural diagram of a phase shift mask according to an embodiment of the present application;
[0033] Figure 2 This is a schematic structural diagram of a phase shift mask according to an embodiment of the present application;
[0034] Figure 3 Schematic diagram of the array structure of the phase shift mask plate of the embodiment of the present application;
[0035] Figure 4 Schematic diagram of the process of preparing a phase-shift mask according to an embodiment of the present application.
[0036] 1-transparent substrate, 2-light-transmitting area, 3-first light-shielding area, 4-second light-shielding area, 5-phase shift area, 6-phase conversion layer, 7-light-shielding layer. DETAILED DESCRIPTION
[0037] The present application will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the relevant inventions, rather than to limit the inventions. It should also be noted that, for ease of description, only the parts related to the invention are shown in the accompanying drawings.
[0038] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.
[0039] It is understood that in the field of display technology, in the process of using a mask plate to expose holes, the mask plate used is usually provided with a light-shielding area around the light-transmitting area to expose and etch the light-transmitting area to form an opening. However, due to the diffraction of light at the edge of the light-transmitting area of the mask plate, the uniformity of the formed opening is poor.
[0040] In order to improve the uniformity of exposure, the conventional mask plate is improved. Specifically, a phase conversion film layer with a small amount of transmittance (such as 5.2%) is used instead of the shading layer of part of the metal Cr around the light-transmitting area as a mask. In the light-transmitting area of the Mask, the outgoing light of the exposure machine is modulated to cause a phase difference in the light, thereby offsetting part of the diffraction diffusion effect, changing the spatial light intensity distribution, and adjusting more energy from low frequency to high frequency. This makes up for the shortcoming of the exposure machine lens that passes low frequencies and blocks high frequencies, increases the spatial image contrast, and thus reduces the difficulty of exposure. Ultimately, the diffraction of the exposure machine is offset, the exposure uniformity is improved, the uniformity of the critical value (CD) of the small holes on the film layer is increased, and the process yield is improved.
[0041] For the above-mentioned improved structure, due to the offsetting effect of the phase conversion layer on the diffracted light, more exposure dose will be required during actual exposure.
[0042] In the related art, in order to improve the excessive demand for exposure dose, a shielding layer with an annular structure is arranged on the periphery of the light-transmitting area, and then a large-area phase conversion layer is arranged on the periphery of the shielding layer to reduce the demand for exposure dose.
[0043] In this structure, since a large-area phase conversion layer is provided, although the uniformity of the exposure is improved during the actual exposure process, it will cause waste of photoresist in the area outside the opening corresponding to the light-transmitting area, thereby affecting subsequent processes, such as affecting other wiring or opening processes in the area outside the opening.
[0044] A phase shift mask is provided in the embodiment of the present application. In order to achieve phase modulation of light by means of a phase conversion layer, the diffraction of the exposure machine is offset, the intensity of light passing through the phase shift zone is reduced, and the exposure uniformity is improved. While improving the uniformity of the opening, the loss of photoresist in the area outside the opening corresponding to the light-transmitting area on the film layer can be avoided, thereby ensuring the smooth progress of subsequent process flows and ultimately improving the process yield. By setting the phase conversion layer on the periphery of the shading area to an annular structure, and then setting a shading layer on the periphery of the phase conversion layer with the annular structure, the phase conversion layer with the annular structure can be used to ensure the exposure uniformity, and the shading layer set on the periphery of the phase conversion layer can also be used to protect the photoresist in the area outside the opening, thereby avoiding the loss of photoresist, ensuring the smooth progress of subsequent process flows and ultimately improving the process yield.
[0045] In order to better understand the phase shift mask and the preparation method thereof provided in the embodiments of the present application, Figures 1 to 4 Elaborate in detail.
[0046] Figure 1 A schematic diagram of the structure of the phase shift mask provided in the embodiment of the present application is shown in FIG. Figure 1 As shown, the phase shift mask plate includes:
[0047] A transparent substrate is provided with a light shielding area and a phase shift area formed around a light transmission area on the transparent substrate. The light transmission area is used to form an opening, and the phase shift area is used to change the phase of light passing through it to reduce the intensity of light passing through the phase shift area.
[0048] The shading area includes a first shading area and a second shading area. The orthographic projection of the first shading area on the transparent substrate surrounds the light-transmitting area. The orthographic projection of the phase shift area on the transparent substrate surrounds the first shading area. The orthographic projection of the second shading area on the transparent substrate surrounds the phase shift area.
[0049] Specifically, Figure 1 As shown, the phase shift mask provided in the embodiment of the present application forms a first light shielding area 3, a second light shielding area 4 and a phase shift area 5 located between the first light shielding area and the second light shielding area around the light transmission area 2 of the transparent substrate 1.
[0050] The light-transmitting area 2 is an exposure area of the phase-shift mask plate, and is used to form openings. For example, on a dielectric film layer or a metal film layer of a substrate, the light-transmitting area of the phase-shift mask plate is used to expose the photoresist to form openings.
[0051] It can be understood that the size and shape of the light-transmitting area can be flexibly set according to the usage scenario of the phase-shift mask plate, and the embodiments of the present application do not limit this.
[0052] The first light-shielding area is an annular area on the transparent substrate whose orthographic projection surrounds the light-transmitting area, so that in the process of forming an opening by using the phase-shift mask plate, a shielding area is formed around the light-transmitting area to block the passage of light.
[0053] Correspondingly, the phase shift zone is an annular area on the transparent substrate whose orthographic projection surrounds the light-transmitting zone. In the process of forming an opening using the phase shift mask, the phase of a small amount of light passing through is modulated to offset the diffraction of the exposure machine, improve the uniformity of exposure, and improve the boundary uniformity of the opening formed on the film layer, thereby ultimately improving the image quality of the product.
[0054] Furthermore, the second shading area is a protective area that surrounds the phase shift area with an orthographic projection on the transparent substrate, so that in the process of forming an opening using the phase shift mask plate, a shielding area is formed around the transparent area to protect the photoresist on the film layer except the opening area, thereby ensuring the normal progress of subsequent processes.
[0055] The phase shift mask plate of the embodiment of the present application can form corresponding light shielding areas and phase shifting areas by disposing a light shielding layer 5 and a phase conversion layer 6 on a transparent substrate.
[0056] like Figure 2 As shown, a shading layer 7 and a phase conversion layer 6 can be arranged on the same side of the transparent substrate, so that the projection of the area where the shading layer is located on the transparent substrate forms the shading area, and the projection of the phase conversion layer on the transparent substrate forms the phase shift area.
[0057] In addition, if Figure 2 As shown, the light shielding layer and the phase conversion layer can be stacked on the transparent substrate, such as the phase conversion layer is arranged close to the transparent substrate, and the light shielding layer is arranged on the phase conversion layer.
[0058] It can be understood that the specific configuration of the light-shielding layer forming the light-shielding area and the phase conversion layer forming the phase-shifting area are merely exemplary descriptions, and the embodiments of the present application do not impose any limitation thereto.
[0059] For example, in other embodiments, the shading layer and the phase conversion layer can be arranged on different sides of the transparent substrate; or, in other embodiments, when the shading layer and the phase conversion layer are arranged on the same side of the transparent substrate, the shading layer and the phase conversion layer can also be arranged on the same layer; or, when the stacked layers are arranged, the shading layer is close to the transparent substrate, and the phase conversion layer is then arranged on the shading layer.
[0060] Optionally, the light shielding layer in the embodiment of the present application may be a metal layer, such as a metal chromium layer.
[0061] The phase conversion layer may be a semi-transparent oxide film layer, such as a film layer having a light transmittance of 5.2%, and may specifically be an oxide film layer containing silicon and molybdenum.
[0062] It can also be understood that the phase conversion layer can also improve the exposure accuracy of 68s and 67s, improve the process edge characteristics, and thus improve the process yield.
[0063] It can be understood that the embodiments of the present application do not limit the specific materials of the light-shielding layer and the phase conversion layer, as long as they can achieve the corresponding light-shielding and phase modulation functions.
[0064] Optionally, in some embodiments of the present application, the width of the edges in the annular structures of the first light-shielding region and the phase-shift region is 0.3 μm to 1.5 μm.
[0065] That is Figure 2 As shown, the width w1 of the side of the light shielding layer of the annular structure around the light-transmitting area may be 0.3 μm to 1.5 μm; the width w2 of the side of the phase conversion layer of the annular structure may be 0.3 μm to 1.5 μm.
[0066] It is understood that the specific width of the side of the annular structure can be flexibly set according to actual conditions, and the embodiments of the present application do not limit this. For example, the two can be made the same according to actual needs, or the width of the side of the annular structure of the phase conversion layer can be appropriately increased in order to improve the exposure uniformity effect.
[0067] It is understandable. Figure 1 and Figure 2 The structure shown is a partial schematic diagram of a phase shift mask plate, which only includes a mask plate structure corresponding to a hole. The actual phase shift mask plate may include Figure 1 and Figure 2 Multiple structural units are shown.
[0068] For example, Figure 3 The top view of the phase-shift mask plate is shown. In some embodiments, the above-mentioned structural units distributed in an array can be formed on a transparent substrate, and the phase-shift mask plate can be used to form openings distributed in an array on a film layer of the substrate.
[0069] It can be understood that the second shading area in this embodiment is the other area except the light-transmitting area and the first shading area. That is, when the phase-shift mask is used to form an array of openings on the film layer of the substrate, the shading layer of the second shading area is formed to cover the large area of photoresist on the film layer, so that in the actual exposure process, the photoresist except the light-transmitting area can be effectively protected to avoid photoresist loss.
[0070] That is, the phase-shift mask plate of this embodiment, due to the phase-shift zone of the annular structure outside the light-transmitting zone and the second shading zone outside the phase-shift zone of the annular structure, can achieve phase modulation of light by utilizing the phase-shift zone of the annular structure to offset the diffraction of the exposure machine, so as to reduce the intensity of light passing through the phase-shift zone, improve exposure uniformity, and improve the uniformity of the opening. At the same time, the second shading zone arranged outside the phase-shift zone can be used to protect the photoresist in the area outside the opening corresponding to the light-transmitting zone, avoid the loss of photoresist, ensure the smooth progress of subsequent process flow, and ultimately improve the process yield.
[0071] On the other hand, an embodiment of the present application also provides a method for preparing a phase-shift mask.
[0072] Specifically, in the preparation method, first, a phase conversion layer and a light-shielding layer can be formed on a transparent substrate; then, the phase conversion layer and the light-shielding layer can be patterned to form a light-shielding pattern layer including a light-shielding area, and a phase conversion pattern layer including a phase shift area, the light-shielding area including a first light-shielding area and a second light-shielding area, the orthographic projection of the first light-shielding area on the transparent substrate surrounds the light-transmitting area; the orthographic projection of the phase shift area on the transparent substrate surrounds the first light-shielding area; the orthographic projection of the second light-shielding area on the transparent substrate surrounds the phase shift area, the light-transmitting area is used to form an opening, and the phase shift area is used to change the phase of light passing through it to reduce the intensity of light passing through the phase shift area.
[0073] Optional, for example Figure 2 and Figure 3 The preparation method of the phase shift mask plate shown in Figure 4 As shown, the method may specifically include the following steps:
[0074] S01, forming the phase conversion layer on the transparent substrate.
[0075] S02, forming the light shielding layer on the phase conversion layer.
[0076] S03, forming a first photoresist layer on the light shielding layer.
[0077] S04, using the light-transmitting area as a mask pattern, patterning the first photoresist layer to form a first photoresist pattern layer.
[0078] S05, using the first photoresist pattern layer as a mask, etching the phase conversion layer and the light shielding layer to form a light-transmitting area.
[0079] S06, forming a second photoresist layer on the light shielding layer.
[0080] S07, using the annular structure of the phase shift region as a mask pattern, patterning the second photoresist layer to form a second photoresist pattern layer.
[0081] S08, using the second photoresist pattern layer as a mask, etching the light shielding layer to form a light shielding pattern layer including a first light shielding area and a second light shielding area, and a phase conversion pattern layer including a phase shift area.
[0082] Specifically, Figure 4 As shown, firstly, a phase conversion layer, such as a semi-transparent oxide film layer, can be formed on the transparent substrate in sequence, and then a light shielding layer, such as a metal chromium layer, can be formed on the phase conversion layer.
[0083] Further, the light shielding layer and the phase conversion layer are exposed and etched to form a light-transmitting area, that is, a first photoresist layer is first formed on the light shielding layer, and then the light-transmitting area is defined on the first photoresist layer using the light-transmitting area as a mask pattern, that is, the first photoresist layer is patterned to form a first photoresist pattern layer. Then, the light shielding layer and the phase conversion layer are exposed and etched using the first photoresist pattern layer as a mask to form openings in the light shielding layer and the phase conversion layer, that is, to form a light-transmitting area.
[0084] Further, the light shielding layer is exposed and etched to form a phase shift region, that is, first a second photoresist layer is formed on the light shielding layer, and then the annular structure of the phase shift region is used as a mask pattern to define an annular phase shift region on the second photoresist layer, that is, the second photoresist layer is patterned to form a second photoresist pattern layer. Then, the light shielding layer is exposed and etched using the second photoresist pattern layer as a mask to form an annular opening around the light-transmitting region of the light shielding layer, that is, the annular opening corresponds to the phase shift region.
[0085] It can be understood that different preparation methods can be used for phase shift mask plates with different structures in the above embodiments, and the embodiments of the present application do not limit this.
[0086] On the other hand, an embodiment of the present application further provides a method for opening holes in a film layer. In the opening method of this embodiment, a film layer can be first formed on a substrate, such as forming a metal film layer or an oxide film layer on a base substrate.
[0087] For example, when forming a pixel function layer on a substrate, a pixel definition layer may be first formed on the substrate.
[0088] Furthermore, the phase-shift mask plate of the above embodiment can be used to form openings on the film layer.
[0089] For example, the phase-shift mask of the above embodiment may be used to perform exposure and etching on the pixel definition layer formed on the substrate to form openings distributed in an array, so as to deposit the light-emitting layer.
[0090] In summary, the phase-shift mask plate, preparation method and film layer opening method provided in the embodiments of the present application form two shading areas and one phase shift area on the periphery of the light-transmitting area of the transparent substrate, and make the orthographic projection of the first shading area on the transparent substrate surround the light-transmitting area, and then make the orthographic projection of the phase shift area on the transparent substrate surround the first shading area, and finally make the orthographic projection of the second shading area on the transparent substrate surround the phase shift area, so that the shading area and the phase shift area with an annular structure are formed in sequence on the transparent substrate around the light-transmitting area, and the second shading area is arranged around the phase shift area outside the phase shift area of the annular structure, so that When the phase-shift mask is used to form an opening on the film layer, due to the phase-shift zone of the annular structure outside the light-transmitting zone and the second shading zone outside the phase-shift zone of the annular structure, the phase-shift zone of the annular structure is used to achieve phase modulation of the light to offset the diffraction of the exposure machine, so as to reduce the intensity of the light passing through the phase-shift zone, improve the exposure uniformity, and improve the uniformity of the opening. At the same time, the second shading zone arranged outside the phase-shift zone can be used to protect the photoresist outside the opening corresponding to the light-transmitting zone, avoid the loss of the photoresist, ensure the smooth progress of the subsequent process flow, and ultimately improve the process yield.
[0091] The above description is only a preferred embodiment of the present application and an explanation of the technical principles used. Those skilled in the art should understand that the scope of the invention involved in the present application is not limited to the technical solution formed by a specific combination of the above technical features, but should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the concept of the invention. For example, the above features are replaced with the technical features with similar functions disclosed in the present application (but not limited to) by each other.
Claims
1. A phase shift mask, characterized in that: include: A transparent substrate, wherein a plurality of structural units are arranged in an array on the transparent substrate, wherein the structural units include a light-transmitting area formed on the transparent substrate, and a light-shielding area and a phase-shifting area formed outside the light-transmitting area, wherein the light-transmitting area is used to form an opening, and the phase-shifting area is used to change the phase of light passing therethrough to reduce the intensity of light passing through the phase-shifting area; The shading layer and the phase conversion layer are arranged on the same side of the transparent substrate, the phase conversion layer is arranged close to the transparent substrate, and the shading layer is arranged on the phase conversion layer; the orthographic projection of the area where the shading layer is located on the transparent substrate forms the shading area, and the orthographic projection of the phase conversion layer on the transparent substrate forms the phase shift area; the shading area includes a first shading area and a second shading area, the orthographic projection of the first shading area on the transparent substrate surrounds the light-transmitting area; the orthographic projection of the phase shift area on the transparent substrate surrounds the first shading area; the orthographic projection of the second shading area on the transparent substrate surrounds the phase shift area; wherein the second shading area is other areas on the transparent substrate except the light-transmitting area, the first shading area and the phase shift area.
2. The phase shift mask according to claim 1, characterized in that: The width of the annular light-shielding layer around the light-transmitting area and the width of the phase conversion layer are 0.3 μm to 1.5 μm.
3. The phase shift mask according to claim 1, characterized in that: The light shielding layer is a metal chromium layer, and the phase conversion layer is a semi-transparent oxide film layer.
4. A method for preparing a phase shift mask, characterized in that: For preparing the phase shift mask plate according to any one of claims 1 to 3, the method comprises: Forming a phase conversion layer and a light shielding layer on a transparent substrate, comprising: forming the phase conversion layer on the transparent substrate; forming the light shielding layer on the phase conversion layer; Patterning is performed on the phase conversion layer and the shading layer to form a shading pattern layer including a shading area and a phase conversion pattern layer in a phase shift area, the shading area includes a first shading area and a second shading area, the orthographic projection of the first shading area on the transparent substrate surrounds the light-transmitting area; the orthographic projection of the phase shift area on the transparent substrate surrounds the first shading area; the orthographic projection of the second shading area on the transparent substrate surrounds the phase shift area, the light-transmitting area is used to form an opening, and the phase shift area is used to change the phase of light passing therethrough to reduce the intensity of light passing through the phase shift area.
5. The method for preparing the phase shift mask according to claim 4, characterized in that: The step of patterning the bit conversion layer and the light shielding layer to form a light shielding pattern layer including a light shielding area and a phase conversion pattern layer in a phase shift area comprises: forming a first photoresist layer on the light shielding layer; Using the light-transmitting area as a mask pattern, patterning the first photoresist layer to form a first photoresist pattern layer; Using the first photoresist pattern layer as a mask, etching the phase conversion layer and the light shielding layer to form a light-transmitting area; forming a second photoresist layer on the light shielding layer; Using the annular structure of the phase shift region as a mask pattern, patterning the second photoresist layer to form a second photoresist pattern layer; The light shielding layer is etched using the second photoresist pattern layer as a mask to form a light shielding pattern layer including a first light shielding area and a second light shielding area, and a phase conversion pattern layer including a phase shift area.
6. A film layer opening method, characterized in that: The method comprises: forming a film layer on a substrate; The phase-shift mask plate according to any one of claims 1 to 3 is used to perform patterning on the film layer to form openings on the film layer.
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