Mask plate manufacturing method and mask plate

Abstract

The invention provides a manufacturing method of a mask plate and the mask plate, and the manufacturing method comprises the following steps: providing a stacking structure which comprises a transparent substrate material layer, a phase shift material layer and a shading material layer which are stacked; a part of the transparent substrate material layer, a part of the phase shift material layer and a part of the shading material layer are removed, so that the first pattern is transferred to the transparent substrate material layer, the phase shift material layer and the shading material layer, a first intermediate is obtained, and the first pattern forms a groove in the transparent substrate material layer; executing a groove depth control process on the groove of the first intermediate to obtain a second intermediate; removing a part of the shading material layer of the second intermediate to transfer the second pattern to the shading material layer to obtain a third intermediate; and performing a height control process on the phase shift material layer of the third intermediate to obtain the mask plate. According to the manufacturing method disclosed by the invention, the mask plate of which the phase shift degree and the transmittance are detected to be unqualified can be re-processed and corrected in time, and the product quality and the production efficiency are effectively ensured.

Description

Technical Field

[0001] The present disclosure relates to the field of electronic manufacturing technology, and in particular to a method for manufacturing a mask plate and a mask plate. Background Art

[0002] A mask, also known as a photomask or a photomask, is a graphic master used in the photolithography process in the manufacture of microelectronics and integrated optoelectronics. It has been widely used in various fields such as semiconductors, flat panel displays, and micro-electromechanical systems.

[0003] Phase Shift Mask (PSM) technology is a common mask technology that can effectively improve pattern contrast and resolution. However, this technology has problems with product quality and low pass rate. Summary of the invention

[0004] The following is a summary of the subject matter of the detailed description of the present disclosure. This summary is not intended to limit the scope of the claims.

[0005] In a first aspect of the present disclosure, a method for manufacturing a mask is provided, the method comprising:

[0006] Providing a stacked structure, the stacked structure comprising a transparent base material layer, a phase shift material layer and a light shielding material layer that are stacked;

[0007] Removing part of the transparent base material layer, part of the phase-shift material layer and part of the light-shielding material layer to transfer the first pattern to the transparent base material layer, the phase-shift material layer and the light-shielding material layer to obtain a first intermediate, wherein the first pattern forms a groove in the transparent base material layer;

[0008] performing a groove depth control process on the groove of the first intermediate body to obtain a second intermediate body;

[0009] removing a portion of the light-shielding material layer of the second intermediate body to transfer the second pattern to the light-shielding material layer to obtain a third intermediate body;

[0010] A height control process is performed on the phase-shift material layer of the third intermediate to obtain the mask.

[0011] In some embodiments, performing a groove depth control process on the groove of the first intermediate body includes:

[0012] detecting a groove depth of the groove;

[0013] If the groove depth does not meet the target depth dimension requirement, continue to remove part of the transparent base material layer to change the groove depth of the groove until the groove depth of the groove meets the target depth dimension requirement.

[0014] In some embodiments, detecting the groove depth of the groove comprises:

[0015] Using atomic force microscopy to detect the surface morphology of the first intermediate;

[0016] Based on the detection result of the atomic force microscope, the groove depth of the groove is determined.

[0017] In some embodiments, the step of continuing to remove a portion of the transparent base material layer to change the groove depth of the groove comprises:

[0018] The transparent base material layer is etched using the light-shielding material layer of the first intermediate body as a mask to change the groove depth of the groove.

[0019] In some embodiments, the stacked structure further includes a first photoresist layer stacked on the light-shielding material layer;

[0020] The removing of part of the transparent base material layer, part of the phase-shift material layer and part of the light-shielding material layer comprises:

[0021] forming the first pattern on the first photoresist layer;

[0022] Using the first photoresist layer as a mask, etching the transparent base material layer, the phase-shift material layer and the light-shielding material layer;

[0023] The first photoresist layer is removed to obtain the first intermediate.

[0024] In some embodiments, the process of controlling the height of the phase-shift material layer of the third intermediate includes:

[0025] detecting the thickness of the phase-shift material layer in the third intermediate body;

[0026] determining a target removal thickness of the phase-shift material layer based on the thickness of the phase-shift material layer in the third intermediate and a target thickness;

[0027] The phase-shift material layer is removed by the target removal thickness.

[0028] In some embodiments, detecting the thickness of the phase-shift material layer in the third intermediate body comprises:

[0029] Using atomic force microscopy to detect the surface morphology of the third intermediate;

[0030] Based on the detection result of the atomic force microscope, the thickness of the phase-shift material layer is determined.

[0031] In some embodiments, removing a portion of the light-shielding material layer of the second intermediate body comprises:

[0032] forming a second photoresist layer on the second intermediate;

[0033] forming the second pattern on the second photoresist layer;

[0034] The light shielding material layer is etched using the second photoresist layer as a mask.

[0035] In some embodiments, removing the phase-shift material layer having the target removal thickness includes:

[0036] The second photoresist layer and the phase-shift material layer are cleaned simultaneously to remove the second photoresist layer and the phase-shift material layer with the target removal thickness.

[0037] A second aspect of the present disclosure provides a mask plate, wherein the mask plate is manufactured by the manufacturing method described in the first aspect.

[0038] In the mask manufacturing method provided by the present invention, the control of phase shift and transmittance is converted into control of structural dimensions in the manufacturing process by respectively executing a groove depth control process and a height control process on the intermediate, so that unqualified structures can be reprocessed and corrected in time during the manufacturing process, which greatly reduces the amount of waste and effectively ensures the product quality and production efficiency of the mask.

[0039] Other aspects will be apparent upon reading and understanding the drawings and detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The accompanying drawings incorporated into the specification and constituting a part of the specification illustrate embodiments of the present disclosure and are used together with the description to explain the principles of the embodiments of the present disclosure. In these drawings, similar reference numerals are used to represent similar elements. The drawings described below are some embodiments of the present disclosure, rather than all embodiments. For those skilled in the art, other drawings can be obtained based on these drawings without paying creative work.

[0041] Figure 1 The figure is a flow chart of a method for manufacturing a mask according to an exemplary embodiment.

[0042] 2(a)-(h) are schematic diagrams showing a method for manufacturing a mask according to an exemplary embodiment.

[0043] Figure 3 This is an enlarged view of area A in Figure 2(h).

[0044] Figure 4FIG. 4 is a flowchart of step S300 according to an exemplary embodiment.

[0045] Figure 5 FIG. 1 is a flowchart of step S200 according to an exemplary embodiment.

[0046] Figure 6 FIG. 5 is a flowchart of step S500 according to an exemplary embodiment.

[0047] Figure 7 FIG. 4 is a flowchart of step S400 according to an exemplary embodiment.

[0048] Figure 8 The figure is a flow chart of a method for manufacturing a mask according to another exemplary embodiment.

[0049] Reference numerals:

[0050] 11-stacked structure; 12-first intermediate; 13-second intermediate; 14-third intermediate; 15-mask;

[0051] 21-first photoresist layer; 22-light shielding material layer; 23-phase shift material layer; 24-transparent base material layer; 25-second photoresist layer;

[0052] 220-light shielding layer; 230-phase shift layer; 240-transparent base layer;

[0053] 31 - light-transmitting area; 310 - groove; 32 - phase-shifting area; 33 - light-shielding area. DETAILED DESCRIPTION

[0054] In order to make the purpose, technical solutions and advantages of the embodiments of the present disclosure clearer, the technical solutions in the disclosed embodiments will be clearly and completely described below in conjunction with the drawings in the embodiments of the present disclosure. Obviously, the described embodiments are part of the embodiments of the present disclosure, rather than all of the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by those skilled in the art without making creative work are within the scope of protection of the present disclosure. It should be noted that the embodiments in the present disclosure and the features in the embodiments can be arbitrarily combined with each other without conflict.

[0055] The binary mask is the most commonly used mask template, which mainly includes a transparent base layer and an opaque light-shielding layer. The light-shielding layer is etched on the base layer to form a mask pattern, and the pattern information is transferred to the product substrate through exposure. However, when the design size reaches below 0.18μm, the pattern size on the traditional binary mask is reduced to a scale close to the wavelength of the light source. The light will diffract at the edge of the pattern and expand laterally. In theory, the fine features that should be blocked by the light-shielding layer will also be illuminated by the light from both sides, making the projected pattern no longer clear in light and dark. Through the phase-shift mask technology, adding a phase-shift layer to the binary mask can make the light waves passing through the adjacent light-transmitting areas produce a 180-degree phase difference. The two will destructively interfere in a specific area of ​​the image plane, reducing the light intensity of the dark field and increasing the light intensity of the bright field, thereby significantly improving the contrast and resolution of the pattern.

[0056] For example, referring to FIG. 2(h), the mask plate 15 includes a light shielding layer 220, a phase shift layer 230, and a transparent base layer 240 which are stacked. The mask plate 15 is usually formed by at least two etchings, wherein etching is performed along a first pattern to transfer the first pattern to the transparent base layer 240 to form a light-transmitting area 31, etching is performed along a second pattern to transfer the second pattern to the phase shift layer 230 to form a phase shift area 32, and the area where the light shielding layer 220 is located forms a light shielding area 33. The light in the light shielding area 33 cannot enter the mask plate 15 because it is blocked by the light shielding layer 220, while the light in the light-transmitting area 31 and the phase shift area 32 can enter the mask plate 15 from the transparent base layer 240 and the phase shift layer 230, respectively, so that the mask plate 15 can project a pattern along the contour range of the second pattern.

[0057] refer to Figure 3 When light is incident on the light-transmitting area 31 and the phase-shifting area 32 respectively, the medium through which it passes through the mask 15 has differences in structure and material, which can change the properties of the light such as the phase and transmittance, and thus also produce differences. Among them, when the phase difference of the light at the adjacent light-transmitting area 31 and the phase-shifting area 32 is 180 degrees, a good destructive interference effect can be obtained, so as to significantly improve the contrast and resolution of the projection pattern of the mask 15. At the same time, in the phase-shifting mask, there are certain requirements for the transmittance of the phase-shifting area 32. On the one hand, it is ensured that enough light can pass through the mask 15 and participate in the imaging process. On the other hand, the difference in light intensity between the dark field and the bright field can be increased by controlling the difference in transmittance between the light-transmitting area 31 and the phase-shifting area 32, so as to further improve the contrast and resolution of the pattern. Therefore, in the phase-shifting mask technology, the phase shift degree and the transmittance can jointly determine the quality of the imaging, and are parameters that have a key impact on the product quality and imaging effect of the mask.

[0058] However, in the existing phase-shift mask manufacturing process, the phase shift and transmittance detection of the mask plate can often only be carried out after the manufacturing is completed. At this time, the etching process has been completed, and the mask plate lacks a structural layer that can serve as a mask (see Figure 2(h)). The mask plate that fails the inspection cannot be reprocessed and corrected, so there are problems with low product quality and pass rate.

[0059] In response to the above problems, the inventors of the present application discovered that, according to the principles of wave optics, the phase shift when a light wave passes through a medium depends on the optical path of the light wave propagating in the medium, and the optical path size is equal to the product of the refractive index n and the thickness S of the medium. In addition, the transmittance of the light wave when passing through the medium is related to the extinction coefficient k and the thickness S of the medium. Therefore, the control of the phase shift and transmittance in the mask can be converted into the control of the thickness of the mask structure layer during the mask manufacturing process.

[0060] Refer to Figure 2(h) and Figure 3 In the mask 15, the phase shift layer 230 is only provided in the phase shift region 32, and the thickness of the transparent base layer 240 in the light-transmitting region 31 and the phase shift region 32 is also different, thereby making the phase shift degree and transmittance of the light in the light-transmitting region 31 and the phase shift region 32 different. Among them, the thickness difference of the transparent base layer 240 in the light-transmitting region 31 and the phase shift region 32 is the groove depth S1, and the thickness difference of the phase shift layer 230 is the target thickness S4. The phase shift degree is related to both the groove depth S1 and the target thickness S4, and since the transparent base layer 240 is a transparent medium, the transmittance difference is related to the target thickness S4. Therefore, by designing the thickness of the phase shift layer 230 and the transparent base layer 240 and controlling the groove depth S1 and the target thickness S4 during the manufacturing process, the light passing through the phase shift area 32 on the mask plate 15 can produce a phase difference of 180 degrees relative to the light-transmitting area 31, and the transmittance of the phase shift area 32 can be controlled to ensure that the phase shift degree and transmittance of the mask plate 15 meet the requirements.

[0061] In order to solve the above problems, the embodiment of the present disclosure provides a method for manufacturing a mask, comprising the following steps: providing a stacking structure, the stacking structure comprising a transparent base material layer, a phase shift material layer and a light shielding material layer stacked; removing part of the transparent base material layer, part of the phase shift material layer and part of the light shielding material layer to transfer a first pattern to the transparent base material layer, the phase shift material layer and the light shielding material layer to obtain a first intermediate, wherein the first pattern forms a groove in the transparent base material layer; performing a groove depth control process on the groove of the first intermediate to obtain a second intermediate; removing part of the light shielding material layer of the second intermediate to transfer the second pattern to the light shielding material layer to obtain a third intermediate; performing a height control process on the phase shift material layer of the third intermediate to obtain a mask. By performing a groove depth control process and a height control process on the intermediate respectively, the control of the phase shift degree and the transmittance is converted into the control of the structural dimensions in the manufacturing process, so that the unqualified structure can be reprocessed and corrected in time during the manufacturing process, which greatly reduces the number of waste products and effectively ensures the product quality and production efficiency of the mask.

[0062] like Figure 1 As shown, this embodiment provides a method for manufacturing a mask, which specifically includes the following steps:

[0063] Step S100: providing a stacking structure, wherein the stacking structure comprises a transparent base material layer, a phase shift material layer and a light shielding material layer which are stacked.

[0064] As shown in FIG2(a), the stacked structure 11 is a blank for making the mask plate 15. The stacked structure 11 includes a light-shielding material layer 22, a phase-shift material layer 23 and a transparent base material layer 24, which are stacked. The phase-shift material layer 23 is located between the light-shielding material layer 22 and the transparent base material layer 24. When making the stacked structure 11, the phase-shift material layer 23 and the light-shielding material layer 22 can be deposited on the transparent base material layer 24 in sequence. The light-shielding material layer 22 can be located above the phase-shift material layer 23, blocking light from passing through the phase-shift material layer 23 while protecting the phase-shift material layer 23. Referring to FIG2(h), the light-shielding material layer 22 in the stacked structure 11 is used to form the light-shielding layer 220 of the mask plate 15, the phase-shift material layer 23 is used to form the phase-shift layer 230 of the mask plate 15, and the transparent base material layer 24 is used to form the transparent base layer 240 of the mask plate 15.

[0065] The light-shielding material layer 22 is mainly composed of opaque materials, and hard light-shielding materials such as chromium, silicon and iron oxide are usually used. These materials can effectively block light from passing through specific areas of the mask, especially areas that do not need to be exposed, so as to form bright areas and dark areas on the mask, thereby forming an accurate graphic outline. Among them, chromium has become the most commonly used light-shielding layer material due to its high mechanical strength and ability to form fine graphics. The phase-shift material layer 23 is used to achieve synchronous adjustment of the phase shift and transmittance through its partial light transmittance, thereby improving the resolution and contrast of the imaging. Typical materials include molybdenum silicide (MoSi), etc. The transparent base material layer 24 can usually be made of synthetic quartz (Quartz) glass material. Compared with ordinary glass, quartz has the advantages of high light transmittance (especially in the deep ultraviolet band), small thermal expansion coefficient, stable optical properties, etc., and its refractive index n is moderate, which is conducive to precise control of the light wave phase. It is an ideal base material in phase-shift mask technology. Of course, the light shielding material layer 22 , the phase shift material layer 23 and the transparent base material layer 24 may also be made of other materials, which are not limited here.

[0066] Step S200: removing part of the transparent base material layer, part of the phase-shift material layer and part of the light-shielding material layer to transfer the first pattern to the transparent base material layer, the phase-shift material layer and the light-shielding material layer to obtain a first intermediate, wherein the first pattern forms a groove in the transparent base material layer.

[0067] like Figure 2(a) to Figure 2(c) As shown, the light shielding material layer 22, the phase shift material layer 23 and the transparent base material layer 24 can be etched in sequence along the contour area of ​​the first pattern, or other removal means can be used to make the first pattern penetrate the light shielding material layer 22 and the phase shift material layer 23, and form a groove 310 on the transparent base material layer 24 to obtain the first intermediate body 12. The groove 310 forms a light-transmitting area 31, and the part between two adjacent light-transmitting areas 31 that is not removed by etching the first pattern and protrudes relative to the groove 310 forms a phase shift area 32.

[0068] Step S300: performing a groove depth control process on the groove of the first intermediate body to obtain a second intermediate body.

[0069] like Figure 2(c) to Figure 2(d)As shown, after step S200, a light-transmitting area 31 is formed on the transparent base material layer 24 of the first intermediate body 12, and the manufacturing operation after the groove depth control process is completed will not affect the groove depth S1 and the related detection results. At this time, it can be regarded as the control point of the groove depth S1, and the groove depth S1 is detected and corrected by executing the groove depth control process. When the groove depth S1 does not match the preset depth, the first intermediate body 12 can be etched again in time. After the groove depth control process is completed, a second intermediate body 13 whose groove depth S1 matches the preset depth can be obtained. It should be noted that the groove depth control process can be completed before the light-shielding material layer 22 is removed to ensure that when the groove depth control process is executed, there is a structural layer that can be used as a mask on the first intermediate body, and at the same time, the phase shift material layer 23 on the phase shift area 32 is prevented from being etched to change the thickness S2 of the phase shift layer 230, thereby affecting the subsequent height control process. For example, the groove depth control process can be performed at the step shown in FIG. 2( c ) using the first photoresist layer 21 (described in detail later) as a mask, or can be performed at the step shown in FIG. 2( f ) using the shading material layer 22 as a mask, without limitation.

[0070] Step S400: removing part of the light-shielding material layer of the second intermediate body to transfer the second pattern to the light-shielding material layer to obtain a third intermediate body.

[0071] like Figure 2(d) to Figure 2(g) As shown, the light shielding material layer 22 can be etched along the contour area of ​​the second pattern on the basis of the second intermediate body 13, or other removal means can be used. The contour area of ​​the second pattern includes the projection area of ​​the light-transmitting area 31 and the phase shift area 32 formed by the first pattern, so that the light shielding material layer 22 in the phase shift area 32 is removed to obtain the third intermediate body 14. On the phase shift area 32 of the third intermediate body 14, light can directly enter the phase shift material layer 23 without being blocked by the light shielding material layer 22.

[0072] Step S500: performing a height control process on the phase-shift material layer of the third intermediate to obtain a mask.

[0073] like Figure 2(g) to Figure 2(h) as well as Figure 3 As shown, after step S400, the third intermediate body 14 is obtained, and the phase-shift material layer 23 on the phase-shift region 32 is exposed on the upper surface of the third intermediate body 14. Part of the phase-shift material layer 23 on the phase-shift region 32 can be removed. The removal method can be, for example, cleaning. At this time, it can be regarded as a control point of the target thickness S4. By executing the height control process, the manufacturing parameters of the phase-shift material layer 23 are determined to ensure that after removing part of the phase-shift material layer 23, the mask plate 15 with the target thickness S4 that meets the requirements can be obtained.

[0074] In this embodiment, reference Figure 2(a) to Figure 2(h)as well as Figure 3 By performing a groove depth control process on the first intermediate 12 at the control point of the groove depth S1, and by performing a height control process on the third intermediate 14 at the control point of the target thickness S4, the control of the phase shift and transmittance of the mask plate 15 is converted into the control of the groove depth S1 and the target thickness S4, so that during the manufacturing process, it is possible to judge whether the mask plate 15 is qualified by the groove depth S1 and the target thickness S4. When the mask plate 15 is unqualified, it can be reprocessed and corrected in time, which greatly reduces the amount of waste and effectively ensures the product quality and production efficiency of the mask plate 15.

[0075] In one embodiment, if Figure 4 As shown, the groove depth control process specifically includes the following steps:

[0076] Step S310: Detecting the groove depth of the groove.

[0077] Step S320: If the groove depth does not meet the target depth dimension requirement, continue to remove part of the transparent base material layer to change the groove depth of the groove until the groove depth of the groove meets the target depth dimension requirement.

[0078] As mentioned above, reference Figure 3 The phase shift is related to both the groove depth S1 and the target thickness S4, while the transmittance is related to the groove depth S1. Therefore, the target depth size of the groove depth S1 can be determined according to the required phase shift and transmittance.

[0079] In one example, a mathematical calculation can be directly performed based on the formula of the groove depth S1, the refractive index n1 of the transparent base material layer 24, the target thickness S4, the refractive index n2 of the phase shift material layer 23, and the refractive index n3 of air and the phase shift degree to obtain the target depth dimension of the groove depth S1. In another example, when individual parameters are not convenient to obtain, such as when it is difficult to obtain the accurate value of n2, a mathematical model can also be established in advance to obtain an empirical formula for calculation (described in detail later).

[0080] In one embodiment, step S310 specifically includes the following steps:

[0081] Step S311: using an atomic force microscope to detect the surface morphology of the first intermediate.

[0082] Step S312: Determine the groove depth of the groove based on the detection result of the atomic force microscope.

[0083] Atomic force microscope (AFM) can provide a true three-dimensional surface image, and does not require special sample processing, can directly observe the surface morphology and physical properties at the nanometer level, and can avoid irreversible damage to the first intermediate 12. Referring to FIG2(c), by detecting the upper surface of the first intermediate 12 and analyzing the detection results, the surface morphology of the first intermediate 12 can be obtained, so that the groove depth S1 at the light-transmitting area 31 can be determined.

[0084] In one embodiment, when the groove depth S1 does not meet the target depth dimension requirement, step S320 specifically includes the following steps until the target depth dimension requirement is met:

[0085] Step S321 : using the light shielding material layer of the first intermediate body as a mask, etching the transparent base material layer to change the groove depth of the groove 310 .

[0086] When the detection finds that the groove depth S1 is insufficient, at this time, there is at least a light shielding material layer 22 above the phase shift material layer 23 of the first intermediate body 12, so the light shielding material layer 22 can be used as a mask to etch the transparent base material layer 24 again along the contour area of ​​the first pattern to increase the groove depth S1, and the first intermediate body 12 whose size does not meet the requirements can be corrected in time, with a large error tolerance. The etching depth each time can be determined according to the actual situation to take into account both production efficiency and accuracy.

[0087] In one embodiment, as shown in FIG. 2( a), the stacked structure 11 further includes a first photoresist layer 21 stacked on the light shielding material layer 22. The first photoresist layer 21 and the phase shift material layer 23 are respectively located on opposite sides of the light shielding material layer 22. The first photoresist layer 21 is formed by a photoresist coated on the light shielding material layer 22. Photoresist is a photosensitive material that undergoes chemical changes under the irradiation of ultraviolet light or other specific light. It is divided into positive photoresist and negative photoresist. The positive photoresist is soluble in a developer after exposure, while the negative photoresist is soluble in a developer before exposure. Therefore, according to the type of photoresist used in the first photoresist layer 21, a specific area of ​​the photoresist layer can be exposed to record a mask pattern.

[0088] like Figure 5 As shown, step S200 specifically includes the following steps:

[0089] Step S210: forming a first pattern on the first photoresist layer.

[0090] Step S220: using the first photoresist layer as a mask, etching the transparent base material layer, the phase-shift material layer and the light-shielding material layer.

[0091] Step S230: removing the first photoresist layer to obtain a first intermediate.

[0092] In one example, referring to FIG. 2( b ), a drawing machine can be used to draw and expose the first photoresist layer 21, and the specific operation is as follows: the first pattern is first input into the drawing machine, and the drawing machine outputs a specific light (such as a laser) to irradiate the first photoresist layer 21 according to the first pattern for point exposure to form a desired first pattern. Then, the first photoresist layer 21 having the first pattern can be used as a mask for etching to transfer the first pattern to the light shielding material layer 22, the phase shift material layer 23 and the transparent base material layer 24.

[0093] In one example (not shown in the drawings), the first photoresist layer 21 can be removed after the first pattern is transferred to obtain the first intermediate 12. Figure 2(c) to Figure 2(d) The first photoresist layer 21 may not be removed first, so that when the groove depth control process is performed in step S300, the first photoresist layer 21 may be used as a mask for further etching until the first photoresist layer 21 is removed after the groove depth control process is completed.

[0094] In one embodiment, if Figure 6 As shown, the height control process specifically includes the following steps:

[0095] Step S510: detecting the thickness of the phase-shift material layer in the third intermediate body.

[0096] Step S520: determining a target removal thickness of the phase-shift material layer based on the thickness of the phase-shift material layer in the third intermediate body and the target thickness.

[0097] Step S530: removing the phase-shift material layer having a target removal thickness.

[0098] like Figure 3 As shown, in the phase shift layer 230, the thickness S2 is equal to the sum of the target removal thickness S3 and the target thickness S4. After determining the thickness S2 and the target thickness S4 respectively, the target removal thickness S3 can be determined, and then the appropriate cleaning intensity is selected to ensure that the target thickness S4 remaining after cleaning meets the requirements.

[0099] Refer to the groove depth control process above, and Figure 3 As shown, the target thickness S4 can be determined according to the required transmittance. In one example, the target thickness S4 can be determined by directly performing mathematical calculations based on the reflectivity R of each medium interface, the extinction coefficient k of the phase shift layer 230, and the calculation formula of the target thickness S4 and the transmittance. In another example, when individual parameters are not convenient to obtain, such as when it is difficult to obtain the accurate value of k, a mathematical model can be established in advance to obtain an empirical formula for calculation.

[0100] In one example, empirical coefficients may be preset to establish a mathematical model, and empirical formulas may be obtained based on the empirical coefficients, so as to determine the target depth dimension of the groove depth S1 and the target thickness S4 based on the required phase shift and transmittance. For example, since the phase shift is in direct proportion to the medium thickness, and the transmittance is in an exponential relationship with the medium thickness with the natural constant e as the base, the following empirical formula may be preset:

[0101] First phase shift = a1*S1

[0102] Second phase shift = a2*S1+a3*S4

[0103]

[0104] Wherein: the first phase shift is the phase shift of the light before the phase-shift material layer 23 is cleaned (refer to FIG. 2( g)), at which time the phase shift of the light is only affected by the groove depth S1; the second phase shift is the phase shift of the light after the phase-shift material layer 23 is cleaned (refer to FIG. 2( h)), that is, the phase shift of the mask 15, at which time both the groove depth S1 and the target thickness S4 can affect the phase shift of the light; a1, a2, a3, a4 and a5 are all preset empirical coefficients.

[0105] Take another stacking structure 11 with the same structure and material, and perform the following steps on the stacking structure 11: Figure 2(a) to Figure 2(h) As shown in the production. A plurality of grooves 310 of different depths are respectively etched at the control points of the groove depth S1 as shown in FIG2(c), and the phase shift of the light is measured at the first measuring point to obtain the first phase shift corresponding to the plurality of groove depths S1, thereby determining the empirical coefficient a1. The first measuring point can be located at the step shown in FIG2(g), at which time the light shielding material layer 22 on the phase shift region 32 has been removed, so as to facilitate the light to pass through for measurement.

[0106] At the control point of the target thickness S4 shown in FIG2(h), the phase shift material layer 23 on the phase shift region 32 is cleaned multiple times with different intensities to obtain multiple phase shift material layers 23 with different target thicknesses S4 on the phase shift regions 32. At the second measurement point (after the step shown in FIG2(h)), the phase shift and transmittance of the light are measured to obtain the second phase shift and transmittance corresponding to multiple different groove depths S1 and target thicknesses S4, respectively, and thus the empirical coefficients a2, a3, a4 and a5 can be determined.

[0107] The phase shift and transmittance can be measured by instruments such as MPM-248 or MPM-193 produced by Lasertech. Of course, other measuring devices or measuring methods can also be used without limitation.

[0108] After determining each empirical coefficient, an empirical formula can be obtained, and the target depth dimension of the groove depth S1 and the target thickness S4 at the corresponding control point can be determined by the required phase shift and transmittance, so that during the production process of the mask template 15, it is possible to judge whether the phase shift and transmittance of the product meet the requirements by directly measuring and comparing the structural dimensions of the intermediate.

[0109] In one embodiment, step S510 specifically includes the following steps:

[0110] Step S511: using an atomic force microscope to detect the surface morphology of the third intermediate;

[0111] Step S512: determining the thickness of the phase-shift material layer based on the detection result of the atomic force microscope.

[0112] As mentioned above, the atomic force microscope can obtain the surface morphology of the sample, and thus can be used to determine the thickness S2 of the phase shift material layer 23 in the third intermediate 14 according to the detected height of the phase shift region 32 and the groove depth S1, and its principle is not repeated here. Through the manufacturing method provided in this embodiment, it is only necessary to detect the groove depth S1 and the thickness S2 at two corresponding control points respectively, so as to achieve precise control of the phase shift degree and transmittance of the mask plate 15, which greatly reduces the difficulty of process control of the mask plate 15 and improves the manufacturing efficiency and product quality of the mask plate 15.

[0113] In one embodiment, if Figure 7 As shown, step S400 specifically includes the following steps:

[0114] Step S410: forming a second photoresist layer on the second intermediate.

[0115] Step S420: forming a second pattern on the second photoresist layer.

[0116] Step S430: using the second photoresist layer as a mask to etch the light shielding material layer.

[0117] like Figure 2(e) to Figure 2(g) As shown, in order to allow light to pass through the phase shift region 32, it is necessary to remove the light shielding material layer 22 on the phase shift region 32 in the second intermediate body 13. The removal method can be to coat the second intermediate body 13 with photoresist again to form a second photoresist layer 25 (refer to Figure 2 (e)), and use the second photoresist layer 25 with the second pattern as a mask (refer to Figure 2 (f)) for etching, and transfer the second pattern to the light shielding material layer 22 (refer to Figure 2 (g)), thereby obtaining the third intermediate body 14. The preparation of the second photoresist layer 25 can refer to the first photoresist layer 21, and will not be repeated here.

[0118] 2(g), after the etching of the light shielding material layer 22 is completed, the second photoresist layer 25 may still exist on the third intermediate 14. In one embodiment, step S530 specifically includes the following steps:

[0119] Step S531: cleaning the second photoresist layer and the phase-shift material layer simultaneously to remove the second photoresist layer and the phase-shift material layer with a target removal thickness.

[0120] like Figure 2(g) to Figure 2(h) As shown, by cleaning, the second photoresist layer 25 is removed while the phase-shift material layer 23 with a target removal thickness S3 is removed, thereby obtaining a mask plate 15 that does not contain photoresist and meets the requirements of quality.

[0121] An exemplary embodiment of the present disclosure provides a method for manufacturing a mask. Figure 8 Combined with Figure 2(a) to Figure 2(h) As shown, the production method comprises the following steps:

[0122] Step S10: providing a stacked structure, the stacked structure comprising a first photoresist layer, a transparent base material layer, a phase shift material layer and a light shielding material layer stacked

[0123] Step S20: forming a first pattern on the first photoresist layer of the stacked structure, and etching the light shielding material layer, the phase shift material layer and the transparent base material layer using the first photoresist layer as a mask until the first pattern forms a groove on the transparent base material layer to obtain a first intermediate.

[0124] Step S30: performing a groove depth control process on the groove of the first intermediate. During the groove depth control process, an atomic force microscope is used to detect the surface morphology of the first intermediate to determine the groove depth S1. When the groove depth S1 does not meet the target depth dimension, the transparent base material layer is etched again using the first photoresist layer or the light-shielding material layer as a mask until the groove depth S1 meets the target depth dimension to obtain a second intermediate.

[0125] Step S40: forming a second photoresist layer on the second intermediate and forming a second pattern on the second photoresist layer, and removing the light shielding material layer by etching using the second photoresist layer as a mask to obtain a third intermediate.

[0126] Step S50: performing a height control process on the phase-shift material layer of the third intermediate. During the height control process, an atomic force microscope is used to detect the surface morphology of the third intermediate to determine the thickness S2 of the phase-shift material layer. The target removal thickness S3 is determined by the target thickness S4 and corresponding cleaning parameters are set. The second photoresist layer and the phase-shift material layer with the target removal thickness S3 are cleaned off on the third intermediate to obtain a mask.

[0127] The specific operation and principle of this embodiment can refer to the above-mentioned embodiment, and will not be described in detail here. In the manufacturing method of this embodiment, by performing a groove depth control process on the first intermediate and a height control process on the third intermediate, the control of the phase shift and transmittance is converted into the control of the structural size during the manufacturing process. It is only necessary to detect the groove depth S1 and thickness S2 at two corresponding control points respectively, so as to achieve precise control of the phase shift and transmittance of the mask plate 15, which greatly reduces the difficulty of process control of the mask plate 15 and improves the manufacturing efficiency and product quality of the mask plate 15. At the same time, when it is detected that the groove depth S1 or thickness S2 does not meet the requirements, the unqualified structure can be reprocessed and corrected in time during the manufacturing process, avoiding the defect that the phase shift and transmittance can only be detected after the manufacturing is completed in the traditional manufacturing method, and the unqualified products cannot be adjusted and corrected, which greatly reduces the number of waste products and effectively ensures the product quality and output efficiency of the mask plate.

[0128] As shown in FIG2(g), this embodiment provides a mask plate 15, which can be manufactured by the manufacturing method in any of the above embodiments. The mask plate 15 includes a light shielding layer 220, a phase shift layer 230 and a transparent base layer 240. By etching the first pattern and the second pattern, the mask plate 15 is provided with light-transmitting areas 31 and phase shift areas 32 arranged alternately. When light passes through the mask plate 15 through the light-transmitting areas 31 and the phase shift areas 32 respectively, a 180-degree phase difference can be generated to obtain a pattern with clear edges. At the same time, the light-transmitting area of ​​the mask plate 15 also has a high transmittance, which can ensure that enough light can pass through and participate in the imaging process.

[0129] The mask plate 15 provided in this embodiment realizes precise control of the phase shift and transmittance by controlling the structural dimensions of the intermediate phase shift material layer 23 and the transparent base material layer 24 respectively during the manufacturing process, which can better meet the phase shift and transmittance requirements of the mask plate product. In addition, the manufacturing method is simple and efficient, with the advantages of high product quality and fast production efficiency, and can provide reliable guarantee for subsequent electronic manufacturing and processing.

[0130] The various embodiments or implementation methods in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments, and the same or similar parts between the various embodiments can be referenced to each other.

[0131] In the description of this specification, reference to the terms "embodiment", "exemplary embodiment", "some embodiments", "illustrative embodiment", "example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present disclosure.

[0132] In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0133] In the description of the present disclosure, it should be noted 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, and are only for the convenience of describing the present disclosure 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 cannot be understood as a limitation on the present disclosure.

[0134] It is to be understood that the terms "first", "second", etc. used in the present disclosure can be used to describe various structures in the present disclosure, but these structures are not limited by these terms. These terms are only used to distinguish a first structure from another structure.

[0135] In one or more of the accompanying drawings, the same elements are represented by similar reference numerals. For the sake of clarity, the parts in the accompanying drawings are not drawn to scale. In addition, some well-known parts may not be shown. For the sake of simplicity, the structure obtained after several steps can be described in one figure. Many specific details of the present disclosure, such as the structure, materials, dimensions, processing technology and technology of the device are described below to more clearly understand the present disclosure. However, as those skilled in the art will appreciate, the present disclosure may not be implemented in accordance with these specific details.

[0136] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present disclosure, rather than to limit them. Although the present disclosure has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present disclosure.

Claims

1. A method for manufacturing a mask, characterized in that: The production method comprises: Providing a stacked structure, the stacked structure comprising a transparent base material layer, a phase shift material layer and a light shielding material layer which are stacked; Removing part of the transparent base material layer, part of the phase-shift material layer and part of the light-shielding material layer to transfer the first pattern to the transparent base material layer, the phase-shift material layer and the light-shielding material layer to obtain a first intermediate, wherein the first pattern forms a groove in the transparent base material layer; performing a groove depth control process on the groove of the first intermediate body to obtain a second intermediate body; removing a portion of the light-shielding material layer of the second intermediate body to transfer the second pattern to the light-shielding material layer to obtain a third intermediate body; A height control process is performed on the phase-shift material layer of the third intermediate to obtain the mask.

2. The method for manufacturing a mask according to claim 1, characterized in that: The performing a groove depth control process on the groove of the first intermediate body comprises: detecting a groove depth of the groove; If the groove depth does not meet the target depth dimension requirement, continue to remove part of the transparent base material layer to change the groove depth of the groove until the groove depth of the groove meets the target depth dimension requirement.

3. The method for manufacturing a mask according to claim 2, characterized in that: The detecting the groove depth of the groove comprises: Using atomic force microscopy to detect the surface morphology of the first intermediate; Based on the detection result of the atomic force microscope, the groove depth of the groove is determined.

4. The method for manufacturing a mask according to claim 2, characterized in that: The step of continuing to remove a portion of the transparent base material layer to change the groove depth of the groove comprises: The transparent base material layer is etched using the light-shielding material layer of the first intermediate body as a mask to change the groove depth of the groove.

5. The method for manufacturing a mask according to any one of claims 1 to 4, characterized in that: The stacked structure further includes a first photoresist layer stacked on the light-shielding material layer; The removing of part of the transparent base material layer, part of the phase-shift material layer and part of the light-shielding material layer comprises: forming the first pattern on the first photoresist layer; Using the first photoresist layer as a mask, etching the transparent base material layer, the phase-shift material layer and the light-shielding material layer; The first photoresist layer is removed to obtain the first intermediate.

6. The method for manufacturing a mask according to any one of claims 1 to 4, characterized in that: The process of controlling the height of the phase-shift material layer of the third intermediate includes: detecting the thickness of the phase-shift material layer in the third intermediate body; determining a target removal thickness of the phase-shift material layer based on the thickness of the phase-shift material layer in the third intermediate and a target thickness; The phase-shift material layer is removed by the target removal thickness.

7. The method for manufacturing a mask according to claim 6, characterized in that: The detecting the thickness of the phase-shift material layer in the third intermediate body comprises: Using atomic force microscopy to detect the surface morphology of the third intermediate; Based on the detection result of the atomic force microscope, the thickness of the phase-shift material layer is determined.

8. The method for manufacturing a mask according to claim 6, characterized in that: The step of removing a portion of the light-shielding material layer of the second intermediate body comprises: forming a second photoresist layer on the second intermediate; forming the second pattern on the second photoresist layer; The light shielding material layer is etched using the second photoresist layer as a mask.

9. The method for manufacturing a mask according to claim 8, characterized in that: The removing the phase-shift material layer having the target removal thickness comprises: The second photoresist layer and the phase-shift material layer are cleaned simultaneously to remove the second photoresist layer and the phase-shift material layer with the target removal thickness.

10. A mask, characterized in that: The mask is manufactured by the manufacturing method according to any one of claims 1 to 9.

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