Photomask and method, apparatus, device, and medium for detecting the same

Abstract

The embodiment of the present disclosure relates to a photomask and a detection method, device, equipment and medium thereof, the photomask comprises a photomask body and a light calibration mark arranged on the photomask body; the photomask body comprises a first material substrate, a first pattern layer of a second material and a second pattern layer of a third material which are sequentially stacked along a first direction, the first pattern layer and the second pattern layer are used to jointly define a transfer pattern of the photomask; the light calibration mark comprises a first mark pattern of the first material, a second mark pattern of the second material and a third mark pattern of the third material which are sequentially arranged along a second direction; wherein the first direction is perpendicular to the second direction. The embodiment of the present disclosure improves the efficiency and accuracy of defect detection of the photomask, thereby improving the yield and reliability of the semiconductor product.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of semiconductor technology, and in particular, to a photomask and a detection method, device, equipment and medium thereof. BACKGROUND

[0002] The photomask is a carrier for image transmission. A designed circuit pattern is exposed on a photosensitive glue by an electronic laser device. The exposed area is developed to form a circuit pattern, becoming a mask similar to a developed negative, and then applied to project and position an integrated circuit. The projected circuit is photo-etched by an integrated circuit lithography machine.

[0003] However, various defects are inevitably formed in the manufacturing process of the photomask, and a detection machine needs to detect the photomask. The traditional photomask detection method has a long detection period and low detection efficiency, which affects the yield and reliability of subsequent semiconductor products. SUMMARY

[0004] Therefore, it is necessary to provide a photomask and a detection method, device, equipment and medium thereof to improve the efficiency and accuracy of defect detection of the photomask, thereby improving the yield and reliability of semiconductor products.

[0005] To achieve the above object and other objects, a first aspect of an embodiment of the present disclosure provides a photomask, comprising a photomask body and a light calibration mark arranged on the photomask body; the photomask body comprises a substrate of a first material, a first pattern layer of a second material and a second pattern layer of a third material which are sequentially stacked along a first direction, and the first pattern layer and the second pattern layer are used to jointly define a transfer pattern of the photomask; the light calibration mark comprises a first mark pattern of the first material, a second mark pattern of the second material and a third mark pattern of the third material which are sequentially arranged along a second direction; and the first direction is perpendicular to the second direction.

[0006] In the above embodiment, the photomask comprises the light calibration mark comprising the first mark pattern of the first material, the second mark pattern of the second material and the third mark pattern of the third material which are sequentially arranged along the second direction; the material of the first mark pattern is the same as that of the substrate, both being the first material; the material of the second mark pattern is the same as that of the first pattern layer, both being the second material, and the material of the third mark pattern is the same as that of the second pattern layer, both being the third material, so that the three different materials corresponding to the first material, the second material and the third material can be found on one light calibration mark. Compared with the traditional photomask detection method, the three materials corresponding to the materials need to be found outside the target photomask detection area, the detection target is stronger and the detection efficiency is higher. Since the adverse effects of the areas outside the target photomask detection area on the detection light are avoided, the accuracy of photomask detection is effectively improved.

[0007] According to some embodiments of the present disclosure, the first mark pattern is located on the same layer as the substrate, the second mark pattern is located on the same layer as the first pattern layer, and the third mark pattern is located on the same layer as the second pattern layer, effectively improving the target and efficiency of obtaining the first mark pattern, the second mark pattern and the third mark pattern in the process of mask detection, and avoiding the problem of wasting time and requiring high experience of the staff due to randomly obtaining the three mark patterns of the first mark pattern, the second mark pattern and the third mark pattern.

[0008] According to some embodiments of the present disclosure, at least one of the first mark pattern, the second mark pattern and the third mark pattern is a rectangle in the orthographic projection on the surface of the substrate, so as to facilitate alignment according to the two perpendicular sides of the rectangle, and improve the efficiency and accuracy of alignment using the mark pattern.

[0009] According to some embodiments of the present disclosure, the length or width of the rectangle ranges from 480nm to 520nm, so as to meet the size requirement of the current conventional chip size for light calibration marks.

[0010] According to some embodiments of the present disclosure, the orthographic projection of the first mark pattern on the surface of the substrate, the orthographic projection of the second mark pattern on the surface of the substrate and the orthographic projection of the third mark pattern on the surface of the substrate are all the same size, so as to reduce the complexity of the preparation of the mark pattern, effectively improve the target and efficiency of obtaining the first mark pattern, the second mark pattern and the third mark pattern in the process of mask detection, and avoid the problem of wasting time and requiring high experience of the staff due to randomly obtaining the three mark patterns of the first mark pattern, the second mark pattern and the third mark pattern.

[0011] According to some embodiments of the present disclosure, the orthographic projection of the first mark pattern on the surface of the substrate, the orthographic projection of the second mark pattern on the surface of the substrate and the orthographic projection of the third mark pattern on the surface of the substrate are all squares, so as to facilitate alignment according to the two perpendicular sides of the square, improve the efficiency and accuracy of alignment using the mark pattern, and effectively improve the target and efficiency of obtaining the first mark pattern, the second mark pattern and the third mark pattern in the process of mask detection.

[0012] According to some embodiments of the present disclosure, the light calibration mark is located in the cutting path area of the mask body, so as to avoid the influence of the light calibration mark on the target pattern of the mask transfer, and improve the accuracy of transferring the target pattern from the mask to the wafer.

[0013] According to some embodiments of the present disclosure, the first material, the second material and the third material are all different, and are selected from one of quartz, molybdenum silicide and chromium alloy, so as to meet the detection requirements of the current standard mask.

[0014] The second aspect of the embodiments of the present disclosure provides a detection method for detecting whether a mask exists defects or not; the method comprises: projecting a target light beam to a target area of the mask, the target area is provided with the light calibration marks; acquiring real-time calibration parameters of the target area to the target light beam; comparing the real-time calibration parameters with corresponding preset standard parameters in a standard database, and judging whether the mask exists defects or not according to the comparison result, so as to improve the efficiency and accuracy of defect detection of the mask.

[0015] According to some embodiments of the present disclosure, the target light beam comprises a first light beam of a first wavelength, a second light beam of a second wavelength and a third light beam of a third wavelength; the projecting the target light beam to the target area of the mask comprises: projecting the first light beam of the first wavelength to the first mark pattern in the target area; projecting the second light beam of the second wavelength to the second mark pattern in the target area; and projecting the third light beam of the third wavelength to the third mark pattern in the target area. Since the target area comprises the first mark pattern, the second mark pattern and the third mark pattern of three different materials, the time spent in searching for the three materials is effectively reduced, and the efficiency and accuracy of defect detection of the mask are improved.

[0016] According to some embodiments of the present disclosure, the real-time calibration parameters comprise a first calibration parameter, a second calibration parameter and a third calibration parameter; the acquiring the real-time calibration parameters of the target area to the target light beam comprises: acquiring the first calibration parameter of the first mark pattern to the first light beam; acquiring the second calibration parameter of the second mark pattern to the second light beam; and acquiring the third calibration parameter of the third mark pattern to the third light beam.

[0017] According to some embodiments of the present disclosure, the preset standard parameters comprise a first standard parameter, a second standard parameter and a third standard parameter; the comparing the real-time calibration parameters with corresponding preset standard parameters, and judging whether the mask exists defects or not according to the comparison result comprises: if the first calibration parameter is greater than or equal to the first standard parameter, it is determined that the mask exists a first defect; if the second calibration parameter is greater than or equal to the second standard parameter, it is determined that the mask exists a second defect; and if the third calibration parameter is greater than or equal to the third standard parameter, it is determined that the mask exists a third defect.

[0018] According to some embodiments of the present disclosure, the mask detection method further comprises: projecting different light beams of different wavelengths to different mark patterns in the target area, respectively measuring reflectivity and transmittance data, and storing the data in the standard database.

[0019] The third aspect of the embodiments of the present disclosure provides a photomask detection device for detecting whether a photomask in any of the embodiments of the present disclosure has defects; the device comprises a projection module and a judgment module, the projection module is configured to project a target light beam to a target region of the photomask, and the target region is provided with the light calibration mark; the judgment module is configured to obtain real-time calibration parameters of the target region to the target light beam, compare the real-time calibration parameters with corresponding preset standard parameters in a standard database, and judge whether the photomask has defects according to the comparison result. Since the target region comprises the first mark pattern, the second mark pattern and the third mark pattern of three different materials, the time spent in searching for the three materials is effectively reduced, and the efficiency and accuracy of defect detection of the photomask are improved.

[0020] The fourth aspect of the embodiments of the present disclosure provides a photomask detection device, comprising a memory and a processor, the memory stores a computer program, and the processor implements the steps of the photomask detection method in any of the embodiments of the present disclosure when executing the computer program.

[0021] The fifth aspect of the embodiments of the present disclosure provides a computer readable storage medium, which stores a computer program, and the computer program is executed by a processor to implement the steps of the photomask detection method in any of the embodiments of the present disclosure.

[0022] In the photomask detection method, device, equipment and medium in the above embodiments, the first material, the second material and the third material corresponding to three different materials can be found on one light calibration mark of the photomask body. Compared with the traditional photomask detection method, the three materials corresponding to the materials need to be found outside the target photomask detection area, the detection target is stronger and the detection efficiency is higher. Since the adverse effects of the area outside the target photomask detection area on the detection light are avoided, the accuracy of photomask detection is effectively improved. Since the target region comprises the first mark pattern, the second mark pattern and the third mark pattern of three different materials, the time spent in searching for the three materials is effectively reduced. BRIEF DESCRIPTION OF DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure, the following will briefly introduce the drawings needed to be used in the embodiment description. Obviously, the drawings in the following description are only some embodiments of the present disclosure, and other drawings can be obtained by those skilled in the art without creating any creative labor.

[0024] Figure 1 The top view schematic diagram of the photomask in an embodiment of the present disclosure is provided;

[0025] Figure 2 The top view schematic diagram of the light calibration mark of the photomask in an embodiment of the present disclosure is provided;

[0026] Figure 3 As shown in the figure, the light shield is provided with a first mark pattern and a second mark pattern. Figure 1 A schematic diagram of a cross-sectional structure of the light shield along the direction of BB' is shown in the figure.

[0027] Figure 4 A schematic diagram of a flow of a light shield detection method provided in an embodiment of the present disclosure is shown in the figure.

[0028] Figure 5 A schematic diagram of a flow of a light shield detection method provided in another embodiment of the present disclosure is shown in the figure.

[0029] Figure 6a A wafer prepared by using the light shield provided in an embodiment of the present disclosure is shown in the figure.

[0030] Figure 6b A local enlarged schematic diagram B corresponding to the rectangular frame region in 6a is shown in the figure.

[0031] Figure 6c As shown in the figure, the light shield is provided with a first mark pattern and a second mark pattern. Figure 6b A corresponding preset image is shown in the figure.

[0032] Figure 7 A schematic diagram of a flow of a light shield detection method provided in another embodiment of the present disclosure is shown in the figure.

[0033] Figure 8 A structural block diagram of a light shield detection device provided in an embodiment of the present disclosure is shown in the figure.

[0034] Figure 9 A structural block diagram of a light shield detection device provided in another embodiment of the present disclosure is shown in the figure.

[0035] Figure 10 A structural block diagram of a light shield detection device provided in another embodiment of the present disclosure is shown in the figure.

[0036] Explanation of reference signs:

[0037] 100, light shield; 10, light shield body; 20, light calibration mark; 11, substrate; 12, first pattern layer; 13, second pattern layer; 21, first mark pattern; 22, second mark pattern; 23, third mark pattern; 300, light shield detection device; 31, image acquisition module; 32, comparison module; 321, gray scale value acquisition unit; 322, gray scale difference value acquisition unit; 323, judgment unit; 41, projection module; 42, judgment module. DETAILED DESCRIPTION

[0038] To facilitate understanding of this disclosure, a more complete description will now be given with reference to the accompanying drawings, in which preferred embodiments of the present disclosure are shown. However, this disclosure may be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

[0039] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of this disclosure.

[0040] It should be understood that when an element or layer is referred to as "on," "adjacent to," "connected to," or "coupled to" other elements or layers, it may be directly on, adjacent to, connected to, or coupled to other elements or layers, or there may be intervening elements or layers. Conversely, when an element is referred to as "directly on," "directly adjacent to," "directly connected to," or "directly coupled to" other elements or layers, there are no intervening elements or layers. It should be understood that although the terms first, second, third, etc., may be used to describe various elements, components, regions, layers, and / or portions, these elements, components, regions, layers, and / or portions should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer, doping type, or portion from another element, component, region, layer, doping type, or portion. Therefore, without departing from the teachings of this invention, the first element, component, region, layer, or portion discussed below may be referred to as the second element, component, region, layer, or portion.

[0041] Spatial relation terms such as “below,” “under,” “below,” “under,” “above,” “above,” etc., are used herein to describe the relationship between one element or feature shown in the figure and other elements or features. It should be understood that, in addition to the orientation shown in the figure, spatial relation terms also include different orientations of the device in use and operation. For example, if the device in the figure is flipped, the element or feature described as “below,” “under,” or “below” will be oriented “above” the other element or feature. Therefore, the exemplary terms “below” and “under” can include both above and below orientations. Furthermore, the device may also include other orientations (e.g., rotated 90 degrees or other orientations), and the spatial descriptive terms used herein will be interpreted accordingly.

[0042] As used herein, the singular forms "a", "an" and "the" include plural referents unless the context clearly dictates otherwise. It will be further understood that the terms "comprises", "comprising", "includes" and / or "including", when used herein, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. In addition, as used herein, the term "and / or" includes any and all combinations of associated items.

[0043] A photomask is used in the process of making semiconductor chips to form a pattern on a semiconductor by using photo-etching technology. In order to copy the pattern on a wafer, the principle of the photomask must be used, similar to the process of copying an image from a negative to a photo using a film when developing a photo. The photomask generally uses quartz glass as a substrate, and a layer of metal chromium and a photosensitive glue is coated on the substrate. The circuit pattern designed by an electronic laser device is exposed on the photosensitive glue, and the exposed area is developed to form a circuit pattern on the metal chromium, which becomes a photomask similar to the negative after exposure, and then is applied to the projection positioning of an integrated circuit. The production and processing procedures generally include exposure, development, photosensitive glue removal, and photo-etching.

[0044] In the conventional photomask detection method, each photomask needs to establish a corresponding detection process before leaving the factory, and different material layers in the photomask need to be found before detection, and these layers are scanned respectively to calibrate the scanning light source of the detection machine. For example, the light source needs to be calibrated for the quartz glass layer of the photomask. If at least three different material layers in the photomask are found in a random way, and then the scanning light source of the detection machine is calibrated, a large amount of time of the relevant engineers is wasted. Moreover, if the scanning light source irradiates outside the target detection area, such as the pellicle of the photomask, it may interfere with the scanning light, affect the accuracy, and even cause misjudgment of the photomask detection result.

[0045] For example, refer to Figure 1 In an embodiment of the present disclosure, a photomask 100 is provided, which includes a photomask body 10 and a light calibration mark 20 arranged on the photomask body 10. The photomask body 10 includes a substrate 11 of a first material, a first pattern layer 12 of a second material, and a second pattern layer 13 of a third material, which are sequentially stacked along a first direction, such as a thickness / height direction. The first pattern layer 12 and the second pattern layer 13 are used to jointly define a transfer pattern of the photomask. The light calibration mark 20 includes a first mark pattern 21 of the first material, a second mark pattern 22 of the second material, and a third mark pattern 23 of the third material, which are sequentially arranged along a second direction. The first direction is perpendicular to the second direction.

[0046] Specifically, in the process of preparing a photomask, some typical defects such as bridge and defocus are inevitably generated, which will affect the yield and pattern accuracy of the prepared photomask to different degrees, therefore, the defect detection step after photolithography is essential. Before the photomask is detected for defects, the scanning light source of the detection machine needs to be calibrated according to different material films in the photomask. For example, the optical microscope (OM) in the defect detection machine emits incident light to the target photomask and receives reflected light reflected from the target photomask, and then determines whether the target photomask has photoresist according to the surface absorbance of the target photomask, the surface absorbance of the target photomask being the difference between the amount of incident light and the amount of reflected light. If it is determined that the target photomask has photoresist, the machine stops defect detection, and the engineer calibrates the scanning light source of the detection machine. The photomask 100 in the embodiment of the present disclosure is provided with the light calibration mark 20 including the first mark pattern 21 of the first material, the second mark pattern 22 of the second material and the third mark pattern 23 of the third material arranged in the second direction in sequence on the photomask body 10; the first material, the second material and the third material are different from each other; the material of the first mark pattern 21 is the same as the material of the substrate 11, which is the first material; the material of the second mark pattern 22 is the same as the material of the first pattern layer 12, which is the second material, and the material of the third mark pattern 23 is the same as the material of the second pattern layer 13, which is the third material, so that the three different materials corresponding to the first material, the second material and the third material can be found on one light calibration mark 20. Compared with the conventional photomask detection method, the three materials corresponding to the materials need to be found outside the target photomask detection area, the detection target is more specific and the detection efficiency is higher; since the adverse effects of the areas outside the target photomask detection area on the detection light are avoided, the accuracy of photomask detection is effectively improved.

[0047] As an example, please refer to Figures 2-3 wherein, Figure 2 schematic diagram of the top view of the photomask in an embodiment of the present disclosure, Figure 3 schematic diagram of the top view of the photomask in an embodiment of the present disclosure, Figure 1The schematic diagram of the cross section structure of the middle mask along the direction of BB' is shown. The first direction is perpendicular to the surface of the substrate 11, for example, the oz direction, and the second direction is parallel to the surface of the substrate 11, for example, the ox direction. By linearly arranging the first mark pattern 21 of the first material, the second mark pattern 22 of the second material and the third mark pattern 23 of the third material in the light calibration mark 20 along the direction parallel to the surface of the substrate 11, for example, along the ox direction, the target property and efficiency of obtaining the first mark pattern 21, the second mark pattern 22 and the third mark pattern 23 in the mask detection process can be effectively improved, and the problem of wasting time and requiring high experience of the staff due to randomly obtaining the three mark patterns of the first mark pattern 21, the second mark pattern 22 and the third mark pattern 23 can be avoided.

[0048] As an example, please continue to refer to Figures 2-3 The first material in the substrate 11 can be quartz, the second material in the first pattern layer 12 can be molybdenum silicide (MoSi), and the third material in the second pattern layer 13 can be chromium alloy. Since the mask is generally made of quartz glass as the substrate, a layer of metal chromium and photosensitive glue is coated on it, and the material of the photosensitive glue includes molybdenum silicide. By setting the light calibration mark to contain the three materials of quartz, molybdenum silicide and chromium alloy, the detection requirements of the current standard mask can be met. In the process of calibrating the scanning light source of the detection machine, the corresponding material can be directly found in the light calibration mark 20, the detection target property is stronger and the detection efficiency is higher. Since the adverse effects of the areas outside the target mask detection area on the detection light are avoided, the precision of the mask detection is effectively improved.

[0049] As an example, please continue to refer to Figures 2-3 The first direction, for example, the oz direction, is perpendicular to the second direction, for example, the ox direction, to avoid the situation that the detection precision is reduced due to uneven light irradiation during the defect scanning detection of the first mark pattern 21, the second mark pattern 22 and the third mark pattern 23 by the scanning machine.

[0050] As an example, please continue to refer to Figures 2-3 The first mark pattern 21 can be arranged on the same layer as the substrate 11, the second mark pattern 22 can be arranged on the same layer as the first pattern layer 12, and the third mark pattern 23 can be arranged on the same layer as the second pattern layer 13, to effectively improve the target property and efficiency of obtaining the first mark pattern 21, the second mark pattern 22 and the third mark pattern 23 in the mask detection process, and avoid the problem of wasting time and requiring high experience of the staff due to randomly obtaining the three mark patterns of the first mark pattern 21, the second mark pattern 22 and the third mark pattern 23.

[0051] As an example, please continue to refer to Figure 2At least one of the first mark pattern 21, the second mark pattern 22 and the third mark pattern 23 has a rectangular orthographic projection on the surface of the substrate 11, for example, the orthographic projection of the first mark pattern 21, the second mark pattern 22 and the third mark pattern 23 on the surface of the substrate 11 are all rectangular, so as to facilitate alignment according to two perpendicular edges of the rectangle, and improve the efficiency and accuracy of alignment using the mark pattern.

[0052] For example, please continue to refer to Figure 2 At least one of the first mark pattern 21, the second mark pattern 22 and the third mark pattern 23 has a rectangular orthographic projection on the surface of the substrate 11, and the length of the rectangle ranges from 480nm to 520nm, for example, the length of the rectangle can be 480nm, 490nm, 500nm, 510nm or 520nm, etc.; the width of the rectangle ranges from 480nm to 520nm, for example, the width of the rectangle can be 480nm, 490nm, 500nm, 510nm or 520nm, etc. The embodiment can meet the size requirements of the current conventional chip size for optical calibration mark 20.

[0053] For example, please continue to refer to Figure 2 The orthographic projection of the first mark pattern 21 on the surface of the substrate 11, the orthographic projection of the second mark pattern 22 on the surface of the substrate 11 and the orthographic projection of the third mark pattern 23 on the surface of the substrate 11 are all the same size, so as to reduce the complexity of mark pattern preparation, effectively improve the target and efficiency of obtaining the first mark pattern 21, the second mark pattern 22 and the third mark pattern 23 in the process of mask detection, and avoid the problem of wasting time and requiring high experience of the workers due to randomly obtaining the three mark patterns.

[0054] For example, please continue to refer to Figure 2 The orthographic projection of the first mark pattern 21 on the surface of the substrate 11, the orthographic projection of the second mark pattern 22 on the surface of the substrate 11 and the orthographic projection of the third mark pattern 23 on the surface of the substrate 11 are all square, so as to facilitate alignment according to two perpendicular edges of the square, improve the efficiency and accuracy of alignment using the mark pattern; at the same time, effectively improve the target and efficiency of obtaining the first mark pattern 21, the second mark pattern 22 and the third mark pattern 23 in the process of mask detection.

[0055] For example, the first material, the second material and the third material are all different, and are selected from one of quartz, molybdenum silicide and chromium alloy, so as to meet the detection requirements of the current standard mask.

[0056] Please refer to Figure 4In some embodiments of the present disclosure, a detection method is provided for detecting whether a photomask in any of the embodiments of the present disclosure has defects; the method comprises the following steps:

[0057] Step S210: projecting a target light beam onto a target region of the photomask, the target region being provided with light calibration marks;

[0058] Step S220: acquiring real-time calibration parameters of the target region to the target light beam;

[0059] Step S230: comparing the real-time calibration parameters with corresponding preset standard parameters in a standard database, and determining whether the photomask has defects according to the comparison result.

[0060] Specifically, please continue to refer to Figure 4 Since the target region of the photomask includes the first, second and third mark patterns of three different materials, the time spent in searching for the three materials is effectively reduced. In this embodiment, the first, second and third materials corresponding to the three different materials can be found on one light calibration mark of the photomask body. Compared with the conventional photomask detection method, which needs to search for the materials corresponding to the three materials outside the target photomask detection region, the target detection is more targeted and the detection efficiency is higher. Since the adverse effects of the regions outside the target photomask detection region on the detection light are avoided, the accuracy of photomask detection is effectively improved.

[0061] As an example, the target light beam can include a first light beam of a first wavelength, a second light beam of a second wavelength and a third light beam of a third wavelength; and the step S210 of projecting the target light beam onto the target region of the photomask comprises:

[0062] Step S211: projecting the first light beam of the first wavelength onto the first mark pattern in the target region;

[0063] Step S212: projecting the second light beam of the second wavelength onto the second mark pattern in the target region;

[0064] Step S213: projecting the third light beam of the third wavelength onto the third mark pattern in the target region.

[0065] As an example, the real-time calibration parameters can include first, second and third calibration parameters; and the step S220 of acquiring the real-time calibration parameters of the target region to the target light beam comprises:

[0066] Step S221: acquiring the first calibration parameter of the first mark pattern to the first light beam;

[0067] Step S222: acquiring the second calibration parameter of the second mark pattern to the second light beam;

[0068] Step S223: Obtain the third calibration parameter of the third mark pattern to the third light beam.

[0069] Specifically, the scanning light source of the calibration detection machine can be controlled to emit a first light beam of a first wavelength, and the first light beam of the first wavelength is projected onto the first mark pattern in the target area. The first calibration parameter of the first mark pattern to the first light beam of the first wavelength is obtained, and then the first calibration parameter is compared with the corresponding preset standard parameter in the standard database. According to the comparison result, it is judged whether the mask exists defects. Similarly, the second calibration parameter of the second mark pattern to the second light beam of the second wavelength is obtained, and then the second calibration parameter is compared with the corresponding preset standard parameter in the standard database. According to the comparison result, it is judged whether the mask exists defects. The third calibration parameter of the third mark pattern to the third light beam of the third wavelength is obtained, and then the third calibration parameter is compared with the corresponding preset standard parameter in the standard database. According to the comparison result, it is judged whether the mask exists defects. In this embodiment, by emitting three kinds of light beams to the detection area in the determined position, the real-time calibration parameters obtained are compared with the corresponding preset standard parameters in the standard database to judge whether the mask exists defects, which effectively improves the efficiency of defect detection of the mask.

[0070] As an example, the preset standard parameters can include the first standard parameter, the second standard parameter and the third standard parameter. In step S230, the real-time calibration parameters are compared with the corresponding preset standard parameters, and according to the comparison result, it is judged whether the mask exists defects, including:

[0071] Step S231: If the first calibration parameter is greater than the first standard parameter, it is determined that the mask exists the first defect.

[0072] Step S232: If the second calibration parameter is greater than the second standard parameter, it is determined that the mask exists the second defect.

[0073] Step S233: If the third calibration parameter is greater than the third standard parameter, it is determined that the mask exists the third defect.

[0074] Specifically, the scanning light source of the calibration detection machine can be controlled to emit a first light beam of a first wavelength, and the first light beam of the first wavelength is projected onto the first mark pattern in the target area. The reflectivity and transmissivity data of the first mark pattern to the first light beam of the first wavelength are obtained, and then the reflectivity is compared with the corresponding standard reflectivity in the standard database, and the transmissivity is compared with the corresponding standard transmissivity in the standard database. According to the comparison result, it is judged whether the mask exists the first defect. Similarly, the reflectivity and transmissivity data of the second mark pattern to the second light beam of the second wavelength are obtained, and then the reflectivity is compared with the corresponding standard reflectivity in the standard database, and the transmissivity is compared with the corresponding standard transmissivity in the standard database. According to the comparison result, it is judged whether the mask exists the second defect. The reflectivity and transmissivity data of the third mark pattern to the third light beam of the third wavelength are obtained, and then the reflectivity is compared with the corresponding standard reflectivity in the standard database, and the transmissivity is compared with the corresponding standard transmissivity in the standard database. According to the comparison result, it is judged whether the mask exists the third defect.

[0075] According to some embodiments of the present disclosure, the target light beam is a laser light beam with variable wavelength emitted by a tunable laser, and the wavelength can be 160 nm, 195 nm or 250 nm.

[0076] According to some embodiments of the present disclosure, the target light beam is a light beam emitted by a halogen light source, and the wavelength range can be adjusted by a filter to be 110 nm to 1000 nm. For example, the wavelength can be 110 nm, 130 nm, 150 nm, 170 nm, 180 nm, 190 nm or 1000 nm.

[0077] According to some embodiments of the present disclosure, in step S230, the real-time calibration parameter is compared with the corresponding preset standard parameter, and according to the comparison result, it is judged whether the mask exists a defect. The determination rule can be:

[0078] If the difference between the first calibration parameter and the first standard parameter is greater than or equal to 0.1%, it is determined that the mask exists the first defect; wherein the range of the first wavelength can be [800 nm, 1000 nm];

[0079] If the difference between the second calibration parameter and the second standard parameter is greater than or equal to 1%, it is determined that the mask exists the second defect; wherein the range of the second wavelength can be [160 nm, 800 nm);

[0080] If the difference between the third calibration parameter and the third standard parameter is greater than or equal to 3%, it is determined that the mask exists the third defect; wherein the range of the third wavelength can be [110 nm, 160 nm).

[0081] According to some embodiments of the present disclosure, different wavelength light beams can be projected onto different mark patterns in the target area to measure reflectivity and transmissivity data respectively and store them in the standard database.

[0082] Please refer to Figure 5 In some embodiments of the present disclosure, a detection method is provided for detecting whether a mask in any embodiment of the present disclosure has defects; the method comprises the following steps:

[0083] Step S310: obtaining a transfer image of a die surface and a corresponding preset image, the die being obtained after pattern transfer from the mask to the wafer;

[0084] Step S320: comparing the transfer image and the corresponding preset image, and determining whether the mask has defects according to the comparison result.

[0085] As an example, please refer to Figure 5 , Figure 6a , Figure 6b and Figure 6c , Figure 6a a wafer prepared according to the mask provided in an embodiment of the present disclosure, Figure 6b a local enlarged view B of the rectangular frame area in Figure 6a a local enlarged view B of the rectangular frame area in Figure 6c a local enlarged view B of the rectangular frame area in Figure 6b the corresponding preset image, by comparing the images in Figure 6b and Figure 6c , it can be determined that the curved frame area in Figure 6b is a defect area. In this embodiment, the computer can be used to obtain a transfer image of a die surface and a corresponding preset image, the die being obtained after pattern transfer from the mask to the wafer; then the transfer image and the corresponding preset image are compared, and whether the mask has defects is determined according to the comparison result, thereby effectively improving the efficiency and accuracy of defect detection of the mask.

[0086] As an example, please refer to Figure 5 and Figure 7 , the step of comparing the transfer image and the corresponding preset image in step S320, and determining whether the mask has defects according to the comparison result, comprises:

[0087] Step S321: obtaining initial gray scale values at different positions of the transfer image and corresponding target gray scale values at different positions of the preset image;

[0088] Step S322: obtaining the difference between the initial gray scale value and the target gray scale value at the same position;

[0089] Step S323: if the absolute value of the difference is greater than or equal to a preset threshold, it is determined that the mask has defects.

[0090] Specifically, since the mask defect can cause abnormality of the target image transferred to the wafer via the mask, by obtaining the difference between the initial gray scale value and the target gray scale value at the same position, and judging whether the absolute value of the difference is greater than or equal to the preset threshold, if yes, it is determined that the mask has defects, thereby effectively improving the efficiency and accuracy of the defect detection of the mask.

[0091] For example, refer to Figure 5 With Figure 7 , the step of comparing the transferred image and the corresponding preset image in step S320, and judging whether the mask has defects according to the comparison result, further comprises:

[0092] In step S324, if the difference is within the preset accuracy range, it is determined that the mask meets the requirements.

[0093] Specifically, if the accuracy of the target image transferred to the wafer via the mask is within the preset accuracy range, the accuracy requirement of the target image transferred by the mask is met, and it is determined that the mask meets the detection requirement, thereby improving the accuracy of the defect detection of the mask.

[0094] It should be understood that, although Figure 4 , Figure 5 and Figure 7 the flowcharts of each step are displayed in sequence according to the direction of the arrow, these steps are not necessarily executed in sequence according to the direction of the arrow. Unless otherwise specified herein, the execution of these steps has no strict order limitation, and these steps can be executed in other orders. Moreover, although Figure 4 , Figure 5 and Figure 7 at least part of the steps can include multiple steps or multiple stages, these steps or stages are not necessarily executed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily sequential, but can be executed in rotation or alternation with at least part of other steps or steps or stages in other steps.

[0095] For example, refer to Figure 8 In some embodiments of the present disclosure, a mask detection device 300 is provided for detecting whether the mask in any embodiment of the present disclosure has defects; the device comprises an image acquisition module 31 and a comparison module 32, the image acquisition module 31 is used to acquire the transferred image of the die surface and the corresponding preset image, the die is obtained after the pattern is transferred to the wafer via the mask; the comparison module 32 is used to compare the transferred image and the corresponding preset image, and judge whether the mask has defects according to the comparison result, so as to improve the efficiency and accuracy of the defect detection of the mask.

[0096] For example, refer to Figures 1-3The photomask for transferring a pattern to a wafer includes a photomask body 10 and a light calibration mark 20 arranged on the photomask body 10. The photomask body 10 includes a substrate 11 of a first material, a first pattern layer 12 of a second material, and a second pattern layer 13 of a third material arranged in sequence along a first direction, such as a thickness / height direction. The first pattern layer 12 and the second pattern layer 13 are used to jointly define a transfer pattern of the photomask. The light calibration mark 20 includes a first mark pattern 21 of the first material, a second mark pattern 22 of the second material, and a third mark pattern 23 of the third material arranged in sequence along a second direction. The first direction and the second direction are oblique to each other. The first material, the second material, and the third material are different from each other. The first material of the first mark pattern 21 is the same as the material of the substrate 11. The second material of the second mark pattern 22 is the same as the material of the first pattern layer 12. The third material of the third mark pattern 23 is the same as the material of the second pattern layer 13. Thus, the three different materials corresponding to the first material, the second material, and the third material can be found on the light calibration mark 20. Before defect detection of the photomask, the scanning light source of the detection machine is calibrated by using the different material layers in the light calibration mark 20. The light calibration mark 20 is arranged in a cutting path of the photomask, so as to avoid affecting the target pattern transferred by the photomask and improve the precision of transferring the target pattern from the photomask to the wafer.

[0097] For example, refer to Figures 2-3 The first material in the substrate 11 can be quartz, the second material in the first pattern layer 12 can be molybdenum silicide (MoSi), and the third material in the second pattern layer 13 can be chromium alloy. Since the photomask generally uses quartz glass as a substrate, a layer of metal chromium and a photosensitive adhesive are coated thereon. The material of the photosensitive adhesive includes molybdenum silicide. By arranging the light calibration mark to include the three materials of quartz, molybdenum silicide, and chromium alloy, the detection requirements of the current standard photomask are met. In the process of calibrating the scanning light source of the detection machine, the corresponding material can be directly found in the light calibration mark 20, so as to improve the detection efficiency and the detection target. Since the adverse effects of the areas outside the target photomask detection area on the detection light are avoided, the precision of photomask detection is effectively improved.

[0098] For example, refer to Figures 2-3 The first direction, such as the oz direction, is perpendicular to the second direction, such as the ox direction, so as to avoid the situation that the detection precision is reduced due to uneven light irradiation during defect scanning detection of the first mark pattern 21, the second mark pattern 22, and the third mark pattern 23 by the scanning machine.

[0099] For example, refer to Figures 2-3The first mark pattern 21 can be arranged on the same layer as the substrate 11, the second mark pattern 22 can be arranged on the same layer as the first pattern layer 12, and the third mark pattern 23 can be arranged on the same layer as the second pattern layer 13, so that the target property and efficiency of obtaining the first mark pattern 21, the second mark pattern 22 and the third mark pattern 23 in the mask detection process are effectively improved, and the problem of time waste and high requirement for the experience of the staff due to random obtaining of the three mark patterns, i.e., the first mark pattern 21, the second mark pattern 22 and the third mark pattern 23, is avoided.

[0100] As an example, please continue to refer to Figure 8 , Figure 6a , Figure 6b and Figure 6c , Figure 6a a wafer prepared according to the mask provided in an embodiment of the present disclosure, Figure 6b a local enlarged view B corresponding to the rectangular frame region in Figure 6a , Figure 6c a local enlarged view B corresponding to the rectangular frame region in Figure 6b , by comparing the images in Figure 6b and Figure 6c , it can be determined that the curved frame region in Figure 6b is a defect region. In this embodiment, the computer is used to obtain the transfer image of the die surface and the corresponding preset image, the die is obtained after the pattern is transferred from the mask to the wafer; then the transfer image and the corresponding preset image are compared, and whether the mask has defects is judged according to the comparison result, so that the efficiency and precision of defect detection of the mask are effectively improved.

[0101] As an example, please refer to Figure 9 , the comparison module 32 includes a gray value acquisition unit 321, a gray difference value acquisition unit 322 and a judgment unit 323, the gray value acquisition unit 321 is used to acquire the initial gray value of different positions on the transfer image and the target gray value of different positions on the corresponding preset image; the gray difference value acquisition unit 322 is used to acquire the difference value of the initial gray value and the target gray value of the same position; the judgment unit 323 is used to determine that the mask has defects if the absolute value of the difference value is greater than or equal to the preset threshold. Since the mask defect will cause the target image transferred from the mask to the wafer to be abnormal, by acquiring the difference value of the initial gray value and the target gray value of the same position, and judging whether the absolute value of the difference value is greater than or equal to the preset threshold, if yes, it is determined that the mask has defects, so that the efficiency and precision of defect detection of the mask are effectively improved.

[0102] As an example, please continue to refer to Figure 9The determining unit 323 is further configured to determine that the photomask meets the detection requirement if the difference is within the preset accuracy range, thereby improving the accuracy of the photomask defect detection.

[0103] Referring to Figure 10 In some embodiments of the present disclosure, a photomask detection device 300 is provided for detecting whether a photomask in any of the embodiments of the present disclosure has defects; the device comprises a projection module 41 and a determination module 42, the projection module 41 is configured to project a target light beam to a target area of the photomask, and the target area is provided with light calibration marks; the determination module 42 is configured to obtain real-time calibration parameters of the target area to the target light beam, compare the real-time calibration parameters with corresponding preset standard parameters in a standard database, and determine whether the photomask has defects according to the comparison result. Since the target area comprises the first mark pattern, the second mark pattern and the third mark pattern of three different materials, the time spent in searching for the three materials is effectively reduced, and the efficiency and accuracy of the photomask defect detection are improved.

[0104] The embodiments of the present disclosure further provide a computer device comprising a memory and a processor, wherein the memory stores a computer program, and the processor implements the steps of the method according to any of the above embodiments when executing the computer program.

[0105] The embodiments of the present disclosure further provide a computer readable storage medium having a computer program stored thereon, wherein the computer program is executed by a processor to implement the steps of the method according to any of the above embodiments.

[0106] In the photomask detection method, device, equipment and medium, the first material, the second material and the third material corresponding to the three different materials can be found on one light calibration mark of the photomask body, and compared with the traditional photomask detection method, the three materials corresponding to the materials need to be found outside the target photomask detection area, the detection target is stronger and the detection efficiency is higher; since the adverse effects of the areas outside the target photomask detection area on the detection light are avoided, the accuracy of the photomask detection is effectively improved. Since the target area comprises the first mark pattern, the second mark pattern and the third mark pattern of three different materials, the time spent in searching for the three materials is effectively reduced.

[0107] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a non-volatile computer readable storage medium, and when executed, can include the processes of the above-mentioned embodiment methods. Any reference to memory, storage, database or other medium used in each embodiment of the present disclosure can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory or optical memory, etc. Volatile memory can include random access memory (RAM) or external cache memory. As an illustration but not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM), etc.

[0108] Any combination of the technical features of the above-mentioned embodiments can be made. In order to make the description simple, all possible combinations of the technical features of the above-mentioned embodiments are not described, but as long as the combination of the technical features does not exist, it should be considered as the scope of the present disclosure.

[0109] The above-mentioned embodiments only express several implementation manners of the present disclosure, and the description is more specific and detailed, but it should not be understood as a limitation on the scope of the patent application. It should be pointed out that for those skilled in the art, without departing from the concept of the present disclosure, some modifications and improvements can be made, which are all within the protection scope of the present disclosure. Therefore, the protection scope of the patent of the present disclosure should be subject to the appended claims.

Claims

1. A reticle inspection method, comprising: The application discloses a method for detecting whether a mask exists defects, the mask comprises a mask body and a light calibration mark arranged on the mask body, the mask body comprises a first material substrate, a first pattern layer of a second material and a second pattern layer of a third material which are sequentially stacked along a first direction, the first pattern layer and the second pattern layer are used for jointly defining a transfer pattern of the mask, the light calibration mark comprises a first mark pattern of a first material, a second mark pattern of a second material and a third mark pattern of a third material which are sequentially arranged along a second direction, wherein the first direction is perpendicular to the second direction; the method comprises the following steps: projecting a first light beam of a first wavelength on the first mark pattern, and acquiring a first calibration parameter of the first mark pattern to the first light beam; projecting a second light beam of a second wavelength on the second mark pattern, and acquiring a second calibration parameter of the second mark pattern to the second light beam; projecting a third light beam of a third wavelength on the third mark pattern, and acquiring a third calibration parameter of the third mark pattern to the third light beam; comparing the first calibration parameter, the second calibration parameter and the third calibration parameter with corresponding preset standard parameters in a standard database, and judging whether the mask exists defects according to a comparison result.

2. The method of claim 1, wherein, The preset standard parameters comprise a first standard parameter, a second standard parameter and a third standard parameter; the comparison of the first calibration parameter, the second calibration parameter and the third calibration parameter with corresponding preset standard parameters, and the judgment of whether the mask exists defects according to a comparison result, comprise the following steps: if the first calibration parameter is greater than the first standard parameter, it is determined that the mask exists a first defect; if the second calibration parameter is greater than the second standard parameter, it is determined that the mask exists a second defect; if the third calibration parameter is greater than the third standard parameter, it is determined that the mask exists a third defect.

3. The method according to any of claims 1-2, characterized by, The first calibration parameter comprises reflectivity and transmissivity data of the first mark pattern to the first light beam, the second calibration parameter comprises reflectivity and transmissivity data of the second mark pattern to the second light beam, the third calibration parameter comprises reflectivity and transmissivity data of the third mark pattern to the third light beam, and corresponding preset standard parameters in the standard database comprise standard reflectivity and standard transmissivity; the comparison of the first calibration parameter, the second calibration parameter and the third calibration parameter with corresponding preset standard parameters in the standard database, comprise the following steps: comparing the reflectivity in the first calibration parameter with the standard reflectivity in the standard database, and comparing the transmissivity in the first calibration parameter with the standard transmissivity in the standard database; comparing the reflectivity in the second calibration parameter with the standard reflectivity in the standard database, and comparing the transmissivity in the second calibration parameter with the standard transmissivity in the standard database; comparing the reflectivity in the third calibration parameter with the standard reflectivity in the standard database, and comparing the transmissivity in the third calibration parameter with the standard transmissivity in the standard database.

4. A reticle inspection apparatus comprising a memory and a processor, the memory storing a computer program, wherein, The computer program is executed by the processor to implement the steps of the method of any one of claims 1 to 3.

5. A computer-readable storage medium having stored thereon a computer program, characterized in that, The computer program is executed by the processor to implement the steps of the method of any one of claims 1 to 3.

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