Overlay mark and semiconductor device
By adopting a design combining multiple sets of linear overlay marks and circular overlay mark patterns in semiconductor devices, the problem of insufficient overlay error measurement accuracy in photolithography technology is solved, and higher overlay measurement accuracy and reliability are achieved.
Patent Information
- Application Number
- CN202422823417.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-19
- Publication Date
- 2025-10-24
- Estimated Expiration
- 2034-11-19
AI Technical Summary
The overlay error measurement method in existing photolithography technology is insufficiently accurate, affecting the performance and reliability of semiconductor devices.
The overlay mark design, which combines multiple groups of linear overlay mark patterns and circular overlay mark patterns, improves measurement accuracy by depicting overlay errors from multiple angles.
The accuracy of semiconductor device overlay measurement is improved, and the detection accuracy and reliability of overlay errors are enhanced.
Smart Images
Figure CN223471238U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to chip manufacturing technical field especially, relate to a kind of overlay mark and semiconductor device. BACKGROUND
[0002] Lithography technology is the core technology of semiconductor manufacturing technology, in the lithography process, overlay error is the most important factor leading to processing defects, with the improvement of lithography resolution, the requirement for alignment accuracy is more and more strict. To ensure the performance of semiconductor devices, it is necessary to ensure the alignment accuracy between multiple lithography processes through overlay inspection.
[0003] The current overlay error measurement method is mainly divided into image based overlay (IBO) and diffraction based overlay (DBO). Among them, IBO method adopts reflection principle, and the marks of the current layer and the previous layer are imaged to the camera through the optical system. Then through the analysis software, the position of two layer marks is analyzed, and the position difference of two layer marks is the overlay error. The DBO method measures the grating acceptance light overlaid on the current layer and the previous layer. The intensity distribution of the first-order diffraction light after the diffraction of two layers of grating and the relative position offset of two layers of grating exist approximately sinusoidal change rule, and there is approximately linear relationship in certain overlay error interval. The intensity of ±1 order diffraction light can be obtained by detecting.
[0004] These two kinds of methods are to measure the overlay marks of the current layer and the previous layer, and then obtain the overlay error, therefore, the overlay mark is the key to affect the precision of semiconductor device overlay measurement. UTILITY MODEL CONTENT
[0005] The utility model embodiment provides a kind of overlay mark and semiconductor device, by adopting the way of combination of multiple sets of linear overlay mark pattern and circular overlay mark pattern, improve the precision of semiconductor device overlay measurement.
[0006] In the first aspect, the utility model embodiment provides an overlay mark, which includes two layers of overlay marks, the two layers of overlay marks are arranged from bottom to top, each layer of overlay mark in the two layers of overlay marks includes multiple sets of linear overlay mark pattern and circular overlay mark pattern, the circular overlay mark pattern is located in the middle of the layer of overlay mark, and the multiple sets of linear overlay mark pattern are located at the periphery of the layer of overlay mark;Wherein, each set of linear overlay mark pattern in the multiple sets of linear overlay mark pattern includes multiple mutually parallel mark lines;The circular overlay mark pattern includes circular mark lines with same center and different radii.
[0007] The overlay marks in the embodiments of the present application can depict overlay errors from multiple angles by setting multiple groups of linear overlay mark patterns and circular overlay mark patterns, the circular overlay mark patterns being located in the middle of the overlay marks of the layer, and the multiple groups of linear overlay mark patterns being located around the overlay marks of the layer, thereby improving the accuracy of overlay measurement of the semiconductor device.
[0008] In a possible implementation, each group of linear overlay mark patterns includes two gratings with different periods.
[0009] In a possible implementation, the two layers of overlay marks include a first layer of overlay marks and a second layer of overlay marks; the multiple groups of linear overlay mark patterns in the first layer of overlay marks include first to sixth groups of linear overlay mark patterns, and the multiple groups of linear overlay mark patterns in the second layer of overlay marks include seventh to twelfth groups of linear overlay mark patterns; the grating arrangement directions in the first, third, and sixth groups of linear overlay mark patterns are the same as the x-axis direction; the grating arrangement directions in the second, fourth, and fifth groups of linear overlay mark patterns are the same as the y-axis direction; the grating arrangement directions in the seventh, ninth, and twelfth groups of linear overlay mark patterns are the same as the x-axis direction; and the grating arrangement directions in the eighth, tenth, and eleventh groups of linear overlay mark patterns are the same as the y-axis direction.
[0010] With the above overlay marks, the overlay deviation in the x-axis direction can be obtained through the first, third, and sixth groups of linear overlay mark patterns, and the overlay deviation in the y-axis direction can be obtained through the second, fourth, fifth, eighth, tenth, and eleventh groups of linear overlay mark patterns.
[0011] In a possible embodiment, the grating periods in the first and fifth groups of linear overlay mark patterns are the same, the grating periods in the second and third groups of linear overlay mark patterns are the same, and the grating periods in the fourth and sixth groups of linear overlay mark patterns are the same; the grating periods in the seventh and eleventh groups of linear overlay mark patterns are the same, the grating periods in the eighth and ninth groups of linear overlay mark patterns are the same, and the grating periods in the tenth and twelfth groups of linear overlay mark patterns are the same.
[0012] In a possible embodiment, the grating periods of the first set of linear overlay mark patterns, the second set of linear overlay mark patterns and the fourth set of linear overlay mark patterns are different from each other; the grating periods of the seventh set of linear overlay mark patterns, the eighth set of linear overlay mark patterns and the tenth set of linear overlay mark patterns are different from each other.
[0013] In a possible embodiment, the grating periods in the first set of linear overlay mark patterns and the seventh set of linear overlay mark patterns are the same, the grating periods in the second set of linear overlay mark patterns and the eighth set of linear overlay mark patterns are the same, and the grating periods in the fourth set of linear overlay mark patterns and the tenth set of linear overlay mark patterns are the same.
[0014] In a possible embodiment, the period of each grating is in a range from 1 μm to 10 μm.
[0015] In a possible embodiment, the length of each grating is in a range from 30 μm to 50 μm, and the width of each grating is half of the grating period.
[0016] In a possible embodiment, the material of the grating is silicon.
[0017] In a second aspect, the embodiments of the utility model provide a semiconductor device, the semiconductor device includes the overlay mark of any one of the first aspect. BRIEF DESCRIPTION OF DRAWINGS
[0018] In order to more clearly illustrate the embodiments of the utility model or the implementation manners in the related art, the following will briefly introduce the drawings needed to be used in the embodiment or related art description, and obviously, the drawings in the following description are some embodiments of the application, and other drawings can also be obtained by those skilled in the art according to these drawings.
[0019] Figure 1 A schematic view of an overlay mark provided by the embodiments of the utility model is shown in the following figure.
[0020] Figure 2 A schematic view of a moire fringe image provided by the embodiments of the utility model is shown in the following figure.
[0021] Figure 3 A schematic view of a moire fringe image provided by the embodiments of the utility model is shown in the following figure. DETAILED DESCRIPTION
[0022] In order to make the purposes, technical solutions and advantages of the present application clearer, the following further describes the present application with reference to the accompanying drawings. Obviously, the embodiments described in the present application are only some of the embodiments of the present application, but not all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of the present application.
[0023] It should be noted that the brief description of the terms in the present application is only for the convenience of understanding the subsequently described embodiments, and is not intended to limit the embodiments of the present application. Unless otherwise specified, these terms should be understood according to their ordinary and general meanings.
[0024] The terms "first", "second", "third", and the like in the specification and claims of the present application and the above-described drawings are used to distinguish similar or similar objects or entities, and do not necessarily mean a specific order or sequence, unless otherwise noted. It should be understood that the terms used in this way can be interchanged under appropriate circumstances.
[0025] The terms "include" and "have" and any variations thereof are intended to cover but not exclusive inclusion, for example, a product or device including a series of components does not have to be limited to all components clearly listed, but can include other components not clearly listed or inherent to these products or devices.
[0026] Before introducing the overlay marks provided by the embodiments of the present application, first introduce the professional terms of the embodiments of the present application for the convenience of understanding.
[0027] Overlay error: refers to the error caused by the misalignment between different lithography layers in the semiconductor manufacturing process. Multiple lithography layers are usually required in semiconductor chip manufacturing, and each layer must be accurately aligned with the previous pattern. If the alignment between these layers is not accurate, overlay error will occur. With the increase of the number of integrated circuit layers and the improvement of complexity, overlay error is a key parameter in the lithography process, and its control is crucial to ensure the normal operation of integrated circuits. By using advanced measurement and control methods, overlay error can be effectively reduced, and the performance and reliability of semiconductor devices can be improved.
[0028] Moire fringe: is the basis for precise measurement of grating displacement. In practical applications, the optical fringe formed by superimposing two periodic grating patterns with similar spatial frequencies is Moire fringe, which can be generated by various principles such as shading effect, diffraction effect and interference effect. Moire fringe is widely used in various fields, including optical measurement, interferometer and precision detection in semiconductor manufacturing, etc.
[0029] Grating: an optical element composed of a large number of fine parallel slits or lines arranged at equal intervals, the main function of the grating is to decompose the incident light into different wavelengths of spectrum through diffraction and interference effect, so as to realize the separation or diffraction of light.
[0030] Lithography technology is the core technology of semiconductor manufacturing technology, in the lithography process, overlay error is the main factor leading to processing defects, with the improvement of lithography resolution, the requirement for alignment accuracy is more and more strict. In order to ensure the performance of semiconductor devices, the first layer overlay mark and the second layer overlay mark need to be measured in multiple steps in the overlay process to ensure the alignment accuracy between multiple lithography processes, and the overlay mark is the key to the accuracy of the overlay error of the semiconductor device.
[0031] Based on this, the application provides an overlay mark, which comprises two layers of overlay marks arranged from bottom to top.
[0032] The overlay mark provided by the utility model is described in detail below in combination with specific embodiments.
[0033] Figure 1 The overlay mark provided by the utility model comprises two layers of overlay marks, namely a first layer of overlay mark and a second layer of overlay mark, and the two layers of overlay marks are arranged from bottom to top. Figure 1 (a) is the first layer of overlay mark, Figure 1 (b) is the second layer of overlay mark. The first layer of overlay mark comprises a plurality of linear overlay mark patterns and a circular overlay mark pattern, the circular overlay mark pattern is located in the middle of the layer of overlay mark, and the plurality of linear overlay mark patterns are located around the layer of overlay mark; each linear overlay mark pattern in the plurality of linear overlay mark patterns comprises a plurality of parallel mark lines; the circular overlay mark pattern comprises circular mark lines with the same center and different radii.
[0034] The second layer of overlay mark comprises a plurality of linear overlay mark patterns and a circular overlay mark pattern, the circular overlay mark pattern is located in the middle of the layer of overlay mark, and the plurality of linear overlay mark patterns are located around the layer of overlay mark; each linear overlay mark pattern in the plurality of linear overlay mark patterns comprises a plurality of parallel mark lines; the circular overlay mark pattern comprises circular mark lines with the same center and different radii.
[0035] Further optionally, the plurality of groups of linear overlay mark patterns in the first layer of overlay marks include first to sixth groups of linear overlay mark patterns, wherein the grating arrangement direction of the first, third, and sixth groups of linear overlay mark patterns is the same as the x-axis direction; and the grating arrangement direction of the second, fourth, and fifth groups of linear overlay mark patterns is the same as the y-axis direction. The first, third, and sixth groups of linear overlay mark patterns can be used to detect overlay errors in the x-axis direction, and the second, fourth, and fifth groups of linear overlay mark patterns can be used to detect overlay errors in the y-axis direction.
[0036] The plurality of groups of linear overlay mark patterns in the second layer of overlay marks include seventh to twelfth groups of linear overlay mark patterns, wherein the grating arrangement direction of the seventh, ninth, and twelfth groups of linear overlay mark patterns is the same as the x-axis direction; and the grating arrangement direction of the eighth, tenth, and eleventh groups of linear overlay mark patterns is the same as the y-axis direction. The seventh, ninth, and twelfth groups of linear overlay mark patterns can be used to detect overlay errors in the x-axis direction, and the eighth, tenth, and eleventh groups of linear overlay mark patterns can be used to detect overlay errors in the y-axis direction.
[0037] The first to sixth groups of linear overlay mark patterns in the first layer of overlay marks each include two gratings with different periods, and the seventh to twelfth groups of linear overlay mark patterns in the second layer of overlay marks each include two gratings with different periods.
[0038] by Figure 1 Taking (a) as an example, the periods of the two gratings from left to right in the first group of linear overlay mark patterns in the first layer of overlay marks are 2.2 μm and 2 μm respectively, the periods of the two gratings from top to bottom in the second group of linear overlay mark patterns are 8.8 μm and 8 μm respectively, the periods of the two gratings from left to right in the third group of linear overlay mark patterns are 8 μm and 8.8 μm respectively, the periods of the two gratings from top to bottom in the fourth group of linear overlay mark patterns are 4 μm and 4.4 μm respectively, the periods of the two gratings from top to bottom in the fifth group of linear overlay mark patterns are 2 μm and 2.2 μm respectively, and the periods of the two gratings from left to right in the sixth group of linear overlay mark patterns are 4.4 μm and 4 μm respectively.
[0039] by Figure 1(b) For example, the periods of the two gratings from left to right in the seventh group of linear overlay mark patterns in the second layer overlay mark are 2 μm and 2.2 μm respectively, the periods of the two gratings from top to bottom in the eighth group of linear overlay mark patterns are 8 μm and 8.8 μm respectively, the periods of the two gratings from left to right in the ninth group of linear overlay mark patterns are 8.8 μm and 8 μm respectively, the periods of the two gratings from top to bottom in the tenth group of linear overlay mark patterns are 4.4 μm and 4 μm respectively, the periods of the two gratings from top to bottom in the eleventh group of linear overlay mark patterns are 2.2 μm and 2 μm respectively, and the periods of the two gratings from left to right in the twelfth group of linear overlay mark patterns are 4 μm and 4.4 μm respectively.
[0040] For example, the periods of the gratings in the first group of linear overlay mark patterns and the fifth group of linear overlay mark patterns in the first layer overlay mark are the same, the periods of the gratings in the second group of linear overlay mark patterns and the third group of linear overlay mark patterns are the same, the periods of the gratings in the fourth group of linear overlay mark patterns and the sixth group of linear overlay mark patterns are the same, the periods of the gratings in the seventh group of linear overlay mark patterns and the eleventh group of linear overlay mark patterns in the second layer overlay mark are the same, the periods of the gratings in the eighth group of linear overlay mark patterns and the ninth group of linear overlay mark patterns are the same, and the periods of the gratings in the tenth group of linear overlay mark patterns and the twelfth group of linear overlay mark patterns are the same.
[0041] For example, the periods of the gratings in the first group of linear overlay mark patterns and the fifth group of linear overlay mark patterns in the first layer overlay mark are the same, the periods of the gratings in the second group of linear overlay mark patterns and the third group of linear overlay mark patterns are the same, the periods of the gratings in the fourth group of linear overlay mark patterns and the sixth group of linear overlay mark patterns are the same, the periods of the gratings in the seventh group of linear overlay mark patterns and the eleventh group of linear overlay mark patterns in the second layer overlay mark are the same, the periods of the gratings in the eighth group of linear overlay mark patterns and the ninth group of linear overlay mark patterns are the same, and the periods of the gratings in the tenth group of linear overlay mark patterns and the twelfth group of linear overlay mark patterns are the same. Figure 1 (a) For example, the first group of linear overlay mark patterns and the fifth group of linear overlay mark patterns in the first layer overlay mark both include gratings of 2.2 μm and 2 μm, the second group of linear overlay mark patterns and the third group of linear overlay mark patterns both include gratings of 8.8 μm and 8 μm, and the fourth group of linear overlay mark patterns and the sixth group of linear overlay mark patterns both include gratings of 4.4 μm and 4 μm.
[0042] (a) For example, the first group of linear overlay mark patterns and the fifth group of linear overlay mark patterns in the first layer overlay mark both include gratings of 2.2 μm and 2 μm, the second group of linear overlay mark patterns and the third group of linear overlay mark patterns both include gratings of 8.8 μm and 8 μm, and the fourth group of linear overlay mark patterns and the sixth group of linear overlay mark patterns both include gratings of 4.4 μm and 4 μm. Figure 1 (b) For example, the seventh group of linear overlay mark patterns and the eleventh group of linear overlay mark patterns in the second layer overlay mark both include gratings of 2 μm and 2.2 μm, the eighth group of linear overlay mark patterns and the ninth group of linear overlay mark patterns both include gratings of 8 μm and 8.8 μm, and the tenth group of linear overlay mark patterns and the twelfth group of linear overlay mark patterns both include gratings of 4 μm and 4.4 μm.
[0043] For example, the periods of the gratings in the first group of linear overlay mark patterns, the second group of linear overlay mark patterns and the fourth group of linear overlay mark patterns in the first layer overlay mark are different from each other; and the periods of the gratings in the seventh group of linear overlay mark patterns, the eighth group of linear overlay mark patterns and the tenth group of linear overlay mark patterns in the second layer overlay mark are different from each other.
[0044] With reference to FIG. 1, the first layer of overlay marks includes a first group of linear overlay mark patterns, a second group of linear overlay mark patterns, a third group of linear overlay mark patterns, and a fourth group of linear overlay mark patterns. The second layer of overlay marks includes a seventh group of linear overlay mark patterns, an eighth group of linear overlay mark patterns, and a tenth group of linear overlay mark patterns. Figure 1 For example, the period of the two gratings in the first group of linear overlay mark patterns in the first layer of overlay marks is 2.2 μm and 2 μm from left to right, the period of the two gratings in the second group of linear overlay mark patterns is 8.8 μm and 8 μm from top to bottom, and the period of the two gratings in the fourth group of linear overlay mark patterns is 4 μm and 4.4 μm from top to bottom.
[0045] For example, the period of the two gratings in the seventh group of linear overlay mark patterns in the second layer of overlay marks is 2 μm and 2.2 μm from left to right, the period of the two gratings in the eighth group of linear overlay mark patterns is 8 μm and 8.8 μm from top to bottom, and the period of the two gratings in the tenth group of linear overlay mark patterns is 4.4 μm and 4 μm from top to bottom. Figure 1 For example, the period of the two gratings in the first group of linear overlay mark patterns in the first layer of overlay marks is the same as the period of the two gratings in the seventh group of linear overlay mark patterns in the second layer of overlay marks, the period of the two gratings in the second group of linear overlay mark patterns in the first layer of overlay marks is the same as the period of the two gratings in the eighth group of linear overlay mark patterns in the second layer of overlay marks, and the period of the two gratings in the fourth group of linear overlay mark patterns in the first layer of overlay marks is the same as the period of the two gratings in the tenth group of linear overlay mark patterns in the second layer of overlay marks.
[0046] For example, the period of the two gratings in the first group of linear overlay mark patterns in the first layer of overlay marks is 2.2 μm and 2 μm from left to right, the period of the two gratings in the seventh group of linear overlay mark patterns in the second layer of overlay marks is 2 μm and 2.2 μm from left to right, i.e., the period of the two gratings in the first group of linear overlay mark patterns is the same as the period of the two gratings in the seventh group of linear overlay mark patterns. The period of the two gratings in the second group of linear overlay mark patterns in the first layer of overlay marks is 8.8 μm and 8 μm from top to bottom, the period of the two gratings in the eighth group of linear overlay mark patterns in the second layer of overlay marks is 8 μm and 8.8 μm from top to bottom, i.e., the period of the two gratings in the second group of linear overlay mark patterns is the same as the period of the two gratings in the eighth group of linear overlay mark patterns. The period of the two gratings in the fourth group of linear overlay mark patterns in the first layer of overlay marks is 4 μm and 4.4 μm from top to bottom, and the period of the two gratings in the tenth group of linear overlay mark patterns is 4.4 μm and 4 μm from top to bottom, i.e., the period of the two gratings in the fourth group of linear overlay mark patterns is the same as the period of the two gratings in the tenth group of linear overlay mark patterns.
[0047] Figure 1 For example, the period of the two gratings in the first group of linear overlay mark patterns in the first layer of overlay marks is 2.2 μm and 2 μm from left to right, the period of the two gratings in the seventh group of linear overlay mark patterns in the second layer of overlay marks is 2 μm and 2.2 μm from left to right, i.e., the period of the two gratings in the first group of linear overlay mark patterns is the same as the period of the two gratings in the seventh group of linear overlay mark patterns. The period of the two gratings in the second group of linear overlay mark patterns in the first layer of overlay marks is 8.8 μm and 8 μm from top to bottom, the period of the two gratings in the eighth group of linear overlay mark patterns in the second layer of overlay marks is 8 μm and 8.8 μm from top to bottom, i.e., the period of the two gratings in the second group of linear overlay mark patterns is the same as the period of the two gratings in the eighth group of linear overlay mark patterns. The period of the two gratings in the fourth group of linear overlay mark patterns in the first layer of overlay marks is 4 μm and 4.4 μm from top to bottom, and the period of the two gratings in the tenth group of linear overlay mark patterns is 4.4 μm and 4 μm from top to bottom, i.e., the period of the two gratings in the fourth group of linear overlay mark patterns is the same as the period of the two gratings in the tenth group of linear overlay mark patterns. Figure 1
[0048] The grating periods of the circular overlay mark pattern in the first layer overlay mark and the circular overlay mark pattern in the second layer overlay mark can be different, so that Figure 1 (a) and Figure 1 For example, the grating period of the circular overlay mark pattern in the first layer overlay mark is 4 μm, and the grating period of the circular overlay mark pattern in the second layer overlay mark is 4.4 μm.
[0049] For example, the grating material of the two layers of overlay marks of the overlay mark is silicon, the period of each grating is in the range of 1 μm to 10 μm, the length of each grating is in the range of 30 μm to 50 μm, and the width of each grating is half of the grating period.
[0050] By using the overlay mark, by arranging a plurality of groups of linear overlay mark patterns and a circular overlay mark pattern, the circular overlay mark pattern is located in the middle of the layer of overlay marks, and the plurality of groups of linear overlay mark patterns are located at the periphery of the layer of overlay marks, the overlay error can be described from multiple angles, and thus the precision of the overlay measurement of the semiconductor device is improved.
[0051] In a possible embodiment, by vertically irradiating the gratings between the first layer overlay mark and the second layer overlay mark by laser, Moiré fringes can be formed, and a device can be used to acquire the Moiré fringe image, and the device can be a camera or a mobile phone, which is not limited herein. For example, Figure 2 and Figure 3 For example, the circular Moiré fringe in the middle is formed by the circular overlay mark pattern in the first layer overlay mark and the second layer overlay mark, and the plurality of groups of linear Moiré fringes at the periphery are formed by the plurality of groups of linear overlay mark patterns in the first layer overlay mark and the second layer overlay mark. Figure 2 and Figure 3 Moiré fringe images of different overlay errors are shown, Figure 2 is a Moiré fringe image without offset in the x-axis and y-axis directions, and there is no phase shift in the circular Moiré fringe and the plurality of groups of linear Moiré fringes, Figure 3 is a Moiré fringe image with offset in the x-axis and y-axis directions.
[0052] For the gratings between the first layer overlay mark and the second layer overlay mark of the overlay mark proposed by the laser vertical irradiation, corresponding Moiré fringe images can be formed, and subsequent overlay error detection can be performed by using the acquired Moiré fringe images, so that Figure 3 For example, the Moiré fringe image with overlay error can be seen, Figure 3 the circular Moiré fringe in the middle has a relative phase shift, and the relative phase shift relationship satisfies the following formula:
[0053]
[0054] wherein, for the grating frequency, for the overlay error in the x-axis direction, for the overlay error in the y-axis direction.
[0055] Figure 3 The relative phase difference between the multiple sets of linear moire fringes satisfies the following formula:
[0056]
[0057] The circular moire fringe image formed by the overlay mark can directly show the offset direction of the overlay error, the coarse measurement of the overlay error, the multiple sets of linear moire fringe images are used to reflect the overlay error in different directions, and then the fine measurement of the overlay error is realized, and the two kinds are combined, the overlay error can be described in multiple scales, and therefore the detection precision of the overlay error is improved.
[0058] Those skilled in the art will understand that the embodiments of the present application can be provided as a method, a system, or a computer program product. Therefore, the present application can adopt a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application can adopt the form of a computer program product implemented on one or more computer usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer usable program codes.
[0059] The present application is described with reference to flowcharts and / or block diagrams according to the method, device (system), and computer program product of the present application. It should be understood that each flow and / or block in the flowcharts and / or block diagrams, and the combination of the flows and / or blocks in the flowcharts and / or block diagrams can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device produce a device that implements the functions specified in the flowcharts and / or block diagrams. Figure 1 one or more flows and / or blocks Figure 1 means for performing the functions specified in one or more flows and / or blocks.
[0060] These computer program instructions can also be stored in a computer readable storage medium that can guide the computer or other programmable data processing device to work in a specific way, so that the instructions stored in the computer readable storage medium produce a product including instruction means, which implements the functions specified in the flowcharts and / or block diagrams. Figure 1 one or more flows and / or blocks Figure 1 means for performing the functions specified in one or more flows and / or blocks.
[0061] These computer program instructions can also be loaded into a computer or other programmable data processing devices, so that a series of operational steps are performed on the computer or other programmable data processing devices to generate computer-implemented processes, thus the instructions executed on the computer or other programmable data processing devices provide processes for implementing the functions specified in the flowchart Figure 1 one or more flows and / or blocks Figure 1 one or more flows and / or blocks
[0062] Obviously, those skilled in the art can make various modifications and variations to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalent technologies, the present application is also intended to include these modifications and variations.
Claims
1. A lithography mark, characterized in that, The overlay mark comprises two layers of overlay marks arranged from bottom to top; Each layer of overlay mark in the two layers of overlay marks comprises a plurality of sets of linear overlay mark patterns and a circular overlay mark pattern, the circular overlay mark pattern is located in the middle of the layer of overlay mark, and the plurality of sets of linear overlay mark patterns are located around the layer of overlay mark; Each set of linear overlay mark patterns in the plurality of sets of linear overlay mark patterns comprises a plurality of parallel mark lines; and the circular overlay mark pattern comprises circular mark lines with the same center and different radii.
2. The overlay mark of claim 1, wherein, Each set of linear overlay mark patterns comprises two gratings with different periods.
3. The overlay mark of claim 1, wherein, The two layers of overlay marks comprise a first layer of overlay mark and a second layer of overlay mark; The plurality of sets of linear overlay mark patterns in the first layer of overlay mark comprise a first set of linear overlay mark patterns to a sixth set of linear overlay mark patterns, and the plurality of sets of linear overlay mark patterns in the second layer of overlay mark comprise a seventh set of linear overlay mark patterns to a twelfth set of linear overlay mark patterns; The arrangement directions of the gratings in the first set of linear overlay mark patterns, the third set of linear overlay mark patterns and the sixth set of linear overlay mark patterns are the same as the direction of the x-axis; the arrangement directions of the gratings in the second set of linear overlay mark patterns, the fourth set of linear overlay mark patterns and the fifth set of linear overlay mark patterns are the same as the direction of the y-axis; The arrangement directions of the gratings in the seventh set of linear overlay mark patterns, the ninth set of linear overlay mark patterns and the twelfth set of linear overlay mark patterns are the same as the direction of the x-axis; and the arrangement directions of the gratings in the eighth set of linear overlay mark patterns, the tenth set of linear overlay mark patterns and the eleventh set of linear overlay mark patterns are the same as the direction of the y-axis.
4. The overlay mark of claim 3, wherein, The periods of the gratings in the first set of linear overlay mark patterns and the fifth set of linear overlay mark patterns are the same, the periods of the gratings in the second set of linear overlay mark patterns and the third set of linear overlay mark patterns are the same, and the periods of the gratings in the fourth set of linear overlay mark patterns and the sixth set of linear overlay mark patterns are the same; The periods of the gratings in the seventh set of linear overlay mark patterns and the eleventh set of linear overlay mark patterns are the same, the periods of the gratings in the eighth set of linear overlay mark patterns and the ninth set of linear overlay mark patterns are the same, and the periods of the gratings in the tenth set of linear overlay mark patterns and the twelfth set of linear overlay mark patterns are the same.
5. The overlay mark of claim 4, wherein, The periods of the gratings in the first set of linear overlay mark patterns, the second set of linear overlay mark patterns and the fourth set of linear overlay mark patterns are different from each other; The periods of the gratings in the seventh set of linear overlay mark patterns, the eighth set of linear overlay mark patterns and the tenth set of linear overlay mark patterns are different from each other.
6. The overlay mark of claim 5, wherein, The periods of the gratings in the first set of linear overlay mark patterns and the seventh set of linear overlay mark patterns are the same, the periods of the gratings in the second set of linear overlay mark patterns and the eighth set of linear overlay mark patterns are the same, and the periods of the gratings in the fourth set of linear overlay mark patterns and the tenth set of linear overlay mark patterns are the same.
7. The overlay mark of any one of claims 1 to 6, wherein, The period of each grating is in the range of 1 μm to 10 μm.
8. The overlay mark of any one of claims 1 to 6, wherein, The length of each grating is in the range of 30 μm to 50 μm, and the width of each grating is half of the period of the grating.
9. The overlay mark of any one of claims 2 to 6, wherein, The material of the grating is silicon.
10. A semiconductor device, characterized by comprising: The overlay mark comprises the grating according to any one of claims 1 to 9.