High-precision alignment method and device and computer storage medium
By using global positioning patterns and local positioning patterns in semiconductor high-precision alignment technology, combined with water satin stripe technology, multiple solutions in traditional technology are solved, and high-precision global two-dimensional position information determination is achieved.
Patent Information
- Application Number
- CN202411397304.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-30
- Publication Date
- 2025-02-18
AI Technical Summary
Due to the periodicity of the pattern, traditional water satin stripe technology is difficult to uniquely determine the global two-dimensional position information, which leads to multiple solutions in semiconductor high-precision alignment technology.
The marking pattern including global positioning patterns and local positioning patterns is adopted, and the global positioning patterns are roughly adjusted, and the local positioning patterns are used for precise alignment. The displacement deviation signal is obtained in combination with the water satin stripe technology to achieve high-precision alignment.
It realizes the reading of macroscopic and microscopic information in two dimensions in the plane in one imaging, and uniquely determines the global two-dimensional position information, which improves the accuracy and reliability of semiconductor high-precision alignment.
Smart Images
Figure CN119478025A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of optical alignment technology, and in particular to a high-precision alignment method, device and computer storage medium. Background Art
[0002] Water satin fringes (also known as moiré fringes) are macroscopic wavy patterns formed by the combination of periodic structures with slight differences. Because the macroscopic wavy patterns can reflect the information of microscopic differences, thus having the effect of signal amplification, they are widely used in many fields, such as medicine, photolithography, electron microscopy, measurement of stress and strain of periodic structures, measurement of small-angle stacking of two-dimensional materials, and high-precision alignment in the semiconductor industry.
[0003] Although traditional water satin stripes can amplify displacement information, due to the periodicity of the pattern, the relationship between the amplified pattern and the displacement is also periodic. This results in multiple solutions for the same signal corresponding position. The relative displacement of the movement can only be determined during continuous local tracking, and the global position information cannot be uniquely determined. Summary of the invention
[0004] The present application provides a high-precision alignment method, device and computer storage medium.
[0005] In order to solve the above technical problems, the present application proposes a high-precision alignment method, which includes: obtaining a first object plate printed with a first marking pattern and a second object plate printed with a second marking pattern; wherein the first marking pattern includes a first local positioning pattern and a first global positioning pattern, and the second marking pattern includes a second local positioning pattern and a second global positioning pattern; coarsely adjusting the first object plate and the second object plate according to the first global positioning pattern and the second global positioning pattern; and aligning the coarsely adjusted first object plate and the second object plate according to the first local positioning pattern and the second local positioning pattern.
[0006] The first global positioning pattern and the second global positioning pattern have the same global positioning area, and any position in the global positioning area is: the first global positioning block of the first global positioning pattern, the second global positioning block of the second global positioning pattern, and one of the blank areas.
[0007] The spacing distance between adjacent first global positioning blocks is greater than the length and / or width of the second global positioning block, and the spacing distance between adjacent second global positioning blocks is greater than the length and / or width of the first global positioning block.
[0008] Wherein, the coarse adjustment of the first object plate and the second object plate according to the first global positioning pattern and the second global positioning pattern includes: moving the first object plate and / or the second object plate so that all first global positioning blocks of the first global positioning pattern and all second global positioning blocks of the second global positioning pattern in the imaging image do not overlap.
[0009] The first local positioning pattern and the second local positioning pattern have the same local positioning area, and the first local positioning block of the first local positioning pattern and the second local positioning block of the second local positioning pattern at least partially overlap in the local positioning area.
[0010] Wherein, the length direction of the first partial positioning block and the length direction of the second partial positioning block that at least partially overlap are consistent.
[0011] The first local positioning pattern comprises a plurality of first local positioning blocks of different sizes, and the first local positioning blocks of the same size are arranged in the same positioning sub-region of the local positioning region.
[0012] The length directions of the first local positioning blocks of different sizes are inconsistent.
[0013] Among them, the first local positioning pattern and the second local positioning pattern align the first object plate and the second object plate after coarse adjustment, including: obtaining water satin stripes of the overlapping part of the first local positioning pattern and the second local positioning pattern according to the imaging image; obtaining a displacement deviation signal according to the water satin stripes; moving the first object plate or the second object plate according to the displacement deviation signal to align the first object plate and the second object plate.
[0014] In order to solve the above technical problems, the present application proposes a high-precision alignment device. In order to solve the above technical problems, the present application proposes that the high-precision alignment device includes: a memory and a processor coupled to each other, and the processor is used to execute the program data stored in the memory to implement the above high-precision alignment method.
[0015] In order to solve the above technical problems, the present application proposes a computer-readable storage medium, wherein the computer-readable storage medium stores program data, and the program data can be executed to implement the high-precision alignment method as described above.
[0016] Different from the prior art, the beneficial effects of the present application are: a high-precision alignment device obtains a first object plate printed with a first marking pattern and a second object plate printed with a second marking pattern; wherein the first marking pattern includes a first local positioning pattern and a first global positioning pattern, and the second marking pattern includes a second local positioning pattern and a second global positioning pattern; the first object plate and the second object plate are roughly adjusted according to the first global positioning pattern and the second global positioning pattern; the first object plate and the second object plate after the rough adjustment are aligned according to the first local positioning pattern and the second local positioning pattern. In the above manner, the traditional macro identification mark and the water satin stripe technology are cleverly combined, and the macroscopic and microscopic information of two dimensions in the plane can be read in one imaging, so as to accurately and uniquely determine the global two-dimensional position information, which can be applied to semiconductor high-precision alignment technology. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.
[0018] Figure 1 is a flow chart of a first embodiment of a high-precision alignment method provided by the present application;
[0019] Figure 2 is a schematic diagram of an embodiment of a first marking pattern provided by the present application;
[0020] Figure 3 is a schematic diagram of an embodiment of a second marking pattern provided by the present application;
[0021] Figure 4 is a schematic diagram of a first embodiment of overlapping imaging of a first marking pattern and a second marking pattern provided by the present application;
[0022] Figure 5 is a schematic diagram of a second embodiment of overlapping imaging of a first marking pattern and a second marking pattern provided by the present application;
[0023] Figure 6 is a schematic diagram of a third embodiment of overlapping imaging of a first marking pattern and a second marking pattern provided by the present application;
[0024] Figure 7 It is a structural schematic diagram of an embodiment of a high-precision alignment device provided by the present application;
[0025] Figure 8 It is a structural diagram of an embodiment of a computer storage medium provided by the present application. DETAILED DESCRIPTION
[0026] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0027] The high-precision alignment method of the present application is applied to a high-precision alignment device, wherein the high-precision alignment device of the present application can be a server, or a system composed of a server and a local terminal cooperating with each other. Accordingly, the various parts of the high-precision alignment device, such as various units, sub-units, modules, and sub-modules, can all be set in the server, or can be set in the server and the local terminal respectively.
[0028] Furthermore, the above-mentioned server can be hardware or software. When the server is hardware, it can be implemented as a distributed server cluster consisting of multiple servers, or it can be implemented as a single server. When the server is software, it can be implemented as multiple software or software modules, such as software or software modules for providing distributed servers, or it can be implemented as a single software or software module, which is not specifically limited here. In some possible implementations, the high-precision alignment method of the embodiment of the present application can be implemented by a processor calling a computer-readable instruction stored in a memory.
[0029] See also Figure 1 , Figure 1 It is a flowchart of the first embodiment of the high-precision alignment method provided by the present application.
[0030] like Figure 1 As shown, the specific steps are as follows:
[0031] Step S11: obtaining a first object plate printed with a first marking pattern and a second object plate printed with a second marking pattern.
[0032] In a specific embodiment of the present application, the first object plate and the second object plate may be a mask plate and a silicon wafer, respectively. The first marking pattern and the second marking pattern may be printed on the first object plate and the second object plate by engraving, or may be sprayed on the first object plate and the second object plate by spraying. The present application does not make any specific limitation.
[0033] The first marking pattern includes a first local positioning pattern and a first global positioning pattern, and the second marking pattern includes a second local positioning pattern and a second global positioning pattern.
[0034] Specifically, in the embodiment of the present application, the global positioning pattern and the local positioning pattern are a set of relative concepts, that is, the global positioning pattern is used for coarse positioning, and the first object plate and the second object plate can be roughly matched according to the global positioning pattern to avoid multiple solutions for the same signal corresponding position.
[0035] In one embodiment of the present application, the pattern periods of the first local positioning pattern and the second local positioning pattern are the same pattern period. In other embodiments of the present application, the periods of the first local positioning pattern and the second local positioning pattern may be different pattern periods.
[0036] The first local positioning pattern and the second local positioning pattern can be stripes arranged according to a certain spatial period, or can be an array of pixel units with an equal period on a photosensitive element in an imaging device. As long as a water satin pattern can be formed on the local positioning pattern and a pattern with corresponding precision can be obtained, it can be used as the first local positioning pattern and the second local positioning pattern in the present application. The stripe pattern is used as an example in the embodiment of the present application.
[0037] See also Figure 2-Figure 3 , Figure 2 is a schematic diagram of an embodiment of the first marking pattern provided in the present application, Figure 3 It is a schematic diagram of an embodiment of the second marking pattern provided in the present application.
[0038] like Figure 2 As shown, the first local positioning pattern includes a local positioning pattern of an x period and a local positioning pattern of a y period, both of which are spatial periods, and the directions of the stripes of the x period and the y period are different. In the embodiment of the present application, the directions of the two can be set to be perpendicular. Further, the x period includes an upper x period and a lower x period, both of which are a relative position description method, and the upper x period and the lower x period refer to two marking areas on the same object plate with different positions and different spatial periods but the same spatial direction. The figure is only an example, and the upper x period and the lower x period can also be other relative position relationships, such as diagonal settings. The y period also includes an upper y period and a lower y period, both of which are a relative position description method, and the upper y period and the lower y period refer to two marking areas on the same object plate with different positions and different spatial periods but the same spatial direction.
[0039] like Figure 3 As shown, the second local positioning pattern includes an x period and a y period.
[0040] The second local positioning pattern corresponds to the first local positioning pattern, that is, among all the positioning patterns, at least one positioning area satisfies the first local positioning pattern and the second local positioning pattern for registration.
[0041] It should be noted that each area in the first local positioning pattern and the second local positioning pattern can be set on the object plate as a separate local positioning pattern, that is, in the embodiment of the present application, the first object plate can only be set Figure 2 The pattern on the x period can also be set at the same time Figure 2 The patterns of the four areas of x-period upper, x-period lower, y-period upper, and y-period lower are the same for the second object plate. However, the positions of the first local positioning pattern of the first object plate and the second local positioning pattern of the second object plate need to correspond. When the first object plate is set on the x-period, the second object plate is set on the x-period. That is, in this embodiment of the application, the first object plate and the second object plate can be aligned by the marking patterns of any one area or multiple areas, and there is no need to use four areas for alignment at the same time.
[0042] Step S12: coarsely adjust the first object plate and the second object plate according to the first global positioning pattern and the second global positioning pattern.
[0043] like Figure 4-Figure 6 As shown, Figure 4 is a schematic diagram of a first embodiment of overlapping imaging of a first marking pattern and a second marking pattern provided by the present application; Figure 5 is a schematic diagram of a second embodiment of overlapping imaging of a first marking pattern and a second marking pattern provided by the present application; Figure 6 It is a schematic diagram of a third embodiment of overlapping imaging of a first marking pattern and a second marking pattern provided by the present application.
[0044] like Figure 4 and Figure 6 As shown, the high-precision alignment device determines whether the first object plate and the second object plate need to be roughly adjusted according to the positions of the first global positioning pattern imaging and the second global positioning pattern imaging, that is, when the first global positioning pattern and the second global positioning pattern are not located at corresponding positions, the first object plate or the second object plate is firstly roughly adjusted by moving until the first global positioning pattern and the second global positioning pattern are aligned, such as Figure 5 shown.
[0045] The first global positioning pattern and the second global positioning pattern have the same global positioning area, and any position in the global positioning area is: the first global positioning block of the first global positioning pattern, the second global positioning block of the second global positioning pattern, and one of the blank areas.
[0046] The spacing distance between adjacent first global positioning blocks is greater than the length and / or width of the second global positioning block, and the spacing distance between adjacent second global positioning blocks is greater than the length and / or width of the first global positioning block.
[0047] like Figure 5As shown, the high-precision alignment device moves the first object plate and / or the second object plate so that all first global positioning blocks of the first global positioning pattern in the imaging image do not overlap with all second global positioning blocks of the second global positioning pattern.
[0048] Step S13: aligning the roughly adjusted first object plate and the second object plate according to the first local positioning pattern and the second local positioning pattern.
[0049] like Figure 5 As shown, the first local positioning pattern and the second local positioning pattern have the same local positioning area, and the first local positioning block of the first local positioning pattern and the second local positioning block of the second local positioning pattern at least partially overlap in the local positioning area.
[0050] The length direction of the at least partially overlapping first local positioning block is consistent with the length direction of the second local positioning block. The first local positioning pattern has multiple first local positioning blocks of different sizes, and the first local positioning blocks of the same size are arranged in the same positioning sub-area of the local positioning area.
[0051] like Figure 2-3 As shown, in the embodiment of the present application, the length directions of the first local positioning blocks of different sizes are inconsistent.
[0052] Specifically, the high-precision alignment device obtains water satin stripes at the overlapping part of the first local positioning pattern and the second local positioning pattern according to the imaging image; obtains a displacement deviation signal according to the water satin stripes; moves the first object plate or the second object plate according to the displacement deviation signal to align the first object plate and the second object plate.
[0053] The imaging system resolution of the first mark pattern is slightly lower than that of the second mark pattern, but the water satin pattern is still visible. By taking the envelope of the light intensity distribution of the overlapping part, the macroscopic oscillation can be seen. By measuring the movement of the envelope oscillation curve, the relative offset between the two alignment mark patterns can be obtained.
[0054] According to the amplification principle of water satin, if the spatial period of the local positioning pattern in the first mark pattern is T1, and the corresponding spatial period in the second mark pattern is T2, then when the first mark pattern moves Δ relative to the second mark pattern, the envelope of the water satin will move:
[0055]
[0056] For the case where the period difference is much smaller than the period, i.e., |T2 - T1| << T1, T2, the movement of the envelope will be much larger than the movement between the patterns, thus amplifying the tiny movement signal. This method of amplifying the water twill pattern can reduce the resolution of the pattern position difference below the diffraction limit of the imaging system, so it has the advantage of high precision.
[0057] Regarding the principle of water twill amplification, this application proves it through Fourier transform as follows:
[0058] Denote the period pattern transmittance distribution of the first marked pattern's local positioning pattern as A1(x), and that of the second marked pattern as A2(x), where x is the spatial coordinate along the period direction. The light intensity distribution of their superimposed pattern is the product of the two transmittance distributions, I(x) = A1(x)A2(x). Performing Fourier transform on the two, due to their respective periodicity, the transform will be converted into a Fourier series expansion. Thus, the two can be decomposed into the following series respectively:
[0059]
[0060] Since the pattern distribution is a finite periodic function and its Fourier series converges uniformly, the terms in the product can be summed by exchanging, so the product of the two can also be written as a trigonometric series expansion. Taking the envelope <A1(x + Δ)A2(x)> of the superimposed distribution A1(x + Δ)A2(x), that is, omitting the high-frequency oscillations and only leaving the low-frequency terms:
[0061]
[0062] When m = n, make Thus it becomes a low-frequency term, and the rest are high-frequency terms, which average to 0 when finding the envelope. So the envelope function can be expressed as:
[0063]
[0064] The envelope function is a function with the independent variable So the displacement signal of Δ is amplified to the displacement of the envelope.
[0065] Through the above method, this application disassembles the alignment marked pattern into two parts. One part is the global positioning pattern, and the other part is the local positioning pattern. Although the global positioning pattern has low precision, it is easy to distinguish the displacement situation on a large scale; although the local positioning pattern may have the problem of multiple solutions, its resolution precision is high. The combination of the two patterns can take into account the advantages of both, thus uniquely determining the displacement solution and accurately giving the displacement measurement value.
[0066] In order to solve the above technical problems, the present application proposes a high-precision alignment device. In order to solve the above technical problems, the present application proposes that the high-precision alignment device includes: a memory and a processor coupled to each other, and the processor is used to execute the program data stored in the memory to implement the above high-precision alignment method.
[0067] In order to solve the above technical problems, the present application proposes a computer-readable storage medium, wherein the computer-readable storage medium stores program data, and the program data can be executed to implement the high-precision alignment method as described above.
[0068] In order to implement the high-precision alignment method of the above embodiment, the present application also provides a high-precision alignment device. Figure 7 , Figure 7 It is a structural schematic diagram of an embodiment of a high-precision alignment device provided by the present application.
[0069] like Figure 7 As shown, the high-precision alignment device 600 of this embodiment includes a processor 61 , a memory 62 , an input / output device 63 , and a bus 64 .
[0070] The processor 61 , the memory 62 , and the input / output device 63 are respectively connected to the bus 64 . The memory 62 stores a computer program. The processor 61 is used to execute the computer program to implement the high-precision alignment method of the above embodiment.
[0071] In this embodiment, the processor 61 may also be referred to as a CPU (Central Processing Unit). The processor 61 may be an integrated circuit chip having the ability to process signals. The processor 61 may also be a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components. The processor 61 may also be a GPU (Graphics Processing Unit), also known as a display core, a visual processor, or a display chip, which is a microprocessor that is specifically used for image computing on computers, workstations, game consoles, and some mobile devices (such as tablet computers, smart phones, etc.). The purpose of the GPU is to convert and drive the display information required by the computer system, and to provide a line scan signal to the display to control the correct display of the display. It is an important component that connects the display and the computer motherboard. As an important component of the computer host, the graphics card is responsible for outputting the display pattern. The general-purpose processor may be a microprocessor or the processor 61 may also be any conventional processor, etc.
[0072] The present application also provides a computer storage medium, such as Figure 8 As shown, the computer storage medium 700 is used to store a computer program 71. When the computer program 71 is executed by a processor, it is used to implement the method described in the embodiment of the high-precision alignment method of the present application.
[0073] The method involved in the embodiment of the high-precision alignment method of the present application, when implemented in the form of a software functional unit and sold or used as an independent product, can be stored in a device, such as a computer-readable storage medium. Based on this understanding, the technical solution of the present application is essentially or part of the contribution to the prior art or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, server, or network device, etc.) or a processor (processor) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk and other media that can store program code.
[0074] The above description is only an implementation mode of the present invention, and does not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.
Claims
1. A high-precision alignment method, characterized in that: The high-precision alignment method comprises: Obtaining a first object plate printed with a first marking pattern and a second object plate printed with a second marking pattern; Wherein, the first marking pattern includes a first local positioning pattern and a first global positioning pattern, and the second marking pattern includes a second local positioning pattern and a second global positioning pattern; coarsely adjusting the first object plate and the second object plate according to the first global positioning pattern and the second global positioning pattern; The first object plate and the second object plate after coarse adjustment are aligned according to the first local positioning pattern and the second local positioning pattern.
2. The high-precision alignment method according to claim 1, characterized in that: The first global positioning pattern and the second global positioning pattern have the same global positioning area, and any position in the global positioning area is: a first global positioning block of the first global positioning pattern, a second global positioning block of the second global positioning pattern, and one of a blank area.
3. The high-precision alignment method according to claim 2, characterized in that: The spacing distance between adjacent first global positioning blocks is greater than the length and / or width of the second global positioning block, and the spacing distance between adjacent second global positioning blocks is greater than the length and / or width of the first global positioning block.
4. The high-precision alignment method according to claim 1, characterized in that: The coarsely adjusting the first object plate and the second object plate according to the first global positioning pattern and the second global positioning pattern comprises: The first object plate and / or the second object plate are moved so that all first global positioning blocks of the first global positioning pattern in the imaging image do not overlap with all second global positioning blocks of the second global positioning pattern.
5. The high-precision alignment method according to claim 1, characterized in that: The first local positioning pattern and the second local positioning pattern have the same local positioning area, and the first local positioning block of the first local positioning pattern and the second local positioning block of the second local positioning pattern at least partially overlap in the local positioning area.
6. The high-precision alignment method according to claim 5, characterized in that: The length direction of the first partial positioning block and the length direction of the second partial positioning block that at least partially overlap are consistent.
7. The high-precision alignment method according to claim 4, characterized in that: The first local positioning pattern comprises a plurality of first local positioning blocks of different sizes, and the first local positioning blocks of the same size are arranged in the same positioning sub-region of the local positioning region.
8. The high-precision alignment method according to claim 7, characterized in that: The length directions of the first local positioning blocks of different sizes are inconsistent.
9. The high-precision alignment method according to claim 1, characterized in that: The step of aligning the first object plate and the second object plate after rough adjustment according to the first local positioning pattern and the second local positioning pattern comprises: Acquire water satin stripes at the overlapping portion of the first local positioning pattern and the second local positioning pattern according to the imaging image; Acquire a displacement deviation signal according to the water satin stripes; The first object plate or the second object plate is moved according to the displacement deviation signal to align the first object plate and the second object plate.
10. A high-precision alignment device, characterized in that: The high-precision alignment device comprises: a memory and a processor coupled to each other, wherein the processor is used to execute program data stored in the memory to implement the high-precision alignment method according to any one of claims 1 to 9.
11. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores program data, and the program data can be executed to implement the high-precision alignment method according to any one of claims 1 to 9.