Method and apparatus for modifying a lithographic pattern to adjust plating uniformity
By dynamically modifying lithographic patterns based on measurement data and substrate plating models, the method enhances plating uniformity and reduces costs in semiconductor processing, addressing the limitations of conventional dummy pattern methods.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- APPLIED MATERIALS INC
- Filing Date
- 2023-03-14
- Publication Date
- 2026-05-19
AI Technical Summary
Conventional methods for enhancing plating uniformity using dummy patterns in semiconductor substrates are costly and do not achieve optimal thickness uniformity, particularly in stepper-based lithography processes.
A method and apparatus that utilize measurement data to modify lithographic patterns dynamically, incorporating substrate plating models to adjust electroplating deposition uniformity by altering dummy patterns and active die orientations, and employing digital lithography for real-time pattern adjustments.
Significantly improves plating thickness uniformity and reduces costs by eliminating the need for multiple masks, enabling rapid learning cycles and high flexibility in pattern corrections, thus optimizing both patterning and plating processes.
Smart Images
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Abstract
Description
Technical Field
[0001] Embodiments of the present principle generally relate to semiconductor processing of semiconductor substrates.
Background Art
[0002] Dies are designed and then multiple patterns of the dies are copied onto a substrate. Often, the die patterns do not completely fill the available surface area of the substrate. When the substrate undergoes a plating process, the thickness of the deposited plating material can vary depending on the die pattern underlying the substrate. In conventional processes, additional copies of the die pattern, or so-called dummy patterns, can be placed in the unused area of the substrate to enhance plating uniformity. However, the inventors have discovered that dummy patterns may not result in optimal uniformity of plating thickness and are costly to manufacture in conventional stepper-based lithography processes.
[0003] Therefore, the inventors have provided methods and apparatuses for improving plating thickness uniformity.
Summary of the Invention
[0004] Methods and apparatuses for modifying plating thickness uniformity based on measurement data are provided herein.
[0005] In some embodiments, a method for electroplating a substrate may include receiving a die design; forming a first lithographic pattern for a first substrate based on the die design; using a digital lithography process to pattern the first substrate with the first lithographic pattern; using an electroplating process to deposit a material on the first substrate with a first electroplating deposition uniformity; using a measurement process to determine at least one parameter of the deposited material on the first substrate; and modifying the first lithographic pattern to form a second lithographic pattern that adjusts the first electroplating deposition uniformity to match a second electroplating deposition uniformity of an electroplating process for a second substrate, at least partially based on at least one parameter of the deposited material from the measurement process for the first substrate.
[0006] In some embodiments, the method further uses a substrate plating model based on deposition-related measurement data by electroplating to facilitate forming a first lithographic pattern for a first substrate or a second lithographic pattern for a second substrate, wherein the substrate plating model includes pattern density data of the die design in forming a first lithographic pattern for a first substrate or a second lithographic pattern for a second substrate, and incorporates the measurement data from the electroplating process into the die design before receiving the die design, wherein the first lithographic pattern includes an active die pattern and a first set of dummy patterns, and the second lithographic pattern includes the active die pattern and less of the deposited material on the second substrate compared to the first substrate. The first lithographic pattern includes an active die pattern, and the second lithographic pattern includes an active die pattern, along with at least one active die pattern of a different orientation that changes at least one parameter of the deposited material on the second substrate compared to the first substrate, where at least one parameter of the deposited material is the thickness of the deposited material at a particular location on the first substrate, and the first or second lithographic pattern has an edge region pattern different from the pattern used in the central region of the first or second substrate, and the die design may include incorporating measurement data from an electroplating process into the die design before receiving the die design, and / or changing the first or second lithographic pattern based on the current flow of the plating bath used in the electroplating process.
[0007] In some embodiments, a non-temporary computer-readable medium storing instructions that, when executed, cause a method for electroplating a substrate to be carried out, the method may include: receiving a die design; forming a first lithographic pattern for a first substrate based on the die design; using a digital lithography process to pattern the first substrate with the first lithographic pattern; using an electroplating process to deposit material on the first substrate with a first electroplating deposition uniformity; using a measurement process to determine at least one parameter of the deposited material on the first substrate; and modifying the first lithographic pattern to form a second lithographic pattern that adjusts the first electroplating deposition uniformity to match a second electroplating deposition uniformity of an electroplating process for a second substrate, at least partially based on at least one parameter of the deposited material from the measurement process for the first substrate.
[0008] In some embodiments, the method for non-temporary computer-readable media further involves using a substrate plating model based on deposition-related measurement data by electroplating to facilitate the formation of a first lithographic pattern for a first substrate or a second lithographic pattern for a second substrate, incorporating measurement data from the electroplating process into the die design prior to receiving the die design, wherein the first lithographic pattern includes an active die pattern and a first set of dummy patterns, and the second lithographic pattern includes an active die pattern and a second set of dummy patterns that alter at least one parameter of the deposited material on the second substrate compared to the first substrate, and the first lithographic pattern includes an active die pattern The present invention may include incorporating measurement data from an electroplating process into the die design prior to receiving the die design, and / or modifying the first or second lithographic pattern based on the current flow of the plating bath used in the electroplating process, wherein the second lithographic pattern includes an active die pattern with at least one active die pattern of a different orientation that alters at least one parameter of the deposited material on the second substrate compared to the first substrate, the at least one parameter of the deposited material being the thickness of the deposited material at a particular location on the first substrate, and the first or second lithographic pattern has an edge region pattern different from the pattern used in the central region of the first or second substrate.
[0009] In some embodiments, an apparatus for electroplating a substrate may include: a substrate plating model on a processing unit configured to determine a digital lithographic pattern that alters the deposition characteristics of an electroplating process based on a die design; a digital lithography patterning tool configured to interact with at least the substrate plating model to form a lithographic pattern of an active die pattern and a dummy pattern on a first substrate based on the die design and the deposition characteristics of an electroplating process; an electroplating tool configured to deposit a first plating material on the first substrate; and a measuring tool configured to determine the deposition parameters of the first plating material on the first substrate, wherein the measuring tool interacts with the substrate plating model or the digital lithography patterning tool to provide deposition parameters that alter a dummy pattern to alter at least one parameter of a second plating material deposited on a second substrate.
[0010] In some embodiments, the apparatus may further include the processing unit being part of a digital lithography patterning tool and / or the measuring tool being part of an electroplating tool.
[0011] Other and further embodiments are disclosed below.
[0012] Embodiments of the present principle, briefly summarized above and described in more detail below, can be understood by referring to exemplary embodiments of the present principle shown in the accompanying drawings. However, since the present principle may allow for other equally valid embodiments, the accompanying drawings only illustrate general embodiments of the present principle and should not be considered limiting in scope. [Brief explanation of the drawing]
[0013] [Figure 1] This figure illustrates a method for adjusting the uniformity of electroplating according to several embodiments of this principle. [Figure 2]This is a plan view of an active die pattern on a substrate according to several embodiments of this principle. [Figure 3] This is a plan view of an active die pattern with a reoriented active die pattern on a substrate, according to several embodiments of this principle. [Figure 4] This is a plan view of the active die pattern and dummy die pattern on a substrate according to several embodiments of this principle. [Figure 5] This is a plan view of an active die pattern and a dummy die pattern having a reoriented dummy die pattern on a substrate, according to several embodiments of this principle. [Figure 6] These are plan views of different active die patterns and dummy die patterns on a substrate based on a central or edge region, according to several embodiments of this principle. [Figure 7] This is a cross-sectional view of an integrated toolset for adjusting electroplating uniformity according to several embodiments of the present principle. [Modes for carrying out the invention]
[0014] For ease of understanding, the same reference numerals are used to designate identical elements common to the figures where possible. The figures are not drawn to a fixed scale and may be simplified for clarity. Elements and features of one embodiment may be usefully incorporated into other embodiments without further description.
[0015] The method and apparatus provide the capability to optimize both patterning and plating processes, improving deposition uniformity and film quality. The method and apparatus incorporate maskless digital lithography and the ability to create customized dummy patternings (outside the active die). Modeling for plating uniformity provides customized design pattern files (e.g., graphic data system (GDS) files) for patterning in near real-time. This principle enables feedback from measurements with extremely fast learning cycle times for subsequent iterations. In traditional processes, the ability to create dummy patterns is limited to production mask patterns or other designed dummy masks. The technique of this principle significantly improves the flexibility and speed of substrate patterning. The technique provides extremely rapid learning by directly incorporating measurement results into subsequent pattern iterations (e.g., completed in hours compared to weeks for building a new mask) and significantly reduces costs by eliminating multiple mask sets per product. This technique also has the advantage of facilitating the dial-in of new products by using internal modeling capabilities to define the next steps (e.g., pattern or tool parameters). Furthermore, its high level of uniformity makes it possible to eliminate the planarization process during manufacturing.
[0016] Electroplating is often used to provide a base material for conductive paths to form redistribution layers and other structures. During electroplating, a uniform electric field is created on the substrate, so that areas with lower pattern density are subjected to the same current as areas with higher pattern density. Areas with lower pattern density are plated more heavily than areas with higher pattern density (meaning that more patterns that should be plated using the same amount of current are plated less on high-density patterns). Conventional processes improve plating uniformity using dummy patterning by using the same product mask or simple uniform array pattern repetitions to fill edge dead spaces on the substrate, resulting in thicker plating due to current concentration during plating deposition. Methods and apparatus of this principle have the advantage of being able to create dummy patterns that adapt to density variations and die asymmetry on the substrate to improve plating thickness uniformity and quality. Unlike conventional processes where patterning is predefined and rarely modified after the initial mask build, this principle has the benefits of flexibility and easy pattern correction of observed problems. The method and apparatus based on this principle enable collaborative process optimization by leveraging lithography and plating as a whole. Moving pattern modeling optimization into the process line accelerates the learning cycle and significantly improves the ability to create new solutions and the flexibility of verification. The ability to input measurement results for the next patterning step is a significant advantage over older processes that lack this capability.
[0017] In some embodiments, the process begins with a base die design (e.g., a GDS file), then a substrate plating model lays out the substrate configuration of the active die and dummy patterning to compensate for pattern density variations, pattern asymmetry, substrate or die layout asymmetry, and / or edge dead space. A digital lithography tool then exposes the active die onto the substrate in a defined array and adds dummy patterning to the substrate determined by the substrate plating model and / or other inputs. The first wafer is then processed, i.e., developed, plated, and stripped, and then measurements are taken to determine the quality and uniformity of the plating deposition. The measurement data is then input into the substrate plating model and / or digital lithography tool, and subsequent iterations of patterning / layout are performed for subsequent substrates.
[0018] Figure 1 shows a method 100 for adjusting electroplating uniformity according to several embodiments. In block 102, an active die design is received, which is to be used in a photolithography process to print a die or “active die” pattern onto a first substrate. As used herein, “active die” is a die or die pattern formed on a substrate to create an actual semiconductor device, structure, or conductive path, etc. A dummy die or dummy pattern is a simulated circuit pattern of a complete or partial die that is not intended to be a working die or active die. In block 104, the active die design 204 is used to form a first lithographic pattern 206 for the first substrate 202, as shown in view 200 of Figure 2. In block 106, the first substrate 202 is patterned with the first lithographic pattern 206 having first electroplating deposition uniformity. In block 108, the first substrate 202 having the first lithographic pattern 206 is electroplated in a plating tank, for example, using an electric current and a bath solution. In block 110, the plating deposition from the electroplating process is subjected to a measurement test after the masking material is removed to determine at least one measurement data point for the electroplated deposited material. In some embodiments, the measurement data may include one or more locations where the thickness of the electroplating is measured. The measurement data may also include the average or mean thickness of the plating material in a particular area of the surface spanning multiple points on the first substrate. The measurement data may be measured in situ using and / or in a separate process or chamber. In block 112, the first lithographic pattern is modified to form second lithographic patterns 350, 450, 550, and 650 (see Figures 3 to 6) having a second electroplating deposition uniformity formed on the second substrate, based on at least one measurement data point acquired from the first substrate 202.
[0019] In some embodiments, Method 100 may be iterative and include several cycles to improve electroplating uniformity to a predefined level. Thus, the second lithographic patterns 350, 450, 550, and 650 may be the initial or first lithographic pattern from which measurement data is collected and fed back into the process. Several examples of pattern expansion are shown in Figures 3 to 6, which are described as “second lithographic patterns”. The second lithographic patterns may also be the “first lithographic patterns” for Method 100 when several iterations are performed to optimize electroplating uniformity. These examples are selected for brevity and are not limiting to any particular form. In some embodiments, based on feedback from measurement data obtained through Method 100, the second lithographic pattern 350 on the second substrate 330 may be as shown in view 300 of Figure 3, and the active die design 204 may be used to invert and / or rotate to form an active die design 306 with a new orientation. By altering the orientation of the design, the variation in pattern density can be balanced to optimize plating uniformity for the active die design 204. For example, but not limited to, areas of different pattern densities in the die design may be located adjacent to each other to enhance electroplating uniformity on the active die design 204 (high-density areas next to low-density areas, and low-density areas next to high-density areas).
[0020] In some embodiments, based on feedback from measurement data obtained through method 100, the second lithographic pattern 450 may be as shown in view 400 of Figure 4. A dummy duplicate pattern 410 of the active die design 204 is used together with the active die design 204 to form the second lithographic pattern 450 on the second substrate 330. The added dummy duplicate pattern 410 facilitates maintaining a similar density across the surface of the second substrate 330 to improve electroplating uniformity. In some embodiments, based on measurement data, a reoriented dummy duplicate pattern 512 may be used together with the active die design 204, as shown in view 500 of Figure 5. As described above, these patterns, whether active or dummy, may be reoriented to position adjacent areas of similar or different pattern density to enhance electroplating uniformity. In some embodiments, the surface area of the second substrate 330 may be divided into a central region 616 and an edge region 620, as shown in view 600 of Figure 6. The second substrate 330 may also be divided into three or more regions. A central region dummy pattern 618 may be used in the central region 616 of the second substrate 330, and an edge region dummy pattern 614 may be used in the edge region 620 of the second substrate 330. Using different dummy patterns in different regions of the substrate allows for greater flexibility in fine-tuning the uniformity of the electroplating.
[0021] View 700 in Figure 7 shows an integrated system for adjusting electroplating on a substrate. An active die design 702 (such as a GDS format file) is introduced into a digital lithography patterning tool 706 and / or a substrate plating model 704. The active die design 702 may also include dummy files, etc., for modifying electroplating uniformity at the start of the process. The substrate plating model 704 may reside on a processing unit 712 configured to determine a digital lithographic pattern that modifies the deposition characteristics of the electroplating process based on the die design and / or prior knowledge. The substrate plating model 704 may utilize machine learning and / or a set of rules to help establish a lithographic pattern that optimizes electroplating on the substrate based on previous electroplating measurement data and / or learned lessons, etc. The substrate plating model 704 may also incorporate electroplating processing time, type of deposition material, solution used in the plating bath during plating, electroplating hardware details (current value, plating speed, etc.), etc., to improve the modeling process. In some embodiments, the substrate plating model 704 may be standalone and have a portion located within or entirely within the digital lithography patterning tool 706. The digital lithography patterning tool 706 uses any available prior knowledge and / or rule set to form a first lithographic pattern and then process that pattern onto a first substrate 202. The digital lithography patterning tool 706 may also accept user input to facilitate the formation of the first lithographic pattern. In some embodiments, the digital lithography patterning tool 706 is configured to interact with at least the substrate plating model 704 to form a lithographic pattern of an active die pattern and a dummy pattern on a first substrate, based on the die design and the deposition characteristics of the electroplating process.
[0022] The first substrate 202 then moves to an electroplating tool 708 configured to deposit plating material on the first substrate 202. In some embodiments, the electroplating tool 708 may communicate with a substrate plating model 704 and / or a digital lithography patterning tool 706 to clarify operating parameters such as deposition material, current settings, solution used, and the like. After the electroplating process, the first substrate 202 undergoes a metrology test. In some embodiments, the metrology test may be performed in situ within the electroplating chamber or tool. A metrology tool 710 is configured to determine deposition parameters of the plating material on the first substrate 202. In some embodiments, the metrology tool 710 may interact with the substrate plating model 704 and / or the digital lithography patterning tool to provide deposition parameters to change dummy patterns and / or active patterns in order to change at least one parameter of a subsequent plating material deposited on a second substrate (not shown). The use of digital lithography enables near real-time feedback on the quality of the plating process to the substrate plating model 704 and / or the digital lithography patterning tool 706 to allow for quick changes in patterning of subsequent substrates without the cost of masks, which are expensive and time-consuming.
[0023] A single digital pattern can be used in place of active and dummy masks, eliminating mask alignment errors and costs associated with multiple masks. Further, the ability to improve the substrate plating model 704 with each run or iteration allows plating uniformity to be improved to a high level that is not easily achievable with conventional processes. The apparatus and method of this principle also enable improved plating uniformity beyond just the feedback of measurement data to the substrate plating model 704 and digital lithography patterning tool 706. Information collected from modeling and learned lessons is also used to improve plating by modifying the active die design. Also, die designers can use the measurement data obtained to design not only the active die for the GDS file but also the pattern for the entire substrate in the first iteration of the method described herein to provide optimal plating uniformity. To further improve plating uniformity, changes such as to the plating contact locations on the substrate can also be incorporated into the process. In some embodiments, the contact locations can be aligned across the substrate to improve the flow of current based on the density of the lithographic pattern.
[0024] Embodiments in accordance with this principle can be implemented in hardware, firmware, software, or any combination thereof. Embodiments can also be implemented as instructions stored using one or more computer-readable media that can be read by and executed by one or more processors. A computer-readable medium can include any mechanism for storing or transmitting information in a form readable by a machine (e.g., a computing platform, or a "virtual machine" operating on one or more computing platforms). For example, a computer-readable medium can include any suitable form of volatile or non-volatile memory. In some embodiments, a computer-readable medium can include a non-transitory computer-readable medium.
[0025] The above describes embodiments of the present principle, but other and further embodiments of the present principle can be devised without departing from its basic scope.
Claims
1. A method for electroplating a circuit board, Receiving the die design, To form a first lithographic pattern for a first substrate based on the die design, Using a digital lithography process to pattern the first substrate with the first lithographic pattern, An electroplating process is used to deposit a material on the first substrate with a first electroplating deposition uniformity, A measurement process is used that employs a substrate plating model based on deposition-related measurement data, including the thickness of electroplating at multiple locations on the substrate, in order to determine at least one parameter of the deposited material on the first substrate, Modifying the first lithographic pattern by the digital lithography process to form a second lithographic pattern for the second substrate, which adjusts the first electroplating deposition uniformity to match the second electroplating deposition uniformity of the electroplating process for the second substrate, based at least partially on the at least one parameter of the deposited material received directly from the measurement process for the first substrate by the digital lithography process for the second substrate. Methods that include...
2. To facilitate the formation of the first lithographic pattern for the first substrate or the second lithographic pattern for the second substrate, a substrate plating model based on deposition-related measurement data is used by electroplating. The method according to claim 1, further comprising:
3. The method according to claim 2, wherein the substrate plating model includes pattern density data of the die design for forming the first lithographic pattern for the first substrate or for forming the second lithographic pattern for the second substrate.
4. Before receiving the die design, measurement data from the electroplating process is incorporated into the die design. The method according to claim 1, further comprising:
5. The method according to claim 1, wherein the first lithographic pattern includes an active die pattern and a first set of dummy patterns, and the second lithographic pattern includes the active die pattern and a second set of dummy patterns that alter at least one parameter of the deposited material on the second substrate compared to the first substrate.
6. The method according to claim 1, wherein the first lithographic pattern includes an active die pattern, and the second lithographic pattern includes the active die pattern along with at least one active die pattern having a different orientation that alters at least one parameter of the deposited material on the second substrate compared to the first substrate.
7. The method according to claim 1, wherein the at least one parameter of the deposited material is the thickness of the deposited material at a specific location on the first substrate.
8. The method according to claim 1, wherein the first lithographic pattern or the second lithographic pattern has an edge region pattern different from the pattern used in the central region of the first substrate or the second substrate.
9. The first lithographic pattern or the second lithographic pattern is changed based on the current value of the plating bath used in the electroplating process. The method according to claim 1, further comprising:
10. A non-temporary computer-readable medium that stores instructions for performing a method of electroplating a substrate when executed, wherein the method is Receiving the die design, To form a first lithographic pattern for a first substrate based on the die design, Using a digital lithography process to pattern the first substrate with the first lithographic pattern, An electroplating process is used to deposit a material on the first substrate with a first electroplating deposition uniformity, A measurement process is used that employs a substrate plating model based on deposition-related measurement data, including the thickness of electroplating at multiple locations on the substrate, in order to determine at least one parameter of the deposited material on the first substrate, Modifying the first lithographic pattern by the digital lithography process to form a second lithographic pattern for the second substrate, which adjusts the first electroplating deposition uniformity to match the second electroplating deposition uniformity of the electroplating process for the second substrate, based at least partially on the at least one parameter of the deposited material received directly from the measurement process for the first substrate by the digital lithography process for the second substrate. Non-temporary computer-readable media, including [specific examples of such media].
11. The method described above is To facilitate the formation of the first lithographic pattern for the first substrate or the second lithographic pattern for the second substrate, a substrate plating model based on deposition-related measurement data is used by electroplating. A non-temporary computer-readable medium according to claim 10, further comprising:
12. The method described above is Before receiving the die design, measurement data from the electroplating process is incorporated into the die design. A non-temporary computer-readable medium according to claim 10, further comprising:
13. The non-temporary computer-readable medium according to claim 10, wherein the first lithographic pattern comprises an active die pattern and a first set of dummy patterns, and the second lithographic pattern comprises the active die pattern and a second set of dummy patterns that alter the at least one parameter of the material deposited on the second substrate compared to the first substrate.
14. The non-temporary computer-readable medium according to claim 10, wherein the first lithographic pattern includes an active die pattern, and the second lithographic pattern includes the active die pattern along with at least one active die pattern having a different orientation that alters at least one parameter of the deposited material on the second substrate compared to the first substrate.
15. The non-temporary computer-readable medium according to claim 10, wherein the at least one parameter of the deposited material is the thickness of the deposited material at a specific location on the first substrate.
16. The non-temporary computer-readable medium according to claim 10, wherein the first lithographic pattern or the second lithographic pattern has an edge region pattern different from the pattern used in the central region of the first substrate or the second substrate.
17. The method described above is The first lithographic pattern or the second lithographic pattern is changed based on the current value of the plating bath used in the electroplating process. A non-temporary computer-readable medium according to claim 10, further comprising:
18. An apparatus for electroplating a substrate, A substrate plating model on a processing unit configured to determine a digital lithographic pattern that modifies the deposition characteristics of the electroplating process based on the die design, A digital lithography patterning tool configured to communicate with at least the substrate plating model in order to form a lithographic pattern of an active die pattern and a dummy pattern on a first substrate based on the die design and the deposition characteristics of the electroplating process, An electroplating tool configured to deposit a first plating material onto the first substrate, A measurement tool that uses a substrate plating model based on deposition-related measurement data including the thickness of electroplating at a plurality of locations on the substrate configured to determine the deposition parameters of the first plating material on the first substrate, wherein the measurement tool communicates directly with the substrate plating model or the digital lithography patterning tool to provide the deposition parameters to modify the dummy pattern to change at least one parameter of the second plating material deposited on the second substrate, and A device equipped with the following features.
19. The apparatus according to claim 18, wherein the processing unit is part of the digital lithography patterning tool.
20. The apparatus according to claim 18, wherein the measuring tool is part of the electroplating tool.