Substrate pre-aligner

Abstract

There is provided a substrate alignment system including: (i) an irradiation unit configured to irradiate an irradiated region including an entire edge of a substrate; (ii) a sensing unit having a field of view covering the entire edge of the substrate even when the substrate is misaligned, the sensing unit comprising a sensor, a fisheye lens before the sensor, the sensor configured to generate a detection signal of the entire edge of the substrate; and (iii) processing circuitry configured to process the detection signal and determine whether the substrate is misaligned. It is determined that the substrate misalignment triggers performance of one or more misalignment correction operations for aligning the substrate.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of and priority to U.S. Patent Application No. 18 / 241,145, filed on August 31, 2023, entitled “SUBSTRATE PRE-ALIGNER,” which is incorporated herein by reference in its entirety. Background Art

[0003] The substrate may be evaluated by a substrate evaluation system, such as a charged particle substrate evaluation system. A charged particle substrate evaluation system is configured to evaluate the substrate by irradiating the substrate with one or more charged particle beams.

[0004] Examples of substrate evaluation systems include: (i) defect review systems such as those developed by Applied Materials of San Jose, California TM Company's Defect Review Scanning Electron Microscope SEMVISION TM ; (ii) metrology systems, such as Applied Materials TM PROVision TM 3E E beam TM Metrology systems; (iii) electron beam inspection systems, such as Applied Materials TM PRIMEVISION TM ; or (iv) critical dimension scanning electron microscope, such as Applied Materials TM VERITYSEM TM Etc. Charged particle evaluation systems are available from companies such as HITACHI in Tokyo, Japan. TM or KLA in Milpitas, California TM Companies such as suppliers, or can be manufactured by other suppliers.

[0005] Irradiating a substrate with one or more charged particle beams requires positioning the substrate within a vacuum chamber.

[0006] The substrate evaluation system includes a factory interface, a load lock chamber, and a target vacuum chamber. The factory interface operates at an atmospheric pressure level, the target vacuum chamber operates at a high vacuum level, and the load lock chamber is configured to receive a substrate from the factory interface, undergo a load lock pressure equalization process that places the load lock chamber at a high vacuum level, and then provide the substrate to a stage of the target vacuum chamber.

[0007] The substrate must be aligned in the target vacuum chamber.

[0008] U.S. Patent Application Publication No. 2008 / 0050006, entitled “Method and Apparatus for Semiconductor Wafer Alignment,” illustrates a wafer alignment system that includes an image acquisition device, an illumination source, a rotatable wafer stage, and an image processor that includes functionality for mapping coordinates in an image of an article (such as a wafer) on the stage to a “world” reference frame at each of a plurality of rotation angles of the stage.

[0009] There is an increasing need to align substrates in an accurate and fast manner. Summary of the invention

[0010] A substrate alignment system is provided, the substrate alignment system comprising: (i) an irradiation unit configured to irradiate an irradiated area including the entire edge of a substrate; (ii) a sensing unit having a field of view covering the entire edge of a substrate even when the substrate is misaligned, the sensing unit comprising a sensor preceded by a fisheye lens, the sensor configured to generate a detection signal of the entire edge of the substrate; and (iii) a processing circuit configured to process the detection signal and determine whether the substrate is misaligned. Determining that the substrate is misaligned triggers execution of one or more misalignment correction operations for aligning the substrate.

[0011] A method for aligning a substrate is provided, the method comprising: (i) irradiating an irradiated area including the entire edge of the substrate by an irradiation unit; (ii) generating a detection signal of the entire edge of the substrate by a sensing unit after irradiating the irradiated area; wherein the sensing unit has a field of view that covers the entire edge of the substrate even when the substrate is misaligned, the sensing unit comprises a sensor, and a fisheye lens is placed in front of the sensor; and (iii) processing the detection signal by a processing circuit and determining whether the substrate is misaligned, wherein determining that the substrate is misaligned triggers the execution of one or more misalignment correction operations for aligning the substrate.

[0012] A non-transitory computer-readable medium for aligning a substrate is provided, the non-transitory computer-readable medium storing instructions which, once executed by a substrate alignment system, cause the substrate alignment system to: (i) illuminate an illuminated area including an entire edge of a substrate by an illumination unit of the substrate alignment system; (ii) generate a detection signal of the entire edge of the substrate by a sensing unit of the substrate alignment system after illuminating the illuminated area, wherein the sensing unit has a field of view covering the entire edge of the substrate even when the substrate is misaligned, the sensing unit comprising a sensor preceded by a fisheye lens; and (iii) process the detection signal by a processing circuit of the substrate alignment system and determine whether the substrate is misaligned, wherein determining that the substrate is misaligned triggers execution of one or more misalignment correction operations for aligning the substrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The subject matter which is regarded as the embodiments is particularly pointed out and distinctly claimed in the concluding portion of the specification. However, the embodiments, as well as samples, features, and advantages of the embodiments, both as to organization and method of operation, may be best understood by reference to the following detailed description when read in connection with the accompanying drawings, in which:

[0014] Figure 1 An example of a substrate alignment system is illustrated;

[0015] Figure 2 An example of a substrate alignment system is illustrated, and a cross section of a substrate evaluation system is also illustrated;

[0016] Figure 3 Examples of substrates and substrate alignment systems are illustrated;

[0017] Figure 4 Examples of substrates and substrate alignment systems are illustrated;

[0018] Figure 5 illustrates examples of substrates and illuminated areas; and

[0019] Figure 6 An example of a method is illustrated.

[0020] It should be understood that for simplicity and clarity of illustration, the elements shown in the figures are not necessarily drawn to scale. For example, for clarity, the size of some of the elements may be exaggerated relative to other elements. In addition, reference numerals may be repeated in the drawings to indicate corresponding or similar elements where deemed appropriate. DETAILED DESCRIPTION

[0021] A substrate alignment system for performing an alignment process is provided. According to an embodiment, alignment is performed while the substrate is in a load lock chamber, particularly while the load lock chamber is undergoing a load lock pressure equalization process. The load lock pressure equalization process is time consuming and takes much longer than aligning the substrate, and performing alignment during the load lock pressure equalization process reduces and even eliminates any time loss associated with performing alignment. Alignment may be performed in a chamber other than a load lock chamber.

[0022] The load lock chamber height is relatively small (e.g., less than 60 cm, 50 cm, 40 cm), and the distance between the sensing unit and the substrate is much smaller than the diameter of the substrate (e.g., less than 60%, 50%, 30%, 20%, etc.). In order to capture the entire edge of the wafer in a single focus, the sensing unit includes a fisheye lens.

[0023] To determine misalignments of tens of microns, the substrate alignment system compensates for the distortion introduced by the fisheye lens.

[0024] The proposed system is highly accurate and does not introduce any significant delay due to alignment.

[0025] The substrate can be a bare wafer, a patterned wafer, a solar panel, etc.

[0026] Figure 1 An example of a substrate alignment system 10 is illustrated, the substrate alignment system comprising:

[0027] a. An irradiation unit 31 configured to irradiate an irradiated area including the entire edge of the substrate. The irradiation unit 31 may provide annular irradiation and may be an annular irradiation unit.

[0028] b. A sensing unit 40 having a field of view covering the entire edge of the substrate even when the substrate is misaligned. The sensing unit comprises a sensor 42 preceded by a fisheye lens 41. The sensor is configured to generate a detection signal of the entire edge of the substrate.

[0029] c. Processing circuitry 12 configured to process the detection signal and determine whether the substrate is misaligned. Determining that the substrate is misaligned triggers execution of one or more misalignment correction operations for aligning the substrate.

[0030] The processing circuitry may be implemented as a central processing unit (CPU) and / or one or more other integrated circuits, such as an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), a full custom integrated circuit, etc., or a combination of such integrated circuits.

[0031] According to an embodiment, the substrate alignment system 10 further includes a controller 14 configured to control the performance of one or more misalignment correction operations for aligning the substrate.

[0032] According to an embodiment, the substrate alignment system 10 further includes a memory unit 16. The memory unit may store instructions to be executed by the processing circuit and / or the controller. The memory unit may store information such as detection signals, misalignment status information about the substrate.

[0033] Figure 2 An example of a cross section of the substrate evaluation system 100 is illustrated and some elements of the substrate alignment system 10 are also illustrated.

[0034] The substrate evaluation system 100 includes a factory interface 110, a load lock chamber 120, and a target vacuum chamber 130. The target vacuum chamber is the destination of the substrate. Figure 1 In the present invention, the target vacuum chamber belongs to the substrate evaluation system and is used to evaluate the substrate.

[0035] It should be noted that the target vacuum chamber may be a substrate processing chamber in which a substrate is processed, such as being fabricated, etched, undergoing a deposition process, or the like.

[0036] The factory interface 110 may be any suitable housing, such as, for example, an equipment front end module (EFEM).

[0037] The factory interface 110 may be configured to receive one or more substrates from substrate carriers 99 (eg, front opening unified unit (FOUP)) docked at various load ports 112 of the factory interface. One of the substrate carriers 99 is illustrated as a storage substrate 200.

[0038] The factory interface robot 114 is configured to transfer substrates between the substrate carrier 99 and the load lock chamber 120 .

[0039] According to an embodiment, the load lock chamber 120 includes:

[0040] a. First load lock station 128 .

[0041] b. Second load lock station 128A.

[0042] c. The first window (in Figure 3 and Figure 4 124).

[0043] d. Second window (in Figure 3 and Figure 4 125 in the figure).

[0044] e. A load lock robot 123 configured to transfer a substrate between a load lock chamber and a target vacuum chamber. The load lock robot may transfer a substrate between a target vacuum chamber and a first load lock station or a second load lock station.

[0045] f. Top (at Figure 3 and Figure 4 127 in the figure).

[0046] g. Bottom (at Figure 3 and Figure 4 126 in the figure).

[0047] h. One or more slit valves and / or doors, such as door 122, configured to open when a substrate is received into or released from the factory interface robot 114.

[0048] i. One or more additional slit valves and / or additional doors (such as additional door 126') configured to open when receiving a substrate to and / or releasing a substrate from a target vacuum chamber 130.

[0049] For simplicity of explanation, it is assumed that the first load lock stage 128 is used during a process of providing a substrate to a target vacuum chamber, and the second load lock stage 128A is used during a process of providing a substrate to a factory interface. This assumption is an example, and any of the load lock stages can be used to transfer a substrate in any direction.

[0050] A vacuum environment, a clean environment, and / or a temperature-controlled environment may be maintained within the load lock chamber 120 and / or the target vacuum chamber 130 .

[0051] The target vacuum chamber 130 includes a mechanical stage 132 for supporting a substrate and moving the substrate within the target vacuum chamber 130 .

[0052] exist Figure 2 In the embodiment shown in FIG. 1 , the controller 14 , the processing circuit 12 , and the memory unit are located outside the substrate evaluation system 100 .

[0053] Figure 3 and Figure 4 Examples of a load lock chamber and some units of the substrate alignment system 10 are illustrated.

[0054] exist Figure 3 In FIG. 1 , the illumination unit 31 is located below the bottom 126 of the load lock chamber and directs its illumination (indicated as 172 ) upward through a first window 124 formed at the bottom 126 of the load lock chamber.

[0055] exist Figure 4 In FIG. 1 , the illumination unit 31 is located above the top 127 of the load lock chamber and directs its illumination (indicated as 172 ) downward through a first window 124 formed at the top 127 of the load lock chamber.

[0056] exist Figure 3 and Figure 4 In both, the sensing unit 40 is located above the top 127 of the load lock and has a field of view (denoted as FOV 171) that covers the entire edge of the substrate even when the substrate is misaligned. The sensing unit 40 views the entire edge of the substrate through a second window 125 located at the top 127 of the load lock chamber.

[0057] exist Figure 3 and Figure 4 , the sensing unit includes a fisheye lens 41 behind a sensor 42. The sensor may be a two-dimensional image sensor including an array of sensing elements. The fisheye lens 41 is configured to capture the entire edge of 300 mm when located at a distance less than 50 mm from the substrate. An example of a fisheye lens is a rated 5 megapixel 185° FOV ADL HFE1414C 1 / 2" 1.4mm (Fisheye) F1.4 Fixed Iris and Manual Focus C-Mount Lens from RMA Electronics, Inc. of Hingham, Massachusetts, USA.

[0058] The sensor 42 may be integrated with an image processor, see, for example, the Alvium 1800u from AlliedVision of Stadtroda, Germany.

[0059] exist Figure 3 and Figure 4 In both, the substrate 200 is supported by the load lock stage 128 .

[0060] According to an embodiment, the load lock stage 128 is configured to perform a misalignment correction operation for aligning a substrate, the misalignment correction operation involving correcting a rotation error in which a notch of the substrate is located at a wrong angle.

[0061] Figure 5 An example of the substrate 200 and the irradiated region 90 is illustrated.

[0062] The illuminated area 90 surrounds the substrate 200, and the boundaries of the illuminated area are spaced to include the edge 202 of the substrate regardless of any misalignment of the substrate.

[0063] Figure 5 Various concentric sub-regions of the image acquired by the sensing unit are also illustrated. The sub-regions include a first sub-region 204, a second sub-region 205 and a third sub-region 206.

[0064] According to an embodiment, the processing circuit is configured to compensate for distortion introduced by the fisheye lens.

[0065] According to an embodiment, the compensation comprises mapping pixels of an image acquired by the sensing unit to mapped pixels reflecting the real portion of the substrate present in the pixel.

[0066] A linear mapping may be applied and includes: assigning a first linear distortion coefficient (C1) to a first sub-region 204 of the image of the illuminated area; assigning a second linear distortion coefficient (C2) to a second sub-region 205 of the image of the illuminated area; and assigning a third linear distortion coefficient (C3) to a third sub-region 206 of the image of the illuminated area. Any relationship may exist between the values ​​of C1, C2, and C3. For example, C1 may exceed C2, and C2 may exceed C3.

[0067] In order to find misalignment of the wafer, the exact location of the notch 201 is determined.

[0068] Assuming that the deepest point of the notch 201 appears in certain pixels of the image captured by the sensor, the distance of the deepest point from the border of the illuminated area can be calculated by linear approximation based on the position of the pixels.

[0069] Assuming that the deepest point of the notch is within the first sub-area, linear compensation consists in calculating the true distance between the deepest point of the notch and the edge of the illuminated area by multiplying the distance (in the image) between the deepest point of the notch and the edge of the illuminated area by C1.

[0070] Assuming that the deepest point of the notch is within the first sub-region, the linear compensation involves calculating the true distance between the deepest point of the notch and the edge of the illuminated area by (a) multiplying C2 by the distance (in the image) of the deepest point from the boundary between the first sub-region and the second sub-region and (b) adding the product of the multiplication of the width of the first sub-region and C1.

[0071] Assuming that the deepest point of the notch is within the third sub-region, the linear compensation includes calculating the true distance between the deepest point of the notch and the edge of the illuminated area by (a) multiplying C3 by the distance (in the image) of the deepest point from the boundary between the second sub-region and the third sub-region, (b) adding the product of the multiplication between the width of the second sub-region and C2, and (b) adding the product of the multiplication between the width of the first sub-region and C1.

[0072] Applying the above linear approximation on the x-coordinate of the deepest point provides the x-axis misalignment.

[0073] Applying the above linear approximation on the y-coordinate of the deepest point provides the y-axis misalignment.

[0074] Figure 6An example of a method 600 for aligning a substrate is illustrated.

[0075] According to an embodiment, the method 600 includes a step 610 of irradiating, by an irradiation unit, an irradiated area including the entire edge of the substrate.

[0076] According to an embodiment, step 610 is followed by step 620 of generating a detection signal of the entire edge of the substrate by a sensing unit after irradiating the irradiated area. The sensing unit has a field of view covering the entire edge of the substrate even when the substrate is misaligned, and the sensing unit includes a sensor with a fisheye lens in front of the sensor.

[0077] According to an embodiment, step 620 is followed by step 630 of processing the detection signal by the processing circuit and determining whether the substrate is misaligned. Determining that the substrate is misaligned triggers the performance of one or more misalignment correction operations for aligning the substrate.

[0078] According to an embodiment, step 630 includes step 632 of compensating, by the processing circuit, for optical distortion introduced by the fisheye lens.

[0079] According to an embodiment, step 632 comprises applying a linear approximation of the optical distortion. Applying the linear approximation may comprise associating different linear distortion coefficients with different concentric sub-regions of the image of the illuminated area.

[0080] According to an embodiment, step 630 is followed by step 640 of at least partially participating in the performance of one or more misalignment correction operations for aligning the substrate.

[0081] Step 640 may include at least one of the following:

[0082] a. Trigger the execution of one or more misalignment correction operations.

[0083] b. Controlling the execution of one or more misalignment correction operations.

[0084] c. Perform one or more misalignment correction operations.

[0085] According to an embodiment, step 610 and step 620 are performed while the substrate is located within the load lock chamber and the sensing unit and the irradiation unit are located outside the load lock chamber.

[0086] According to an embodiment, steps 610 and 620 are performed while the load lock chamber is undergoing a load lock pressure equalization process. This reduces or even eliminates any impact of performing steps 610 and 620 on the throughput of the substrate evaluation system because performing steps 610 and 612 is shorter in duration than the load lock pressure equalization process.

[0087] According to an embodiment, step 610 includes irradiating the irradiated area through a first window formed in the load lock chamber, and step 620 includes acquiring an image of the entire edge of the substrate through a second window formed in the load lock chamber by the sensing unit.

[0088] According to an embodiment, the distance between the fisheye lens and the substrate is less than one third of the diameter of the substrate.

[0089] According to an embodiment, the one or more misalignment correction operations include rotating the substrate.

[0090] According to an embodiment, the one or more misalignment correction operations include generating at least one indication regarding at least one misalignment selected from an x-axis misalignment and a y-axis misalignment, and correcting the x-axis misalignment and the y-axis misalignment using the at least one indication by a mechanical stage of a target vacuum chamber by receiving a substrate while positioning the mechanical stage at a position to compensate for the x-axis misalignment and the y-axis misalignment.

[0091] In the preceding description, numerous specific details are set forth in order to provide a thorough understanding of embodiments of the present disclosure.

[0092] However, those skilled in the art will appreciate that embodiments of the present disclosure may be practiced without these specific details. In other instances, well-known methods, processes, and components have not been described in detail to avoid obscuring embodiments of the present disclosure.

[0093] The subject matter which is regarded as an embodiment of the present disclosure is particularly pointed out and distinctly claimed in the concluding portion of the specification. However, the embodiments of the present disclosure, both as to organization and method of operation, together with the objects, features, and advantages of the disclosure, may be best understood by reference to the following detailed description when read in conjunction with the accompanying drawings.

[0094] It should be understood that for simplicity and clarity of illustration, the elements shown in the figures are not necessarily drawn to scale. For example, for clarity, the size of some of the elements may be exaggerated relative to other elements. In addition, reference numerals may be repeated in the drawings to indicate corresponding or similar elements where deemed appropriate.

[0095] Since most of the illustrated embodiments of the present disclosure can be implemented using electronic components and circuits known to those skilled in the art, in order to understand and appreciate the basic concepts of the embodiments of the present disclosure and in order not to confuse or depart from the teachings of the embodiments of the present disclosure, the details will not be explained to a greater extent than is deemed necessary as illustrated above.

[0096] Any reference in the specification to a method shall apply mutatis mutandis to a system capable of performing the method and to a non-transitory computer readable medium storing instructions which, once executed, cause the method to be performed.

[0097] Any reference in the specification to a system shall apply mutatis mutandis to a method executable by the system and to a non-transitory computer readable medium storing instructions executable by the system.

[0098] Any reference in the specification to a non-transitory computer readable medium shall apply mutatis mutandis to methods that may be performed upon execution of instructions stored in the non-transitory computer readable medium and shall apply mutatis mutandis to systems configured to execute instructions stored in the non-transitory computer readable medium.

[0099] The term "and / or" means additionally or alternatively. For example, A and / or B means only A, or only B, or both A and B.

[0100] In the foregoing description, embodiments of the present disclosure have been described with reference to specific examples of embodiments. It will, however, be evident that various modifications and changes may be made therein without departing from the broader spirit and scope of the appended claims.

[0101] Furthermore, the terms "front," "rear," "top," "bottom," "upper," "lower," and the like in the specification and claims, if any, are used for descriptive purposes and not necessarily for describing permanent relative positions. It is to be understood that the terms so used are interchangeable where appropriate such that the embodiments of the disclosure described herein are, for example, capable of operation in other orientations than those illustrated or otherwise described herein.

[0102] Those skilled in the art will recognize that the boundaries between logic blocks are merely illustrative, and will recognize that alternative embodiments may merge logic blocks or circuit elements or impose an alternate decomposition of functionality upon various logic blocks or circuit elements. It should be understood, therefore, that the architectures described herein are merely exemplary, and that in fact many other architectures may be implemented that achieve the same functionality.

[0103] Any reference to the terms "comprising" or "having" or "including" should be applied mutatis mutandis to "consisting of" and / or to "consisting essentially of.

[0104] Any arrangement of components that achieve the same functionality is effectively "associated" such that the desired functionality is achieved. Thus, any two components combined herein to achieve a particular functionality may be considered to be "associated" with each other such that the desired functionality is achieved, regardless of architecture or intermediate components. Likewise, any two components so associated may also be considered to be "operably connected" or "operably coupled" to each other such that the desired functionality is achieved.

[0105] Furthermore, those skilled in the art will recognize that the boundaries between the operations described above are merely illustrative. Multiple operations may be combined into a single operation, a single operation may be distributed among additional operations, and the operations may be performed at least partially overlapping in time. Furthermore, alternative embodiments may include multiple instances of a particular operation, and in various other embodiments, the order of the operations may be altered.

[0106] Also, for example, in one embodiment, the illustrated examples may be implemented as a circuit system located on a single integrated circuit or within the same device. Alternatively, the examples may be implemented as any number of separate integrated circuits or separate devices interconnected with each other in a suitable manner.

[0107] Also, for example, the examples or portions thereof may be implemented as software or code representations of physical circuitry or logical representations convertible into physical circuitry, such as in any appropriate type of hardware description language.

[0108] However, other modifications, changes, and substitutions are possible. Accordingly, the specification and drawings are to be regarded as illustrative rather than restrictive.

[0109] In the claims, any reference numerals placed between brackets shall not be interpreted as limiting the claims. The word "comprising" does not exclude the presence of other elements or steps other than those listed in the claims. In addition, the term "one" or "a kind" as used herein is defined as one or more than one. Moreover, even when the same claim includes the introductory phrase "one or more" or "at least one" and indefinite articles such as "one" or "a kind", the use of introductory phrases such as "at least one" and "one or more" in the claims should not be interpreted as implying that any particular claim containing such introduced claim elements by the indefinite article "one" or "a kind" is limited to an embodiment containing only one such element. The same applies to the use of definite articles. Unless otherwise stated, terms such as "first" and "second" are used to arbitrarily distinguish between the elements described by such terms. Therefore, these terms are not necessarily intended to indicate the time or other priority of such elements. The fact that certain measures are recited in mutually different claims does not indicate that the combination of these measures cannot be used advantageously.

[0110] Although certain features of the embodiments have been illustrated and described herein, many modifications, substitutions, changes and equivalents will now occur to those skilled in the art. It is therefore to be understood that the appended claims are intended to cover all such modifications and changes that fall within the true spirit of the embodiments.

Claims

1. A substrate alignment system, comprising: an irradiation unit configured to irradiate an irradiated area including the entire edge of the substrate; a sensing unit having a field of view covering the entire edge of the substrate even when the substrate is misaligned, the sensing unit comprising a sensor preceded by a fisheye lens, the sensor being configured to generate a detection signal of the entire edge of the substrate; as well as A processing circuit is configured to process the detection signal and determine whether the substrate is misaligned; wherein determining that the substrate is misaligned triggers execution of one or more misalignment correction operations for aligning the substrate. 2 . The substrate alignment system of claim 1 , wherein the irradiation unit is configured to irradiate the irradiated area when the substrate is located in a load lock chamber, wherein the sensing unit and the irradiation unit are located outside the load lock chamber. 3 . The substrate alignment system of claim 2 , wherein the irradiation unit is configured to irradiate the irradiated area while the load lock chamber undergoes a load lock pressure equalization process.

4. The substrate alignment system according to claim 2, wherein the irradiation unit is configured to irradiate the irradiated area through a first window formed in the load lock chamber, and wherein the sensing unit is configured to acquire an image of the entire edge of the substrate through a second window formed in the load lock chamber. 5 . The substrate alignment system of claim 2 , wherein a distance between the fisheye lens and the substrate is less than one third of a diameter of the substrate. 6 . The substrate alignment system of claim 1 , wherein the one or more misalignment correction operations include rotating the substrate.

7. The substrate alignment system of claim 1, wherein the one or more misalignment correction operations include generating at least one indication regarding at least one misalignment selected from an x-axis misalignment and a y-axis misalignment.

8. The substrate alignment system of any one of claims 1 to 7, wherein the processing circuit is configured to compensate for optical distortion introduced by the fisheye lens.

9. A substrate alignment system according to claim 8, wherein the processing circuit is configured to compensate for the optical distortion introduced by the fisheye lens by applying a linear approximation of the optical distortion, wherein applying the linear approximation includes associating different linear distortion coefficients with different concentric sub-regions of the image acquired by the sensing unit. 10 . The substrate alignment system of claim 1 , further comprising a controller configured to control the one or more misalignment correction operations for aligning the substrate.

11. A method for aligning a substrate, the method comprising: irradiating an irradiated area including the entire edge of the substrate by an irradiation unit; generating a detection signal of the entire edge of the substrate by a sensing unit after illuminating the illuminated area, wherein the sensing unit has a field of view covering the entire edge of the substrate even when the substrate is misaligned, the sensing unit comprising a sensor preceded by a fisheye lens; and The detection signal is processed by processing circuitry and a determination is made whether the substrate is misaligned, wherein a determination that the substrate is misaligned triggers performance of one or more misalignment correction operations for aligning the substrate. 12 . The method of claim 11 , further comprising performing the irradiating while the substrate is located in a load lock chamber, wherein the sensing unit and the irradiating unit are located outside the load lock chamber. 13 . The method of claim 12 , further comprising performing the irradiating while the load lock chamber is undergoing a load lock pressure equalization process.

14. The method of claim 12, wherein the irradiating comprises irradiating the irradiated area through a first window formed in the load lock chamber, and wherein the method comprises acquiring, by the sensing unit, an image of the entire edge of the substrate through a second window formed in the load lock chamber. 15 . The method of claim 12 , wherein a distance between the fisheye lens and the substrate is less than one third of a diameter of the substrate.

16. The method of claim 11, wherein the one or more misalignment correction operations include rotating the substrate.

17. The method of claim 11, wherein the one or more misalignment correction operations include generating at least one indication of at least one misalignment selected from an x-axis misalignment and a y-axis misalignment.

18. The method of any one of claims 11 to 17, further comprising compensating, by the processing circuit, for optical distortion introduced by the fisheye lens.

19. The method of claim 18, further comprising compensating, by the processing circuit, for optical distortion introduced by the fisheye lens by applying a linear approximation of the optical distortion, wherein applying the linear approximation comprises associating different linear distortion coefficients with different concentric sub-regions of the image acquired by the sensing unit.

20. A non-transitory computer readable medium for aligning a substrate, the non-transitory computer readable medium storing instructions that, upon execution by a substrate alignment system, cause the substrate alignment system to: irradiating an irradiated area including the entire edge of the substrate by an irradiation unit of the substrate alignment system; generating a detection signal of the entire edge of the substrate by a sensing unit of the substrate alignment system after the irradiating the irradiated area, wherein the sensing unit has a field of view covering the entire edge of the substrate even when the substrate is misaligned, the sensing unit comprising a sensor preceded by a fisheye lens; and The detection signal is processed by processing circuitry of the substrate alignment system and a determination is made whether the substrate is misaligned; wherein a determination that the substrate is misaligned triggers execution of one or more misalignment correction operations for aligning the substrate.

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