Side-by-side off-center die stacking targets

Abstract

A system and method of overlay metrology is disclosed. The overlay metrology system can include a detector and a controller. The controller can be configured to execute program instructions causing a processor to acquire an image of overlay targets of a specimen. The specimen can include one or more dies corresponding to one or more substrates. The overlay targets can include one or more measurement regions, each measurement region corresponding to a die. Each measurement region can include one or more die marks positioned on the die and a substrate mark positioned on the substrate. The processor can be configured to determine a plurality of overlay measurements based on the image.

Description

Technical Field

[0001] This disclosure generally relates to stacking metrics and, more specifically, to stacking metrics for stacked substrates using side-by-side stacking targets. Background Technology

[0002] Alignment metrics refer to measurements of the relative alignment of layers on a sample (e.g., but not limited to, a semiconductor device). Alignment measurement or alignment measurement error typically refers to measurements of misalignment of manufactured features on two or more sample layers. Alignment can include misalignment of features between different substrates, such as die alignment of dies stacked on another substrate. Proper alignment is essential for proper device operation.

[0003] The need to reduce feature size and increase feature density has led to a corresponding increase in the demand for accurate and efficient overlay metrology systems. Metrology systems typically determine metrology data associated with a sample by measuring or otherwise verifying a dedicated metrology target (i.e., an overlay target) across a sample distribution. Accordingly, the sample is typically mounted on a translation stage and translated so that the metrology target is sequentially moved into the measurement field of view. Summary of the Invention

[0004] According to one or more illustrative embodiments of this disclosure, a stacking target configured for stacked substrates is disclosed. In one illustrative embodiment, the stacking target may include one or more measurement regions, each corresponding to a die. In another illustrative embodiment, each measurement region may include one or more die markers positioned on one or more dies. In another illustrative embodiment, the measurement region may include substrate markers positioned on one or more substrates, wherein the substrate markers are not obscured by the die. In another illustrative embodiment, the substrate markers may include a first-direction substrate marker aligned with respect to the die markers along a first direction. In another illustrative embodiment, the substrate markers may include a second-direction substrate marker aligned with respect to the die markers along a second direction, wherein the second direction is different from the first direction.

[0005] In a further aspect, the substrate mark in each measurement region may further include an acquisition mark, wherein the acquisition mark is aligned along the first direction relative to the second-direction substrate mark and along the second direction relative to the first-direction substrate mark. In another illustrative embodiment, the one or more measurement regions may include two or more measurement regions corresponding to two or more dies, wherein at least one substrate mark in each measurement region is shared among the multiple measurement regions. In another illustrative embodiment, the two or more measurement regions may include four or more measurement regions corresponding to four or more dies. In another illustrative embodiment, at least one substrate mark shared among the multiple measurement regions in each measurement region may include the acquisition mark, the first-direction substrate mark, and the second-direction substrate mark.

[0006] In a further aspect, the stacking target may comprise a 3×3 grid configured for marking four dies arranged in a 2×2 configuration, wherein the space between each die is used for the substrate marking. In another illustrative embodiment, the center mark of the marked 3×3 grid may include the acquisition mark and may be configured to be shared among the four or more measurement areas corresponding to the four dies. In another illustrative embodiment, each corner of the marked 3×3 grid may include a corresponding die mark for the corresponding die among the four or more dies.

[0007] In a further embodiment, the stacking target may be configured to be accommodated within a single field of view having a width and height of no more than 2000 micrometers. In another illustrative embodiment, the stacking mark may be configured to be accommodated within a single field of view having a width of no more than 600 micrometers. In another illustrative embodiment, the die mark of the die may include a transparent mark contained in the die structure of the die above the substrate structure of the one or more substrates. In another illustrative embodiment, the stacking mark may include at least one of an Advanced Imaging Metrics (AIM) style target or a box-in-box style target.

[0008] According to one or more illustrative embodiments of this disclosure, a stacking measurement system is disclosed. In one illustrative embodiment, the stacking measurement system may include a detector. In another illustrative embodiment, the system may include a controller communicatively coupled to the detector. The controller may include one or more processors configured to execute program instructions. In another illustrative embodiment, the program instructions may cause the processor to acquire an image of a stacking target of a sample. The sample may include one or more dies corresponding to one or more substrates. In another illustrative embodiment, the stacking target may include one or more measurement regions, each measurement region corresponding to a die. In another illustrative embodiment, each measurement region may include one or more die markers located on the die. In another illustrative embodiment, the measurement region may include a substrate marker located on the substrate, wherein the substrate marker is not obscured by the die. In another illustrative embodiment, the substrate marker may include a first-direction substrate marker aligned with respect to a die marker along a first direction. In another illustrative embodiment, the substrate marker may include a second-direction substrate marker aligned with respect to the die marker along a second direction, wherein the second direction is different from the first direction. In another illustrative embodiment, the program instructions may cause the processor to determine, based on the image, multiple stack-up measurements corresponding to the one or more measurement regions and the one or more dies.

[0009] According to one or more illustrative embodiments of this disclosure, a stacking measurement system is disclosed. In one illustrative embodiment, the stacking measurement system may include an optical subsystem. In another illustrative embodiment, the system may include a controller. The controller may include one or more processors configured to execute program instructions. In another illustrative embodiment, the program instructions may cause the one or more processors to acquire an image emitted from a stacking target of a sample. In another illustrative embodiment, the image may include one or more measurement regions. In another illustrative embodiment, the sample may include one or more dies corresponding to one or more substrates. In another illustrative embodiment, the stacking target may include the one or more measurement regions, each measurement region corresponding to a die. In another illustrative embodiment, each measurement region may include a substrate mark located on the substrate and not obscured by the one or more dies. In another illustrative embodiment, the substrate mark may include a first-direction substrate mark offset relative to a first die edge along a first direction. In another illustrative embodiment, the substrate mark may include a second-direction substrate mark offset relative to a second die edge along a second direction, wherein the second direction is different from the first direction. In another illustrative embodiment, the controller may determine, based on the image, multiple stacked measurements corresponding to the one or more measurement areas and the one or more dies.

[0010] According to one or more illustrative embodiments of this disclosure, a method is disclosed. In one illustrative embodiment, the method may include acquiring an image of a stacked target of a sample. In another illustrative embodiment, the image may include one or more measurement regions. In another illustrative embodiment, the sample may include one or more dies corresponding to one or more substrates. In another illustrative embodiment, the stacked target may include the one or more measurement regions, each measurement region corresponding to a die. In another illustrative embodiment, each measurement region may include one or more die markers positioned on one or more dies. In another illustrative embodiment, the measurement region may include a substrate marker positioned on the one or more substrates, wherein the substrate marker is not obscured by the one or more dies. In another illustrative embodiment, the substrate marker may include a first-direction substrate marker aligned relative to the die marker along a first direction. In another illustrative embodiment, the substrate marker may include a second-direction substrate marker aligned relative to the die marker along a second direction, wherein the second direction is different from the first direction. In another illustrative embodiment, the method may include determining multiple stacked measurements based on the image, corresponding to the one or more measurement regions and the one or more dies.

[0011] It should be understood that the foregoing general description and the following detailed description are for illustrative and explanatory purposes only, and are not necessarily intended to limit the invention as claimed. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the general description, serve to explain the principles of the invention. Attached Figure Description

[0012] Those skilled in the art will better understand the many advantages of this disclosure by referring to the accompanying drawings.

[0013] Figure 1A A conceptual diagram illustrating a system for stacking weights and measures according to one or more embodiments of this disclosure.

[0014] Figure 1B The illustration shows a schematic diagram of an optical subsystem according to one or more embodiments of the present disclosure, the optical subsystem having a barrel lens configured to adjust the size of the field of view.

[0015] Figure 2 This describes the stacking target of a sample comprising four bare wafers according to one or more embodiments of the present disclosure.

[0016] Figure 3A This illustration shows a top view of a stacked target comprising a side-by-side structure combined with transparent markers, according to one or more embodiments of the present disclosure.

[0017] Figure 3B This describes a side-by-side marking of stacked targets with zero rotation according to one or more embodiments of the present disclosure.

[0018] Figure 3C This describes a side-by-side label of a stacked target having a rotational offset corresponding to a rotation, according to one or more embodiments of the present disclosure.

[0019] Figure 4A This describes the stacking target of four bare dies according to one or more embodiments of the present disclosure.

[0020] Figure 4B This describes a transparent structure on a bare die according to one or more embodiments of the present disclosure. Figure 4A The overlapping targets.

[0021] Figure 4C This describes a stacking target of four bare wafers according to one or more embodiments of the present disclosure, wherein the bare wafers have a box-in-box transparent mark.

[0022] Figure 4D This describes the stacking target of four bare dies according to one or more embodiments of the present disclosure.

[0023] Figure 5 This describes a stacking target of four bare sheets without bare sheet markings but having critical dimensions measured from the edge of the bare sheets, according to one or more embodiments of this disclosure.

[0024] Figure 6 This illustration shows a side view of a stacked target of three substrates of a height according to one or more embodiments of the present disclosure.

[0025] Figure 7 A flowchart illustrating the process of a method for superimposing weights and measures according to one or more embodiments of the present disclosure is provided. Detailed Implementation

[0026] This disclosure has specifically shown and described certain embodiments and their specific features. The embodiments set forth herein should be considered illustrative rather than restrictive. It will be readily apparent to those skilled in the art that various changes and modifications in form and detail can be made without departing from the spirit and scope of this disclosure. The disclosed objects will now be described in detail with reference to the accompanying drawings.

[0027] refer to Figures 1A to 7 According to one or more embodiments of the present disclosure, a system and method for performing overlapping units using side-by-side overlapping markers are disclosed.

[0028] Embodiments of this disclosure relate to measuring stacking pairs in stacked die-to-wafer and / or die-to-die settings using side-by-side stacking markers. In embodiments, multiple off-axis dies can be measured simultaneously. Stacking target markers can be positioned close enough to allow simultaneous imaging of all markers on the dies in a single field of view. Side-by-side marking methods and transparent marking methods can be combined to improve accuracy. In embodiments, die edges are used instead of die markers to determine stacking pairs. In embodiments, die markers are used for each die and compared with substrate markers between the dies to determine stacking pairs. For example, stacking pairs can be determined for four dies in a 2×2 pattern in a single image, where each die has a kerf in the middle. Substrate markers located in the kerf of the carrier wafer can be shared between the dies to allow for smaller stacking targets. In embodiments, shared acquisition markers at the center of the stacking targets can be used to determine and compensate for rotational errors of the carrier wafer. Furthermore, substrate markers in two directions (e.g., the X and Y directions) can be shared with corresponding dies on opposite sides of the kerf.

[0029] The dynamic field of view can be adjusted using the telescope lens. Changing the size of the field of view allows for maximizing resolution when observing the entire stacked target and magnification when observing a single transparent bare mark.

[0030] Figure 1A This is a conceptual diagram of a system 100 for superimposing weights and measures according to one or more embodiments of the present disclosure.

[0031] In one embodiment, system 100 includes an optical subsystem 102 for performing overlay measurements on sample 104. In another embodiment, optical subsystem 102 includes an illumination subsystem 106 and a collection subsystem 110. Collection subsystem 110 may include a detector 112.

[0032] In one embodiment, system 100 includes a controller 122 communicatively coupled to optical subsystem 102. Controller 122 may include one or more processors 124 and a memory device 126 or memory. For example, one or more processors 124 may be configured to execute a set of program instructions maintained in memory device 126.

[0033] Figure 1BThis is a schematic diagram of an optical subsystem 102 according to one or more embodiments of the present disclosure. An illumination subsystem 106 is configured to generate illumination for illuminating the sample 104 in the form of one or more illumination beams 108. A collection subsystem 110 is configured to collect light 138 from the illuminated sample 104. Furthermore, the one or more illumination beams 108 may be spatially confined such that they illuminate selected portions of the sample 104. For example, each of the one or more illumination beams 108 may be spatially confined to illuminate a specific superimposed target 302. In an embodiment, the collection subsystem 110 may be spatially confined to a field of view (FOV) defining the area being observed.

[0034] In one embodiment, the collection subsystem 110 includes a telescope lens 140. For example, the telescope lens 140 may be positioned within a collection path defined by the collection subsystem 110 and directed to the detector 112.

[0035] Detector 112 may comprise any detector 112 known in metrology techniques. For example, detector 112 may comprise, but is not limited to, multi-pixel detectors, such as complementary metal-oxide-semiconductor (CMOS) detectors, charge-coupled device (CCD) detectors, or the like. Detector 112 may be located in the field plane 150 of the collection subsystem 110 rather than in the pupil plane 114.

[0036] In one embodiment, the optical subsystem 102 includes a translation stage 116 for moving the sample 104 through the measurement field of view of the optical subsystem 102.

[0037] In one embodiment, the optical subsystem 102 includes an objective lens 136 for focusing an illumination beam 108 onto a sample 104. For example, the objective lens 136 may be configured to collect measurement light emitted from the sample 104 in response to the illumination beam 108, according to a metrology formula.

[0038] The optical subsystem 102 may include one or more beam splitters 146 for splitting light (e.g., for splitting illumination beam 108).

[0039] According to the "unit recipe", system 100 can be configured for certain types of samples or features of sample 104. For example, system 100 can be programmed to calculate superimposed measurements of certain types of features according to the unit recipe.

[0040] Figure 2 This describes the overlapping target 302 of sample 104 according to one or more embodiments of the present disclosure.

[0041] In an embodiment, sample 104 may contain any number of dies. For example, sample 104 may contain one or more dies 204. For example, die 204 may include normal dies 204 (e.g., electrical function dies) and / or dummy dies 204 (e.g., non-electrical function dies). For example, sample 104 may contain, for example, dies 204 ...304 204 204 304 204 204 304 204 304 204 304 204 304 204 304 204 304 404 204 Figure 2 The bare die to wafer bare die 204 shown is illustrated. For example, substrate 202 may be a carrier wafer. By another example, sample 104 may contain, as... Figure 6 The bare films shown are bare films 204a and 204b.

[0042] In this embodiment, the field of view (FOV) 206 may be adjustable. It should be noted that the field of view (FOV) defines what is seen and captured by the detector 112. Enlarging or decreasing the size of the FOV 206 allows observation of the entirety or a smaller portion of the overlay target 302, as shown. The field of view size can be configured to be adjusted by adjusting the telescope lens 140 in the collection path 110 of the overlay measurement system 100. For example, the size of the FOV 206 can be adjusted (e.g., magnified) to observe a single mark, such as a transparent blank mark on the blank 204. This allows for higher resolution when observing portions of the overlay target 302. For example, the controller 122 can be configured to guide the adjustment of the field of view size configured for observing transparent marks. For example, the controller 122 can send control signals to an actuator configured to adjust the telescope lens 140 to magnify (decrease) the size of the FOV 206. The controller 122 can be further configured to acquire a transparent image of the transparent marker and guide different adjustments of the field of view size (e.g., reduction) configured to observe the entire superimposed target 302.

[0043] Alternatively and / or additionally, the field of view size can be adjusted by adjusting the numerical aperture (NA) of the optical subsystem 102. For example, the NA can be adjusted in any way. For example, the NA can be adjusted by a translation component (e.g., using an actuator to move the lens), an exchange component, an adjustment iris or aperture stop component, which can increase or decrease the size to allow more or less light to pass through, thereby adjusting the numerical aperture and / or the like.

[0044] It should be noted that the adjustment of the field of view (FOV) can be configured to be performed in different modes, such as during a mode configured for a relatively low sampling rate (i.e., processing power), for example, for a pair of targets 302 with a transparent stencil structure. Similarly, sample 104 may contain two types of pairs of targets 302: a first group containing a transparent stencil structure and a second group (without) a transparent stencil structure. This allows switching between a mode that observes only the entire pair of targets 302 and a mode that adjusts the FOV to observe both the entire pair of targets 302 and a single transparent stencil structure to improve (spatial) resolution. Controller 122 can be configured to switch between such modes based on the imaged pair of targets 302.

[0045] The superimposed target 302 can be configured to be contained within a single field of view 206 having a width and height of no more than 2000 micrometers. The superimposed target 302 can be configured to be contained within a single field of view 206 having a width and height of no more than 600 micrometers. The superimposed target 302 can be configured to be contained within a single field of view 206 having a width and height of no more than 400 micrometers.

[0046] However, it should be understood that Figures 2 to 6 The descriptions of Sample 104 and its superimposed target 302, along with the associated descriptions, are for illustrative purposes only and should not be construed as restrictive. In fact, Sample 104 and its superimposed target 302 may include any suitable design and configuration.

[0047] Figure 3AThis is a top view of a stacking target 302 comprising a side-by-side structure 322 combined with a transparent marker 304b on a die 204, according to one or more embodiments of the present disclosure. Combining the side-by-side structure 322 with the transparent marker 304b allows for improved stacking accuracy. For example, the stacking of the die 204 may be based on a comparison of the die structure 324 with the substrate structure 326 seen "through" the die structure 324 and the substrate structure 322 seen from the "side" of the die 204 (e.g., in a scribe line). The die marker 304b may comprise structures configured to serve as transparent markers, such as the transparent die structure 324 within the die 204 itself and the substrate structure 326 associated with an auxiliary substrate 202 (e.g., a carrier wafer). For example, the substrate structure 326 may be disposed in and / or on the substrate 202, such as beneath the transparent die structure 324. The transparency mark 304b can be "transparent" in the sense that the substrate structure 326 can be imaged from above through the die 204 and the transparent die structure 324. For example, the transparent die structure 324 may be above, beside, and / or similar to the substrate structure 326, but not necessarily overlap / obscure the view of the substrate structure 326. For example, as shown, the transparent die structure 324 may comprise a larger rectangle above a smaller rectangle that does not overlap with the smaller rectangle. In this way, the mark 304b may comprise (or be) a die mark 304b and a transparency mark 304, the transparency mark 304 comprising the die structure 324 of the die 204, the die structure 324 being above the substrate structure 326 of one or more substrates 202 (e.g., auxiliary substrates). The auxiliary substrate may comprise any other substrate, such as a carrier wafer or other die above or below the die 204.

[0048] Substrate mark 304a (which is adjacent to die / transparency mark 304b) may include a structure 322 configured for side-by-side stack-up measurement. For example, structure 322 on substrate 202 may be associated with the side-by-side mark 304a on the left. Structure 322 of auxiliary substrate 202 may be compared with one or more of structures 324, 326 of die 204 to determine side-by-side stack-up.

[0049] In an embodiment, determining a stacking measurement includes (i) determining a side-by-side stacking pair between at least one of the substrate markers 304a and the die marker 304b (e.g., between structures 322 and 324); (ii) determining a transparent stacking pair (e.g., between structures 324 and 326 of the die marker 304b) based on the die marker 304b; and (iii) determining a die stacking pair based on the side-by-side stacking pair and the transparent stacking pair. For example, the die stacking pair can be calculated using any number of computational methodologies. For example, the transparent stacking pair and the side-by-side stacking pair can be averaged together to calculate the die stacking pair, which can be a single stacking pair measurement in a single direction for a single die 204, such as a stacking pair measurement in the X direction (e.g., horizontal direction) for the upper right die 204. This process can be repeated for multiple directions (e.g., X and Y directions) for each die using the corresponding substrate structure 322 of the substrate marker 304a associated with each direction. For example, in the case of four dies 204, eight die stack measurements can be determined by corresponding to two die stack measurements for each die 204.

[0050] Determining bare wafer pairs, compared to side-by-side pairs, can involve differentially weighting transparent pairs. For example, pair measurements can be weighted according to the following equation:

[0051] (Equation 1)

[0052] (Equation 2)

[0053] OVL x and OVL y These are the overlay measurements in the X and Y directions, respectively; a and b are the weights; OVL x STT It is a transparent overlap in the X direction; OVL y STT It is a transparent stacking pair in the Y direction; OVL x SBS They are side-by-side stacked pairs in the X direction; and OVL y SBS It is a side-by-side stacked pair in the Y direction. Measurements of transparent structure bare sheet stacks can be more heavily weighted, for example, where a is a constant greater than b.

[0054] Figures 3B to 3C Description of one or more embodiments of the present disclosure having Figure 3B Zero rotation and having Figure 3CThe structure of the side-by-side markers 304 of the Advanced Imaging Metrics (AIM) overlay target 302 with rotational offset 410 is described. The side-by-side markers 304 can be used to determine the rotational error of the substrate 202. For example, rotational errors may occur when the carrier wafer is misaligned and rotated relative to the detector 112. Rotational errors can cause overlay measurement errors. Other methodologies may take multiple moving and measuring images of the same overlay target to replace rotational errors with tooling errors. For example, relaxation in the system may contribute to rotational errors, and other methodologies may perform repeated measurements, resulting in the relaxation being averaged. However, embodiments of this disclosure may be able to measure the rotational error itself using a single image of the side-by-side structure in a single field of view (FOV) of a single overlay target 302. This eliminates the need for moving and measuring measurements, thereby increasing processing power.

[0055] For example, the first mark 304 can be compared with the second mark 304 to determine the rotation offset 410, such as Figure 3C As shown in the figure. For example, the first center of symmetry can be based on Figure 4A The acquisition mark 306 is used, and the second center of symmetry may be based on a different substrate mark 304a that should be horizontally or vertically aligned with the first substrate mark. For example, the rotation offset 410 may be a vertical displacement and / or rotation amount in degrees. The rotation offset 410 may be determined based on the position of the acquisition mark 306 (e.g., center of symmetry, corner, or similar) and the position of the first orientation substrate mark 308 or the second orientation substrate mark 312.

[0056] If there is no error, then the position offset 414 can be a desired measurement between the two marks. For example, the position offset 414 can be based on the desired distance between the marks, converted to pixel distance. The desired position of the second mark can be determined based on the desired pixel distance (e.g., the number of horizontal pixels). The desired position of the second mark can be compared with the actual position of the second mark to determine the rotation offset 410. For example, in Figure 3C In this case, the rotation offset 410 can be based on the number of vertical pixels between the expected position and the actual position of the second marker. The actual distance 412 can be a measurement between the centers of markers 304.

[0057] Stacking measurements can be based on adjustments (e.g., mathematical adjustments) configured to account for sample rotation based on rotation offset 410. For example, obtaining multiple rotation offsets 410 between marker 306 and other substrate markers 308, 312 can be used to reduce noise. For example, rotation offset 410 can be averaged and adjusted. Using a small-angle approximation, the equation for angular rotation as a function of rotation offset 410 can be as follows:

[0058] (Equation 3)

[0059] Each offset is a vector rotation offset distance 410 of the horizontal mark 308 or the vertical mark 312 in the X or Y direction; and α R It is the angular rotation error.

[0060] For example, a marker with an angular offset of 0.01° and a spacing of 100 micrometers will introduce an error of 17.5 nanometers. This amount of error can be calculated using trigonometry, lookup tables, and / or the like and used to adjust the overlay measurements.

[0061] Figure 4A It is an AIMid style overlay target 302 of four bare dies 204 according to one or more embodiments of this disclosure.

[0062] As shown, the stacking target 302 may include a measurement region 360 for measuring the stacking of each die 204. Each measurement region 360 can be used to determine a specific stacking measurement, such as a die stacking of a single die 204. Any number of measurement regions 360 may be used. For example, two or more measurement regions 360 may be used. For example, four or more measurement regions 360 may be used. Measurement regions 360 may include two or more measurement regions 360 corresponding to two or more dies 204. Measurement regions 360 may include four or more measurement regions 360 corresponding to four or more dies 204.

[0063] For example, the four measurement regions 360 may each overlap one another and use at least one shared substrate marker 304a to determine the stack pair. For example, the acquisition marker 306 at the center of the stack pair target 302 may be shared by the 2×2 overlap pattern of the measurement regions 360, as shown. The controller 122 may determine the stack pair of each die 204 based on the corresponding measurement region 360. For example, a single image of the stack pair target 302 may contain multiple measurement regions 360, as shown. Each measurement region 360 may be cropped to analyze the stack pair of the corresponding die 204.

[0064] In an embodiment, the stacking target 302 includes a die mark 304b, such as a die mark 310. For example, the die mark 310 may be used for each die 204.

[0065] In an embodiment, the stacking target 302 includes substrate markings 304a, such as substrate markings 306, 308, and 312. The substrate markings 304a may be characterized in that they are placed in a substrate region (e.g., a cleavage path of the auxiliary substrate 202, as shown) that is not obscured by the bare die 204 (i.e., does not overlap with it).

[0066] At least one substrate mark 304a of each measurement region 360 may be shared among multiple measurement regions 360. For example, a first-direction substrate mark 308 and a second-direction substrate mark 312 may be (or include) common marks shared between two dies 204 as shown (for the purpose of side-by-side stacking of adjacent dies 204). For example, the acquisition mark 306, the first-direction substrate mark 308, and the second-direction substrate mark 312 may all be shared.

[0067] A first-direction substrate mark 308 is aligned relative to die mark 310 or more die marks along a first direction (e.g., the X direction). A second-direction substrate mark 312 is aligned relative to die mark 310 or more die marks along the first direction (e.g., the Y direction). For example, the second direction may differ from the first direction, such as being orthogonal to each other (i.e., 90°). In this way, the side-by-side stack pairs (and rotational offsets) can be determined along two different axes (e.g., the X and Y directions).

[0068] In an embodiment, the stacking target 302 includes one or more (e.g., two or more) first-direction substrate markers 308, one or more (e.g., two or more) second-direction substrate markers 312, and an acquisition marker 306. For example, two numbers of first-direction substrate markers 308 (one on top of the other) can be used to measure the X-direction stacking of four dies, as shown.

[0069] Marker 304 can be configured in any layout.

[0070] For example, as shown, the stack target 302 may include a 3×3 grid of markings 304 for four dies 204 arranged in a 2×2 die configuration, wherein the space between each die 204 (e.g., substrate dicing) is used for substrate markings 306, 308, 312.

[0071] The center marker of the 3×3 grid of marker 304 may include (or be) an acquisition marker 306. Acquisition marker 306 may be configured to determine the rotational offset 410 of sample 104, such as... Figure 3C As shown in the figure. Each corner of the 3×3 grid marked 304 may contain a corresponding die mark 304b corresponding to the corresponding die 204.

[0072] A center marker (e.g., acquisition marker 306) can be configured to be shared among four or more measurement areas 360 corresponding to the die 204.

[0073] The acquisition mark 306 can be aligned along the first direction relative to the second direction substrate mark 312 and also along the second direction relative to the first direction substrate mark 304. In other words, the acquisition mark 306 can be below the mark 308 and to the left of the mark 312.

[0074] The mark 304 of the overlapping target 302 can be of any style. For example, the overlapping target 302 can contain at least one of the following: AIM style target (such as...) Figure 4D As shown, (including orthogonal gratings) or box-in-box style targets (such as...) Figure 4C As shown, this includes boxes within boxes. Other styles may include, but are not limited to, strip-within-a-strip style targets.

[0075] Figure 4B It is a transparent structure 326 on the bare die 204 according to one or more embodiments of this disclosure. Figure 4A The overlapping target 302.

[0076] For example, the overlay target 302 may include a transparent structure 326 in the bare die mark 310.

[0077] The first-direction die distance 402 and the second-direction die distance 404 can be used to determine corresponding overlay measurements, for example, by comparing such die distances 402, 404 with a expected (e.g., designed) distance. For example, the expected distance may be known based on the design of sample 104 and may correspond to the distance at which side-by-side markers 304 will be separated when perfectly positioned with zero overlay. For example, the difference between the (known) expected distance and the first-direction die distance 402 may correspond to (and / or be) the overlay measurement corresponding to die 204 in the corresponding direction (e.g., the X direction).

[0078] As mentioned above, obtaining the marker distances 406 and 408 can be used to determine the rotation offset 410 or similar.

[0079] Mark 304 can be used for on-axis determination. For example, the diagonal axial alignment of structure 326 (e.g., 45° angle) can be compared with the diagonal alignment of the marked point (e.g., 45° angle). The diagonal axial alignment of the structure of any of the marks 304 can, for example, be used to improve the accuracy of the rotational offset 410 error and can be based on... Figure 3C The center of marker 304 is compared side by side and Figure 4B The diagonal axis of the structure marked 304.

[0080] Figure 4C This describes a stacking target 302 of four bare dies 204 according to one or more embodiments of the present disclosure, wherein the bare dies 204 have a box-in-box transparent mark 310.

[0081] The region of interest 350 can be used to determine one or more parameters. For example, the region of interest 350 can be used to determine the center of symmetry, the spacing between structures 324 and 326, the vertical / horizontal alignment of each mark 304, and / or the like.

[0082] The markers 304 (e.g., all markers 304) may be characterized by a region of interest 350, which is positioned with 180° rotational symmetry about the center of the markers 304, as shown. For example, the center of symmetry of each marker 304 may be determined based on the region of interest 350. For example, any image processing algorithm may be configured to identify two regions of interest 350 (e.g., the right and left sides of a square box). The centers of the two regions of interest 350 on the left and right sides may be the center of symmetry of a single marker 304 in a first direction. This may be performed twice, for the region of interest in the first direction and the region of interest in the second direction. By another example, the region of interest may be a filled square (e.g., made of... Figure 4B (as shown in structure 324), and the center can be identified by calculating the center of the square (e.g., the center of the outer edge of the square).

[0083] Figure 4D It is a stacked target 302 of four bare dies 204 according to one or more embodiments of the present disclosure.

[0084] It should be noted that Figure 4D The markings contain grating structures, such as periodic gratings. Each set of gratings can correspond to the region of interest, 350.

[0085] Figure 5 It is a stacked target 302 of four bare pieces 204 without bare piece markings but having a critical dimension 504 measured from the edge 506 of the bare piece, according to one or more embodiments of the present disclosure.

[0086] The optical subsystem 102 can be configured for bright-field measurement, for example, in a bright-field configuration and used to determine the critical dimension 504 of the structure 502 of the stacked target 302. For example, Figure 5 The die 204 in the sample does not have any die markings. Pairing measurements (including die pairings of each die 204 in each direction) can be determined based on one or more critical dimensions 504. For example, a die pair in a first direction can be determined based on a first structure 502 according to the first direction substrate marking 304 and first critical dimensions 504 (CD1), (CD2) of the first die edge 506. Similarly, for a second direction, second critical dimensions (CD3), (CD4) can be determined based on a second structure of the second direction substrate marking and a second die adjacent to the first die edge 506. For example, the first critical dimensions 504 can be compared with expected critical dimensions based on a known design of sample 104, where the difference corresponds to a pair misalignment.

[0087] Figure 6 This is a side view of a stacked target 302 of three substrates (e.g., carrier substrate 202, first substrate 204a, second substrate 204b) stacked according to one or more embodiments of the present disclosure.

[0088] As shown, the methodology described herein can be applied to die-to-die (D2D) and / or die-to-wafer (D2W) samples 104. For example, the auxiliary substrate may be a base substrate (e.g., a carrier wafer) and / or one or more dies (stacked dies in a D2D configuration). In the D2D case, a substrate marker may be positioned on an auxiliary die 204a below die 204b. A second transparent marker structure 304d may be positioned below a first transparent marker structure 304c. In this way, three or more stacked substrates can be used with the methodology described herein.

[0089] Figure 7 This document describes a process flowchart of a method 700 for superimposing units of measurement according to one or more embodiments of this disclosure. It should be noted that the embodiments and implementation techniques previously described herein in the context of system 100 should be interpreted as extending to method 700. It should be further noted herein that the steps of method 700 may be implemented in whole or in part by system 100. However, it should be further understood that method 700 is not limited to system 100, as additional or alternative system-level embodiments may implement all or part of the steps of method 700.

[0090] In step 702, an image of the superimposed target 302 of sample 104 is acquired, wherein the image includes one or more measurement regions 360. For example, optical subsystem 102 may use detector 112 to capture / acquire / receive images of the superimposed target 302.

[0091] In step 704, based on the image from step 702, overlapping measurements corresponding to one or more measurement areas and one or more dies are determined. For example, overlapping measurements can be determined for each die 204 in a first direction and a second direction. For example, one or more methodologies described herein can be used, which may include, but are not necessarily limited to, a compact configuration of a single image corresponding to the overlapping measurement areas of the respective die 204 and the shared marker 304, combining weighted sums of side-by-side / transparent markers, or determining the overlapping based on adjustments for rotational offset errors.

[0092] In another step (not shown), the fabrication of sample 104 is controlled by one or more processes based on overlay measurements. This may involve adjusting process parameters (e.g., die placement parameters, optical frequency, intensity, or processing time) to minimize overlays. Adjustments can be made manually by an operator or automatically by the control system in response to overlay measurements. For example, if the overlay measurement is greater than a predetermined threshold, process parameters can be adjusted to reduce the overlay. Conversely, if the overlay measurement is less than the threshold, process parameters can be kept constant or adjusted to slightly reduce the overlay to keep it within an optimal range. Such processes can include semiconductor fabrication, photolithography, and many others.

[0093] Refer again Figures 1A to 1BVarious components are described in more detail according to one or more embodiments of this disclosure.

[0094] One or more processors 124 of controller 122 may comprise any processor or processing component known in the art. For the purposes of this disclosure, the terms “processor” or “processing element” may be broadly defined to encompass any device having one or more processing or logic elements (e.g., one or more microprocessor devices, one or more application-specific integrated circuit (ASIC) devices, one or more field-programmable gate arrays (FPGAs), or one or more digital signal processors (DSPs)). In this sense, one or more processors 124 may comprise any device configured to execute algorithms and / or instructions (e.g., program instructions stored in memory). In embodiments, one or more processors 124 may be embodied as a desktop computer, mainframe computer system, workstation, graphics computer, parallel processor, networked computer, or any other computer system configured to execute a program configured to operate with or in conjunction with operating system 100, as described throughout this disclosure. Furthermore, different subsystems of system 100 may include processors or logic elements suitable for implementing at least a portion of the steps described in this disclosure. Therefore, the foregoing description should not be construed as limiting the embodiments of this disclosure, but is merely illustrative. Furthermore, the steps described throughout this disclosure can be implemented by a single controller or alternatively by multiple controllers. Additionally, controller 122 may comprise one or more controllers housed within a common housing or multiple housings. In this manner, any controller or combination of controllers can be individually packaged as a module suitable for integration into system 100. Furthermore, controller 122 can analyze or otherwise process data received from one or more detectors 112 and feed the data to additional components within or outside system 100.

[0095] Furthermore, memory device 126 may include any storage medium known in the art suitable for storing program instructions executable by one or more associated processors 124. For example, memory device 126 may include non-transitory memory media. As additional examples, memory device 126 may include, but is not limited to, read-only memory, random access memory, magnetic or optical memory devices (e.g., magnetic disks), magnetic tape, solid-state drives, and the like. It should be further noted that memory device 126 may be housed together with one or more processors 124 in a common controller housing.

[0096] In this regard, controller 122 may perform any of the various processing steps associated with overlay measurements. For example, controller 122 may be configured to generate control signals to guide or otherwise control optical subsystem 102 or any of its components. For example, controller 122 may be configured to receive signals corresponding to an image from one or more detectors 112. By another example, controller 122 may generate one or more correctable terms for additional manufacturing tools based on overlay measurements from optical subsystem 102, as feedback and / or feedforward control of one or more additional manufacturing tools.

[0097] In addition, the controller 122 may calibrate or otherwise modify the overlay measurement based on known, assumed, or measured characteristics of the sample 104 that may also affect the image (e.g., but not limited to sidewall angles or other sample asymmetries).

[0098] Refer again Figure 1B Various components of the optical subsystem 102 are described in more detail according to one or more embodiments of the present disclosure.

[0099] In one embodiment, the lighting subsystem 106 includes a lighting source 128 configured to generate at least one lighting beam 108. The lighting from the lighting source 128 may include light of one or more selected wavelengths, including, but not limited to, ultraviolet (UV) radiation, visible light radiation, or infrared (IR) radiation.

[0100] The illumination source 128 may comprise any type of illumination source suitable for providing at least one illumination beam 108. In an embodiment, the illumination source 128 is a laser source. For example, the illumination source 128 may comprise, but is not limited to, one or more narrow-band laser sources, broadband laser sources, supercontinuum laser sources, white light laser sources, or the like. In this respect, the illumination source 128 may provide an illumination beam 108 with high coherence (e.g., high spatial coherence and / or temporal coherence). In an embodiment, the illumination source 128 comprises a laser sustained plasma (LSP) source. For example, the illumination source 128 may comprise, but is not limited to, an LSP lamp, an LSP bulb, or an LSP chamber suitable for housing one or more elements that emit broadband illumination when excited into a plasma state by a laser source.

[0101] In an embodiment, the illumination subsystem 106 includes one or more optical components adapted to modify and / or adjust the illumination beam 108 and guide the illumination beam 108 to the sample 104. For example, the illumination subsystem 106 may include one or more illumination lenses 130 (e.g., to collimate the illumination beam 108, to relay illumination of the pupil plane 120 and / or the field plane 132, or the like). In an embodiment, the illumination subsystem 106 includes one or more illumination control optics 134 to shape or otherwise control the illumination beam 108. For example, the illumination control optics 134 may include, but are not limited to, one or more field stops, one or more pupil stops, one or more polarizers, one or more filters, one or more beam splitters, one or more diffusers, one or more equalizers, one or more apodizers, one or more beam shapers, or one or more mirrors (e.g., static mirrors, translation mirrors, scanning mirrors, or the like).

[0102] The collection subsystem 110 may include one or more optical elements adapted to modify and / or adjust the collected light 138 from the sample 104. In one embodiment, the collection subsystem 110 includes one or more collection lenses 140 (e.g., barrel lenses 140). In another embodiment, the collection subsystem 110 includes one or more collection control optics 142 to shape or otherwise control the collected light 138. For example, the collection control optics 142 may include, but is not limited to, one or more field stops, one or more pupil stops, one or more polarizers, one or more filters, one or more beam splitters, one or more diffusers, one or more equalizers, one or more apodizers, one or more beam shapers, or one or more mirrors (e.g., static mirrors, translation mirrors, scanning mirrors, or the like). In another example, the collection subsystem 110 may include one or more collection field planes 150.

[0103] Refer again Figure 1A It should be noted in this document that one or more components of system 100 may be communicatively coupled to various other components of system 100 in any manner known in the art. For example, one or more processors 124 may be communicatively coupled to each other and to other components via wired connections (e.g., copper wires, optical fibers, and the like) or wireless connections (e.g., RF coupling, IR coupling, WiMax, Bluetooth, 3G, 4G, 4G LTE, 5G, and the like). By another example, controller 122 may be communicatively coupled to one or more components of optical subsystem 102 via any wired or wireless connection known in the art.

[0104] In embodiments, one or more processors 124 may comprise any one or more processing elements known in the art. In this sense, one or more processors 124 may comprise any microprocessor-type device configured to execute software algorithms and / or instructions. In embodiments, one or more processors 124 may comprise a desktop computer, mainframe computer system, workstation, graphics computer, parallel processor, or other computer system (e.g., a networked computer) configured to execute a program of operating system 100, as described throughout this disclosure. It should be understood that the steps described throughout this disclosure may be implemented by a single computer system or alternatively by multiple computer systems. Furthermore, it should be understood that the steps described throughout this disclosure may be implemented on any one or more of the one or more processors 124. Generally, the term "processor" may be broadly defined to encompass any device having one or more processing elements that execute program instructions from memory 126. Additionally, different subsystems of system 100 may include processors or logic elements suitable for implementing at least a portion of the steps described throughout this disclosure. Therefore, the above description should not be interpreted as a limitation of this disclosure, but is merely illustrative.

[0105] Those skilled in the art will recognize that, for clarity of concept, the components (e.g., operations), apparatuses, objects, and accompanying discussions described herein are used as examples, and various configuration modifications are carefully considered. Therefore, the specific examples and accompanying discussions used herein are intended to represent their more general categories. In general, the use of any specific example is intended to represent its category, and the omission of specific components (e.g., operations), apparatuses, and objects should not be considered limiting.

[0106] Those skilled in the art will understand that various vehicles exist that can be used to implement the processes and / or systems and / or other technologies (e.g., hardware, software, and / or firmware) described herein, and the preferred vehicle will vary depending on the environment in which the process and / or system and / or other technology is deployed. For example, if the implementer determines that speed and accuracy are of utmost importance, then the implementer may choose a primary hardware and / or firmware vehicle; alternatively, if flexibility is of utmost importance, then the implementer may choose a primary software implementation; or, alternatively, the implementer may choose a combination of hardware, software, and / or firmware. Thus, there are several possible vehicles that may affect the processes and / or apparatus and / or other technologies described herein, none of which are inherently superior to another, because any vehicle to be used depends on the environment in which the vehicle will be deployed and the implementer's specific concerns (e.g., speed, flexibility, or predictability), and thus any of these can vary.

[0107] The foregoing description is presented to enable those skilled in the art to make and use the invention as provided in the context of a particular application and its requirements. Those skilled in the art will appreciate various modifications to the described embodiments, and that the general principles defined herein may be applied to other embodiments. Therefore, the invention is not intended to be limited to the specific embodiments shown and described, but is to be accorded the broadest scope consistent with the principles and novel features disclosed herein.

[0108] Regarding the use of substantially any plural and / or singular terms in this document, those skilled in the art can convert them from plural to singular and / or from singular to plural depending on the context and / or application. For clarity, various singular / plural substitutions are not explicitly described herein.

[0109] All methods described herein may include storing the results of one or more steps of the method embodiments in memory. The results may include any of the results described herein and may be stored in any manner known in the art. The memory may include any memory described herein or any other suitable storage medium known in the art. After the results have been stored, they may be accessed in memory and used by any of the method or system embodiments described herein, formatted for display to a user, used by another software module, method, or system, and the like. Furthermore, the results may be stored “permanently,” “semi-permanently,” “temporarily,” or for a period of time. For example, the memory may be random access memory (RAM), and the results may not necessarily be stored in memory indefinitely.

[0110] Upon further careful consideration, each of the embodiments of the methods described above may include any other step of any other method described herein. Furthermore, each of the embodiments of the methods described above may be performed by any of the systems described herein.

[0111] The objectives described herein sometimes refer to different components contained within or connected to other components. It should be understood that such depicted architectures are illustrative only, and many other architectures can in fact be implemented to achieve the same functionality. Conceptually, any arrangement of components used to achieve the same functionality is effectively “associated” to achieve the desired functionality. Therefore, any two components combined herein to achieve a particular functionality can be considered as “associated” with each other to achieve the desired functionality, regardless of the architecture or intermediate components. Similarly, any two such associated components can also be considered as “connected” or “coupled” with each other to achieve the desired functionality, and any two components that can be suchly associated can also be considered as “coupleable” with each other to achieve the desired functionality. Specific examples of coupleability include (but are not limited to) components that can physically cooperate and / or physically interact and / or wirelessly interact and / or logically interact and / or logically interact.

[0112] Furthermore, it should be understood that the invention is defined by the appended claims. Those skilled in the art will understand that, generally, the terms used herein and especially in the appended claims (e.g., the body of the appended claims) are intended to be “open-ended” terms (e.g., the term “including” should be interpreted as “including (but not limited to)”, the term “having” should be interpreted as “at least having”, the term “includes” should be interpreted as “including (but not limited to)”, and the like). Those skilled in the art will further understand that if a particular number of claims is desired to be introduced, this intention will be explicitly stated in the claims, and the absence of such a statement will not indicate this intention. For example, as an aid to understanding, the appended claims may contain the introductory phrases “at least one” and “one or more” to introduce the claims. However, the use of such phrases should not be construed as implying that introducing a claim statement with the indefinite article "a / an" limits any particular claim containing such an introductory claim statement to an invention containing only one such statement, even if the same claim contains the introductory phrase "a or more" or "at least one" and indefinite articles such as "a" or "an" (e.g., "a" and / or "an" should generally be interpreted as meaning "at least one" or "a or more"); the foregoing also applies to the use of definite articles used to introduce claim statements. Furthermore, even if a specific number of claim statements is explicitly stated, those skilled in the art will recognize that such a statement should generally be interpreted as meaning at least the number of stated statements (e.g., a bare statement of "two statements" (without other modifiers) generally means at least two statements or two or more statements). Furthermore, in examples where a convention similar to "at least one of A, B, and C and similar" is used, this construction is generally intended to be understood by a person skilled in the art as having the meaning of the convention (e.g., "a system having at least one of A, B, and C" would include (but is not limited to) systems having only A, only B, only C, both A and B, both A and C, both B and C, and / or both A, B, and C, and similar systems). In examples where a convention similar to "at least one of A, B, or C and similar" is used, this construction is generally intended to be understood by a person skilled in the art as having the meaning of the convention (e.g., "a system having at least one of A, B, or C" would include, but is not limited to, systems having only A, only B, only C, both A and B, both A and C, both B and C, and / or both A, B, and C, and similar systems). Those skilled in the art will further understand that any transition words and / or phrases presenting two or more alternatives, whether in the description, claims or drawings, should be understood to include the possibility of one, any, or both of the items.For example, the phrase “A or B” would be understood as including the possibility of “A” or “B” or “A and B”.

[0113] It is believed that this disclosure and its many accompanying advantages will be understood from the foregoing description, and it will be appreciated that various changes can be made to the form, construction, and arrangement of the components without departing from the disclosed object or sacrificing all its material advantages. The forms described are merely illustrative, and the appended claims are intended to cover and encompass such changes. Furthermore, it should be understood that the invention is defined by the appended claims.

Claims

1. A pair of overlapping targets, the pair of overlapping targets comprising: One or more measurement regions, each corresponding to a bare die, wherein each measurement region includes: One or more wafer markers, located on one or more wafers; and A substrate marker positioned on one or more substrates, wherein the substrate marker is not obscured by the one or more dies, wherein the substrate marker comprises: A first-direction substrate mark, which is aligned with a die mark along a first direction; and A second-direction substrate mark is aligned relative to the die mark along a second direction, wherein the second direction is different from the first direction.

2. The stacked target of claim 1, wherein the substrate mark in each measurement region further includes an acquisition mark, wherein the acquisition mark is aligned along the first direction relative to the second direction substrate mark and along the second direction relative to the first direction substrate mark.

3. The stacked target according to claim 2, wherein the one or more measurement regions comprise two or more measurement regions corresponding to two or more dies, wherein at least one substrate mark of each measurement region is shared among the multiple measurement regions.

4. The stacked target according to claim 3, wherein the two or more measurement areas include four or more measurement areas corresponding to four or more dies.

5. The stacked target of claim 4, wherein the at least one substrate mark shared among a plurality of measurement regions in each measurement region comprises: The acquisition marker; First direction substrate marking; and The second direction substrate marking.

6. The stacking target of claim 5, wherein the stacking target comprises a 3×3 grid configured for marking four dies arranged in a 2×2 configuration, wherein the space between each die is used for the substrate marking, wherein the center mark of the 3×3 grid of markings includes the acquisition mark, and wherein the center mark is configured to be shared among the four or more measurement areas corresponding to the four dies, wherein each corner of the 3×3 grid of markings includes a corresponding die mark of the corresponding die among the four or more dies.

7. The stacked target according to claim 1, wherein the stacked target is configured to be contained within a single field of view having a width and height of no more than 2000 micrometers.

8. The stacked target of claim 1, wherein the stacked target is configured to be contained within a single field of view having a width of no more than 600 micrometers.

9. The stacking target of claim 1, wherein the die marking of the die includes a transparent marking, the transparent marking being included in the die structure of the die above the substrate structure of the one or more substrates.

10. The stacked target of claim 1, wherein the stacked target comprises at least one of: an Advanced Imaging Metrics (AIM) style target or a box-in-box style target.

11. A superimposed system of weights and measures, comprising: Detector; and A controller, communicatively coupled to the detector and comprising one or more processors configured to execute program instructions, thereby causing the one or more processors to: Acquire an image of a sample stacking target, wherein the sample includes one or more dies corresponding to one or more substrates, wherein the stacking target includes: one or more measurement regions, each measurement region corresponding to a die, wherein each measurement region includes: one or more die markers positioned on one or more dies; and a substrate marker positioned on the one or more substrates, wherein the substrate marker is not obscured by the one or more dies, wherein the substrate marker includes: a first-direction substrate marker aligned with respect to the die marker along a first direction; and a second-direction substrate marker aligned with respect to the die marker along a second direction, wherein the second direction is different from the first direction. Based on the image, multiple stacked measurements corresponding to the one or more measurement areas and the one or more bare wafers are determined.

12. The stacked measurement system of claim 11, wherein the determination of the plurality of stacked measurements comprises: The rotational offset is determined based on the position of the acquired marker and the position of either the first-direction substrate marker or the second-direction substrate marker. The multiple stacked measurements are based on adjustments configured to take into account sample rotation based on the rotational offset.

13. The stacking measurement system of claim 12, wherein the die marking includes a transparent marking, the transparent marking comprising the die structure of the die above the substrate structure of the one or more substrates. The determination of the plurality of stacked measurements includes: Determine a side-by-side stacking pair between at least one of the substrate markings and the die marking; Based on the one or more bare film markings, a transparent stacking pair is determined; and The die stacking pairs are determined based on the side-by-side stacking pairs and the transparent stacking pairs.

14. The stacking measurement system of claim 13, wherein determining the die stacking pair based on the side-by-side stacking pair and the transparent stacking pair comprises: When determining the die stack pair, the transparent stack pair is weighted differently compared to the side-by-side stack pair.

15. The stacked measurement system of claim 13, wherein the controller is further configured to: The adjustment of the field of view of the superimposed measurement system is configured to observe the transparent marker; Obtain the transparent mark image; and Different adjustments to the field of view size are configured to observe the entirety of the stacked target.

16. The superimposed measurement system of claim 15, wherein the field of view of the superimposed measurement system is configured to be adjusted by adjusting the lens in the collection path of the superimposed measurement system.

17. A superimposed system of weights and measures, comprising: Optical subsystem; and A controller comprising one or more processors configured to execute program instructions, thereby causing the one or more processors to: Acquire an image emitted from the superimposed target of the sample, wherein the image includes one or more measurement regions. The sample includes one or more bare wafers corresponding to one or more substrates. The stacked targets include: The one or more measurement regions, each corresponding to a bare die, wherein each measurement region includes: A substrate marker, positioned on a substrate, wherein the substrate marker is not obscured by the one or more dies, wherein the substrate marker comprises: A first-direction substrate mark, which is offset along a first direction relative to the edge of the first die; and A second-direction substrate mark, offset relative to the edge of the second die along a second direction, wherein the second direction is different from the first direction, and Based on the image, multiple stacked measurements corresponding to the one or more measurement areas and the one or more bare wafers are determined.

18. The stacking measurement system of claim 17, wherein the optical subsystem is configured for the bright-field critical dimensions of the structure of the stacked target.

19. The stacked measurement system of claim 17, wherein the determination of the plurality of stacked measurements comprises: The first critical dimension is determined based on the first orientation substrate mark and the first structure of the first die edge; and The second critical dimension is determined based on the second orientation substrate marking and the second structure of the second die edge. The multiple stacking measurements are based on the first critical dimension and the second critical dimension.

20. A method comprising: Acquire an image of the sample superimposed on the target, wherein the image includes one or more measurement regions. The sample includes one or more bare wafers corresponding to one or more substrates. The stacked targets include: The one or more measurement regions, each corresponding to a bare die, wherein each measurement region includes: One or more wafer markers, located on one or more wafers; and A substrate marker, positioned on one or more substrates, wherein the substrate marker is not obscured by the one or more dies, wherein the substrate marker comprises: A first-direction substrate mark, which is aligned with a die mark along a first direction; and A second-direction substrate mark, aligned relative to the die mark along a second direction, wherein the second direction differs from the first direction. Based on the image, multiple stacked measurements corresponding to the one or more measurement areas and the one or more bare wafers are determined.

21. The method of claim 20, wherein the determination of the plurality of stacked measurements comprises: The rotational offset is determined based on the position of the acquired marker and the position of either the first-direction substrate marker or the second-direction substrate marker. The multiple stacked measurements are based on adjustments configured to take into account sample rotation based on the rotational offset.

22. The method of claim 21, wherein the die marking includes a transparent marking, the transparent marking comprising a die structure of the die above a substrate structure of the one or more substrates. The determination of the plurality of stacked measurements includes: Determine a side-by-side stacking pair between at least one of the substrate markings and the die marking; Based on the one or more bare film markings, a transparent stacking pair is determined; and The die stacking pairs are determined based on the side-by-side stacking pairs and the transparent stacking pairs.

23. The method of claim 22, wherein determining the die pair based on the side-by-side stack pair and the transparent stack pair comprises: When determining the die stack pair, the transparent stack pair is weighted differently compared to the side-by-side stack pair.

24. The method of claim 22, further comprising: The field of view size is adjusted to guide observation of the transparent marker; Receive the transparent mark image of the transparent mark; and Different adjustments to the field of view size are configured to observe the entirety of the stacked target.

25. The method of claim 24, wherein the field of view size is configured to be adjusted by adjusting the lens in the collection path of the stacked measurement system.

Images