System and method for die bonding with diffraction based alignment marks on the die

Abstract

A bonding detector system comprising a radiation sensor, one or more processors, instructions, or other components is described. The system comprises a radiation sensor configured to generate a signal based on a pattern of diffracted radiation received from a diffraction based alignment mark of a semiconductor die. The instructions cause the one or more processors to determine a position of the diffraction based alignment mark based on the signal; and generate, based on the position, a signal configured to cause alignment of the semiconductor die to a bonding location.

Description

SYSTEM AND METHOD FOR DIE BONDING WITH DIFFRACTION BASED ALIGNMENT MARKS ON THE DIECROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority of EP application 24174904.3 which was filed on May 8, 2024 and EP application 24192225.1 which was filed on August 1, 2024 which are incorporated herein in their entirety by reference.TECHNICAL FIELD

[0002] The present disclosure relates generally to a method and tool for die bonding.BACKGROUND

[0003] In manufacturing processes of integrated circuits (ICs), multiple finished or unfinished ICs (e.g., whole wafers, diced wafers, partially diced wafers, chips, die, etc.) may be placed in contact, stacked, bonded, or otherwise joined (e.g., to heterogeneous or homogeneous devices) at various points in the fabrication process. Heterogeneous integration, e.g., the integration of different circuits or other patterned devices, may rely upon joining of specific portions (for example, conductive contact elements) of multiple die — where these specific portions may be aligned in three-dimensional space to ensure functional connectivity. Alignment of these die, which may have multiple fabrication layers, different critical dimensions, different nodes, packaging, etc., with each other may require different techniques than used for lithography during fabrication. As the physical sizes of IC components continue to shrink, and their structures continue to become more complex, accuracy and throughput in integration become more important. For applications such as heterogeneous integration, it may be desirable to obtain both accurate and fast placement of die with respect to one another. In the context of semiconductor manufacture, improvements in die placement and alignment (e.g., improvements in heterogeneous integration) lead to improvements in IC manufacturing and integration abilities.SUMMARY

[0004] According to an embodiment, there is provided a bonding detector system comprising: a radiation sensor configured to generate a signal based on a pattern of diffracted radiation received from a diffraction based alignment mark of a semiconductor die; one or more processors; and instructions, when executed by the one or more processors, configured to cause the one or more processors to at least: determine a position of the diffraction based alignment mark based on the signal; and generate, based on the position, a signal configured to cause alignment of thesemiconductor die to a bonding location.

[0005] According to an embodiment, there is provided a semiconductor die comprising: a diffraction based alignment mark configured to receive incident radiation from a radiation source and generate a pattern of diffracted radiation, the pattern of diffracted radiation indicating a position of the diffraction based alignment mark, wherein the semiconductor die is configured to be aligned to a bonding location based on the position and the semiconductor die is to be bonded to the bonding location based on the alignment of the semiconductor die to the bonding location.

[0006] According to an embodiment, there is provided a bonding detector method comprising: generating, with a radiation sensor, a signal based on a pattern of diffracted radiation received from a diffraction based alignment mark of a semiconductor die; determining, with one or more processors, a position of the diffraction based alignment mark based on the signal; and generating, with the one or more processors, based on the position, a signal configured to cause alignment of the semiconductor die to a bonding location.

[0007] According to an embodiment, there is provided a method comprising: forming a diffraction based alignment mark in a semiconductor die, the diffraction based alignment mark configured to receive incident radiation from a radiation source and generate a pattern of diffracted radiation, the pattern of diffracted radiation indicating a position of the diffraction based alignment mark, wherein the semiconductor die is configured to be aligned to a bonding location based on the position and the semiconductor die is to be bonded to the bonding location based on the alignment of the semiconductor die to the bonding location.

[0008] According to another embodiment, a non-transitory, machine-readable medium is provided having instructions thereon, the instructions when executed by a processor being configured to perform a method as described herein.BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate one or more embodiments and, together with the description, explain these embodiments. Embodiments of the invention will now be described, by way of example only, with reference to the accompanying schematic drawings in which corresponding reference symbols indicate corresponding parts, and in which:

[0010] Figure 1A is a schematic diagram illustrating an exemplary die bonding method, according to one or more embodiments.

[0011] Figure IB is another schematic diagram illustrating the exemplary die bonding method, according to one or more embodiments.

[0012] Figure 1C is another schematic diagram illustrating the exemplary die bonding method, according to one or more embodiments.

[0013] Figure ID is another schematic diagram illustrating the exemplary die bonding method, according to one or more embodiments.

[0014] Figure 2A is a schematic diagram illustrating an example method of die placement, according to one or more embodiments.

[0015] Figure 2B is another schematic diagram illustrating an example method of die placement, according to one or more embodiments.

[0016] Figure 2C is another schematic diagram illustrating an example method of die placement, according to one or more embodiments.

[0017] Figure 2D is another schematic diagram illustrating an example method of die placement, according to one or more embodiments.

[0018] Figure 2E is another schematic diagram illustrating an example method of die placement, according to one or more embodiments.

[0019] Figure 2F is another schematic diagram illustrating an example method of die placement, according to one or more embodiments.

[0020] Figure 3A is a schematic diagram illustrating portions of an example system for die bonding, according to one or more embodiments.

[0021] Figure 3B is another schematic diagram illustrating portions of an example system for die bonding, according to one or more embodiments.

[0022] Figure 3C is another schematic diagram illustrating portions of an example system for die bonding, according to one or more embodiments.

[0023] Figure 3D is another schematic diagram illustrating portions of an example system for die bonding, according to one or more embodiments.

[0024] Figure 3E is another schematic diagram illustrating portions of an example system for die bonding, according to one or more embodiments.

[0025] Figure 3F is another schematic diagram illustrating portions of an example system for die bonding, according to one or more embodiments.

[0026] Figure 3G is another schematic diagram illustrating portions of an example system for die bonding, according to one or more embodiments.

[0027] Figure 3H is another schematic diagram illustrating portions of an example system for die bonding, according to one or more embodiments.

[0028] Figure 31 is another schematic diagram illustrating portions of an example system for die bonding, according to one or more embodiments.

[0029] Figure 3J is another schematic diagram illustrating portions of an example system for die bonding, according to one or more embodiments.

[0030] Figure 4 illustrates another example embodiment of the system shown in Figure 3A - 3J,according to one or more embodiments.

[0031] Figure 5 illustrates several example diffraction based alignment marks having various forms, shapes, and sizes, according to one or more embodiments.

[0032] Figure 6 is a flowchart which illustrates an exemplary method of donor die alignment and placement, according to one or more embodiments.

[0033] Figure 7 is a block diagram of an example computer system, according to one or more embodiments of the present disclosure.DETAILED DESCRIPTION

[0034] Embodiments of the present disclosure are described in detail with reference to the drawings, which are provided as illustrative examples of the disclosure so as to enable those skilled in the art to practice the disclosure. Notably, the figures and examples below are not meant to limit the scope of the present disclosure to a single embodiment, but other embodiments are possible by way of interchange of some or all of the described or illustrated elements. Moreover, where certain elements of the present disclosure can be partially or fully implemented using known components, only those portions of such known components that are necessary for an understanding of the present disclosure will be described, and detailed descriptions of other portions of such known components will be omitted so as not to obscure the disclosure. Embodiments described as being implemented in software should not be limited thereto, but can include embodiments implemented in hardware, or combinations of software and hardware, and vice-versa, as will be apparent to those skilled in the art, unless otherwise specified herein. In the present specification, an embodiment showing a singular component should not be considered limiting; rather, the disclosure is intended to encompass other embodiments including a plurality of the same component, and vice-versa, unless explicitly stated otherwise herein. Moreover, applicants do not intend for any term in the specification or claims to be ascribed an uncommon or special meaning unless explicitly set forth as such. Further, the present disclosure encompasses present and future known equivalents to the known components referred to herein by way of illustration.

[0035] Although specific reference may be made in this text to the manufacture of ICs, it should be explicitly understood that the description herein has many other possible applications. For example, it may be employed in the manufacture of integrated optical systems, guidance and detection patterns for magnetic domain memories, liquid-crystal display panels, thin-film magnetic heads, etc. The skilled artisan will appreciate that, in the context of such alternative applications, any use of the terms “wafer” or “die” in this text should be considered as interchangeable with the more general terms “substrate” and “target portion”, respectively. The term “wafer” may be used generally to refer to a large unit of manufacture (which may be the largest unit of manufacture), while the term “die” may be used to refer to a smaller unit of manufacture which may correspond to a lithography pattern, a portion of a lithography pattern, multiple lithography patterns, etc. A “die” may correspond to aportion of “wafer” — that is a “die” may be produced by dicing or otherwise dividing a “wafer”. The term “die” should be considered interchangeable with the term chip, chiplet, or other terms for IC divisions. A patterning device (for example, a lithography device) can comprise, or can form, one or more patterns, which may correspond to one or more die. The patterns can be generated utilizing CAD (computer-aided design) programs, based on a pattern or design layout, this process often being referred to as EDA (electronic design automation). As used throughout this application “or”, unless indicated otherwise, takes a non-exclusive meaning, e.g., encompassing both “and” and “or”. “Each”, “every”, “all”, “corresponding”, “individual” and other relational terms encompass substantially “each”, “every”, “all”, etc., including cases in which each, every, all, corresponding, individual, etc. may include relationship which are not one-to-one, or do not include every possible item. For example, every may exclude items, such as items determined to be defective during testing. Each may exclude items, such as edge items, which are not used. All may exclude items, such as excess items. Corresponding may not require that items correspond in an exactly one to one manner. For example, a first item may correspond to two of a second item or vice versa. In some cases, individual may refer to multiple of an item, such as each item A has individual item B, where an item A may have two of an item B.

[0036] Reference is now made to Figures 1A-1D, which are schematic diagrams illustrating an exemplary die bonding method consistent with embodiments of the present disclosure. The exemplary die bonding method is depicted in relation to a reference set of axes, which are consistent through the schematic illustrations. The reference axes are provided for ease of description only and are not to be taken as limiting. Included methods and apparatuses may instead be described with reference to a different set of axes (e.g., cylindrical coordinates, polar coordinates, etc.), a different origin point (e.g., an origin point in the donor die, an origin point in an acceptor, origin point in between the donor die and acceptor, etc.), or a different orientation. The reference set of axes is chosen such that the fabrication plane of the die (i.e., a substrate surface) lies in the x-y plane and where the fabrication direction is parallel or antiparallel to the z-axis for both the donor die and acceptor locations.

[0037] As shown in Figures 1A-1D, the exemplary die bonding method may involve a donor die 102 and an acceptor die 104, or more generally an acceptor location, or bonding location. An acceptor location, or bonding location may be any location on a given layer, which can include an interposer layer. This includes instances where multiple dies are stacked on top of each other. Depending on the process flow, one may want to start with, for example, the wafer, and then stack dies of different sizes to different heights (e.g., like a city skyline). Another way may be to build the stacks first, and then add the stacks onto the die. Or a combination of the two, first make partial stacks, then add them to the wafer, and finally add the finishing touches.

[0038] Herein, the term “donor” and the term “acceptor” are used for ease of description. It should be understood that the term “donor” and the term “acceptor” are provided for reference and are relative descriptions, and that elements described as corresponding to a “donor” can instead correspond to an“acceptor” and vice versa. Further, while just one donor die and acceptor die are depicted in Figure 1 A, it will be appreciated that there may be multiple such die and that multiple donor die may be essentially simultaneously bonded with multiple acceptor (bonding) locations, e.g., die where, for example, multiple die are still part of (all or part) a substrate in or on which they are formed.

[0039] The donor die 102 may have one or more electrically active areas 106 or other features on an alignment face of the donor die 102. The one or more electrically active areas may be conductive, formed from a material such as metal. The one or more electrically active areas may correspond to one or more vias (e.g., one or more through silicon vias (TSVs)), one or more electrical contact lines, one or more contact pads, one or more packaging pads, or other one or more electrically conductive areas.

[0040] The donor die 102 may have one or more electrically inert areas (for example, an electrically insulating area) outside of the one or more electrically active areas 106, such as on the alignment face of the donor die 102. The one or more electrically active areas 106 may be recessed (as shown) with respect to one or more other surfaces of the donor die 102. The one or more electrically active areas 106 may correspond to one or more contacts (e.g., to source, to drain, to gate, etc.) to one or more electrical devices within the donor die 102 (not shown). The acceptor die 104, likewise, may have one or more electrically active areas 108, which may have one or more similar properties to the one or more electrically active areas 106.

[0041] The donor die 102 may also or instead have one or more doped areas 110, such as on an alignment face of the donor die 102, recessed below the alignment face of the donor die 102, etc. While the term “doped” is used, it should be understood that the one or more doped areas 110 may be any areas which, through the course of fabrication, come to have one or more different electrical characteristics than the bulk of the substrate (e.g., silicon wafer). The one or more doped areas 110 may correspond to source, drain, gate, ground, or other areas of a circuit which is doped or otherwise altered (e.g., through implantation, oxide growth, thin fdm deposition, etc.) to have a different electrical characteristic than the bulk of the substrate. The one or more doped areas 110 may include one or more conductive layers (e.g., one or more highly doped or electrically conductive layers) or one or more insulative layers (e.g., one or more oxide layers). The donor die 102 may have one or more undoped areas (for example, an area where the substrate retains the characteristic of the bulk substrate) outside of the one or more doped areas 110, such as on the alignment face of the donor die 102. The one or more doped areas 110 may be recessed, buried, coplanar (as shown), etc. with respect to one or more other surfaces of the donor die 102. The one or more doped areas 110 may correspond to one or more regions (e.g., to one or more source regions, one or more drain regions, one or more gate regions, one or more dielectric regions, etc.) of one or more electrical devices within the donor die 102 or one or more regions which may form one or more electrical devices across both the donor die 102 and the acceptor die 104 once those die are bonded. The acceptor die 104, likewise, may have one or more doped areas 112, which may have one or more similar properties to the one or moredoped areas 110.

[0042] As shown in Figures 1 A and IB, the exemplary die bonding method may involve alignment of at least one of the electrically active areas 106 or doped areas 110 of the donor die 102 with at least one of the electrically active areas 108 or doped areas 112 of the acceptor die 104. The exemplary die bonding method may involve bringing the donor die 102 into contact with the acceptor die 104 while maintaining alignment between, e.g., one or more electrically active areas 106 and one or more electrically active areas 108 so that the one or more electrically active areas 106 and the one or more electrically active areas 108 may be joined for cross-die electrical communication. The exemplary die bonding method may involve aligning one or more doped areas 110 of the donor die 102 with one or more doped areas 112 of the acceptor die 104. Aligning may encompass bringing into contact, aligning one or more edges of various regions, having overlap, having non-overlap, or any other appropriate alignment scheme. The exemplary die bonding method may involve applying or maintaining pressure between the donor die 102 and the acceptor die 104, while bonding occurs between the donor die 102 and the acceptor die 104. The donor die 102 may be supported by a carrier 114, which may be a substrate which is transparent to a range of radiation (e.g., infrared radiation, a portion of the optical spectrum, etc.). The acceptor die 104 may likewise be supported by a carrier 116, which may or may not be transparent to a range of radiation. The alignment may be complicated by the multiple layers of the donor die 102 or the multiple layers of the acceptor die 104, which may be optically opaque.

[0043] Figures 1A and IB depict a cross-sectional view of portions of the exemplary die bonding method showing relative positioning between the donor die 102 and the acceptor die 104 (e.g., an acceptor location). As shown in Figure 1A, the donor die 102 and the acceptor die 104 may be brought together along the z-axis, while the position of the donor die 102 or the acceptor die 104 may be adjusted in the x-y plane (e.g., perpendicular to the z-axis of approach), such as to improve alignment between the donor die 102 and the acceptor die 104. As shown in Figure IB, alignment can be achieved between, e.g., one or more electrically active areas 106 and one or more electrically active areas 108 or between one or more doped areas 110 of the donor die 102 with one or more doped areas 112 of the acceptor die 104.

[0044] Once aligned, the donor die 102 and the acceptor die 104 are bonded together. In an embodiment, the bonding is a direct or fusion bonding (e.g., involving van der Waals forces). In an embodiment, the bonding is an intermolecular bonding, e.g., van der Waals bonding. In an embodiment, the bonding may include covalent, ionic, or metallic (e.g., chemical) bonding, e.g., hydrogen bonding. In an embodiment, the bonding is aided by a material (e.g., a suitable bonding or adhesive material) applied to an alignment surface of the donor die 102 or acceptor die 104 or provided to a gap between the donor die 102 and the acceptor die 104 (e.g., in the form of gas or liquid). In some embodiments, physical contact between the donor die 102 and the acceptor die 104 may include bonding, such as through a bonding wavefront generated by contact (or atomic levelproximity), such as of a surface prepared for hydrogen bonding.

[0045] As shown in Figure IB, the donor die 102 and the acceptor die 104 may be annealed after contact as depicted by the wavy lines (while wavy lines are shown here at both the donor die 102 and the acceptor die 104, the annealing agent need not be provided at both the donor die 102 and the acceptor die 102 nor needs to be applied in the direction(s) shown). Annealing may be or include heat annealing, electrical annealing, electrostatic processes, etc. In some embodiments, annealing may include annealing of in-plane (or prominent) regions that are bonded or annealing of one or more recessed areas which may increase the volume of fdl in a recess area (such as through thermal expansion, capillary force, etc.) and may cause physical contact and bonding of areas previously not in contact. As shown in Figure 1C, annealing may cause physical or chemical changes, such as in the one or more electrically active areas 106 of the donor die 102 or in the one or more electrically active areas 108 of the acceptor die 104, which may cause or improve physical contact or electrical contact between an electrically active area 106 and an electrically active area 108. Annealing may therefore produce or enhance electrical connectivity between elements of the donor die 102 and the acceptor die 104 (e.g., integration). This electrical connectivity may occur even if an electrically active area 106 and an electrically active area 108 differ — for example, have different recessed depths, are made up of different materials, have different dimensions, etc. In an embodiment, the prior bonding described with respect to Figure 1A may be temporary during one or more portions of the annealing process, wherein the annealing process forms tight connections between donor die 102 and the acceptor die 104. In an embodiment, the annealing may occur in the system where the bonding occurs. In an embodiment, the annealing may occur in a separate system from the system in which the bonding occurs, e.g., the donor and acceptor dies are transported out of the bonding system into an annealing system which can include one or more heating elements (e.g., one or more electrical heating elements, one or more elements to provide radiation heating, etc.) to provide the heat for the annealing.

[0046] Once the donor die 102 and the acceptor die 104 are bonded, the carrier 114 may be removed as shown in Figure IB. Additionally or alternatively, the carrier 116 may be removed as well. Alternatively, once the donor die 102 and the acceptor die 104 are annealed, the carrier 116 may be removed as shown in Figure 1C. Additionally or alternatively, the carrier 114 may be removed as well.

[0047] Figure ID depicts a plan view of an example die bonding method according to this disclosure. As shown in Figure ID, the donor die 102 or the acceptor die 104 (e.g., an acceptor location) may have one or more die alignment marks along the x-y plane to facilitate alignment of the die as a whole. A die alignment mark may be a diffraction based alignment mark, for example, or other types of marks. Alignment marks in the x-y plane of a die (e.g., one or more die (alignment) marks 120 on the donor die 102 or one or more die (alignment) marks 122 on the acceptor die 104) may reduce the area available for circuitry. One or more alignment marks may be placed in a waste area, such as an area between chips, which may then be destroyed (e.g., removed) during dicing. Dicing herein refersto mechanical separation of areas of a substrate (e.g., a unit of manufacture) into smaller areas (e.g., dies or chips) which may contain one or more units of operation (e.g., a logic device, a memory unit, etc.). Dicing may operate using any appropriate method — for example, scribing and breaking, mechanical sawing, laser cutting, etc. — and may destroy (e.g., grind to powder or otherwise render inoperable for circuitry placement) a non-zero linewidth portion of the substrate volume when separating die. Alignment marks may be additively or substractively fabricated, such as by etching or deposition in the z-direction. Alignment marks 120 and 122 may be the same or different. Alignment marks 120 and 122 may be a multi-directional alignment mark, i.e., capable of determining alignment in more than one direction, such as a bi-direction alignment mark, an example of which is shown as mark 120 in Figure ID. The alignment mark 120 or alignment mark 122 may be a fine alignment mark, such as for alignment in the pm scale. The alignment mark 120 may be located on the donor die 102 while the acceptor die 104 may have an alignment mark 122 located in a waste area, or vice versa. Alternatively or additionally, one or more electrically active or doped areas of the donor die 102 or one or more electrically active or doped areas of the acceptor die 104 (not shown in Figure ID) or other surface features may function as a reference for alignment (e.g., an alignment mark) of the donor die 102 or the acceptor die 104.

[0048] The donor die 102 and the acceptor die 104 may be aligned in up to three dimensions before or during contact between the donor die 102 and the acceptor die 104. For example, the donor die 102 or the acceptor die 104 may be positioned in the x-y plane as the donor die 102 in the acceptor die 104 are contacted. The donor die 102 or the acceptor die 104 may be positioned by operation of a die actuator or other die-scale elements, such as by piezoelectric stepper elements, or by operation of a chuck or other carrier structure-scale elements, such as by a motor or other actuator. The position of the donor die 102 or the acceptor die 104 may be adjusted with respect to up to six degrees of freedom. For example, given an origin point at a central part of the donor die 102, the donor die 102 may be positioned by movement along the X axis (e.g., in a positive or negative X direction), along the y-axis (e.g. in a positive or negative Y direction), along the z-axis (e.g., in a positive or negative Z direction). The donor die 102 may also be positioned rotationally with respect to each of those axes — e.g., rotated with respect to the x-axis, rotated with respect to the y-axis, rotated with respect to the z- axis. That is, the donor die 102 may be positioned by free movement in space accounted for by six different types of movement (where the movements listed above are provided as examples but where the movements may be described by other axes). Of course, the acceptor die 104 may be positioned alone or combined with positioning of the donor die 102. Positioning or adjustment of position herein, unless the context otherwise requires, includes displacement, rotation or any combination thereof.

[0049] In some embodiments, the donor die 102 and the acceptor die 104 may be measured with respect to a reference plane or structure (e.g., the X-Y plane), including with respect to the same reference plane or structure, but the donor die 102 or the acceptor die 104 may be flipped (before or after measurement) so that the fabrication surface of the donor die 102 and the fabrication surface ofthe acceptor die 104 may be bonded (see, e.g., the bottom diagram of Figure ID). The one or more alignment marks (e.g., the alignment marks 120 and 122) may be on the fabrication surface of the donor die 102 and the acceptor die 104, respectively. Once the donor die 102 or the acceptor die 104 is flipped, one or more alignment mark may be rendered invisible (such as due to opacity of a die) to an alignment measurement tool. The alignment of the flipped die may therefore be performed based on previously measured positions of the die (e.g., of the one or more alignment marks of the die) with respect to a structure, such as the donor die 102 with respect to carrier 114 or such as the acceptor die 104 with respect to the carrier 116.

[0050] Figures 2A-2F are schematic diagrams illustrating an example method of die placement. Figures 2A-2F are described with reference to “donor” (e.g., a “donor die”, a “donor substrate” comprising multiple “donor die”, or a “donor location” as a general term for any of these) and “acceptor” (e.g., an “acceptor die”, “acceptor substrate” comprising multiple “acceptor die”, or an “acceptor location”), which are relative descriptors and donor die may instead be acceptor die and vice versa. Figures 2A-2F are described with respect to donor die and acceptor die; but may instead be a donor substrate or acceptor substrate, where a “substrate” may comprise multiple “die”, including un-diced (e.g., unseparated) die in the form of all or part of a semiconductor wafer; or more generally a “donor” or “acceptor” location or other feature. Figure 2A-2F are cross-sectional views of die placement of donor dies (e.g., donor die 202A, 202B, 202C) on acceptor dies (e.g., acceptor die 204A and acceptor die 204B). In some embodiments, multiple steps which are depicted as occurring substantially simultaneously in Figures 2A-2F may be performed sequentially. In some embodiments, multiple steps which are depicted as occurring sequentially in Figures 2A-2F may be performed substantially simultaneously. In some embodiments, multiple donor dies may be aligned or placed on their respective acceptor dies substantially simultaneously, including donor dies which are proximate (including adjacent) or distant (e.g., non-adjacent but within the same acceptor substrate). In some embodiments, steps may be performed in a different order.

[0051] Figure 2A is a cross-sectional view of donor dies 202A-202C which are to be placed on acceptor dies 204A-204B (e.g., acceptor locations). The donor dies 202A-202C are supported by a carrier 214. The donor dies 202A-202C may be adhered to the carrier 214 in any appropriate manner, such as by vacuum adhesion, electrostatic adhesion, intermolecular adhesion, van der Waals adhesion, mechanical interlocking, surface reaction, static friction, gravitational force, etc. The donor dies 202A-202C may be adhered to the carrier 214 by use of, for example, an adhesive (e.g., glue), such as an organic, polymer glue. The carrier 214 may be a transparent substrate, such as glass, sapphire, polymer, etc. substrate. The donor dies 202A-202C may be placed on the carrier 214 by any appropriate method, such as by a pick and place tool. The carrier 214 may be supported by a chuck or any other appropriate support structure.

[0052] The acceptor dies 204A-204B (e.g., acceptor or bonding locations) are supported by a support structure 216. In an embodiment, the acceptor dies 204A-204B may be part of an undiced or partiallydiced acceptor wafer. The acceptor dies 204A-204B may be adhered to the support structure 216 in any appropriate manner, such as by vacuum adhesion, electrostatic adhesion, intermolecular adhesion, mechanical interlocking, surface reaction, static friction, gravitational force, etc. The acceptor dies 204A-204B may be adhered to the support structure 216 by use of, for example, an adhesive (e.g., glue), such as an organic, polymer glue. In an embodiment, where, for example, the acceptor dies 204A-204B are diced die, the support structure may be a carrier (e.g., like carrier 214) and may be a transparent substrate, such as glass, sapphire, polymer, etc. substrate. The acceptor dies 204A-204B may be placed on the support structure 216 by any appropriate method, such as by a pick and place tool. The support structure 216 may be, or may be supported by, a chuck or any other appropriate structure.

[0053] The donor dies 202A-202C and the acceptor dies 204A-204B may be aligned with one another at alignment points 203 A and 205A (for donor die 202A and acceptor die 204A), alignment points 203B and 205B (for donor die 202B and acceptor die 204B), and alignment points 203C and 205C (for donor die 202C and acceptor die 204B). In some embodiments, multiple donor die may be placed on a single acceptor die, and vice versa, such as depending on integration goals. The alignment points 203 A-203C are depicted for the donor dies 202A-202C, while the alignment points 205A-205C are depicted for the acceptor dies 204A-204B. These alignment points are provided for ease of description only and need not be physical features. There may be multiple alignment points per die. The alignment points may be alignment marks (for example, the diffraction based alignment marks of Figure ID), die edges, die corners, other features on edges or surfaces of die, a substrate, or other structures. The alignment points may be used to align donor and acceptor die or other substrates, such as by measurement of the locations of various alignment points and then adjustment of the position of the donor or acceptor die, such as by movement of a carrier supporting the die, to align an alignment point of the donor die with an alignment point of the acceptor die (or vice versa). The alignment points may be aligned directly to one another (e.g., as depicted in Figures 2A-2F). In some embodiments, the alignment points may be aligned relative to one another (e.g., in a predetermined relationship, such as separated by a vector), such as depicted in the bottom of Figure ID, where the alignment marks are non-overlapping.

[0054] In Figure 2 A, the carrier 214 (or the support structure 216 which forms a carrier) may be positioned, such as in the X-Y plane, in order to align the alignment point 203A of the donor die 202A with the alignment point 205A of the acceptor die 204A.

[0055] In Figure 2B, the donor die 202A may be released from the carrier 214 by any appropriate mechanism, such as release mechanism 230A. The donor die 202A meets the acceptor die 204A (e.g., an acceptor location) at alignment point 207A. The release of the donor die 202A may be facilitated by gravity, by electrostatic forces, by physical forces, radiation mediated release, etc. The alignment of the donor die 202A and the acceptor die 204A at the alignment point 207A (which represents a combination of the alignment point 203 A and the alignment point 205 A of Figure 2A) may beassisted by any appropriate alignment mechanism, including self-alignment (e.g., attraction of one area of the donor die 202A to a corresponding area of the acceptor die 204A). In an embodiment, the release occurs while donor die 202A is in (at least partial) contact with acceptor die 204A. In an embodiment, the release occurs before donor die 202A is in contact with the acceptor die 204 A.

[0056] In Figure 2C, the carrier 214 (and alternately or additionally the support structure 216 which forms a carrier) may be moved to bring another donor die (e.g., the donor die 202C) into alignment with another acceptor die or location (e.g., the acceptor die 204B). The alignment of alignment point 203C (of donor die 202C) and alignment point 205C (of acceptor die 204B) may be based on measurements of the relative positions of the alignment points (such as using a diffraction based alignment mark - e.g., 120 in Figure ID - or feature on a die or carrier structure, using a position of an alignment point on another donor or acceptor die, etc.). The alignment of alignment point 203C (of donor die 202C) and alignment point 205C (of acceptor die 204B) may be based on one or more substantially simultaneous measurement of the relative positions of an alignment point, such as using an alignment mark or feature of a die or carrier structure, using an alignment target or feature of another donor or acceptor die, etc. Although alignment of only one donor die (e.g., the donor die 202C) and acceptor die (e.g., the acceptor die 204B) is depicted, alignment of one or more sets of donor and acceptor dies or substrates may occur substantially simultaneously, such as if for a given relative position of the carrier 214 and the support structure 216 the alignment points of multiple donor dies are aligned with the alignment points of multiple acceptor dies. However, the ability to place multiple donor dies substantially simultaneously may depend on the placement of the donor dies on the carrier 214 and the ability of the release mechanism to release multiple donor dies.

[0057] In Figure 2D, the donor die 202C may be released from the carrier 214 by any appropriate mechanism, such as release mechanism 230C. The donor die 202C meets the acceptor die 204B at alignment point 207C. The release of the donor die 202C may be facilitated by gravity, by electrostatic forces, by physical forces, radiation mediated release, etc. The alignment of the donor die 202C and the acceptor die 204B (e.g., an acceptor location) at the alignment point 207C (which represents a combination of the alignment point 203C and the alignment point 205C of Figure 2A) may be assisted by any appropriate alignment mechanism, including self-alignment. In an embodiment, the release occurs while donor die 202B is in (at least partial) contact with acceptor die 204B. In an embodiment, the release occurs before donor die 202B is in contact with the acceptor die 204B.

[0058] In Figure 2E, the carrier 214 (and alternately or additionally the support structure 216 which forms a carrier) may be moved to bring another donor die (e.g., the donor die 202B) into alignment with another acceptor die (e.g., the acceptor die 204B). The alignment of alignment point 203B (of donor die 202B) and alignment point 205B (of acceptor die 204B) may be based on previous measurements of the relative positions of the alignment points (such as using an alignment mark on a die or carrier structure, using an alignment point on another donor or acceptor die, etc.). Thealignment of alignment point 203B (of donor die 202B) and alignment point 205B (of acceptor die 204B) may be based on one or more substantially simultaneous measurement of the relative positions of an alignment point, such as using an alignment mark or feature of a die or carrier structure, using an alignment target or feature of another donor or acceptor die, etc. As depicted, the donor die 202B and the donor die 202C are aligned to the same acceptor die (e.g., the acceptor die 204B). In some embodiments, the donor die are placed on the acceptor die in a substantially one-to-one relationship (e.g., as depicted for the donor die 202A and the acceptor die 204A). In some embodiments, multiple donor die (or acceptor die) may be placed on the same acceptor die (or donor die). In some embodiments, multiple donor die (or acceptor die) may be placed on un-diced (e.g., unseparated) acceptor die (or donor die), such as all or part of a substrate containing acceptor die (or donor die). In some embodiments, a donor die may be placed on a acceptor die that has multiple die, including stacked (e.g., bonded) die, such as in a three layer die bonding stack.

[0059] In Figure 2F, the donor die 202B may be released from the carrier 214 by any appropriate mechanism, such as release mechanism 230B. The donor die 202B meets the acceptor die 204B at alignment point 207B. The release of the donor die 202B may be facilitated by gravity, by electrostatic forces, by physical forces, radiation mediated release, etc. The alignment of the donor die 202B and the acceptor die 204B at the alignment point 207B (which represents a combination of the alignment point 203B and the alignment point 205B of Figure 2A) may be assisted by any appropriate alignment mechanism, including self-alignment. In an embodiment, the release occurs while donor die 202B is in (at least partial) contact with acceptor die 204B. In an embodiment, the release occurs before donor die 202B is in contact with the acceptor die 204B.

[0060] Figures 3A-3J are schematic diagrams illustrating portions of an example system 301 for die bonding (e.g., including a bonding detector system). Figures 3A-3J are described with reference to “donor” (e.g., a donor substrate or wafer, a donor die, etc.) and “acceptor” (e.g., a bonding location, an acceptor location, an acceptor substrate or wafer, an acceptor die, etc.), which are relative descriptors as used herein and donor may instead be acceptor and vice versa. Each of Figures 3 A, 3C, 3E, 3G, and 31 is a plane view of the system 301 during placement of donor die on an acceptor die (e.g., an acceptor or bonding location). Each of Figures 3B, 3D, 3F, 3H, and 3J is a cross-sectional view of the system 301 during placement of donor die on the acceptor die. The views of the system 301 in various figures represent different operations of the system 301, but operations depicted as occurring in different figures may occur at different times or may instead be performed simultaneously and operations depicted as occurring in the same figure may instead be performed individually or at different times. A donor substrate 300 and an acceptor substrate 350 are depicted as circular, but may instead be any appropriate shape, including rectangular, square, etc. The donor substrate 300 (and acceptor substrate 350) may be the substrate in or on which the donor die (or acceptor die) have been formed. The donor substrate 300 (or acceptor substrate 350) may be a “reconstructed wafer”, in which donor die (acceptor die) (or other disparate portions of asemiconductor substrate) are arranged or supported on a carrier, e.g., to be in position suitable for die bonding. So, the donor substrate 300 (acceptor substrate 350) may be a carrier and donor die (acceptor die), where the donor die (acceptor die) may be held (e.g., adhered) to the carrier by any appropriate method, such as by gravitational force, by adhesive (e.g., organic, polymer adhesive), by electrostatic forces, etc. The donor substrate 300 (acceptor substrate 350) may contain previously tested donor die (acceptor die), such as donor die (acceptor die) that passed a failure analysis or other post fabrication testing. The donor substrate 300 (acceptor substrate 350) may contain donor die (acceptor die) from the same or different semiconductor substrates (e.g., fabrication substrates), including donor die (acceptor die) of different types, different dimensions, etc. The donor substrate 300 (acceptor substrate 350) may have donor die (acceptor die) placed on the donor substrate 300 (acceptor substrate 350) by any appropriate method, such as a pick and place tool. The donor substrate 300 (acceptor substrate 350) may be supported, such as by a carrier structure, vacuum chuck, electrostatic chuck, etc., by either a top side (e.g., fabrication face) or backside (e.g., bulk substrate or carrier structure face) or by different faces at various points. The donor substrate 300 or donor die (acceptor substrate 350 or acceptor die) may have fabricated devices on multiple faces, such as through silicon vias (TSVs), contact pads, etc., such that both a top side and backside are fabrication faces.

[0061] In Figure 3A, the donor substrate 300 may be placed on a substrate chuck 320A. The substrate chuck 320 A may be an appropriate substrate chuck, such as to support the donor substrate 300 in the form of a semiconductor substrate or a carrier of the donor substrate 300. The substrate chuck 320A may be supported by a support structure 322A. The support structure 322A may be a moveable support structure, which may move in the X-Y plane, such as from a first position where the substrate chuck 320A receives the donor substrate 300 to a second position where the donor substrate 300 may be subjected to metrology. The substrate chuck 320A may comprise (e.g., support) one or more die actuators or other mechanical or electrical actuators which may move a donor die or the donor substrate 300 in one or more dimensions, including in the X-Y plane, in the Z-direction, rotationally, etc. The substrate chuck 320A may have one or more alignment marks, such as to allow a camera or other measurement system to track the position of the substrate chuck 320 A. The substrate chuck 320A may have multiple sets of alignment marks, such as coarse alignment marks or fine alignment marks. The substrate chuck 320A may move, such as by action of the support structure 322A, from one position to another, in free space, etc. The support structure 322A may be configured to move in multiple directions and in multiple scales (e.g., in a coarse step and a fine step), such as by multiple motors or steppers. The support structure 322A may be activated by a controller of the example system 301 — where the controller or processor system of the example system 301 (not depicted in Figures 3 A - 3J, but which may be formed by or included in the computer system CS shown in Figure 7 and described below) may also control the placement of the donor substrate 300 on the substrate chuck 320A and other operations described herein.

[0062] The substrate chuck 320A may have a measurement point (or alignment point), such asidentified by a cruciform measurement mark 327 and a round zero measurement mark 328, which are provided merely as examples and where any appropriate zero measurement mark may be used. The measurement point may be used to place the donor substrate 300 on the substrate chuck 320A, such as during movement of the substrate onto the chuck (for example, by insertion of the donor substrate by a substrate handler). The measurement point may be used to measure relative positions of the donor die of the donor substrate 300 once the donor substrate 300 is placed on the substrate chuck 320A. The placement of the donor die may be measured, such as with up to nm precision, with respect to the measurement point. The measurement of the position of the donor die after their placement may be obtained from any appropriate measurement system, such as optical microscopy, reflectometry, etc.

[0063] Figure 3A also depicts a further substrate chuck 320B on a support structure 322B. The substrate chuck 320B may be any appropriate substrate chuck, such as substantially identical to the substrate chuck 320A. The support structure 322B may be any appropriate support structure, such as substantially identical to the support structure 322A. In some embodiments, the substrate chuck 320B and the substrate chuck 320A may be substantially indistinguishable. In some embodiments, the support structure 322B and the support structure 322A may be substantially indistinguishable.Although two substrate chucks and two support structures are depicted, in some embodiments more or less substrate chucks and support structures may be present in the system 301. Operations depicted as performed by the substrate chuck 320B (substrate chuck 320A) may instead or additionally be performed by any appropriate substrate chuck. Likewise, operations depicted as performed by the support structure 322B (support structure 322A) may instead or additionally be performed by any appropriate support structure.

[0064] Figure 3A also depicts flipper 330. The flipper 330 may be any appropriate apparatus in system 301 which may flip a substrate (e.g., donor substrate 300), such as about the longitudinal axis or plane of the donor substrate 300 depicted in Figure 3 A. The flipper 330 will be described in more detail in reference to Figures 3E and 3F.

[0065] In Figure 3B, a cross-sectional view of a donor substrate 300 is depicted. The donor substrate 300 comprises a carrier 314 which supports one or more donor die (e.g., donor die 302A-302C). The substrate may have one or more alignment points, such as alignment point 315, used to measure a relative position of the donor die 302A-302C with respect to the carrier. The donor die may have alignment points, such as alignment points 303A-303C for donor die 302A-302C, respectively. The alignment points are provided as schematic representations in these drawings for ease of description, and may be any appropriate alignment points, including diffraction based or other alignment marks, fabricated features, edge features, etc., as previously described. While the donor substrate 300 is on a substrate chuck (e.g., the substrate chuck 320A of Figure 3 A), the positions of the donor die (e.g., the donor die 302A-302C) are measured, such as by metrology tool 340 A. The positions may be measured as absolute positions, relative positions, positions relative to other die, positions relative to an alignment point of the substrate, etc. The measured positions may be stored by a controller (orsensor system, which may be formed by or included in the computer system shown in Figure 7 and described below) of the system 301, such as for later positioning of the donor substrate 300. The metrology tool 340A may include an optical sensor such as a diffracted radiation sensor, a camera, including a still camera, a video camera, etc., or other optical sensors. The metrology tool 340A may include a radiation source 341 A, such as a laser as one example, configured to irradiate an alignment mark with radiation, or other components. The metrology tool 340A may include a radiation sensor 343A or other similar sensors. The metrology tool 340A may include a capacitive sensor or other similar sensors. The metrology tool 340A may be any appropriate tool for measurement of a position of a donor die, measurement of a position of an alignment point of the donor die, measurement of a position of (a diffraction based) alignment mark of the donor die, etc.

[0066] In Figure 3C, the donor substrate 300 is supported by the substrate chuck 320A, which is supported by the support structure 322A. Once the position of the donor dies are measured, the substrate chuck 320A may be moved, such as out of the measurement position. The support structure 322A may move (e.g., along direction 324) to the position of the support structure 322B, while the support structure 322B may move (e.g., along direction 323) to the position of the support structure 322A. The positions are provided as examples, and the support structures may move to different positions. For example, in some embodiments, the support structure 322B may move to a loading position, such as to receive an acceptor substrate (e.g., the acceptor substrate 350). The substrate chuck 320A may then occupy another position in the system 301 (e.g., a bonding position, a flipping position, etc.). The position the substrate chuck 320A moves to after measurement of the positions of the donor die (e.g., after the measurement depicted in Figure 3B) may be configured to allow the flipper 330 to accept the donor substrate 300 from the substrate chuck 320A.

[0067] In Figure 3D, the movement of the donor substrate 300 to a position other than the measurement position of Figure 3B is depicted. The movement may correspond to the movement of the donor substrate 300 in the direction 324, such as by movement of the support structure 322A, of Figure 3C. This figure is provided to show continuity of the die bonding process in both plane and cross-sectional views, but may occur substantially simultaneously with the process depicted in Figure 3C or Figure 3E, where, as previously described, steps which are depicted as occurring separately, including sequentially, may be performed substantially simultaneously.

[0068] In Figure 3E, the acceptor substrate 350 may be placed on a substrate chuck 320B. The substrate chuck 320B may be an appropriate substrate chuck, as previously described. The substrate chuck may be supported by a support structure 322B, which may be any appropriate support structure, as previously described.

[0069] In Figure 3E, the donor substrate 300 may be transferred to the flipper 330. The flipper 330 may accept (e.g., take) the donor substrate from the substrate chuck 320A, such as by use of edge clamps, vacuum clamps, finger prongs, etc. The flipper 330 may hold the donor substrate by one or more edges (e.g., one or more edges of the carrier 314) or one or more sides (for example, a backsideof the carrier 314 which does not support the donor die). The flipper 330 may rotate the donor substrate 300 upside down (e.g., with respect to the direction of the gravitational force). The flipper 330 may hold the donor substrate 300 upside down (e.g., opposite to) with respect to the X-Y plane which it previously occupied — or in any other appropriate direction. The flipper 330 may hold the donor substrate 300 or place the donor substrate 300 into a support structure, such that the donor substrate 300 faces the plane of the acceptor substrate 350. The flipper 330 may rotate or displace the donor substrate 300 in the X-Y plane, as well as displace or rotate the donor substrate 300 out of the X-Y plane. The flipper 330 may be any appropriate rotational or translational apparatus in the system 301.

[0070] In Figure 3F, a cross-sectional view of the acceptor substrate 350 is depicted. The acceptor substrate 350 comprises a carrier 316 which supports one or more acceptor dies (e.g., acceptor die 304A-304C). The substrate may have one or more alignment points, such as alignment point 317. The acceptor die may have alignment points, such as alignment points 305A-305C for acceptor die 304A- 304C, respectively. The alignment points are provided as schematic representations in these drawings for ease of description, and may be any appropriate alignment points, including (diffraction based) alignment marks, fabricated features, edge features, etc., as previously described. While the acceptor substrate 350 is on the substrate chuck (e.g., the substrate chuck 320B of Figure 3E), the positions of the one or more acceptor dies (e.g., the acceptor die 304A-304C) are measured, such as by metrology tool 340B. The metrology tool 340B may be the same as the metrology tool 340A used to measure the positions of the one or more donor dies (e.g., the donor die 302A-302C of Figure 3B) or a different metrology tool. For example, the metrology tool 340B may include a radiation source 34 IB, such as a laser as one example, configured to irradiate an alignment mark with radiation, or other components. The metrology tool 340B may include a radiation sensor 343A or other similar sensors. The metrology tool 340A may include a capacitive sensor or other similar sensors. The metrology tool 340B may measure a different number of positions, substantially different positions (e.g., arranged differently on the acceptor substrate than the positions on the donor substrate 300 as measured by the metrology tool 340A), different positions relative to dies (e.g., the donor die 302A-302C versus the acceptor die 304A-304C), etc. than the metrology tool 340 A. The positions may be measured as absolute positions, relative positions, positions relative to other die, positions relative to an alignment point of the substrate, etc. The measured positions may be stored by a controller (or sensor system, which may be formed by or included in the computer system shown in Figure 7 and described below) of the system 301, such as for later positioning of the acceptor substrate 350. The metrology tool 340B may include an optical sensor such as a camera, including a still camera, a video camera, etc., or other optical sensors. The metrology tool 340B may include a radiation source 341B, such as a laser as one example, configured to irradiate an alignment mark with radiation, or other components. The metrology tool 340B may include a radiation sensor 343B or other similar sensors. The metrology tool 340B may include a capacitive sensor or other similar sensors. The metrology tool 340B may beany appropriate tool for measurement of a position of a donor die, measurement of a position of an alignment point of the donor die, measurement of a position of alignment mark of the donor die, etc. The acceptor substrate 350 may experience deformation due to the holding by a substrate chuck, etc. The metrology tool 340B may also enable determination of deformation of the acceptor substrate by measuring locations. A controller may determine the deformation of the acceptor substrate 350 based on those measured locations (e.g., from curve fitting, using a physical deformation model, etc.).

[0071] In Figure 3F, the donor substrate 300 is supported by a bonding support structure 332. The bonding support structure 332 may be part of the flipper 330 (of Figure 3E) or the donor substrate 300 may be placed into the bonding support structure 332 by the flipper 330. The bonding support structure 332 may hold the donor substrate 300 opposite to a plane of the acceptor substrate 350. The bonding support structure 332 may hold the donor substrate by the carrier 314, including by one or more edges of the carrier 314. While in the bonding support structure 332, the position of the donor substrate 300 may be measured, such as by metrology tool 340C, to enable, for example, relative positioning between the donor substrate 300 and the acceptor substrate 350. The metrology tool 340C may be any appropriate metrology tool. The metrology tool 340C may measure locations of the donor die (e.g., the donor die 302A-302C), locations of the alignment point 315, etc. The metrology tool 340C may measure significantly fewer locations than the metrology tool 340A or 340B, and the controller may determine the position of the acceptor substrate 350 based on those fewer locations (e.g., from curve fitting, using physical deformation models, etc.). The controller may determine updated positions for the donor die (e.g., the donor die 302A-302C) based on a combination of the measured locations of the donor die 302A-302C (such as from Figure 3B) and the measured position of the donor substrate 300. The donor substrate 300 may experience deformation due to holding by a substrate chuck, the movement of the flipper 330, suspension from the bonding support structure 332, etc. The metrology tool 340C may also enable determination of deformation of the donor substrate by measuring locations. As noted above, the metrology tool 340C may measure significantly fewer locations than the metrology tools 340A and 340B, and the controller may determine the deformation of the donor substrate 300 based on those fewer locations (e.g., from curve fitting, using a physical deformation model, etc.) than those measured by the metrology tool 340A on the donor substrate 300 or by metrology tool 340B on the acceptor substrate 350.

[0072] In Figure 3G, the acceptor substrate 350 is supported by the substrate chuck 320B, which is supported by the support structure 322B. Once the position of the acceptor dies are measured, the substrate chuck 320B may be moved, such as to align with the donor substrate 300 supported by the flipper (e.g., supported by the bonding support structure 332 of Figure 3F). The support structure 322B may move (e.g., along direction 326) to the position of the support structure 322A, while the support structure 322A may move (e.g., along direction 325) to the position of the support structure 322B. The positions are provided as examples, and the support structures may move to different positions. For example, in some embodiments, the support structure 322A may move to a loadingposition, such as to receive an additional acceptor substrate (e.g., the acceptor substrate 350). The substrate chuck 320B may then occupy another position in the system 301 (e.g., a bonding position). The position the substrate chuck 320B moves to after measurement of the positions of the acceptor die (e.g., after the measurement depicted in Figure 3F) may be configured to place a donor die of the donor substrate 300 onto the acceptor die of the acceptor substrate 350. The substrate chuck 320B may be aligned with the donor substrate 300 in the flipper 330, which may be held above the plane of the substrate chuck 320B (as depicted in Figure 3G for a top down view in which the donor substrate 300 is at least partially above the plane of the substrate chuck 320B (e.g., obscuring the substrate chuck 320A).

[0073] In Figure 3H, the donor substrate 300 and the acceptor substrate 350 are aligned. The donor substrate 300 may be aligned to the acceptor substrate 350 by movement of the bonding support structure 332, such as in any of the directions or orientations 333. The acceptor substrate 350 may be aligned with the donor substrate 300 by movement of a substrate chuck (e.g., the substrate chuck 320B of Figure 3G) or the support structure (e.g., the support structure 322B of Figure 3G). The donor substrate 300 and the acceptor substrate 350 may be aligned to one another, including by both coarse and fine alignment, such as by alignment of the relative positions of one or more alignment point (e.g., the alignment point 315 of the donor substrate 300 and the alignment point 317 of the acceptor substrate 350). In some embodiments, the donor substrate 300 and the acceptor substrate 350 may be aligned, such as by coarse alignment. In some embodiments, once the donor substrate 300 and the acceptor substrate 350 are aligned, one or more donor die of the donor substrate 300 may be aligned with one or more acceptor die of the acceptor substrate 350. In Figure 3H, the alignment of the donor die 302B with the acceptor die 304B (e.g., of the alignment point 303 B of donor die 302B with the alignment point 305B of acceptor die 304B) is depicted. Once a donor die is aligned with a acceptor die, that donor die may be placed on the acceptor die, by any appropriate method, such as die actuator activation, gravitational acceleration, electrostatic actuation, etc.

[0074] In Figure 31, an additional donor substrate (e.g., donor substrate 300-2 having a carrier 314-2) is placed on the substrate chuck 320A for additional placement of donor dies on acceptor dies. In some embodiments, the additional donor substrate may be placed on the substrate chuck 320A after the substrate of the previous donor substrate is removed from the substrate chuck 320A — for example, if the substrate of a donor substrate is removed from the flipper 330 and re-placed on the substrate chuck 320A. In some embodiments, the previous donor substrate may be removed from the flipper 330 without recourse to the substrate chuck 320A, such as by removal from the flipper to an additional substrate chuck (not depicted) or any other appropriate removal procedure. The additional donor substrate may be placed on the substrate chuck 320A after the previous donor substrate is accepted by the flipper 330 or at any time when the substrate chuck 320A (or another substrate chuck) is free. The additional donor substrate (e.g., the donor substrate 300-2) may be substantially identical to or different from the previous donor substrate (e.g., the donor substrate 300). The processing of thedonor substrate 300-2 by placement of the donor dies on acceptor dies may proceed as previously described in relation to Figures 3A-3H, such as by placement on an additional acceptor substrate (not depicted). The donor substrate 300-2 may be placed on the substrate chuck 320A while the donor dies of the donor substrate 300 are placed on the acceptor dies of the acceptor substrate 350, such as substantially simultaneously.

[0075] In Figure 3J, the positions of the donor die (e.g., the donor die 302A-2 to 302C-2) or of mark 315-2 are measured, as previously described in relation to Figure 3B.

[0076] In Figure 3 J, additional donor die of the donor substrate 300 are placed on the acceptor die of the acceptor substrate 350. The position of the donor substrate 300, the acceptor substrate 350, or a combination thereof may be adjusted to align an additional donor die of the donor substrate 300 with a acceptor die of the acceptor substrate 350. As depicted, the donor substrate 300 is positioned (such as by movement in the directions or orientations 334) to align the alignment point 303A of the donor die 302 A with the alignment point 305 A of the acceptor die 304 A. The donor die 302 A may then be placed on the acceptor die 304 A by any appropriate method, such as previously described. The donor die 302B is depicted as bonded to the acceptor die 304B, subsequent to their alignment at alignment point 307B in Figure 3H. As will be realized, the various steps of Figures 3A-H can be repeated as appropriate to bond multiple dies and process multiple donor and acceptor substrates.

[0077] Figures 4-5 illustrate additional details of the system(s) and method(s) described above. Figures 4-5 illustrate using the determined position of a diffraction based alignment mark to generate, based on the position, a signal configured to cause alignment of a semiconductor die to a bonding location. This contrasts with die-to-wafer bonding tools that rely on image recognition to determine the position of donor and acceptor dies. Die-to-wafer bonding accuracy requirements are becoming more stringent, with required placement accuracy being down to 50 nm and below. Attempts at alignment with this accuracy by image recognition utilize extreme optical microscopy techniques ( these techniques use fluorescent molecules which would be difficult to add to dies for image recognition based die to wafer placement) that must be realized at high speed to enable economical throughput (which is extremely difficult). Using one, two, three, or more diffraction based alignment marks per die to determine a die’s (x, y, and Rz) position provides sub-nanometer bonding alignment accuracy at economical throughputs. This diffraction based alignment mark technique can be integral to a bonding detector system or method such as one or more of those illustrated in Figures 1A - ID, 2A - 2F, or 3A - 3J.

[0078] For example, Figure 4 illustrates another example embodiment of system 301 described above and shown in Figure 3A - 3J. In Figure 4, donor die 302A - 302C of the donor substrate 300 or carrier 314 are placed on the acceptor substrate 350. The position of the donor substrate 300, the acceptor substrate 350 (e.g., using bonding support structure 332 and / or a wafer stage 450 in this example), or a combination thereof may be adjusted to align donor die 302A-302C of the donor substrate 300. This may be accomplished using corresponding alignment points 303A-303C and305A-305C, for example. As depicted, the donor substrate 300 is positioned (such as by movement in the directions or orientations 334 shown in Figure 3J) to align the alignment point 303A of the donor die 302A with the alignment point 305A of the acceptor substrate 350. The donor die 302A may then be placed on the acceptor substrate 350 by any appropriate method, such as previously described. These steps can be repeated as appropriate to bond multiple dies and process multiple donor and acceptor substrates.

[0079] In this example, the alignment points 302A-302C (and 305A-305C) may be aligned using diffraction based alignment marks 120 (also shown in Figure ID). Note that in some embodiments, alignment points 302A-302C (and 305A-305C) may be the diffraction based alignment marks 120. As shown in Figure 4, diffraction based alignment marks 120 may lie along the x-y plane to facilitate alignment of a die. Diffraction based alignment marks 120 may be additively or subtractively fabricated, such as by etching or deposition in the z-direction. Diffraction based alignment marks 120 may be all the same or different. Diffraction based alignment marks 120 may each be a multidirectional alignment mark, i.e., capable of determining alignment in more than one direction, such as a bi-direction alignment mark, an example of which is shown as mark 120 in Figure ID and described above. The diffraction based alignment marks 120 may be fine alignment marks, such as for alignment in the pm scale, or course alignment marks. The diffraction based alignment marks 120 may be located on a front (acceptor facing) or back (carrier facing) side of a donor die 302A-302C. There may be one, two, three, or more diffraction based alignment marks 120 per donor die 302A- 302C, for example.

[0080] In some embodiments, at least two diffraction based alignment marks 120 are in a layer of a semiconductor donor die 302A, 302B, or 302C that faces a bonding location (alignment points 305 A- 305C in this example) during bonding, in a layer of the semiconductor die 302A, 302B, or 302C that faces away from the bonding location during bonding, or both (e.g., as shown in Figure 4). A bonding location may be or be on a semiconductor wafer (e.g., an example of substrate 300 described above), as shown in this example, may comprise another semiconductor die (e.g., an acceptor die) as described above, or may include other locations. In some embodiments, the diffraction based alignment marks 120 are spaced as far apart as possible in a semiconductor die 302A, 302B, or 302C. In some embodiments, diffraction based alignment marks 120 are spaced horizontally or vertically from each other in a semiconductor die 302 A, 302B, or 302C to facilitate scanning of at least two diffraction based alignment marks 120 in a single scan using the radiation sensor 343A (Figure 3J).

[0081] The positions of the donor die (e.g., the donor die 302A-302C) are measured, such as by metrology tool 340A (Figure 3J) using diffraction based alignment marks 120. The positions may be measured as absolute positions, relative positions, positions relative to other die, positions relative to an alignment point of the substrate 300, etc. The measured positions may be stored by a controller (or sensor system, which may be formed by or included in the computer system shown in Figure 7 and described below) of the system 301, such as for later positioning of the donor substrate 300. Themetrology tool 340A may include a radiation source 341A (Figure 3J), such as a laser as one example, configured to irradiate a diffraction based alignment mark 120 with radiation, or other components. The metrology tool 340A may include a radiation sensor 343 A (Figure 3 J) or other similar sensors.

[0082] For example, the radiation source 341 A (Figure 3J) is configured to irradiate a diffraction based alignment mark 120 with radiation. The radiation sensor 343A (Figure 3J) is configured to generate a signal based on a pattern of diffracted radiation received from the diffraction based alignment mark 120 (of semiconductor donor die 302A, 302B, and / or 302C). One or more processors (e.g., which may be included in a controller comprising a computer system - see Figure 7) are configured to determine a position of the diffraction based alignment mark 120 based on the signal; and generate, based on the position, a signal configured to cause alignment of the semiconductor die 302 A, 302B, and / or 302C to a bonding location. Bonding locations correspond to alignment points 305 A, 305B, and / or 305C in this example.

[0083] In this example, the radiation source 341 A (Figure 3J) may comprise a laser, a source of visible light, a source of UV light, and / or other light (e.g., level sensing is done with UV light (-100 to 200 nm), depending on the material one could also use near infrared or infrared (>1000 nm) light for the diffraction based measurements - this is important to view the mark facing the acceptor, Because one looks through structures in the thinned substrate.) A radiation source may be a laser, a lamp, a diode, an LED, etc., and / or other sources. The radiation sensor 343A (Figure 3J) may comprise an interferometric microscopy detector, such as an interferometric microscope-based alignment sensor or other sensors. In some embodiments, the radiation sensor is configured to look “through” a (e.g., thinned) substrate or die with a diffraction based alignment mark 120. The requirement to look through the thinned substrate depends on whether the mark is on the front or on the back of the die. Looking through the die is more difficult compared to having the mark on the backside, but both options are contemplated. The radiation source 341 A projects or otherwise irradiates radiation onto a diffraction based alignment mark 120. The radiation may have one or more intensities or colors of light radiation, or other characteristics. The redirected (by a diffraction based metrology mark 120) radiation is passed to the radiation sensor 343A such as a spectrometer detector and / or other sensors, which measures a spectrum (intensity as a function of wavelength) of the specular reflected and / or diffracted radiation. The radiation sensor 343A generates a metrology signal conveying alignment data and / or other data indicative of properties of the reflected radiation.Typically, to obtain a diffraction spectrum that is free of interference from surrounding structures, the diffraction based alignment mark 120, in an embodiment, comprises one or more periodic structures (e.g., gratings) larger than the width (e.g., diameter) of a radiation spot. The width of the spot may be smaller than the width and length of the diffraction based alignment mark 120. The diffraction based alignment mark 120, in other words, is ‘underfilled’ by the radiation, and the diffraction signal is essentially free from any signals from product features and the like outside the diffraction based alignment mark 120 itself.

[0084] Detecting such radiation comprises detecting intensity (amplitude) and / or phase shifts in (diffracted) radiation received from one or more geometric features of the diffraction based alignment mark 120. The one or more phase and / or amplitude shifts correspond to one or more dimensions of a feature. For example, the phase and / or amplitude of reflected radiation from one side of a feature is different relative to the phase and / or amplitude of reflected radiation from another side of the feature. Detecting the one or more phase and / or amplitude (intensity) shifts in the radiation from the metrology mark comprises measuring local phase shifts (e.g., local phase deltas) and / or amplitude variations that correspond to different portions of a diffraction based alignment mark 120. For example, the radiation from a specific area of a mark may comprise a sinusoidal waveform having a certain phase and / or amplitude. The radiation from a different area of the mark may also comprise a sinusoidal waveform, but one with a different phase and / or amplitude. Detecting radiation also comprises measuring a phase and / or amplitude difference in radiation of different diffraction orders. Detecting the one or more local phase and / or amplitude shifts may be performed using Fourier transformations, Hilbert transformations, for example, and / or other techniques. Interferometry techniques and / or other operations may be used to measure phase and / or amplitude differences in reflected radiation of different diffraction orders.

[0085] The signal generated by radiation sensor 343A (Figure 3J) comprises an electronic signal that represents and / or otherwise corresponds to the radiation from a diffraction based alignment mark 120 (or marks). The metrology signal may indicate a position of a mark 120, for example, or other information. Generating the metrology signal comprises sensing the radiation and converting the sensed radiation into the electronic signal. In some embodiments, generating the metrology signal comprises sensing different portions of the radiation from different portions and / or different geometries of a mark 120 (or marks) and combining the different portions of the sensed radiation to form the signal.

[0086] In some embodiments, based on the signal from radiation sensor 343A (Figure 3J) the one or more processors (Figure 7) are configured to determine the position of the diffraction based alignment mark(s) 120 in a first planar dimension (e.g., x or y), determine the position of the diffraction based alignment mark in a first and second planar dimension (e.g., x and y), and / or determine a rotational position (e.g., Rx, Ry, Rz) of the diffraction based alignment mark. The one or more processors are configured to control bonding of the semiconductor die 302A-302C aligned to the bonding location (e.g., alignment points 305A-305C) based on the position(s) or other information (e.g., as described above).

[0087] In some embodiments, a semiconductor die 302A, 302B, or 302C comprises at least two diffraction based alignment marks 120. The radiation sensor 343A (Figure 3J) is configured to generate corresponding signals based on patterns of diffracted radiation received from the diffraction based alignment marks 120 and the one or more additional diffraction based alignment marks. The one or more processors (Figure 7) are configured to determine positions of the diffraction basedalignment marks 120 based on the corresponding signals; and generate, based on the positions, one or more signals configured cause alignment of the semiconductor die 302A, 302B, or 302C to a bonding location (e.g., corresponding alignment point 305 A, 305B, or 305C).

[0088] As described herein, a diffraction based alignment mark 120 may take many different forms, have different shapes, or have different sizes. For example, a diffraction based alignment mark 120 comprises a periodic structure. In some embodiments, a diffraction based alignment mark 120 comprises a grating. The periodic structure may repeat in two dimensions, for example. In some embodiments, one diffraction based alignment mark 120 comprises a first periodic structure that repeats in a first direction, and a second diffraction based alignment mark 120 comprises a second periodic structure that repeats in a second direction. The second direction is different than the first direction in this example. In some embodiments, the periodic structure of a diffraction based alignment mark 120 has a dimension of about 5 pm or less. In some embodiments, a diffraction based alignment mark 120 has an area of 10,000 square microns or less, 7000 square microns or less, or 4000 square microns or less. In some embodiments, a cross-wise dimension of the mark 120 is 160 pm or smaller, 100 pm or smaller, 50 pm or smaller, or 40 pm or smaller.

[0089] Figure 5 illustrates several example diffraction based alignment marks 120 having various forms, shapes, and sizes. Figure 5 illustrates examples of fine 500 and coarse 502 diffraction based alignment marks 120. Figure 5 also illustrates examples of uni-directional 504 and bi-directional 506 fine 500 diffraction based alignment marks 120. Uni-directional 504 fine 500 diffraction based alignment marks 120 may comprise a grating with lines running in a single direction (vertically in this example). Uni-directional 504 fine 500 diffraction based alignment marks 120 may have larger 510 (40 x 80 pm as one example) or smaller 512 (30 x 50 pm, or 40 x 50 pm as two examples) sizes, or other configurations. Bi-directional 506 fine 500 diffraction based alignment marks 120 may comprise a grating with lines running in multiple directions (at different angles, or in horizontal and vertical directions in these examples). Bi-directional 506 fine 500 diffraction based alignment marks 120 may have larger 520 (40 x 160 pm as one example) or smaller 522 and 524 (50 x 50 pm, or 40 x 40 pm as two examples) sizes, or other configurations. These marks 120 may be configured for radiation with certain characteristics (e.g., intensities, colors - see 522 versus 524, etc.) Coarse 502 diffraction based alignment marks 120 may be dual period marks, for example, or have other characteristics.

[0090] Though measurement prior to bonding is described in the examples above, note that some or all of these measurements may also or instead be carried out during bonding. For example, in some embodiments, determining the position(s) of the one or more semiconductor donor dies for bonding alignment may be performed separately from, and in advance of, bonding. However, in some embodiments, determining the position of the one or more semiconductor donor dies for alignment may be performed during bonding, for example when the one or more semiconductor donor dies approach the one or more corresponding acceptor locations.

[0091] Figure 6 is a flowchart which illustrates an exemplary method of alignment and placement of one or more semiconductor donor dies. Each of these operations is described in detail below. The operations of method 600 presented below are intended to be illustrative. In some embodiments, method 600 may be accomplished with one or more additional operations not described, or without one or more of the operations discussed. Additionally, the order in which the operations of method 600 are illustrated in Figure 6 and described below is not intended to be limiting. In some embodiments, one or more portions of method 600 may be implemented by one or more systems described herein, such as system 301 shown in Figure 3 A - 3 J and Figure 4, and described above, for example. In some embodiments, one or more portions of method 600 may be implemented (e.g., by simulation, modeling, etc.) in one or more processing devices (e.g., one or more processors or a processor system that forms, or forms part of computer system CS shown in Figure 7 and described below). The one or more processing devices may include one or more devices executing some or all of the operations of method 600 in response to instructions stored electronically on an electronic storage medium. The one or more processing devices may include one or more devices configured through hardware, firmware, or software to be specifically designed for execution of one or more of the operations of method 600, for example.

[0092] At an operation 610, a plurality of donor die locations are obtained. This comprises determining a position of one or more semiconductor donor dies relative to one or more carrier marks on a carrier of the one or more semiconductor donor dies. The donor die locations or position may be obtained via measurement of one or more positions of the donor dies along one or more dimensions. The donor dies may lie on or be part of a donor substrate (e.g., the carrier, a semiconductor substrate, etc.), and the locations of the plurality of donor dies may be obtained with respect to the marks on that donor substrate. The locations of the plurality of donor dies may be measured in-plane (e.g., in the x-y plane). The locations of the plurality of donor dies may also be measured via a first method in-plane and measured out of plane (e.g., in the Z direction) via a second method. For example, the locations of the plurality of donor dies may be measured based on one or more images in-plane. The locations of the plurality of donor dies may be obtained from a two-dimensional image, which may show locations of an edges or comer of a donor die with respect to positions on a support structure or on a die actuator. The locations of the plurality of donor dies may be obtained based on one or more features (for example, one or more electrically active areas) on an exposed surface of the donor die. These one or more features of the donor die may be used as an alignment mark or reference mark. In some embodiments, alignment marks may be included as exposed features of the donor die. The alignment marks may be specifically added for die bonding or may be alignment marks corresponding to previous fabrication steps. The plurality of donor die locations may be measured or obtained from storage.

[0093] For example, each of the one or more semiconductor donor dies may comprise one or more die marks (e.g., similar to or the same as what is shown in Fig. ID and described above). The one ormore die marks may comprise one or more features of a die, and the one or more carrier marks may comprise one or more features of the carrier used to determine the position of the one or more semiconductor donor dies relative to the one or more carrier marks. The one or more die marks and the one or more carrier marks may comprise the same or different types of mark. In some embodiments, for example, the one or more die marks or one or more carrier marks comprise one or more periodic marks, such as gratings. In some embodiments, the one or more die marks or one or more carrier marks comprise one or more alignment marks, one or more image based overlay marks, features of a die or carrier, or other marks.

[0094] In some embodiments, the one or more die marks comprise a diffraction based alignment mark configured to generate a pattern of diffracted radiation for a radiation sensor. The diffraction based alignment mark comprises a periodic structure, such as a grating, for example. The periodic structure may repeat in two dimensions, have a dimension of about 5 pm or less, or have other characteristics. In some embodiments, the diffraction based alignment mark has an area of 10,000 square microns or less, 7000 square microns or less, or 4000 square microns or less; or a cross-wise dimension of the mark is 160 pm or smaller, 100 pm or smaller, 50 pm or smaller, or 40 pm or smaller. In some embodiments, operation 610 comprises forming one or more diffraction based alignment marks in a semiconductor die (e.g., using lithography based semiconductor manufacturing operations or other operations).

[0095] In some embodiments, the position of the one or more semiconductor donor dies relative to the one or more carrier marks is determined by an optical sensor, a diffracted radiation sensor, a capacitive sensor, or other sensors. This sensor may be or be part of metrology tool 340A, 340B, or 340C (e.g., shown in Fig. 3A - 3J and described above), or other components of the systems described herein. For example, the one or more carrier marks may comprise a capacitive pattern, and the position of the one or more semiconductor donor dies relative to the one or more carrier marks may be determined by a capacitive sensor. In this example, the capacitive sensor and the capacitive pattern may be part of a capacitive sensing arrangement comprising the capacitive sensor, a capacitive pattern on a carrier or a donor die, or other components. In some embodiments, the carrier may comprise the capacitive sensor. The position of the carrier of the plurality of donor dies may be determined using the capacitive sensing arrangement, and the donor dies may be aligned to one or more corresponding acceptor locations for bonding based on the determined position (e.g., as described herein).

[0096] In some embodiments, the position of the one or more semiconductor donor dies relative to the one or more carrier marks is provided as a feedforward signal to a donor die or acceptor substrate positioning system (e.g., as described above with respect to Figures 1A-1D, 2A-2F, or 3A-3J).

[0097] At an operation 620, one or more corresponding acceptor die locations (e.g., acceptor locations) are obtained. The acceptor dies may lie on or be part of an acceptor substrate (e.g., a carrier, a semiconductor substrate, etc.), and the locations of the plurality of acceptor dies may be obtainedwith respect to that acceptor substrate. The locations of the plurality of acceptor die may be obtained in any appropriate method, including any of those described in reference to the operation 610.

[0098] At an operation 630, one or more donor dies are selected from the plurality of donor dies. The one or more donor dies may be selected based on position (e.g., along a row, along a column), displacement (e.g., donor die closest to an ideal position), thickness (e.g., thicker dies may be placed before thinner dies, including if donor dies include two or more types of dies), etc. A donor die may have a corresponding acceptor die, such as an acceptor die in a corresponding location on an acceptor substrate (e.g., acceptor die carrier structure). In some embodiments, an acceptor die may be selected, by any appropriate method, and a donor die selected based on its correspondence to the selected acceptor die. The one or more donor dies and the acceptor die(s) may be brought together such that a donor die and its corresponding acceptor die are separated by a distance which may be traversed by the die placement method. The donor die and acceptor die may be grossly aligned (e.g., coarse aligned), such as to within a threshold of coarse alignment. The donor die and acceptor die may be held in proximity by one or more substrates, chucks, actuators, adhesives, etc.

[0099] At an operation 640, the relative position between a selected donor die and a corresponding acceptor die is adjusted to have alignment between the donor die and the corresponding acceptor die. Adjusted includes cases in which locations are minimally or substantially not adjusted (e.g., after measurement or bringing into proximity), such as if a measured location corresponds to the acceptor location within a threshold. In an embodiment, the position of the donor die may be adjusted by action of a die actuator, a substrate holder, a chuck, etc. The position of the donor die may be adjusted by action of a substrate handling apparatus. The position of the donor die may be adjusted in one or more directions, such as in the X-Y plane. Alternatively or additionally to adjustment of the location of the donor die, the position of the acceptor die may be adjusted, by any appropriate method, such as any of those previously described. Adjustment of the relative position between the donor and acceptor die may include iterative measurement of donor or acceptor die location, including as adjustment occurs.

[0100] Adjustment of the location of the donor die may occur based on an alignment location for the donor die. The alignment location may be an acceptor (e.g., acceptor location) for placement of the donor die. An acceptor (e.g., acceptor location) may be obtained, such as at operation 620, from measurement of the acceptor die position. The acceptor may correspond to a location of the acceptor die. The acceptor may correspond to a plurality of locations on the acceptor die. The acceptor may be a position (e.g., a position in three dimensions such as along X, Y, and Z axes, positions in six directions such as along X, Y, and Z axes and with respect to angles of rotation about those axes, etc.). The acceptor may be a set of positions, for example two or more positions of or on an acceptor die to which areas of the donor die are to be bonded. Additionally or alternatively, adjustment of the location of the acceptor die may occur based on an alignment location for the acceptor die. The alignment location may be an acceptor (e.g., acceptor location) for placement of the donor die. An acceptor (e.g., acceptor location) may be obtained, such as at operation 610, from measurement of thedonor die position. The acceptor may correspond to a location of the donor die. The acceptor may correspond to a plurality of locations on the donor die.

[0101] As an alignment example, a radiation sensor may be configured to generate a signal based on a pattern of diffracted radiation received from a diffraction based alignment mark of a semiconductor die. The radiation may be generated from a radiation source such as a laser or other radiation sources. One or more processors (e.g., that are part of a controller or processor system) may be configured determine a position of the diffraction based alignment mark based on the signal; and generate, based on the position, a signal configured to cause alignment of the semiconductor die (e.g., a donor die) to a bonding (or acceptor) location (e.g., a semiconductor wafer, another semiconductor die, etc.). In some embodiments, the one or more processors determine the position of the diffraction based alignment mark in a first planar dimension, determine the position of the diffraction based alignment mark in a first and second planar dimension, and / or determine a rotational position of the diffraction based alignment mark; and control bonding of the semiconductor die aligned to the bonding location based on the position(s).

[0102] In some embodiments, the diffraction based alignment mark of the semiconductor die faces the bonding location during bonding. In some embodiments, the diffraction based alignment mark of the semiconductor die faces away from the bonding location during bonding.

[0103] In some embodiments, the semiconductor (donor) die comprises at least two diffraction based alignment marks, including the diffraction based alignment mark and one or more additional diffraction based alignment marks. The radiation sensor is configured to generate corresponding signals based on patterns of diffracted radiation received from the diffraction based alignment mark and the one or more additional diffraction based alignment marks; and the one or more processors determine positions of the diffraction based alignment mark and the one or more additional diffraction based alignment marks based on the corresponding signals; and generate, based on the positions, one or more signals configured cause alignment of the semiconductor die to the bonding location. Each diffraction based alignment mark of the at least two diffraction based alignment marks may comprises a periodic structure that repeats in two dimensions. In some embodiments, one diffraction based alignment mark of the at least two diffraction based alignment marks comprises a first periodic structure that repeats in a first direction, and a second diffraction based alignment mark of the at least two diffraction based alignment marks comprises a second periodic structure that repeats in a second direction, with the second direction being different than the first direction.

[0104] In some embodiments, the at least two diffraction based alignment marks are in a layer of the semiconductor die that faces the bonding location during bonding, in a layer of the semiconductor die that faces away from the bonding location during bonding, or both. The at least two diffraction based alignment marks may be spaced as far apart as possible in the semiconductor die. In some embodiments, the at least two diffraction based alignment marks are spaced horizontally or vertically from each other in the semiconductor die to facilitate scanning of the at least two diffraction basedalignment marks in a single scan using the radiation sensor.

[0105] Alignment operations may be performed by one or more components of the system 301 shown in Figure 3 A - 3J and Figure 4, and described above, or other systems. For example, a controller or processors system (e.g., similar to or the same as computer system CS shown in Figure 7 and described below) included in the system 301 may perform one or more such operations.

[0106] At an operation 650, a selected donor die (or one or more donor dies) is placed on a corresponding acceptor die (or one or more acceptor dies) at a bonding location (or locations). The donor die may be placed on the acceptor die by any appropriate method, such as by movement of a die actuator, by radiation-mediated bonding, by stamping, by electrostatic attraction, etc. The donor die may experience alignment, including self-alignment, as the donor die is brought into contact with the acceptor die. The donor die may be adhered to the acceptor die as it contacts the acceptor die, such as by van der Waals forces. In some embodiments, an additional donor die may be placed on the same or different acceptor die.

[0107] At an operation 660, it is determined if additional donor die remain for placement at additional bonding locations. If additional donor die (e.g., on the donor substrate or carrier) remain for placement, the flow continues to the operation 630 where another donor die is selected. If no additional donor die remain for placement, flow continues to operation 670, where the bonding of the plurality of dies is completed.

[0108] In an embodiment, a particular donor die and acceptor die are bonded at the time the donor die is placed on the acceptor die, e.g., through intermolecular bonding. In an embodiment, the donor die is bonded, such as through annealing or other bonding process, to the acceptor die after placement of the donor die on the acceptor die. In an embodiment, a bonding of a donor and acceptor die is completed before a next donor die is placed on an acceptor die. In an embodiment, bonding of a donor and acceptor die is completed after a plurality of donor dies are placed on respective acceptor dies, e.g., after all the donor dies on a donor substrate or carrier are placed. In an embodiment, a donor die placed on a acceptor die is annealed to form or enhance electrical connection. In an embodiment, the annealing of a particular donor die and acceptor die can be done prior to a next donor die is placed on a acceptor die. In an embodiment, annealing of a donor and acceptor die is completed after a plurality of donor dies are placed on respective acceptor dies, e.g., after all the donor dies on a donor substrate or carrier are placed. The donor die may be held against the acceptor die for a bonding or annealing time period. A donor die and acceptor die pair may be released from a substrate or other holding apparatus before annealing or after annealing has occurred.

[0109] Further embodiments of the invention are disclosed in the list of numbered clauses below:1. A bonding detector system comprising: a radiation sensor configured to generate a signal based on a pattern of diffracted radiation received from a diffraction based alignment mark of a semiconductor die; one or more processors; andinstructions, when executed by the one or more processors, configured to cause the one or more processors to at least: determine a position of the diffraction based alignmentmark based on the signal; and generate, based on the position, a signal configured to cause alignment of the semiconductor die to a bonding location.2. The system of clause 1, wherein the diffraction based alignment mark comprises a periodic structure.3. The system of clause 2, wherein the periodic structure repeats in two dimensions.4. The system of clause 3, wherein the periodic structure has a dimension of about 5 pm or less.5. The system of any of the previous clauses, wherein the diffraction based alignment mark comprises a grating.6. The system of any of the previous clauses, wherein the diffraction based alignment mark has an area of 10,000 square microns or less, 7000 square microns or less, or 4000 square microns or less, or wherein a cross-wise dimension of the mark is 160 pm or smaller, 100 pm or smaller, 50 pm or smaller, or 40 pm or smaller.7. The system of any of the previous clauses, wherein the instructions are configured to cause the one or more processors to determine the position of the diffraction based alignment mark in a first planar dimension, determine the position of the diffraction based alignment mark in a first and second planar dimension, and / or determine a rotational position of the diffraction based alignment mark; and control bonding of the semiconductor die aligned to the bonding location based on the position(s).8. The system of any of the previous clauses, wherein the diffraction based alignment mark of the semiconductor die faces the bonding location during bonding.9. The system of any of clauses 1-7, wherein the diffraction based alignment mark of the semiconductor die faces away from the bonding location during bonding.10. The system of any of the previous clauses, wherein the bonding location comprises a semiconductor wafer.11. The system of any of the previous clauses, wherein the bonding location comprises another semiconductor die.12. The system of any of the previous clauses, wherein the semiconductor die is a donor die, and the bonding location is an acceptor location for bonding.13. The system of any of clauses 1-11, wherein the semiconductor die is an acceptor die, and the bonding location comprises a donor die.14. The system of any of the previous clauses, wherein: the semiconductor die comprises at least two diffraction based alignment marks, including the diffraction based alignment mark and one or more additional diffraction based alignment marks; the radiation sensor is configured to generate corresponding signals based on patterns of diffracted radiation received from the diffraction based alignment mark and the one or more additional diffraction based alignment marks; and the instructions, when executed by the one or more processors, are further configured to cause the one or more processors: determine positions of the diffraction based alignment mark and the one or more additional diffractionbased alignment marks based on the corresponding signals; generate, based on the positions, one or more signals configured cause alignment of the semiconductor die to the bonding location.15. The system of clause 14, wherein each diffraction based alignment mark of the at least two diffraction based alignment marks comprises a periodic structure that repeats in two dimensions.16. The system of clause 14, wherein one diffraction based alignment mark of the at least two diffraction based alignment marks comprises a first periodic structure that repeats in a first direction, and a second diffraction based alignment mark of the at least two diffraction based alignment marks comprises a second periodic structure that repeats in a second direction, the second direction being different than the first direction.17. The system of any of clauses 14-16, wherein the at least two diffraction based alignment marks are in a layer of the semiconductor die that faces the bonding location during bonding, in a layer of the semiconductor die that faces away from the bonding location during bonding, or both.18. The system of any of clauses 14-17, wherein the at least two diffraction based alignment marks are spaced as far apart as possible in the semiconductor die.19. The system of any of clauses 14-17, wherein the at least two diffraction based alignment marks are spaced horizontally or vertically from each other in the semiconductor die to facilitate scanning of the at least two diffraction based alignment marks in a single scan using the radiation sensor.20. The system of any of the previous clauses, further comprising a radiation source configured to irradiate the diffraction based alignment mark with radiation.21. A semiconductor die comprising: a diffraction based alignment mark configured to receive incident radiation from a radiation source and generate a pattern of diffracted radiation, the pattern of diffracted radiation indicating a position of the diffraction based alignment mark, wherein the semiconductor die is configured to be aligned to a bonding location based on the position and the semiconductor die is to be bonded to the bonding location based on the alignment of the semiconductor die to the bonding location.22. The semiconductor die of clause 21, wherein the diffraction based alignment mark comprises a periodic structure.23. The semiconductor die of clause 22, wherein the periodic structure repeats in two dimensions.24. The semiconductor die of clause 23, wherein the periodic structure has a dimension of about 5 pm or less.25. The semiconductor die of any of clauses 21-24, wherein the diffraction based alignment mark comprises a grating.26. The semiconductor die of any of clauses 21-25, wherein the diffraction based alignment mark has an area of 10,000 square microns or less, 7000 square microns or less, or 4000 square microns or less, or wherein a cross-wise dimension of the mark is 160 pm or smaller, 100 pm or smaller, 50 pm or smaller, or 40 pm or smaller.27. The semiconductor die of any of clauses 21-26, wherein the position of the diffraction basedalignment mark is configured to be determined in a first planar dimension, determined in a first and second planar dimension, and / or determined in a rotational dimension.28. The semiconductor die of any of clauses 21-27, wherein the diffraction based alignment mark of the semiconductor die faces the bonding location during bonding.29. The semiconductor die of any of clauses 21-27, wherein the diffraction based alignment mark of the semiconductor die faces away from the bonding location during bonding.30. The semiconductor die of any of clauses 21-29, wherein the bonding location comprises a semiconductor wafer.31. The semiconductor die of any of clauses 21-30, wherein the bonding location comprises another semiconductor die.32. The semiconductor die of any of clauses 21-31, wherein the semiconductor die is a donor die, and the bonding location is an acceptor location for bonding.33. The semiconductor die of any of clauses 21-31, wherein the semiconductor die is an acceptor die, and the bonding location comprises a donor die.34. The semiconductor die of any of clauses 21-33, wherein: the die comprises at least two diffraction based alignment marks, including the diffraction based alignment mark and one or more additional diffraction based alignment marks, with each diffraction based alignment mark configured to receive the incident radiation from the radiation source and generate its own pattern of diffracted radiation, such that patterns of diffracted radiation from the at least two diffraction based alignment marks indicate positions of each diffraction based alignment mark, and the semiconductor die is configured to be aligned to the bonding location based on the positions of each diffraction based alignment mark.35. The semiconductor die of clause 34, wherein each diffraction based alignment mark of the at least two diffraction based alignment marks comprises a periodic structure that repeats in two dimensions.36. The semiconductor die of clause 34, wherein one diffraction based alignment mark of the at least two diffraction based alignment marks comprises a first periodic structure that repeats in a first direction, and a second diffraction based alignment mark of the at least two diffraction based alignment marks comprises a second periodic structure that repeats in a second direction, the second direction being different than the first direction.37. The semiconductor die of any of clauses 34-36, wherein the at least two diffraction based alignment marks face the bonding location during bonding, the at least two diffraction based alignment marks face away from the bonding location during bonding, or both.38. The semiconductor die of any of clauses 34-37, wherein the at least two diffraction based alignment marks are spaced as far apart as possible in the semiconductor die.39. The semiconductor die of any of clauses 34-37, wherein the at least two diffraction based alignment marks are spaced horizontally or vertically from each other in the semiconductor die tofacilitate scanning of the at least two diffraction based alignment marks in a single scan using a radiation sensor.40. The semiconductor die of any of clauses 21-39, wherein a layer of the semiconductor die with a diffraction based alignment mark comprises a contact pad layer.41. A bonding detector method comprising: generating, with a radiation sensor, a signal based on a pattern of diffracted radiation received from a diffraction based alignment mark of a semiconductor die; determining, with one or more processors, a position of the diffraction based alignment mark based on the signal; and generating, with the one or more processors, based on the position, a signal configured to cause alignment of the semiconductor die to a bonding location.42. The method of clause 41, wherein the diffraction based alignment mark comprises a periodic structure.43. The method of clause 42, wherein the periodic structure repeats in two dimensions.44. The method of clause 43, wherein the periodic structure has a dimension of about 5 pm or less.45. The method of any of the previous clauses, wherein the diffraction based alignment mark comprises a grating.46. The method of any of the previous clauses, wherein the diffraction based alignment mark has an area of 10,000 square microns or less, 7000 square microns or less, or 4000 square microns or less, or wherein a cross-wise dimension of the mark is 160 pm or smaller, 100 pm or smaller, 50 pm or smaller, or 40 pm or smaller.47. The method of any of the previous clauses, further comprising determining, with the one or more processors, the position of the diffraction based alignment mark in a first planar dimension, determining the position of the diffraction based alignment mark in a first and second planar dimension, and / or determining a rotational position of the diffraction based alignment mark; and controlling, with the one or more processors, bonding of the semiconductor die aligned to the bonding location based on the position(s).48. The method of any of the previous clauses, wherein the diffraction based alignment mark of the semiconductor die faces the bonding location during bonding.49. The method of any of clauses 41-47, wherein the diffraction based alignment mark of the semiconductor die faces away from the bonding location during bonding.50. The method of any of the previous clauses, wherein the bonding location comprises a semiconductor wafer.51. The method of any of the previous clauses, wherein the bonding location comprises another semiconductor die.52. The method of any of the previous clauses, wherein the semiconductor die is a donor die, and the bonding location is an acceptor location for bonding.53. The method of any of clauses 41-51, wherein the semiconductor die is an acceptor die, and the bonding location comprises a donor die.54. The method of any of the previous clauses, wherein: the semiconductor die comprises at least two diffraction based alignment marks, including the diffraction based alignment mark and one or more additional diffraction based alignment marks; and the radiation sensor is configured to generate corresponding signals based on patterns of diffracted radiation received from the diffraction based alignment mark and the one or more additional diffraction based alignment marks; the method further comprising: determining, with the one or more processors, positions of the diffraction based alignment mark and the one or more additional diffraction based alignment marks based on the corresponding signals; generating, with the one or more processors, based on the positions, one or more signals configured cause alignment of the semiconductor die to the bonding location.55. The method of clause 54, wherein each diffraction based alignment mark of the at least two diffraction based alignment marks comprises a periodic structure that repeats in two dimensions.56. The method of clause 54, wherein one diffraction based alignment mark of the at least two diffraction based alignment marks comprises a first periodic structure that repeats in a first direction, and a second diffraction based alignment mark of the at least two diffraction based alignment marks comprises a second periodic structure that repeats in a second direction, the second direction being different than the first direction.57. The method of any of clauses 54-56, wherein the at least two diffraction based alignment marks are in a layer of the semiconductor die that faces the bonding location during bonding, in a layer of the semiconductor die that faces away from the bonding location during bonding, or both.58. The method of any of clauses 54-57, wherein the at least two diffraction based alignment marks are spaced as far apart as possible in the semiconductor die.59. The method of any of clauses 54-57, wherein the at least two diffraction based alignment marks are spaced horizontally or vertically from each other in the semiconductor die to facilitate scanning of the at least two diffraction based alignment marks in a single scan using the radiation sensor.60. The method of any of the previous clauses, further comprising irradiating, with a radiation source, the diffraction based alignment mark with radiation.61. A method comprising: forming a diffraction based alignment mark in a semiconductor die, the diffraction based alignment mark configured to receive incident radiation from a radiation source and generate a pattern of diffracted radiation, the pattern of diffracted radiation indicating a position of the diffraction based alignment mark, wherein the semiconductor die is configured to be aligned to a bonding location based on the position and the semiconductor die is to be bonded to the bonding location based on the alignment of the semiconductor die to the bonding location.62. The method of clause 61, wherein the diffraction based alignment mark comprises a periodic structure.63. The method of clause 62, wherein the periodic structure repeats in two dimensions.64. The method of clause 63, wherein the periodic structure has a dimension of about 5 pm or less.65. The method of any of clauses 61-64, wherein the diffraction based alignment mark comprisesa grating.66. The method of any of clauses 61-65, wherein the diffraction based alignment mark has an area of 10,000 square microns or less, 7000 square microns or less, or 4000 square microns or less, or wherein a cross-wise dimension of the mark is 160 pm or smaller, 100 qm or smaller, 50 qm or smaller, or 40 qm or smaller.67. The method of any of clauses 61-66, wherein the position of the diffraction based alignment mark is configured to be determined in a first planar dimension, determined in a first and second planar dimension, and / or determined in a rotational dimension.68. The method of any of clauses 61-67, wherein the diffraction based alignment mark of the semiconductor die faces the bonding location during bonding.69. The method of any of clauses 61-67, wherein the diffraction based alignment mark of the semiconductor die faces away from the bonding location during bonding.70. The method of any of clauses 61-69, wherein the bonding location comprises a semiconductor wafer.71. The method of any of clauses 61-70, wherein the bonding location comprises another semiconductor die.72. The method of any of clauses 61-71, wherein the semiconductor die is a donor die, and the bonding location is an acceptor location for bonding.73. The method of any of clauses 61-71, wherein the semiconductor die is an acceptor die, and the bonding location comprises a donor die.74. The method of any of clauses 61-73, wherein: the die comprises at least two diffraction based alignment marks, including the diffraction based alignment mark and one or more additional diffraction based alignment marks, with each diffraction based alignment mark configured to receive the incident radiation from the radiation source and generate its own pattern of diffracted radiation, such that patterns of diffracted radiation from the at least two diffraction based alignment marks indicate positions of each diffraction based alignment mark, and the semiconductor die is configured to be aligned to the bonding location based on the positions of each diffraction based alignment mark.75. The method of clause 74, wherein each diffraction based alignment mark of the at least two diffraction based alignment marks comprises a periodic structure that repeats in two dimensions.76. The method of clause 74, wherein one diffraction based alignment mark of the at least two diffraction based alignment marks comprises a first periodic structure that repeats in a first direction, and a second diffraction based alignment mark of the at least two diffraction based alignment marks comprises a second periodic structure that repeats in a second direction, the second direction being different than the first direction.77. The method of any of clauses 74-76, wherein the at least two diffraction based alignment marks face the bonding location during bonding, the at least two diffraction based alignment marks face away from the bonding location during bonding, or both.78. The method of any of clauses 74-77, wherein the at least two diffraction based alignment marks are spaced as far apart as possible in the semiconductor die.79. The method of any of clauses 74-77, wherein the at least two diffraction based alignment marks are spaced horizontally or vertically from each other in the semiconductor die to facilitate scanning of the at least two diffraction based alignment marks in a single scan using a radiation sensor.80. The method of any of clauses 61-79, wherein a layer of the semiconductor die with a diffraction based alignment mark comprises a contact pad layer.

[0110] Figure 7 is a diagram of an example computer system CS that may be used to implement one or more of the operations described herein. Computer system CS may be, include, or be included in the controller of the system 301 shown in Figure 3 A - 3 J and described above, or other systems described herein. For example, computer system CS may form a processor system that controls or performs other functions associated with one or more components of the system 301. Computer system CS includes a bus BS or other communication mechanism for communicating information, and a processor PRO (or multiple processors) coupled with bus BS for processing information. Computer system CS also includes a main memory MM, such as a random-access memory (RAM) or other dynamic storage device, coupled to bus BS for storing information and instructions to be executed by processor PRO. Main memory MM also may be used for storing temporary variables or other intermediate information during execution of instructions by processor PRO. Computer system CS further includes a read only memory (ROM) ROM or other static storage device coupled to bus BS for storing static information and instructions for processor PRO. A storage device SD, such as a magnetic disk or optical disk, is provided and coupled to bus BS for storing information and instructions.

[0111] Computer system CS may be coupled via bus BS to a display DS, such as a cathode ray tube (CRT) or flat panel or touch panel display for displaying information to a computer user. An input device ID, including alphanumeric and other keys, is coupled to bus BS for communicating information and command selections to processor PRO. Another type of user input device is cursor control CC, such as a mouse, a trackball, or cursor direction keys for communicating direction information and command selections to processor PRO and for controlling cursor movement on display DS. This input device typically has two degrees of freedom in two axes, a first axis (e.g., x) and a second axis (e.g., y), that allows the device to specify positions in a plane. A touch panel (screen) display may also be used as an input device.

[0112] In some embodiments, portions of one or more methods described herein may be performed by computer system CS in response to processor PRO executing one or more sequences of one or more instructions contained in main memory MM. Such instructions may be read into main memory MM from another computer-readable medium, such as storage device SD. Execution of the sequences of instructions included in main memory MM causes processor PRO to perform one or more process steps (operations) described herein. One or more processors in a multi-processing arrangement mayalso be employed to execute the sequences of instructions contained in main memory MM. In some embodiments, hard-wired circuitry may be used in place of or in combination with software instructions. Thus, the description herein is not limited to any specific combination of hardware circuitry and software.

[0113] The term “computer-readable medium” and / or “machine readable medium” as used herein refers to any medium that participates in providing instructions to processor PRO for execution. Such a medium may take many forms, including but not limited to, non-volatile media, volatile media, and transmission media. Non-volatile media include, for example, optical or magnetic disks, such as storage device SD. Volatile media include dynamic memory, such as main memory MM. Transmission media include coaxial cables, copper wire and fiber optics, including the wires that comprise bus BS. Transmission media can also take the form of acoustic or radiation waves, such as those generated during radio frequency (RF) and infrared (IR) data communications. Computer- readable media can be non-transitory, for example, a floppy disk, a flexible disk, hard disk, magnetic tape, any other magnetic medium, a CD-ROM, DVD, any other optical medium, punch cards, paper tape, any other physical medium with patterns of holes, a RAM, a PROM, and EPROM, a FLASH- EPROM, any other memory chip or cartridge. Non-transitory computer readable media can have instructions recorded thereon. The instructions, when executed by a computer, can implement any of the operations described herein. Transitory computer-readable media can include a carrier wave or other propagating electromagnetic signal, for example.

[0114] Various forms of computer readable media may be involved in carrying one or more sequences of one or more instructions to processor PRO for execution. For example, the instructions may initially be borne on a magnetic disk of a remote computer. The remote computer can load the instructions into its dynamic memory and send the instructions over a telephone line using a modem. A modem local to computer system CS can receive the data on the telephone line and use an infrared transmitter to convert the data to an infrared signal. An infrared detector coupled to bus BS can receive the data carried in the infrared signal and place the data on bus BS. Bus BS carries the data to main memory MM, from which processor PRO retrieves and executes the instructions. The instructions received by main memory MM may optionally be stored on storage device SD either before or after execution by processor PRO.

[0115] Computer system CS may also include a communication interface CI coupled to bus BS. Communication interface CI provides a two-way data communication coupling to a network link NDL that is connected to a local network LAN. For example, communication interface CI may be an integrated services digital network (ISDN) card or a modem to provide a data communication connection to a corresponding type of telephone line. As another example, communication interface CI may be a local area network (LAN) card to provide a data communication connection to a compatible LAN. Wireless links may also be implemented. In any such implementation, communication interface CI sends and receives electrical, electromagnetic, or optical signals thatcarry digital data streams representing various types of information.

[0116] Network link NDL typically provides data communication through one or more networks to other data devices. For example, network link NDL may provide a connection through local network LAN to a host computer HC. This can include data communication services provided through the worldwide packet data communication network, now commonly referred to as the “Internet” INT. Local network LAN (Internet) may use electrical, electromagnetic, or optical signals that carry digital data streams. The signals through the various networks and the signals on network data link NDL and through communication interface CI, which carry the digital data to and from computer system CS, are exemplary forms of carrier waves transporting the information.

[0117] Computer system CS can send messages and receive data, including program code, through the network(s), network data link NDL, and communication interface CL In the Internet example, host computer HC might transmit a requested code for an application program through Internet INT, network data link NDL, local network LAN, and communication interface CL One such downloaded application may provide all or part of a method described herein, for example. The received code may be executed by processor PRO as it is received, and / or stored in storage device SD, or other nonvolatile storage for later execution. In this manner, computer system CS may obtain application code in the form of a carrier wave.

[0118] While the concepts disclosed herein may be used for manufacturing with a substrate such as a silicon wafer, it shall be understood that the disclosed concepts may be used with any type of manufacturing system (e.g., those used for manufacturing on substrates other than silicon wafers).

[0119] In addition, the combination and sub-combinations of disclosed elements may comprise separate embodiments. For example, one or more of the operations described above may be included in separate embodiments, or they may be included together in the same embodiment.

[0120] The descriptions above are intended to be illustrative, not limiting. Thus, it will be apparent to one skilled in the art that modifications may be made as described without departing from the scope of the claims set out below.

Claims

1. CLAIMS1. A bonding detector system comprising: a radiation sensor configured to generate a signal based on a pattern of diffracted radiation received from a diffraction based alignment mark of a semiconductor die; one or more processors; and instructions, when executed by the one or more processors, configured to cause the one or more processors to at least: determine a position of the diffraction based alignment mark based on the signal; and generate, based on the position, a signal configured to cause alignment of the semiconductor die to a bonding location.

2. The system of claim 1, wherein the diffraction based alignment mark comprises a periodic structure repeating in two dimensions.

3. The system of claim 2, wherein the periodic structure has a dimension of about 5 pm or less.

4. The system of claim 1, wherein the diffraction based alignment mark has an area of 10,000 square microns or less, 7000 square microns or less, or 4000 square microns or less, or wherein a crosswise dimension of the mark is 160 pm or smaller, 100 pm or smaller, 50 pm or smaller, or 40 pm or smaller.

5. The system of claim 1, wherein the instructions are configured to cause the one or more processors to determine the position of the diffraction based alignment mark in a first planar dimension, determine the position of the diffraction based alignment mark in a first and second planar dimension, and / or determine a rotational position of the diffraction based alignment mark; and control bonding of the semiconductor die aligned to the bonding location based on the position(s).

6. The system of claim 1, wherein the diffraction based alignment mark of the semiconductor die faces the bonding location during bonding.

7. The system of claim 1, wherein the semiconductor die is a donor die, and the bonding location is an acceptor location for bonding.

8. The system of claim 1, wherein: the semiconductor die comprises at least two diffraction based alignment marks, including thediffraction based alignment mark and one or more additional diffraction based alignment marks; the radiation sensor is configured to generate corresponding signals based on patterns of diffracted radiation received from the diffraction based alignment mark and the one or more additional diffraction based alignment marks; and the instructions, when executed by the one or more processors, are further configured to cause the one or more processors: determine positions of the diffraction based alignment mark and the one or more additional diffraction based alignment marks based on the corresponding signals; generate, based on the positions, one or more signals configured cause alignment of the semiconductor die to the bonding location.

9. A semiconductor die comprising: a diffraction based alignment mark configured to receive incident radiation from a radiation source and generate a pattern of diffracted radiation, the pattern of diffracted radiation indicating a position of the diffraction based alignment mark, wherein the semiconductor die is configured to be aligned to a bonding location based on the position and the semiconductor die is to be bonded to the bonding location based on the alignment of the semiconductor die to the bonding location.

10. The semiconductor die of claim 9, wherein the periodic structure has a dimension of about 5 pm or less.

11. The semiconductor die of claim 9 or 10, wherein the diffraction based alignment mark has an area of 10,000 square microns or less, 7000 square microns or less, or 4000 square microns or less, or wherein a cross-wise dimension of the mark is 160 pm or smaller, 100 pm or smaller, 50 pm or smaller, or 40 pm or smaller.

12. A bonding detector method comprising: generating, with a radiation sensor, a signal based on a pattern of diffracted radiation received from a diffraction based alignment mark of a semiconductor die; determining, with one or more processors, a position of the diffraction based alignment mark based on the signal; and generating, with the one or more processors, based on the position, a signal configured to cause alignment of the semiconductor die to a bonding location.

13. The method of claim 12, wherein the diffraction based alignment mark comprises a periodic structure repeating in two dimensions and having a dimension of about 5 pm or less.

14. A method comprising: forming a diffraction based alignment mark in a semiconductor die, the diffraction based alignment mark configured to receive incident radiation from a radiation source and generate a pattern of diffracted radiation, the pattern of diffracted radiation indicating a position of the diffraction based alignment mark, wherein the semiconductor die is configured to be aligned to a bonding location based on the position and the semiconductor die is to be bonded to the bonding location based on the alignment of the semiconductor die to the bonding location.

15. The method of claim 14, wherein: the die comprises at least two diffraction based alignment marks, including the diffraction based alignment mark and one or more additional diffraction based alignment marks, with each diffraction based alignment mark configured to receive the incident radiation from the radiation source and generate its own pattern of diffracted radiation, such that patterns of diffracted radiation from the at least two diffraction based alignment marks indicate positions of each diffraction based alignment mark, and the semiconductor die is configured to be aligned to the bonding location based on the positions of each diffraction based alignment mark.

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