Sealed bonded structure and method of forming the same

Abstract

A bonded structure is disclosed. The bonded structure includes a first element having a front side and a back side opposite the front side. The first element has a first conductive pad and a first non-conductive field region at the front side of the first element. The bonded structure also includes a second element having a second conductive pad and a second non-conductive field region at a front side of the second element. The second conductive pad is bonded to the first conductive pad along an interface structure. The bonded structure also includes an integrated device coupled with or formed with the first element or the second element. The bonded structure also includes an elongate conductive structure extending from the back side of the first element to the interface structure. The elongate conductive structure provides an effective closed contour around the integrated device.

Description

[0001] Cross-reference to related applications

[0002] This application claims priority to U.S. Nonprovisional Patent Application No. 16 / 839,756, filed April 3, 2020, and also to U.S. Provisional Patent Application No. 62 / 860,728, filed June 12, 2019, entitled “MEMS SEAL RING USING DBI,” the entire contents of each of these applications are incorporated herein by reference in their entirety. Technical Field

[0003] This field generally relates to bonding structures, and more specifically, to bonding structures that provide improved sealing between two elements (e.g., two semiconductor elements). Background Technology

[0004] In semiconductor device manufacturing and packaging, some integrated devices are sealed to isolate them from the external environment to, for example, reduce contamination, maintain a vacuum or pressure, or prevent damage to the integrated device. For instance, some microelectromechanical systems (MEMS) devices include cavities defined by covers that are attached to substrates using adhesives such as solder. However, some adhesives may be permeable to gases, allowing gases to penetrate the adhesive and enter the cavity over time. Moisture or certain gases (such as hydrogen or oxygen) can damage sensitive integrated devices or affect device performance. Other adhesives (such as solder) introduce their own long-term reliability issues. Therefore, there remains a continuous need for improved sealing for integrated devices. Attached Figure Description

[0005] Specific embodiments of the invention will now be described with reference to the following accompanying drawings, which are exemplary and not restrictive.

[0006] Figure 1A This is a schematic side cross-sectional view of a bonding structure according to one embodiment.

[0007] Figures 1B to 1E The diagram illustrates the manufacturing process. Figure 1A The process flow of the bonding structure is shown in the figure.

[0008] Figure 2A This is a schematic cross-sectional view of the interface structure according to one embodiment before the formation of the conductive structure.

[0009] Figure 2B After the formation of the conductive structure Figure 2A A schematic cross-sectional view of the interface structure.

[0010] Figure 2C This is a schematic cross-sectional view of the interface structure after the formation of the conductive structure, according to one embodiment.

[0011] Figure 3A yes Figure 2A An enlarged view of one corner of the interface structure shown in the figure.

[0012] Figure 3B yes Figure 2B An enlarged view of one corner of the interface structure shown in the figure.

[0013] Figure 4 This is a schematic side cross-sectional view of a portion of a bonding structure according to one embodiment.

[0014] Figure 5A This is a schematic side cross-sectional view of a portion of the bonding structure according to another embodiment.

[0015] Figure 5B This is a schematic side cross-sectional view of a portion of the bonding structure according to another embodiment.

[0016] Figure 5C This is a schematic side cross-sectional view of a portion of the bonding structure according to another embodiment.

[0017] Figure 6A This is a schematic cross-sectional view of a portion of the interface structure according to one embodiment before the formation of the conductive structure.

[0018] Figure 6B After the formation of the conductive structure Figure 6A A schematic cross-sectional view of the interface structure.

[0019] Figure 7 This is a schematic side cross-sectional view of a portion of a bonding structure according to one embodiment.

[0020] Figure 8A This is a schematic cross-sectional view of a portion of the interface structure according to one embodiment before the formation of the conductive structure.

[0021] Figure 8B After the formation of the conductive structure Figure 8A A schematic cross-sectional view of the interface structure.

[0022] Figure 9 This is a schematic side cross-sectional view of a portion of a bonding structure according to one embodiment.

[0023] Figure 10A This is a schematic cross-sectional view of a portion of the interface structure according to one embodiment before the formation of the conductive structure.

[0024] Figure 10B After the formation of the conductive structure Figure 10A A schematic cross-sectional view of the interface structure.

[0025] Figure 11A This is a schematic side cross-sectional view of a portion of a bonding structure according to one embodiment.

[0026] Figure 11B This is a schematic side cross-sectional view of a portion of the bonding structure according to another embodiment.

[0027] Figure 11C This is a schematic side cross-sectional view of a portion of the bonding structure according to another embodiment.

[0028] Figure 11D This is a schematic side cross-sectional view of a portion of the bonding structure according to another embodiment.

[0029] Figure 11E This is a schematic side cross-sectional view of a portion of the bonding structure according to another embodiment.

[0030] Figure 12A This is a schematic cross-sectional view of a portion of the interface structure according to one embodiment before the formation of the conductive structure.

[0031] Figure 12B After the formation of the conductive structure Figure 12A A schematic cross-sectional view of the interface structure.

[0032] Figure 13A This is a schematic side cross-sectional view of a portion of a bonding structure according to one embodiment.

[0033] Figure 13B This is a schematic side cross-sectional view of a portion of the bonding structure according to another embodiment.

[0034] Figure 13C This is a schematic side cross-sectional view of a portion of the bonding structure according to another embodiment.

[0035] Figures 14A to 14E The illustration shows a process flow for manufacturing a bonding structure according to one embodiment.

[0036] Figure 15 This is a schematic diagram of an electronic system comprising one or more bonding structures according to various embodiments. Detailed Implementation

[0037] The various embodiments disclosed herein relate to elements (e.g., semiconductor elements) having conductive interface features and non-conductive features. The various embodiments disclosed herein relate to interface structures that connect two elements in a manner that effectively hermetically seals components of an element (e.g., integrated devices) to isolate them from the external environment. For example, in some embodiments, the element may include conductive interface features (e.g., copper). copper ) or copper ( CuThe bonding structure includes a conductive interface feature (e.g., a silicon oxide layer) and a non-conductive interface feature. In some embodiments, the conductive interface feature may include a plurality of conductive pads. In some embodiments, the conductive interface feature may include laterally elongated conductive features. For example, in some embodiments, the bonding structure may include a plurality of elements bonded to each other along the interface structure. The integrated device may be coupled to or formed together with a semiconductor element. For example, in some embodiments, the bonding structure may include a microelectromechanical system (MEMS) device in which a cap (first element) is bonded to a carrier (second element). The MEMS element (integrated device) may be disposed in a cavity at least partially defined by the cap and the carrier. In some embodiments, the carrier may include an integrated device die (e.g., a processor die having active circuitry). In other embodiments, the carrier may include a substrate (e.g., a semiconductor substrate), an interposer, etc.

[0038] In some embodiments, the conductive interface features of a semiconductor device may include grooves, and portions of non-conductive interface features may be disposed within the grooves. In some embodiments, when the semiconductor device is annealed, the grooves in the conductive interface features may prevent and / or mitigate hillocks. hillock The formation of ).

[0039] In some arrangements, the interface structure may include one or more conductive interface features disposed around the integrated device, and one or more non-conductive interface features to connect the first and second elements and define an effective loop or effective closed profile. In some embodiments, the interface structure may include a first conductive interface feature, a second conductive interface feature, and a solid-state non-conductive interface feature disposed between the first and second conductive interface features. In some embodiments, each element may include an associated conductive interface feature, and the conductive interface features may be directly bonded to each other to connect the two semiconductor elements.

[0040] Figure 1AThis is a schematic side cross-sectional view of a bonding structure 1 according to one embodiment. The bonding structure 1 may include a first element 10 bonded to a second element 12 along an interface structure 14. In the illustrated embodiment, the first and second elements 10, 12 are directly bonded to each other without an intermediate adhesive. The first element 10 may include a non-conductive field region 16 at a front side 10a and a plurality of conductive contact pads 18. The non-conductive field region 16 may form a portion of the bonding layer for the bonding structure 1. In various embodiments, the non-conductive field region 16 may include an inorganic dielectric material, such as silicon oxide, silicon nitride, silicon oxynitride, silicon carbonitride, etc. The conductive contact pads 18 may include any suitable metal or conductor, such as copper, etc. Some or all of the contact pads 18 may be configured to provide electrical communication between one or more electronic components of the bonding structure 1 and an external device (e.g., a system board). The first element 10 may also include a conductive structure 20. The conductive structure 20 may include any suitable type of metal or conductor, such as copper, tungsten, polysilicon, etc. In some embodiments, the conductive structure 20 may include an alloy. although Figure 1A Only one material is shown for the conductive structure 20, but the conductive structure 20 may include one or more materials or one or more layers of conductive material. The conductive structure 20 may extend from the back side 10b of the first element 10 to the interface structure 14 or beyond the interface structure 14, terminating in the second element 12. Figure 1A In some embodiments, the conductive structure 20 may extend through the body region 13 (e.g., a bulk semiconductor region, such as silicon, III-V material, polysilicon or glass, sapphire, quartz, etc.) and may contact and terminate at the contact 18 on the front side 10a of the first element 10. As shown, the conductive structure 20 may contact the back side of the contact pad 18. Various plan views illustrated herein (e.g.) Figure 2B As shown, the conductive structure 20 may include transversely elongated structures disposed around the internal region of the bonding structure 1. The conductive structure 20 may define an effectively closed profile to seal the internal region and isolate it from the external environment.

[0041] The second element 12 may include a non-conductive field region 26 and a plurality of conductive pads 28 at the front side 12a. The non-conductive field region 26 may form a portion of the bonding layer for the bonding structure 1. In various embodiments, the non-conductive field region 26 may include an inorganic dielectric material, such as silicon oxide, silicon nitride, silicon oxynitride, silicon carbonitride, etc. The conductive contact pads 28 may include any suitable metal or conductor, such as copper. Some or all of the contact pads 28 may be configured to provide electrical connectivity between one or more electronic components and / or external devices (e.g., system boards) of the bonding structure 1. The second element 12 may include interconnects 30 formed in the non-conductive field region 26. The interconnects 30 may include lateral conductive traces to electrically connect the contact pads 18, 28 to be bonded to contact pads electrically connected to the integrated device 34. The first element 10 and the second element 12 may define a cavity 32. The bonding structure 1 may include an integrated device 34, which may be disposed within the cavity 32. The integrated device 34 may include any suitable type of device, such as microelectromechanical systems (MEMS) devices, RF devices, electronic devices (such as active electronic devices with active circuitry, passive electronic devices, etc.), optical devices (such as sensors, transmitters, etc.) or any other suitable type of device.

[0042] In the illustrated embodiments, the first element 10 may include a cover shaped to define a cavity 32 or disposed over a cavity (not shown) in the second element 12. For example, in the illustrated embodiments, the cavity 32 may be etched into the first element 10. In some embodiments, the second element 12 may include a cover shaped to define a cavity. The cavity 32 may include an air cavity, which may be under vacuum, or may be filled with a suitable filler material (e.g., colloid, molding compound, etc.). The first and second elements 10, 12 may include any other suitable type of element, which may or may not include semiconductor material. For example, in some embodiments, elements 10, 12 may include various types of optics, which may not include semiconductor material.

[0043] In the illustrated embodiments, the first element 10 and / or the second element 12 may comprise semiconductor elements formed of one or more semiconductor materials. In some embodiments, the second element 12 may comprise a carrier having a front side 12a to which the first element 10 is bonded. In some embodiments, the carrier may comprise a substrate, such as a semiconductor substrate (e.g., a silicon interposer with conductive interconnects), a printed circuit board (PCB), a ceramic substrate, a glass substrate, or any other suitable carrier. In such embodiments, the carrier may transmit signals between the integrated device 34 and a larger package structure or electronic system. In some embodiments, the second element 12 may comprise an integrated device die with active circuitry, such as a processor die configured to process signals converted by the integrated device 34. The integrated device 34 may comprise MEMS elements, such as MEMS switches, accelerometers, gyroscopes, etc. The integrated device 34 may be coupled to or formed together with the first semiconductor element 10 or the second semiconductor element 12. In some embodiments, active circuitry may be additionally or alternatively formed in the first element 10.

[0044] In some configurations, it may be important to isolate or separate the integrated device die 34 from the external environment (e.g., from exposure to liquids, gases, and / or contaminants). For example, for some integrated devices, exposure to unwanted materials such as moisture or gases (e.g., oxides of hydrogen, oxygen, sulfur, or nitrogen, or various combinations thereof) may damage the integrated device 34 or other components of structure 1. Therefore, it may be important to provide an interface structure 14 to effectively or substantially seal (e.g., hermetically or nearly hermetically sealed) the cavity 32 and the integrated device 34 to isolate unwanted materials. The interface structure 14 may be arranged to prevent and / or substantially inhibit unwanted materials from the external environment of structure 1 through the interface structure 14 to the interior of structure 1 (e.g., cavity 32). For example, in the various embodiments disclosed herein, the conductive structure 20 may extend through the first element 10 to the interface structure 14 or through the interface structure 14 to the second element 12 to substantially seal the interior of the bonded structure 1 (e.g., cavity 34 and devices formed therein or thereon) to isolate it from the external environment.

[0045] The embodiments disclosed herein can utilize materials with low gas permeability and can be arranged to reduce or eliminate gas ingress into cavity 32. In other embodiments, cavity 32 can be filled with different materials, such as nitrogen, to maintain a certain pressure for improving the performance of device 34. In some embodiments, the permeation of this filling gas from the inside to the outside of cavity 32 can be beneficial for maintaining pressure to sustain the performance of device 34 throughout the product's lifespan. For example, the permeation rate of certain gases (such as hydrogen) through metal can be significantly lower than the permeation rate of gases through other materials (such as dielectric materials or polymers). For example, hydrogen can decompose into its constituent atoms at or near the outer surface of structure 1. The decomposed atoms can diffuse through the material of elements 10, 12 or interface structure 14 and recombine at or near the interior of structure 1 (e.g., cavity 32). The diffusion rate of hydrogen through metal can be approximately proportional to the square root of the pressure. Other gases (such as rare gases) may not permeate metal at all. In comparison, gases can pass through polymer or glass (silicon oxide) materials much faster (e.g., proportional to pressure) because gas molecules can pass through without breaking down into atoms on the outer surface of structure 1.

[0046] Therefore, the embodiments disclosed herein can advantageously employ materials such as metals for the conductive structure 20, which defines an effective annular or closed pattern around the integrated device 34 to seal the internal regions of the bonded structure (e.g., cavity 32) to isolate them from the external environment and harmful gases. In some embodiments, the effective annular or closed conductive pattern may include a fully closed loop around the integrated device 34, which can improve sealing relative to other arrangements. In some embodiments, the effective annular or closed conductive pattern may include an incomplete annular pattern around the device 34, such as a mostly or partially annular pattern, allowing one or more gaps to exist in the metal. Since the permeation rate of gas through a metal (such as copper) is significantly less than the permeation rate of gas through a dielectric or non-conductive material (e.g., silicon oxide, silicon nitride, etc.), the interface structure 14 having the conductive structure 20 can provide improved sealing for the internal regions of the bonded structure 1.

[0047] However, in some embodiments, it may not be desirable to utilize an interface structure 14 comprising only metal or significantly wide metal lines. When the interface structure 14 includes wide metal lines or patterns, planarization processes suitable for robust direct bonding of the metal lines and surrounding dielectric can be challenging and may result in problems including noticeable indentations, dielectric rounding, and inconsistent bonding surface profiles during chemical mechanical polishing (CMP) or other processing steps. Indentations in the metal lines can adversely affect the ability to wire bond the metal lines of the first element 10 to the second element 12, especially when using direct metal-to-metal bonding techniques. Relatively large dielectric regions near the metal lines can reduce the bonding line width or interfere with direct bonding of adjacent pads. Therefore, in various embodiments, the interface structure 14 may include one or more conductive interface features embedded within or otherwise adjacent to one or more non-conductive interface features. The conductive interface features can provide an effective barrier to prevent or reduce the permeation of unwanted materials into the cavity 32 and / or into the integrated device 34 and / or to prevent or reduce the permeation of desired gases filled in the cavity 32 into the external environment. Furthermore, conductive interface features can be made thin enough and can be scattered or embedded with non-conductive interface features to reduce or eliminate the harmful effects of depressions.

[0048] In some embodiments disclosed herein, the interface structure 14 may be at least partially defined by a non-conductive field region 16 and a plurality of conductive pads 18 at the front side 10a of the first element 10, and a non-conductive field region 26 and a plurality of conductive pads 28 at the front side 12a of the second element 12. In some embodiments, the interface structure 14 may include at least a portion of a conductive structure 20, for example, a portion of the conductive structure 20 extending through the non-conductive field region 16 and / or contacting the pads 18 in the first element 10. In some embodiments, the non-conductive field region 16 and the plurality of conductive pads 18 at the front side 10a may be respectively bonded to the corresponding non-conductive field region 26 and the corresponding plurality of conductive pads 28 at the front side 12a. For example, the non-conductive field region 16 may be directly bonded to the corresponding non-conductive field region 26 without adhesive along the bonding interface 15. The contact pads 18 may also be directly bonded to the contact pads 28 without adhesive along the bonding interface 15.

[0049] Interface structure 14 may provide mechanical and / or electrical connections between the first and second elements 10, 12. In some embodiments, interface structure 14 may only provide mechanical connections between elements 10, 12, which may be used to seal cavity 32 and / or integrated device 34 to isolate it from the external environment. In other embodiments, interface structure 14 may also provide electrical connections between elements 10, 12 for, for example, grounding and / or for the transmission of electrical signals. For example, an electrical connection may be provided between directly bonded contact pad pairs 18, 28. In other embodiments, interface structure 14 may provide optical connections between elements 10, 12.

[0050] The bonding surfaces (e.g., the front side 10a of the first element 10 and the front side 12a of the second element 12) can be polished or planarized, activated, and terminated using suitable materials. For example, in various embodiments, one or both of the non-conductive field regions 16, 26 may comprise an inorganic dielectric material, such as silicon oxide. The bonding surfaces can be polished to a root mean square (rms) surface roughness of less than 2 nm (e.g., less than 1 nm, less than 0.5 nm, etc.). The polished bonding surfaces can be activated, for example, by processes including atmospheric or vacuum plasma methods. In various embodiments, the bonding surfaces can be terminated using nitrogen, for example, by using wet or dry etching with a nitrogen-containing solution (e.g., very light etching (VSE)) or by using plasma etching with nitrogen. As explained herein, the non-conductive field regions 16, 26 of the bonding surfaces can contact at room temperature to form a direct bond without the application of external pressure and without the need for adhesives. In some embodiments, components 10, 12 may be further heated to enhance the bonding strength between the opposing bonding surfaces of components 10, 12, and to form reliable electrical and mechanical contacts at the interface between components 10, 12. For example, in some embodiments, the corresponding contact pads 18, 28 may be flush with the surfaces of the corresponding non-conductive field regions 16, 26, or may be recessed below the non-conductive field regions 16, 26, for example, recessed in the range of 0 nm to 20 nm, or in the range of 4 nm to 10 nm. The non-conductive field regions 16, 26 may be directly bonded to each other at room temperature without adhesive, and the bond structure 1 may subsequently be annealed. During annealing, the contact pads 18, 28 may expand and contact each other to form a direct metal-to-metal bond. The direct metal-to-metal bond can provide electrical and mechanical connections between the two components 10, 12. Additional details of the direct bonding process used in each embodiment of the disclosed embodiments can be found in U.S. Patent Nos. 7,126,212; 8,153,505; 7,622,324; 7,602,070; 8,163,373; 8,389,378; 7,485,968; 8,735,219; 9,385,024; 9,391,143; 9,431,368; 9,953,941; 9,716,033; 9,852,988; 10,032,068; 10,434,749; and 10,446,532, the contents of each of which are incorporated herein by reference in their entirety and for all purposes.

[0051] Any suitable type of integrated device or structure can be used in conjunction with the disclosed embodiments. For example, in some embodiments, the first and second elements 10, 12 may include integrated device dies, such as processor dies, memory dies, and / or radio frequency (RF) or optical devices. Furthermore, while the disclosed embodiments include cavity 32, in other arrangements, the cavity may be absent. Instead, the interior of the bonding structure 1 may alternatively include sensitive circuitry or devices without cavities, which may be sealed or protected by conductive structure 20 and directly bonded contact pads 18, 28. For example, the embodiments disclosed herein can be used with any suitable integrated device or integrated device die where it may be desirable to seal active components to isolate them from external environments, gases, liquids, plasmas, or unwanted materials. Furthermore, the disclosed embodiments can be used to achieve other purposes. For example, in some arrangements, the disclosed interface structure 14 can be used to provide electromagnetic shielding or a Faraday cage to reduce or prevent unwanted electromagnetic radiation from entering structure 1, and / or to prevent various types of signal leakage. Of course, the cavity can be filled with any suitable fluid, such as liquid, gas or other suitable substance that can improve the thermal, electrical or mechanical properties of structure 1.

[0052] In some embodiments, the conductive structure 20 may include vias (e.g., substrate vias (TSVs)). In some embodiments, the TSV may include filled vias or conformal vias. In the illustrated embodiment, the conductive structure 20 may include filled vias, wherein a conductive material (such as a copper-like metal) may fill channels or trenches formed in the first element 10. Filled vias may include layered filled vias, wherein the conductive filler comprises multiple conductive layers deposited on a barrier layer or seed layer. The conductive filler layers may have different widths. In other embodiments, the conductive structure 20 may include conformal filled vias, wherein the conductive layer is conformally coated inside the channels or trenches formed in the first element 10, but may not fill the channels or trenches.

[0053] Figures 1B to 1E The diagram illustrates the manufacturing process. Figure 1A The process flow of bonding structure 1 is shown in the figure. Figure 1B The system may provide a first element 10 and a second element 12. The first element 10 may include a non-conductive field region 16 and a plurality of conductive pads 18 at a front side 10a. The second element 12 may include a non-conductive field region 26 and a plurality of conductive pads 28 at a front side 12a. The second element 12 may include interconnects 30 formed in the non-conductive field region 26. An integrated device 34 may be disposed on the front side 12a of the second element 12. The integrated device 34 may be mechanically and / or electrically coupled to the second element 12, for example, through the interconnects 30.

[0054] The front sides 10a and 12a of the first and second elements 10 and 12 can be prepared for bonding, respectively. For example, as described above, the front side 10a of the first element 10 and the front side 12a of the second element 12 can be polished or planarized, activated, and terminated using a suitable material. The polished bonding surfaces can be activated, for example, by a process including atmospheric or vacuum plasma methods. In various embodiments, the bonding surfaces of the non-conductive field regions 16 and 26 can be terminated using nitrogen, for example, by using wet or dry etching with a nitrogen-containing solution, or by using plasma etching with nitrogen. In some embodiments, the corresponding contact pads 18 and 28 can be flush with the surface of the corresponding non-conductive field regions 16 and 26, or can be recessed below the non-conductive field regions 16 and 26, for example, recessed in the range of 1 nanometer to 20 nanometers, or in the range of 4 nanometers to 10 nanometers.

[0055] exist Figure 1C In this embodiment, the first element 10 and the second element 12 are in contact at room temperature without the application of external pressure and without adhesive to form a direct dielectric bond along the bonding interface 15. Non-conductive field regions 16, 26 can be directly bonded to each other at room temperature without adhesive, and the bond structure 1 can subsequently be annealed. During annealing, contact pads 18, 28 can expand and contact each other to form a direct metal-to-metal bond without adhesive along the bonding interface 15. In various embodiments, the conductive bond between contact pads 18, 28 can provide both mechanical and electrical connections between elements 10, 12. Therefore, in the illustrated embodiment, the non-conductive field region 16 and the plurality of conductive pads 18 of the first element 10 can be directly bonded to the corresponding non-conductive field region 26 and the corresponding plurality of conductive pads 28 of the second element 12, respectively. In some embodiments, the first element 10 can directly contact the second element 12 without intermediate adhesive. The first element 10 and the second element 12 can define a cavity 32.

[0056] In some embodiments, the number of conductive pads 18 of the first element 10 may be the same as the number of conductive pads 28 of the second element 12. In some embodiments, the number of conductive pads 18 may be different from the number of conductive pads 28. In such embodiments, one pad of one element may be bonded to two or more pads of another element. Although Figure 1AThe illustration shows each contact pad 18 of the first element 10 being directly connected to a corresponding contact pad 28 of the second element 12. However, in some embodiments, one or more contact pads 28, 18 of one element may not have corresponding contact pads 18, 28 of the other element. In some embodiments, the number of contact pads 18 may be the same as the number of contact pads 28. In some other embodiments, the number of contact pads 18 may be more or less than the number of contact pads 28. In some embodiments, one contact pad 18 may contact two or more contact pads 28. In some embodiments, the bonded non-conductive field regions 16, 26 and the bonded conductive pads 18, 28 may at least partially define the interface structure 14. In the illustrated embodiment, in the cavity 32 (see also...) Figure 2A The first element 10 is surrounded by multiple (e.g., three) rows or rings of conductive pads R1, R2, R3. However, in various embodiments, any number of rows or rings of conductive pads may be present. In some applications, having multiple pads instead of an elongated conductive structure for direct bonding can be advantageous. For example, in some applications, having multiple conductive pads can mitigate or eliminate problems associated with having a single elongated conductive structure, such as dents, rounding, and / or uneven metal loading during the manufacturing process. In other embodiments, when the first element 10 and the second element 12 are in contact, the non-conductive field region 16 and the non-conductive field region 26 may be bonded, while the multiple conductive pads 18 may not be bonded to the multiple conductive pads 28.

[0057] exist Figure 1D In this process, trenches or channels 36 can be formed in the first element 10. Channels 36 can extend from the back side 10b of element 10 to the interface structure 14. For example... Figure 1D The channel 36 shown extends from the back side 10b of element 10 to the middle row R2 of the three rows of contact pads surrounding cavity 32. However, channel 36 may extend to any one(s) of the plurality of conductive pads. Channel 36 may be formed in any suitable manner. In some embodiments, channel 36 may be formed by drilling (e.g., laser drilling) or etching (e.g., wet etching or dry etching). In some embodiments, contact pads 18 in the middle ring R2 may serve as etching stops when channel 36 is formed. In some embodiments, where there are no pads 18 in the ring R2 of the first element 10, contact pads 28 in the middle ring R2 may serve as etching stops when channel 36 is formed. In some embodiments, channel 36 may be formed at the edge of interface structure 14. In some other embodiments, channel 36 may extend through the interface structure and into element 12.

[0058] exist Figure 1EIn this embodiment, a conductive structure 20 may be provided in channel 36. In some embodiments, such as... Figure 2B As shown, the conductive structure 20 may extend around the cavity 32 and / or integrated device 34 in an effectively closed or annular pattern. For example, the conductive structure 20 may extend around the cavity 32 and / or device 34 in a complete annular or closed shape. In other arrangements, the conductive structure 20 may extend substantially around the entire periphery of the cavity 32, but may include one or more gaps. In some embodiments, the conductive structure 20 and the plurality of pads 18, 28 may include the same or similar materials. In some embodiments, the conductive structure 20 may include a noble metal. In some embodiments, the conductive structure 20 and / or the plurality of pads 18, 28 may include any suitable conductor, such as copper, gold, tungsten, titanium, tin, nickel, silicon nitride, etc. The illustrated process for forming the conductive structure 20 may be referred to as the final via process, wherein the conductive structure 20 is formed after the first element 10 and the second element 12 are bonded. In some embodiments, one or more layers of conductive and / or non-conductive materials may be provided in the channel 36. For example, after forming the channel 36, a barrier layer may be formed on the sidewalls of the channel 36. In some embodiments, the barrier layer may include silicon oxide, silicon nitride, etc. An adhesive layer can be formed on the barrier layer. In some embodiments, the adhesive layer may include titanium nitride (TiN), titanium (Ti), tantalum nitride (TaN), and / or tritium (T). Another conductive material (e.g., Cu) may be provided on the adhesive layer.

[0059] Figure 2A This is a schematic cross-sectional view of an implemented interface structure 14 after direct bonding but before the formation of the conductive structure 20. Figure 2B yes Figure 2A A schematic cross-sectional view of the interface structure 14 after the formation of the conductive structure 20 through the first element 10. Figure 2C This is a schematic cross-sectional view of the interface structure 14' according to another embodiment. Figure 3A yes Figure 2A The enlarged view of one corner of the interface structure 14 shown in the figure. Figure 3B yes Figure 2B An enlarged view of a corner of the interface structure 14 shown in the figure. Although Figure 2B The perfect alignment of pads 18 and 28 is depicted, but they may be offset from each other during bonding.

[0060] Interface structure 14 may include bonded non-conductive field regions 16, 26 and bonded conductive pads 18, 28. In some embodiments, as shown, the plurality of conductive pads 18, 28 may include three rings R1, R2, R3 of the conductive pads, and the conductive pads may include intermediate pads 18a, 28a, outer pads 18b, 28b and inner pads 18c, 28c. The inner pads 18c, 28c are closer to the interior of the bonding structure 1 (e.g., closer to cavity 32) than the intermediate pads 18a, 28a and the outer pads 18b, 28b. The intermediate pads 18a, 28a are located between the outer pads 18b, 28b and the inner pads 18c, 28c. Interface structure 14 may also include at least a portion of conductive structure 20. Interface structure 14 may have any number of conductive pads 18, 28. The plurality of conductive pads 18, 28 shown have rectangular (e.g., square) pads of the same size. However, in some embodiments, the plurality of conductive pads 18b, 28b may include any suitable size and shape, and may include pads of different shapes. For example, the pads may be polygonal pads or circular pads (e.g., circular pads). In some embodiments, the pads in the interface structure may be pads of different sizes. Therefore, as Figure 2A and 3A As shown, prior to the formation of the conductive structure 20, the directly bonded pads 18, 28 may include an array of multiple bonded pads provided in one or more rings around the cavity 32.

[0061] As described above, conductive material can be provided in channel 36 and can extend from the back side of contact pad 18 to the back side 10b of first element 10 to form an effectively closed conductive structure 20. In the illustrated embodiment, the conductive structure 20 extends from the back side 10b of first element 10 (see [link to documentation]). Figure 1E The contact pad 18a extends into the intermediate ring R2 of the contact pad. As shown, the conductive structure 20 can extend around the cavity 32 in an effective annular pattern, which includes a complete annular pattern without significant gaps. However, in other embodiments, one or more gaps may exist between portions of the conductive structure 20, but without a direct path to the cavity 32.

[0062] Advantageously, the conductive structure 20 and the contact pads 18a, 28a can cooperate to define a substantially sealed ring around the interior of the bonding structure 1 (e.g., around the cavity 32) to prevent liquids, gases, or contaminants from entering and / or leaving the cavity 32. In some embodiments, the conductive structure 20 may define a substantially sealed ring at or near the outer edge of the entire interface structure (e.g., interface structure 14). In some other embodiments, the conductive structure 20 may be targeted at the interface structure (e.g., Figure 2C The interface structure 14' shown in the diagram partially defines a substantially sealed ring.

[0063] exist Figure 2C In this embodiment, the conductive structure 20 may define a substantially sealed ring around the cavity 32 defined at a portion of the interface structure 14'. Other portions of the interface structure 14' may be disposed outside the substantially sealed ring. In some embodiments, a large portion of the interface structure 14' may be located outside the substantially sealed ring. In some other embodiments, a small portion of the interface structure 14' may be located outside the substantially sealed ring. Although... Figure 2C Only one basic sealing ring is depicted, but another embodiment may have two or more such sealing rings around two or more such cavities.

[0064] Furthermore, providing the elongated conductive structure 20 after directly bonding the contact pads 18, 28 can avoid undesirable pitting effects that can occur if the elongated conductive structures are directly bonded to each other to form a closed profile. In some embodiments, the conductive structure 20 and the bonding pads 18a, 28a can be electrically inert, such that the conductive structure 20 and the bonding pads 18a, 28a are used only to seal the interior of the bonding structure 1. In other embodiments, the conductive structure 20 can also be electrically connected to the bonding pads 18a, 28a. For example, in some embodiments, the conductive structure 20 and the bonding pads 18a, 28a can be connected to electrical ground. In other embodiments, the conductive structure 20 and the bonding pads 18a, 28a can provide power and / or can transmit electrical signals to and / or from devices in the bonding structure 1. Further details of the interface structures used in each embodiment of the disclosed embodiments can be found in U.S. Patent Nos. 10,002,844, 10,522,499, and U.S. Publication 2019 / 0348336, the contents of each of which are incorporated herein by reference in their entirety and for all purposes.

[0065] Figure 4 This is a schematic side cross-sectional view of a portion of a bonding structure according to one embodiment. The bonding structure may include... Figure 3B The interface structure 14. The cross-section of the bonding structure may include a first element 10 bonded to the second element 12 along the interface structure 14. The first element 10 may include a non-conductive field region 16. The second element 12 may include a non-conductive field region 26. The cross-section of the bonding structure may also include a conductive structure 20.

[0066] The conductive structure 20 can extend from the back side 10b of the first element 10 to the interface structure 14. For example... Figure 4As shown, the conductive structure 20 can extend from the back side 10b of the first element 10 through a portion of the non-conductive field region 26 and the non-conductive field region 16. Therefore, in some embodiments, the conductive structure 20 can provide a metallic seal for the gaps between the plurality of conductive pads 18, 28. In some embodiments, the conductive structure 20 can extend from the back side 10b of the first element 10 completely through the non-conductive field regions 16, 26. In some embodiments, the conductive structure 20 can extend from the back side 10b of the first element 10 completely through the first and second elements 10, 12 to the back side 12b of the second element 12.

[0067] Figures 5A to 5C This is a schematic side cross-sectional view of a portion of the bonding structure 1 according to various embodiments. Unless otherwise stated, Figures 5A to 5C The components can be used with Figure 1 to Figure 4 Components with the same number are identical or substantially similar. A portion of bonding structure 1 may include... Figure 3B The interface structure 14, for example, the conductive structure 20, can be mechanically and / or electrically connected to the middle row R2 of the directly bonded contact pads 18a, 28a. Figures 5A to 5C The cross sections shown in the figure may share similar components and features.

[0068] Figures 5A to 5C The cross-section of the bonding structure may include a first element 10 bonded to the second element 12 along the interface structure 14. The first element 10 may include a non-conductive field region 16 and a plurality of conductive pads 18. In some embodiments, the plurality of conductive pads 18 may include a middle pad 18a, an outer pad 18b, and an inner pad 18c. The second element 12 may include a non-conductive field region 26 and a plurality of conductive pads 28. In some embodiments, the plurality of conductive pads 28 may include a middle pad 28a, an outer pad 28b, and an inner pad 28c. In some embodiments, the cross-section of the bonding structure may also include a conductive structure 20 and an interconnect 30, which may connect one of the conductive pads (e.g., an outer pad 28b) to another conductive pad (e.g., an inner pad 28c) and / or components associated with the bonding structure 1. Figures 5A to 5C Each conductive structure in the conductive structure 20 shown can define an effective closed profile around the interior of the bonding structure 1, for example around the cavity 32, in order to provide an effective seal for the interior of the bonding structure 1.

[0069] Figure 5AThe conductive structure 20 illustrated extends from the back side 10b of the first element 10 to the interface structure 14. For example, the conductive structure 20 extends through the body region 13, the non-conductive field region 16, a portion of the middle pad 18a of the plurality of conductive pads 18 on the first element 10, a portion of the middle pad 28a of the plurality of conductive pads 28 on the second element 12, and a portion of the non-conductive field region 26. The conductive structure 20 may terminate at and contact a lateral feature 40 formed in the second element 12. In some embodiments, the lateral feature 40 may include an interconnect 30 and may be electrically active. In other embodiments, the lateral feature 40 may be electrically inert. Figure 5A The lateral feature 40 can be at least partially embedded in the non-conductive field region 26. In some embodiments, by extending the conductive structure 20 across the bonding interface 25 between the first element 10 and the second element 12 through the intermediate pads 18a, 28a, a more reliable seal can be provided compared to a conductive structure 20 that does not extend across the bonding interface 15 between elements 10, 12 through the conductive pads 18, 28a. In some embodiments, the conductive structure 20 can extend to the lateral feature 40, which can be an etch stop for forming a channel for the conductive structure 20. The etch stop can include, for example, silicon nitride. Although Figure 5A Pads 18a and 28a are shown as being wider than conductive structure 20, but in some embodiments, pads 18a and 28a may be narrower than conductive structure 20 and therefore not visible in the final structure.

[0070] Lateral feature 40 may comprise any conductive or non-conductive material. Lateral feature 40 may comprise a loop at least partially surrounding cavity 32 or integrated device 34. In some embodiments, lateral feature 40 may comprise a continuous line defining a complete loop around cavity 32. In some other embodiments, lateral feature 40 may comprise a discontinuous loop around cavity 32. In some embodiments, lateral feature 40 may provide lateral electrical connections within structure 1.

[0071] Figure 5B The conductive structure 20 shown extends from the back side 10b of the first element 10 to the interface structure 14. For example, the conductive structure 20 extends through the body region 13 and the non-conductive field region 16, and is disposed around and above the intermediate contact pad 18a. A portion of the conductive structure 20 may be disposed along at least one sidewall of the sidewall of the intermediate pad 18a of the plurality of conductive pads 18. Therefore, in Figure 5BIn this configuration, the effectively closed conductive structure 20 can extend to the bonding interface 15, the sidewall of the intermediate pad 18a, and the back side of the intermediate pad 18a. The conductive structure 20 can be conformally deposited on the contact pad 18a in the channel 36. In some embodiments, the conductive structure 20 can extend beyond the bonding interface 15 into the non-conductive field region 26. In such embodiments, a portion of the conductive structure 20 can be positioned along the sidewall of the intermediate pad 28a of the plurality of conductive pads 28. In some other embodiments, the conductive structure 20 can extend below the intermediate pad 28a and into the non-conductive field region 26. The conductive structure 20 can contact lateral features (not shown) below the intermediate pad 28a. Although Figure 5B The conductive structure 20 is depicted centered on the contact pad 18a, but the conductive structure 20 may be offset relative to the contact pad 18a. In some other embodiments, the conductive structure 20 may be offset relative to the contact pad 18a such that the conductive structure 20 is disposed only around one or more sidewalls of the contact pad 18a.

[0072] Figure 5C The illustrated cross-section includes two conductive pads 18b and 18c on the first element 10 and three conductive pads 28a to 28c on the second element 12. Therefore, Figure 5C The bonding structure 1 in the middle may not include the middle row R2 of the contact pad 18a. Figure 5C The conductive structure 20 shown extends from the back side 10b of the first element 10 through the non-conductive field region 16 to the bonding interface 15 and the intermediate pad 28a of the second element 12. In the illustrated embodiment, the conductive structure 20 terminates at and contacts the front side of the intermediate contact pad 28a. In other embodiments, the conductive structure 20 may extend through a portion of the thickness of the intermediate pad 28a of the conductive pads 28. In other embodiments, a portion of the conductive structure 20 may be provided along at least a portion of the sidewall of the intermediate pad 28a among the plurality of conductive pads 28. In other embodiments, the conductive structure 20 may extend below the intermediate pad 28a among the conductive pads 28 or may terminate on a lateral feature 40 below the intermediate pad 28a.

[0073] Figure 6A This is a schematic cross-sectional view of a portion of the interface structure 14 according to one embodiment, after direct bonding but before the formation of the conductive structure 20. Figure 6B This is a schematic cross-sectional view of the interface structure 14 after the formation of the conductive structure 20. Figure 6A and 6BThe interface structure 14 shown may include non-conductive field regions 16, 26 that are directly bonded and a plurality of conductive contact pads 18, 28 that are directly bonded. In some embodiments, the plurality of conductive pads may include two rows of conductive pads (e.g., an outer row and an inner row), which may include outer pads 18b, 28b and inner pads 18c, 28c. Figure 6B The diagram illustrates a conductive structure 20 disposed between outer pads 18b, 28b and inner pads 18c, 28c and extending through at least a portion of the bonded field regions 16, 26. Figure 6A and Figure 6B In the middle, there may be no intermediate row of contact pads 18a and 28a.

[0074] Figure 7 This is a schematic side cross-sectional view of a portion of a bonding structure 1 according to one embodiment. The bonding structure may include... Figure 6B The interface structure 14 may contain only an outer ring and an inner ring of contact pads. The cross-section of the bonding structure 1 may include a first element 10 bonded to the second element 12 along the interface structure 14. The first element 10 may include a non-conductive field region 16 and a plurality of conductive pads 18. The plurality of conductive pads 18 may include an outer pad 18b and an inner pad 18c. The second element 12 may include a non-conductive field region 26 and a plurality of conductive pads 28. The plurality of conductive pads 28 may include an outer pad 28b and an inner pad 28c. The cross-section of the bonding structure may also include a conductive structure 20 between the outer pads 18b, 28b and the inner pads 18c, 28c.

[0075] The conductive structure 20 can extend from the back side 10b of the first element 10 to the interface structure 14. For example... Figure 7As shown, the conductive structure 20 can extend from the back side 10b of the first element 10 through a portion of the body region 13, the non-conductive field region 16, and the non-conductive field region 26 to terminate at and contact the lateral feature 40 formed in the second element 12. In the illustrated embodiment, the lateral feature 40 is at least partially embedded (e.g., fully embedded or buried) in the non-conductive field region 26 of the second element. Advantageously, the conductive structure 20 can provide a conductive seal in the gap between the bonded outer pads 18b, 28b and the bonded inner pads 18c, 28c. In other embodiments, the lateral feature 40 can be at least partially disposed in the body region 17 of the second element 12, in which case the conductive structure 20 can extend from the back side 10b of the first element 10 completely through the non-conductive field regions 16, 26. In other embodiments, the conductive structure 20 can extend from the back side 10b of the first element 10 completely through the first and second elements 10, 12 to the back side 12b of the second element 12. As described above, in some embodiments, the lateral feature 40 may be electrically inert, and the interconnect 30 may be wired around the lateral feature 40. As described above, in other embodiments, the lateral feature 40 may be electrically active.

[0076] Figure 8A This is a schematic cross-sectional view of a portion of the interface structure 14 according to one embodiment, after direct bonding but before the formation of the conductive structure 20. Figure 8B This is a schematic cross-sectional view of the interface structure 14 after the formation of the conductive structure 20. Unless otherwise stated, Figures 8A to 8B The components can be used with Figure 1 to Figure 7 Components with similar numbers are generally similar or identical. Figure 8A and 8B The interface structure 14 shown may include bonded non-conductive field regions 16, 26 and a plurality of bonded conductive pads 18, 28. In some embodiments, the plurality of conductive pads may include multiple rows or rings of conductive pads (e.g., (a plurality of) middle rows, outer rows and inner rows), which may include middle pads 18a, 28a, outer pads 18b, 28b and inner pads 18c, 28c. Figure 8B The diagram illustrates a conductive structure 20 disposed between outer pads 18b and 28b and inner pads 18c and 28c. For example... Figure 8B As shown, the interface structure 20 can be mechanically connected and extends between pads 18a, 28a of two adjacent intermediate rows.

[0077] Figure 9 This is a schematic side cross-sectional view of a portion of a bonding structure 1 according to one embodiment. The bonding structure 1 may include... Figure 8BThe interface structure 14. The cross-section of the bonding structure may include a first element 10 bonded to the second element 12 along the interface structure 14. The first element 10 may include a non-conductive field region 16 and a plurality of conductive pads 18. The plurality of conductive pads 18 may include multiple (e.g., two) rows or rings of intermediate pads 18a', 18a”, outer pads 18b, and inner pads 18c. The second element 12 may include a non-conductive field region 26 and a plurality of conductive pads 28. The plurality of conductive pads 28 may include multiple (e.g., two) rows or rings of intermediate pads 28a', 28a”, outer pads 28b, and inner pads 28c. The cross-section of the bonding structure may also include a conductive structure 20 between the intermediate pads 18a', 28a' and other intermediate pads 18a”, 28a”.

[0078] The conductive structure 20 can extend from the back side 10b of the first element 10 to the interface structure 14. For example... Figure 9 As shown, the conductive structure 20 can extend from the back side 10b of the first element 10 through a portion of the body region 13, the non-conductive field region 16 of the first element 10, and the non-conductive field region 26 of the second element 12. The conductive structure 20 can contact the intermediate pads 18a', 18a”, 28a', 28a” and extend between the intermediate pads 18a', 18a”, 28a', 28a”. Therefore, in Figure 9 In this embodiment, the conductive structure 20 may be wide enough to span the contact pads of the two rings. In some embodiments, the conductive structure 20 may extend from the back side 10b of the first element 10 completely through the non-conductive field regions 16, 26. In some embodiments, the conductive structure 20 may extend from the back side 10b of the first element 10 completely through the first and second elements 10, 12 to the back side 12b of the second element 12.

[0079] Figure 10A This is a schematic cross-sectional view of a portion of the interface structure 14 according to one embodiment, after direct bonding but before the formation of the conductive structure 20. Figure 10B This is a schematic cross-sectional view of the interface structure 14 after the formation of the conductive structure 20. Figure 10A and 10B The interface structure 14 shown may include bonded non-conductive field regions 16, 26 and a plurality of bonded conductive pads 18, 28. In some embodiments, the plurality of conductive pads may include a row of conductive pads, and the conductive pads may include outer pads 18d, 28d and inner pads 18e, 28e positioned closer to the cavity 32 than the outer pads 18d, 28d. Figure 10B The diagram illustrates a conductive structure 20 disposed between the outer pads 18b and 28b and the outer side 42 of the interface structure 14. Figure 10BIn some embodiments, the conductive structure 20 may define an effectively closed profile around the interior of the bonding structure and may be disposed outside the contact pads 18d, 18e, 28d, 28e. In the illustrated embodiment, the conductive structure 20 may be laterally inserted relative to the outer side 42, such that the bonding field regions 16, 26 are exposed at the outer side 42. In other embodiments, as explained herein, the conductive structure 20 may be exposed at the outer side 42.

[0080] Figure 11A This is a schematic side cross-sectional view of a portion of a bonding structure 1 according to one embodiment. The bonding structure may include... Figure 10B The interface structure 14 includes a conductive structure 20 disposed on the outer side of contact pads 18, 28. The cross-section of the bonding structure may include a first element 10 bonded to the second element 12 along the interface structure 14. The first element 10 may include a non-conductive field region 16 and a plurality of conductive pads 18. The plurality of conductive pads 18 may include an outer pad 18d and an inner pad 18e. The second element 12 may include a non-conductive field region 26 and a plurality of conductive pads 28. The plurality of conductive pads 28 may include an outer pad 28d and an inner pad 28e. The cross-section of the bonding structure may also include the conductive structure 20 between the outer pads 18b, 28b and the outer side 42 of the interface structure 14.

[0081] The conductive structure 20 can extend from the back side 10b of the first element 10 to the interface structure 14. For example... Figure 11A As shown, the conductive structure 20 can extend from the back side 10b of the first element 10 through portions of the body region 13, the non-conductive field region 16, and the non-conductive field region 26. In the illustrated embodiment, the conductive structure 20 can terminate within the non-conductive field region 26 of the second element 12. In some embodiments, the conductive structure 20 can extend from the back side 10b of the first element 10 completely through the non-conductive field regions 16 and 26. In some embodiments, the conductive structure 20 can extend from the back side 10b of the first element 10 completely through the first and second elements 10 and 12 to the back side 12b of the second element 12.

[0082] The cross-section of the bonding structure may further include a conductive via 44. The conductive via 44 can extend from the back side 10b of the first element 10 to the outer pad 18d. In some embodiments, in the absence of the conductive pad 18d, the conductive pad 28d can be directly bonded to the conductive via 44. In some embodiments, the conductive via 44 can extend from the back side 10b of the first element 10 to the inner pad 18e. The conductive via 44 can be formed before or after bonding the first element 10 and the second element 12. In some embodiments, the conductive via 44 can be elongated. In some embodiments, the conductive via 44 can provide electrical pathways on the back side 10b of the first element 10 for the conductive pads 18, 28. The conductive via 44 on the back side 10b can be configured to connect to the system board via, for example, wire bonding, solder balls, etc. Figures 11A to 11D and Figure 13B In this embodiment, both the via 44 and the conductive structure 20 extend from one side (the back side 10b of the first element 10). However, in some embodiments, the via 44 and the conductive structure 20 may extend from different sides of the bonding structure (the back side 10b of the first element 10 and the back side 12b of the second element 12). In some other embodiments, the via 44 and / or the conductive structure 20 may extend from both sides of the bonding structure (the back side 10b of the first element 10 and the back side 12b of the second element 12).

[0083] Figure 11B This is a schematic side cross-sectional view of a portion of a bonding structure according to one embodiment. Figure 11B Generally similar to Figure 11A In addition to Figure 11B In this configuration, interconnect 30 extends horizontally through the non-conductive field region 26 beneath the conductive structure 20 to the outer side 42 of the interface structure. Interconnect 30 can provide electrical communication with one or more conductive pads of conductive pads 18, 28.

[0084] Figure 11C This is a schematic side cross-sectional view of a portion of the bonding structure 1 according to one embodiment. Figure 11C Generally similar to Figure 11A In addition to Figure 11C In this configuration, the conductive structure 20 extends from the back side 10b of the first element 10 through the non-conductive field region 16 and the non-conductive field region 26, and partially through the body portion 17 of the second element 12 (e.g., silicon (Si)). In some embodiments, with Figure 11A Compared to the embodiments shown, Figure 11C The illustrated embodiment provides an improved seal for cavity 32.

[0085] Figure 11D This is a schematic side cross-sectional view of a portion of a bonding structure 1 according to one embodiment. Figure 11D Generally similar to Figure 11AIn addition to Figure 11D In this configuration, the conductive structure 20 extends from the back side 10b of the first element 10 through the first element 10 and the second element 12 to the back side 12b of the second element 12. In some embodiments, with Figure 11A Compared to the embodiments shown, Figure 11D The illustrated embodiment can provide an improved seal for cavity 32.

[0086] Figure 11E This is a schematic side cross-sectional view of a portion of the bonding structure 1 according to one embodiment. Figure 11E Generally similar to Figure 11A In addition to Figure 11E In this embodiment, the conductive structure 20 includes a first conductive structure 20a and a second conductive structure 20b. The first conductive structure 20a extends from the back side 10b of the first element 10 to the interface structure 14, and the second conductive structure 20b extends from the back side 12b of the second element 12 to the interface structure 14. The first conductive structure 20a may contact the second conductive structure 20b. In other embodiments, the first conductive structure 20a and the second conductive structure 20b may be laterally offset.

[0087] Figure 12A This is a schematic cross-sectional view of a portion of the interface structure 14 according to one embodiment, after direct bonding but before the formation of the conductive structure 20. Figure 12B This is a schematic cross-sectional view of the interface structure 14 after the formation of the conductive structure 20. Figure 12A and 12B The interface structure 14 shown may include bonded non-conductive field regions 16, 26 and a plurality of bonded conductive contact pads 18, 28. In some embodiments, the plurality of conductive pads may include multiple rows of conductive pads, which may include outer pads 18d, 28d and inner pads 18e, 28e, with the inner pads 18e, 28e being closer to the cavity 32 than the outer pads 18d, 28d. Figure 12B The diagram illustrates a conductive structure 20 disposed along the outer side 42 (e.g., the outermost or outermost surface) of the interface structure 14 and exposed thereon.

[0088] Figure 13A This is a schematic side cross-sectional view of a portion of a bonding structure 1 according to one embodiment. The bonding structure 1 may include... Figure 12BThe interface structure 14 includes a conductive structure 20 exposed on the outer side 42. The cross-section of the bonding structure 1 may include a first element 10 bonded to the second element 12 along the interface structure 14. The first element 10 may include a non-conductive field region 16 and a plurality of conductive contact pads 18. The plurality of conductive contact pads 18 may include an outer pad 18d and an inner pad 18e. The second element 12 may include a non-conductive field region 26 and a plurality of conductive contact pads 28. The plurality of conductive pads 28 may include an outer pad 28d and an inner pad 28e. The cross-section of the bonding structure may also include the conductive structure 20 disposed along the outer side 42 of the interface structure 14. In some embodiments, the conductive structure 20 may be exposed to the external environment. Figure 13A The conductive structure 20 shown is tapered. However, in other embodiments, the conductive structure 20 may not be tapered. In some embodiments, the conductive structure 20 may be electroplated onto a portion of the outer surface of the bonding structure. In some embodiments, the conductive structure 20 may be formed in a channel 36, which is formed during a dicing process for monolithicizing the bonding structure. For example, the conductive structure 20 may include a conformal via, wherein the conductive structure comprises a conductive material consistent with the surface of the channel 36. Figure 13A In the illustrated embodiment, the conductive structure 20 extends through a portion of the body region 13, the non-conductive field region 16 of the first element 10, the non-conductive field region 26 of the second element 12, and the body region 17 of the second element 12. In the illustrated embodiment, the conductive structure 20 may terminate within the body region 17 of the second element 12.

[0089] Figure 13B This is a schematic side cross-sectional view of a portion of the bonding structure 1 according to one embodiment. Figure 13B Generally similar to Figure 13A ,Apart from Figure 13B The cross-section of the bonding structure includes a conductive via 44. The conductive via 44 can extend from the back side 10b of the first element 10 to the outer pad 18d. In some embodiments, the conductive via 44 can extend from the back side 10b of the first element 10 to the inner pad 18e. The conductive via 44 can be formed before or after bonding the first element 10 and the second element 12. In some embodiments, the conductive via 44 can be elongated. In some embodiments, the conductive via 44 can provide electrical pathways on the back side 10b of the first element 10 to the conductive pads 18, 28.

[0090] Figure 13C This is a schematic side cross-sectional view of a portion of the bonding structure 1 according to one embodiment. Figure 13C Generally similar to Figure 13A However, with Figure 13A The conductive structure 20 is different; the conductive structure 20 may include a filled via in Figures 13A to 13CSince the conductive structure 20 is disposed along the outer side 42 of the interface structure 14, the conductive structure 20 can mitigate or prevent the bond structure from being damaged (e.g., cracked) during the manufacturing process (e.g., cutting) and / or during the use of the bond structure.

[0091] Figures 14A to 14E The diagram illustrates the process flow for manufacturing the bonding structure 1 according to various embodiments. Figures 14A to 14E In the diagram, a first element 10 directly bonded to a second element 12 along interface structure 14 is shown. In some embodiments, interface structure 14 may include a non-conductive field region and a conductive pad. Figures 14A to 14E In the manufacturing process shown, multiple bonding structures 1 can be formed from the wafer.

[0092] exist Figure 14A The system may provide a first element 10 and a second element 12. In some embodiments, the first element 10 may include a non-conductive field region (not shown) and a plurality of conductive pads (not shown) on the front side 10a of the first element 10. In some embodiments, the second element 12 may include a non-conductive region (not shown) and a plurality of conductive pads (not shown) on the front side 12a of the second element 12. The second element 12 may also include a cavity 32 formed on the front side 12a. In some embodiments, one or more components may be disposed in the cavity 32. In some embodiments, one or more components may be embedded in the first element 10 and / or the second element 12.

[0093] exist Figure 14B In this configuration, the first element 10 and the second element 12 can be bonded to each other along the interface structure 14. As described above, the first element 10 and the second element 12 can be directly bonded to each other without adhesive. The first element 10 and the second element 12 can be electrically and / or mechanically connected to each other. The first element 10 and the second element 12 can define a cavity 32. The cavity 32 can be closed and sealed to isolate it from the external environment.

[0094] exist Figure 14C In this process, a channel 36 can be formed. The channel 36 can extend from the back side 10b of the element 10 to the interface structure 14. In some embodiments, the channel 36 can extend from the back side 10b of the element 10 through the interface structure 14 to the body region of the second element 12. In some embodiments, the channel 36 can be formed by drilling (e.g., laser drilling) or etching (e.g., wet etching or dry etching).

[0095] exist Figure 14DIn this process, a conductive structure 20 can be formed. In some embodiments, the conductive structure 20 may include vias. In some embodiments, vias may include filled vias or conformal vias. In some embodiments, filled vias may include layered filled vias, wherein the conductive filler comprises multiple layers. In some embodiments, the conductive structure 20 may include noble metals. In some embodiments, the conductive structure 20 may include any suitable conductor, such as copper, gold, tungsten, titanium, titanium nitride, tantalum, tantalum nitride, tin, nickel, silicon nitride, etc.

[0096] exist Figure 14E In this embodiment, portions of the first element 10 and / or the second element 12 may be etched away to form the bonding structure 1. In the illustrated embodiment, the first element 10 may serve as a cover for the cavity 32. In some embodiments, the second element 12 may have a larger size than the first element 10. In some embodiments, the second element 12 may include a carrier. In some applications, MEMS components may be disposed within the cavity 32. In some embodiments, the first element 10 and / or the second element 12 may include interconnects formed in the elements 10, 12.

[0097] Figure 15 This is a schematic diagram of an electronic system 80 comprising one or more bonding structures 1 according to various embodiments. System 80 may include any suitable type of electronic device, such as a mobile electronic device (e.g., a smartphone, tablet computing device, laptop computer, etc.), a desktop computer, an automobile or components thereof, a stereo system, a medical device, a camera, or any other suitable type of system. In some embodiments, electronic system 80 may include a microprocessor, a graphics processor, an electronic recording device, or a digital memory. System 80 may include one or more device packages 82 that are mechanically and electrically connected to system 80, for example, via one or more motherboards. Each package 82 may include one or more bonding structures 1. Figure 15 The system 80 shown may include any of the bonding structures and interface structures shown and described herein, 1 and 14.

[0098] In one aspect, a bonding structure is disclosed. The bonding structure may include a first element having a front side and a back side opposite the front side. The first element may have a first plurality of conductive contact pads and a first non-conductive field region at the front side of the first element. The bonding structure may also include a second element having a second plurality of conductive contact pads and a second non-conductive field region at the front side of the second element. The second plurality of contact pads may be directly bonded to the first plurality of contact pads along the interface structure without intermediate adhesive. At least some of the directly bonded contact pads may provide electrical communication between the first and second elements. The bonding structure may also include an integrated device coupled to or formed with the first or second element. The bonding structure may also include a laterally elongated conductive structure extending from the back side of the first element to the interface structure. The elongated conductive structure may provide an effective closed profile around the integrated device.

[0099] In one embodiment, the first non-conductive field region and the second non-conductive field region are directly bonded without an intermediate binder.

[0100] In one embodiment, the bonding structure further includes a cavity within the bonding structure.

[0101] An elongated conductive structure can extend around the cavity within an effective closed profile. In one embodiment, the interface structure includes a bonding interface between the first and second elements. The elongated conductive structure can extend from the back side of the first element at least to the bonding interface.

[0102] In one embodiment, elongated conductive structures are continuously disposed around the integrated device to define a fully closed profile.

[0103] In one embodiment, an elongated conductive structure contacts a first contact pad among a plurality of first contact pads.

[0104] In one embodiment, the second element further includes a second contact pad among a second plurality of contact pads on the front side of the second element. An elongated conductive structure may extend through the bonding interface of the interface structure to contact the second contact pad. The first element may also include a third contact pad among a first plurality of contact pads on the front side of the first element. The second element may also include a fourth contact pad among a second plurality of contact pads on the front side of the second element. A third conductive pad may be directly bonded to the fourth conductive pad. An elongated conductive structure may be disposed between the second and third conductive pads and contact both the second and third conductive pads. The elongated conductive structure may contact the fourth conductive pad. The bonding structure may also include a via that extends at least partially through the first element from the back side. The via may contact the third conductive pad. The elongated conductive structure may extend at least partially through a second non-conductive field region. The elongated conductive structure may contact the first contact pad among the first plurality of contact pads or the second contact pad among the second plurality of contact pads. The elongated conductive structure may extend completely through the second non-conductive field region and partially through the bulk semiconductor portion of the second element. Slender conductive structures can extend through the entire thickness of the bonding structure.

[0105] In one embodiment, the second element further includes a lateral feature at least partially embedded in a second non-conductive field region. An elongated conductive structure may extend through at least a portion of the second non-conductive field region to contact the lateral feature. The lateral feature may include a ring disposed around the integrated device.

[0106] In one embodiment, an elongated conductive structure is exposed on the outermost surface of the bonded structure.

[0107] In one embodiment, the bonding structure further includes a second elongated conductive structure that extends from the back side of the second element, opposite the front side of the second element, to the interface structure. The second elongated conductive structure can provide an effective closed profile around the integrated device.

[0108] In one embodiment, one of the first plurality of contact pads and one of the second plurality of contact pads define a first pair of bonding pads, and another contact pad of the first plurality of contact pads and another contact pad of the second plurality of contact pads define a second pair of bonding pads. An elongated conductive structure may be located between the first pair of bonding pads and the second pair of bonding pads. The first and second bonding pads may be electrically connected via interconnects.

[0109] On one hand, a bonding structure is disclosed. The bonding structure may include a first element and a second element. The second element is bonded to the first element along an interface structure. The interface structure may include conductive interface features and non-conductive interface features disposed around the conductive interface features. The conductive interface features can provide mechanical and electrical connections between the first and second elements. The bonding structure may also include an integrated device coupled to or formed with the first or second element. The bonding structure may also include a laterally elongated conductive structure extending from the back side of the first element to the interface structure. The elongated conductive structure can provide an effective closed profile around the integrated device.

[0110] In one embodiment, the conductive interface features include a plurality of directly bonded conductive pads disposed around the integrated device.

[0111] In one embodiment, the first element and the second element are directly bonded without an intermediate adhesive.

[0112] In one embodiment, the bonding structure further includes a via extending at least partially through the first element from the back side of the first element, the via potentially contacting a conductive interface feature.

[0113] In one embodiment, an elongated conductive structure extends through the interface structure.

[0114] In one embodiment, the elongated conductive structure extends through the entire thickness of the bonding structure.

[0115] In one aspect, a method for forming a bonding structure is disclosed. The method may include providing a first element including a first contact pad at a bonding surface of the first element. The method may further include providing a second element including a second contact pad at a bonding surface of the second element. The method may further include directly bonding the first contact pad of the first element to the second contact pad of the second element along the interface structure without an intermediate adhesive. The method further includes forming a transversely elongated channel extending from the back side of the first element at least to the interface structure. The method may further include providing an elongated conductive structure within the channel.

[0116] In one embodiment, bonding includes: directly bonding a first non-conductive field region of a first element to a second non-conductive field region of a second element along the interface structure without an intermediate adhesive.

[0117] In one embodiment, forming an elongated channel includes extending from the back side of the first element to at least the bonding surface of the second element. Forming an elongated channel may include forming an elongated channel extending from the back side of the first element through the entire thickness of the bonding structure.

[0118] Unless the context explicitly requires otherwise, throughout the specification and claims, the terms “comprising,” “comprise,” “including,” “include,” etc., should be interpreted as open-ended inclusion, not exclusive or exhaustive; that is, in the sense of “including but not limited to.” The term “coupled,” as commonly used herein, means that two or more elements can be directly connected or connected via one or more intermediate elements. Similarly, the term “connected,” as commonly used herein, means that two or more elements can be directly connected or connected via one or more intermediate elements. Furthermore, the terms “in this document,” “above,” “below,” and similar terms used in this application refer to the entire application and not any particular part thereof. Where the context permits, singular or plural terms used in the above specific embodiments may also include either the plural or the singular, respectively. The term “or” in relation to a list of two or more items covers all of the following interpretations: any of the items in the list, all of the items in the list, and any combination of the items in the list.

[0119] Furthermore, the conditional language used herein, such as “can,” “could,” “might,” “may,” “for example,” “such as,” “e.g.,” “like,” “for instance,” etc., unless otherwise specifically stated or otherwise understood in the context in which they are used, is generally intended to convey that certain embodiments include certain features, elements, and / or states that are not included in other embodiments. Therefore, such conditional language is not generally intended to imply that one or more embodiments require features, elements, and / or states in any way.

[0120] Although certain embodiments have been described, these embodiments are presented by way of example only and are not intended to limit the scope of this disclosure. In fact, the novel apparatuses, methods, and systems described herein can be embodied in a variety of other forms; furthermore, various omissions, substitutions, and changes can be made to the form of the methods and systems described herein without departing from the spirit of this disclosure. For example, while blocks are presented in a given arrangement, alternative embodiments may utilize different components and / or circuit topologies to perform similar functionality, and some blocks may be deleted, moved, added, subdivided, combined, and / or modified. Each of these blocks can be implemented in a variety of different ways. Any suitable combination of elements and actions of the various embodiments described above can be combined to provide further embodiments. The appended claims and their equivalents are intended to cover such forms or modifications that fall within the scope and spirit of this disclosure.

Claims

1. A bonded structure comprising: a first element having a front side and a back side opposite the front side, the first element having a first plurality of electrically conductive contact pads and a first electrically non-conductive field region at the front side of the first element, the first electrically non-conductive field region and the first plurality of electrically conductive contact pads disposed on a semiconductor region of the first element; a second element having a second plurality of electrically conductive contact pads and a second electrically non-conductive field region at a front side of the second element, the second plurality of electrically conductive contact pads directly bonded to the first plurality of electrically conductive contact pads along a bonding interface without an intervening adhesive, at least some of the directly bonded contact pads providing electrical communication between the first element and the second element; an integrated device coupled to or formed in the first element or the second element; and a laterally elongated electrically conductive structure disposed in a trench having a sidewall that extends from the back side of the first element, through the semiconductor region and the first electrically non-conductive field region, and across the bonding interface, the laterally elongated electrically conductive structure providing an effective closed profile around the integrated device.

2. The bonded structure of claim 1, wherein the first electrically non-conductive field region and the second electrically non-conductive field region are directly bonded without an intervening adhesive.

3. The bonded structure of claim 1, further comprising a cavity in the bonded structure, the laterally elongated electrically conductive structure extending in the effective closed profile around the cavity.

4. The bonded structure of claim 1, wherein the laterally elongated electrically conductive structure extends from the back side of the first element at least to the bonding interface.

5. The bonded structure of claim 1, wherein the laterally elongated electrically conductive structure is continuously disposed around the integrated device to define a fully closed profile.

6. The bonded structure of claim 1, wherein the laterally elongated electrically conductive structure contacts a first electrically conductive contact pad of the first plurality of electrically conductive contact pads.

7. The bonded structure of claim 1, wherein the second element further comprises a second electrically conductive contact pad of the second plurality of electrically conductive contact pads at the front side of the second element, and wherein the laterally elongated electrically conductive structure extends through the bonding interface to contact the second electrically conductive contact pad.

8. The bonded structure of claim 7, wherein the first element further comprises a third electrically conductive contact pad of the first plurality of electrically conductive contact pads at the front side of the first element, and wherein the second element further comprises a fourth electrically conductive contact pad of the second plurality of electrically conductive contact pads at the front side of the second element, the third electrically conductive contact pad directly bonded to the fourth electrically conductive contact pad.

9. The bonded structure of claim 8, wherein the laterally elongated electrically conductive structure is disposed between and contacts the second electrically conductive contact pad and the third electrically conductive contact pad. ​ 10. The bonded structure of claim 8, wherein the laterally-elongate conductive structure contacts the fourth conductive contact pad.

11. The bonded structure of claim 8, further comprising a via extending at least partially through the first element from a backside of the first element, the via in contact with the third conductive contact pad.

12. The bonded structure of claim 11, wherein the laterally-elongate conductive structure extends at least partially through the second non-conductive field region.

13. The bonded structure of claim 12, wherein the laterally-elongate conductive structure extends completely through the second non-conductive field region and partially through a bulk semiconductor portion of the second element.

14. The bonded structure of claim 13, wherein the laterally-elongate conductive structure extends through an entire thickness of the bonded structure.

15. The bonded structure of claim 11, wherein the laterally-elongate conductive structure contacts a first conductive contact pad of the first plurality of conductive contact pads or a second conductive contact pad of the second plurality of conductive contact pads.

16. The bonded structure of claim 1, wherein the second element further comprises a lateral feature at least partially embedded in the second non-conductive field region, the laterally-elongate conductive structure extending through at least a portion of the second non-conductive field region to contact the lateral feature.

17. The bonded structure of claim 16, wherein the lateral feature comprises a ring disposed around the integrated device.

18. The bonded structure of claim 1, wherein the laterally-elongate conductive structure is exposed on an outermost surface of the bonded structure.

19. The bonded structure of claim 1, further comprising a second laterally-elongate conductive structure extending from a backside of the second element opposite a front side of the second element to the bonding interface, the second laterally-elongate conductive structure providing an effective closed contour around the integrated device.

20. The bonded structure of claim 1, wherein one conductive contact pad of the first plurality of conductive contact pads and one conductive contact pad of the second plurality of conductive contact pads define a first pair of bonding pads, and another conductive contact pad of the first plurality of conductive contact pads and another conductive contact pad of the second plurality of conductive contact pads define a second pair of bonding pads, the laterally-elongate conductive structure being located between the first pair of bonding pads and the second pair of bonding pads, and the first pair of bonding pads and the second pair of bonding pads being electrically connected by an interconnect.

21. A bonded structure, comprising: a first element having a semiconductor region; a second element bonded to the first element along an interface structure, the interface structure comprising a conductive interface feature and a non-conductive interface feature disposed around the conductive interface feature, the conductive interface feature providing a mechanical and electrical connection between the first element and the second element; an integrated device coupled to or formed in the first or second element; a laterally elongated conductive structure disposed in a trench extending from a backside of the first element through the semiconductor region to and at least partially through the interface structure, the laterally elongated conductive structure providing an effective closed profile around the integrated device.

22. The bonded structure of claim 21, wherein the conductive interface feature comprises a plurality of directly bonded conductive pads disposed around the integrated device.

23. The bonded structure of claim 21, wherein the first and second elements are directly bonded without an intervening adhesive.

24. The bonded structure of claim 21, further comprising a via extending at least partially through the first element from a backside of the first element, the via in contact with the conductive interface feature.

25. The bonded structure of claim 21, wherein the laterally elongated conductive structure extends through the interface structure.

26. The bonded structure of claim 21, wherein the laterally elongated conductive structure extends through an entire thickness of the bonded structure.

27. A method of forming a bonded structure, comprising: providing a first element including a first contact pad at a bonding surface of the first element; providing a second element including a second contact pad at a bonding surface of the second element; directly bonding the first contact pad of the first element to the second contact pad of the second element along an interface structure without an intervening adhesive, the interface structure providing mechanical and electrical connections between the first and second elements; after the direct bonding, forming a laterally elongated channel from a backside of the first element, through a semiconductor region of the first element, at least to the interface structure; and after forming the laterally elongated channel, providing a laterally elongated conductive structure within the channel, the laterally elongated conductive structure extending continuously around a plurality of sides of an integrated device coupled to or formed in the first or second element.

28. The method of claim 27, wherein bonding comprises: directly bonding a first non-conductive field region of the first element to a second non-conductive field region of the second element along the interface structure without an intervening adhesive.

29. The method of claim 27, wherein forming the laterally-elongated channel comprises: forming the laterally elongated channel from a backside of the first element at least to the bonding surface of the second element.

30. The method of claim 27, wherein forming the laterally-elongated channel comprises: forming the laterally elongated channel through an entire thickness of the bonded structure from a backside of the first element.

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