Power distribution for stacked electronic devices

Abstract

A stacked electronic device is disclosed. The stacked electronic device has a die stack including two or more interconnected dies, for example a lower die, an upper die, and a middle die between the lower die and the upper die. A plurality of through-substrate vias (TSVs) can provide signal transmission to the dies of the stack. A power supply line is configured to provide power to the middle die without passing power through the lower die. In some embodiments, an external line can provide power through a top surface of the upper die of the stack, while signals are provided through a bottom surface.

Description

[Technical field]

[0001] The technical field relates to stacked electronic devices, and in particular to power distribution for stacked electronic devices.

[0002] [Citation to Related Applications] This application claims priority to U.S. Provisional Patent Application No. 63 / 263004, filed on October 25, 2021, entitled POWER DISTRIBUTION FOR STACKED ELECTRONIC DEVICES, which is incorporated by reference in its entirety and incorporated herein by reference for all purposes. [Background technology]

[0003] Multiple semiconductor elements (e.g., integrated device dies) may be stacked on top of each other in various applications, such as processors, high bandwidth memory (HBM) devices, or other devices that utilize vertical integration. The stacked elements can be in electrical communication with each other. Signals and power can be transmitted through the die via through substrate vias (TSVs). Summary of the Invention

[0004] According to one aspect of the invention, there is provided an apparatus comprising: a die stack including at least three interconnected dies, the dies including a lower die, an upper die, and an intermediate die between the lower die and the upper die; having a plurality of through-substrate vias (TSVs) that enable signal transmission to a die in the die stack; An apparatus is provided that includes a power supply line configured to provide power to a middle die without passing power to a bottom die.

[0005] According to another aspect of the invention, there is provided an apparatus comprising: a stack of multiple stacked dies including signal through-substrate vias (TSVs); and bond wires or edge traces that provide power to one or more dies above the bottom die in the stack.

[0006] According to yet another aspect of the present invention, there is provided a method of manufacturing an electronic module, comprising the steps of: mechanically and electrically coupling at least three dies in the stack, the coupling step including enabling signal connections between the dies via through-substrate vias (TSVs); A method is provided that includes providing power connection lines to a middle die in a stack without conducting power through TSVs.

[0007] According to yet another aspect of the present invention there is provided an apparatus comprising: a die stack including at least two interconnected dies, the dies including an upper die and a lower die having an active front surface and a rear surface, the upper die being attached to the rear surface of the lower die; a plurality of through-substrate vias (TSVs) through the lower die, the TSVs enabling signal transmission to an upper die in the die stack; An apparatus is provided having power supply lines configured to provide power to a back surface of a lower die, the lower die including power vias that conduct power from the back surface to devices on the lower die without passing through all metallization levels of the lower die.

[0008] According to yet another aspect of the present invention, there is provided a die stack comprising: a plurality of stacked dies, at least a bottom die of the stacked dies having through substrate vias (TSVs) extending from an upper die surface to a lower die surface; A die stack is provided that includes an external power supply line that provides power to at least one die in the die stack without passing power through the bottom die.

[0009] According to yet another aspect of the present invention, there is provided an integrated circuit die comprising: a semiconductor substrate portion having a front surface and a back surface that includes at least some portion of an integrated device; a back-end-of-line (BEOL) portion formed on the semiconductor substrate portion, the BEOL portion including a metal interconnect; a plurality of through-substrate vias (TSVs) extending through the BEOL portion and the semiconductor substrate portion; An integrated circuit die is provided that features power supply vias that extend from a backside of a semiconductor substrate portion to an integrated device without extending entirely through a BEOL portion. [Brief description of the drawings]

[0010] [Figure 1] 1 is a schematic cross-sectional view of a stack of multiple integrated device dies, carriers, and through-substrate vias (TSVs) configured to enable power delivery and signal transfer. [Diagram 2] FIG. 1 illustrates a schematic cross-section of a stack of multiple integrated device dies arranged in a stair-like configuration, a carrier, TSVs configured to enable signal transmission, a first set of wiring layers, a second set of wiring layers, a first power supply line, and a second power supply line, in accordance with one embodiment. [Diagram 3] FIG. 1 illustrates a schematic cross-section of a stack of multiple integrated dies, a carrier, TSVs configured to enable signal transfer, first and second sets of wiring layers, and edge traces on the sidewalls of the stack, according to another embodiment. [Figure 4] FIG. 1 illustrates a schematic cross-section of a stack of two integrated device dies, a carrier, TSVs configured to enable signal transfer and power transmission, a first set of wiring layers, and a first power supply line in accordance with another embodiment. [Diagram 5] FIG. 2 illustrates a schematic cross-section of a first set of wiring layers including a power distribution network (PDN) in accordance with another embodiment. [Figure 6]FIG. 1 illustrates a schematic cross-section of a stack of multiple integrated device dies, a carrier, TSVs configured to enable signal transmission, first and second sets of wiring layers, edge traces on sidewalls of the stack, and a heat sink overlying the die stack, in accordance with another embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] The same reference numbers are used throughout the detailed description and drawings to refer to like features.

[0012] Power distribution to multiple dies in a die stack is a challenge, which becomes even more challenging as the stack grows taller. Currently, the technology trend for wiring the die stack is through through-substrate vias (TSVs). Advantageously, direct lines through the die stack can be efficiently provided via TSVs, especially when the die stack is connected by direct hybrid bonding. However, with respect to power distribution, TSVs are relatively resistive, dissipate power and generate heat, and take up a significant amount of space within the die. Thus, delivering power to the top of the die stack becomes more difficult as the number of dies in the stack increases. Various embodiments disclosed herein use TSVs to deliver signals through the die stack, but provide power to the middle of the stack without passing it through the lower dies. For example, a power distribution network (PDN) can be provided between the top surface of a first die and the bottom surface of a second die located above the first die. In various embodiments, peripheral connections (e.g., wires or tab bonds in edge traces, conductive paste, plated copper) can bring the power to the PDN without first passing it through the lower die, and the TSVs can be used for signaling without sacrificing power distribution through the die. Thus, power can be brought to multiple dies in a die stack without passing it through the TSVs in the lower die. In some embodiments, power is provided through normal carrier connections (solder balls, direct bonds, wire bonds) and thus is provided into the package without a separate connection to the motherboard. In other embodiments, power can be brought to the motherboard through a separate connection (e.g., wire bonds) from the motherboard. Such configurations have utility in various applications where solder bumps cannot be tolerated, such as automotive under-the-hood applications.For example, in some embodiments, at least one die in a die stack (e.g., the bottom (lowest) die) can receive power from its top surface (e.g., reverse or back surface) while receiving signals from its bottom surface (e.g., front surface), thereby freeing up space at the interface of the carrier and back-end-of-line (BEOL) layer of the bottom die. In other embodiments, signals are provided to the middle and top dies of the stack through TSVs in the lower die, while power is provided to the middle and top dies of the stack without first passing through the lower die.

[0013] Power distribution that bypasses the lower die with signals utilizing TSVs benefits a variety of die stack fabrications in a variety of electronic applications. Such a configuration advantageously facilitates signal routing with minimal loss while also facilitating power distribution with minimal loss and minimal heat generation, and such power distribution can be done across multiple power / voltage domains. Power distribution independent of constraints on signal routing through TSVs can be beneficial in a wide variety of applications.

[0014] For example, in radio frequency (RF) communication systems, such as cellular systems (e.g., 4G, LTE, 5G, etc.), Bluetooth, Wi-Fi, satellite, etc., the signal chain converts digital to RF signals, where the power supply requirements at each point in the signal chain are different from each other. In many applications, there are at least three dies (or chips) in the signal chain: a digital baseband processor, a transceiver that converts digital signals from the baseband processor to RF transmit signals and RF receive signals from the RF front end to digital signals for the baseband processor, and an RF front end that performs signal conditioning (e.g., amplification, switching, duplexing, diplexing, and / or filtering). A power distribution network for a multi-layer die stack as described herein allows for the fabrication of various combinations of these chips. In one embodiment, the die stack may include the three chips described in the signal chain (i.e., the baseband processor, the transceiver, and the RF front end). In another embodiment, the die stack can include two dies, where the first die further includes a combination baseband processor and transceiver, and the second die includes a front-end die. In another embodiment, the die stack can include two dies, where the first die further includes a combination baseband processor and transceiver, and the second die includes an RF front-end die. In another embodiment, the die stack can include two dies, where the first die further includes a combination baseband processor and transceiver, and the second die includes an RF front-end die.

[0015] The power distribution for multi-layer die stacks described herein can also be used in controller / regulator chipsets, processor-memory applications, digital processing combined with analog front-ends, and more. For controller / regulator chipsets, most electronics are powered by some type of voltage regulator. This voltage regulator can be a DC-DC converter (e.g., operating from a battery voltage) or an AC-DC converter. Examples of voltage regulators include step-down converters, boost converters, switching regulators, and power management integrated circuits (PMICs). Each of these types of voltage regulators is controlled by a controller chip, often a pulse-width modulation (PWM) controller. The voltage regulator and controller chips operate under different technologies, and the voltage regulator is often a different process technology (e.g., GaN devices).

[0016] In processor-memory applications, die stacks that may benefit from signaling through TSVs with independent power distribution lines include a two-die stack where one die includes a CPU and the other includes a memory die, a two-die stack where one die includes a GPU and the other includes a memory die, and a three-die stack where one die includes a CPU, a second die includes a GPU, and a third die includes a memory die. For all of these examples, benefits may be gained from stacking multiple memory dies by various processes, where the stack includes at least two memory dies, and where the memory die stack further includes independent signaling and power distribution as described herein.

[0017] For digital processing in analog front-end applications, a digital processing chip (e.g., a CPU, microcontroller, or digital signal processing (DSP)) is often combined with an analog front-end that can provide basic amplification of the analog signal as well as analog-to-digital and digital-to-analog conversion. The digital signal chip then provides the algorithms to process this data. The digital processing chip and the analog front-end are in some cases combined with a sensor chip. The analog and digital chips may have different power supply requirements for a number of different voltage domains, and the sensor chip may have even different power requirements. Thus, different stacks of dies can be formed using multiple power distribution networks for the multiple die stacks described herein, i.e., a two-die stack where one die includes an analog front and a second die includes a digital processing chip, a two-die stack where one die includes an analog front end and a second die includes a sensor, and a three-die stack where one die includes a digital processing chip, a second die includes an analog front end, and a third die includes a sensor.

[0018] Additional examples of technologies that may benefit from the power distribution and signaling systems described herein include radar chipsets, LiDAR chipsets (or more generally optical / photonic chipsets), serializer / deserializer (SerDes) chipsets for high speed data transmission, MEMS applications, automotive chipsets, clock and timing distribution. High performance clock generation chips may be stacked with one or more other chips for wireless infrastructure, instrumentation, or automatic test equipment (ATE applications), and bus applications (e.g., bus controllers and bus transceivers).

[0019] FIG. 1 shows a stack 1 of multiple integrated device dies attached to a carrier 2, such as another larger die, an interposer, a base device, or a package substrate (e.g., a printed circuit board, a ceramic substrate, etc.). A metallization layer 3 (e.g., a back-end-of-line, or BEOL layer) may be deposited on a semiconductor layer 17 having a front surface 4 of each die. A first die 1a may be attached face-down to the carrier 2, a second middle die 1b may be attached face-down to the first die 1a, and a third upper die 1c may be attached face-down to the second die 1b. Through-substrate vias 5 (TSVs) including a dielectric lining layer 5a and a conductive material 5b may extend through the first die 1a and the second die 1b to electrically couple to one or more of the first die 1a, the second die 1b, and the third die 1c. For example, as shown, one or more of the TSVs 5 may be electrically coupled to the first die 1a, the second die 1b, and / or the third die 1c. In the stacked structure of FIG. 1, the TSVs 5 may provide electrical communication to the carrier 2 for power, signaling, and ground (sometimes referred to as ground). However, TSVs have a relatively high resistance, which dissipates power sent along the TSVs. Thus, it would be advantageous, particularly in conjunction with direct hybrid bonding, to reduce the power consumption associated with using TSVs for power distribution while retaining the benefits of using TSVs to transmit signals.

[0020] FIG. 2 illustrates one embodiment of a stacked electronic device 15. The stacked electronic device 15 includes a die stack 1 attached to a carrier 2, such as another larger die, an interposer, a base device, a packaging substrate (e.g., a printed circuit board, a ceramic substrate, etc.), another base device, or a system board. In some embodiments, the die stack 1 forms an IC package to be mounted on a system board. In some embodiments, the stacked electronic device 15 including the carrier 2 forms an IC package to be mounted on a system board. The die stack 1 may include at least three interconnected dies. The dies may include a first lower die 1a, one or more second intermediate dies 1b (one shown), and a third upper die 1c. The second intermediate die 1b may be disposed between the first lower die 1a and the third upper die 1c. The first die 1a, the second die 1b, and the third die 1c may be comprised of the same type of die, or one or more of the dies may be different from each other. In various embodiments, for example, one or more of the dies may include a processor die, a memory die, etc., such as those described above for RF communication chipsets, voltage regulator chipsets, memory stacks deposited on graphics or central processors, digital processing chipsets with analog front ends, radar chipsets, LiDAR chipsets (or more generally optical / photonic chipsets), serializer / deserializer (SerDes) chips for high speed data transmission, MEMS applications, automotive chipsets, chipsets for clock and timing distribution, etc. Each die may have an active front side 4 and a back side 6. Active circuitry (e.g., at least one transistor) may be provided at or near the active front side 4. In some embodiments, the back side 6 may be free of active circuitry.

[0021] A through substrate via (TSV) 13 or multiple through substrate vias (TSVs) 13, each including a dielectric layer 13a and a dielectric material 13b, may be provided through at least the first lower die 1a and the second intermediate die 1b to enable signal transmission to the dies in the stack 1. The semiconductor layer 17 may be made of bulk or epitaxial single crystal semiconductor material for integrated circuit dies, or other substrate materials, such as quartz or ceramic, for other types of devices, such as interposers. As shown in FIG. 2, the TSV 13 can only provide signal transmission, but cannot distribute power to the second die 1b and the third die 1c. Alternatively, as shown in FIG. 2, a first external power supply line 7 (e.g., a first wire bond or tab bond) may be configured to provide power to the second intermediate die 1b and / or other dies in the stack. A second external power supply line 8 (e.g., a second wire bond or tab bond) may be configured to provide power to the third upper die 1c. The external power supply lines 7, 8 may provide power to the middle die 1b and / or the upper die 1c from a die or board (e.g., from the carrier 2 as shown) located below the lower die 1a, such that the power supply lines 7, 8 bypass the lower die 1a. In some embodiments, the power supply for the lower die 1a may be provided from a lower surface (front surface 4 in the illustrated orientation) of the lower die 1a. In other embodiments, the power supply to the lower die may be provided from a surface 26 of the lower die. In other embodiments, the external power supply lines provide power to the middle die and / or the lower die from a power source located above the upper die and bypass the upper die. In yet other embodiments, some of the power supplies for the middle die and / or top die are provided through TSVs in the lower die, while other power supplies for the middle die and / or top die are provided through external power supply lines, such as wire bonds as shown, without passing through the lower die.

[0022] In FIG. 2, the lower die 1a is disposed face down (e.g., with its active front surface 4 down) on the carrier 2, the middle die 1b is disposed face down (e.g., with its active front surface 4 down) on the lower die 1a, and the third die 1c is disposed face down (e.g., with its active front surface 4 down) on the middle die 1b. In some embodiments, the back surface 6 may be devoid of active circuitry. Thus, in the illustrated embodiment, with the active surfaces, i.e., front surfaces 4, of the dies 1a, 1b, and 1c facing down, the bottom surfaces of the dies in the stack are the front surfaces 4 of the dies, and the top surfaces of the dies are the back surfaces 6. Those skilled in the art will recognize that in other embodiments, some or all of the dies may instead be stacked face up, such that their top surfaces are their front surfaces. As shown, the top surface (back surface 6 in the illustrated embodiment) of the lower die 1a has a first wiring structure 9 with a first power distribution network (PDN) configured to distribute power from a first external power supply line 7 (lower wirebonds) to the middle die 1b. The top surface (back surface 6 in the illustrated embodiment) of the middle die 1b has a second wiring structure 10 with a PDN configured to distribute power from the first external power supply line 7 (upper wirebonds) to the upper die 1c. Furthermore, the wiring structures 9, 10 on the top surfaces of the lower die 1a and / or middle die 1b may further include a ground wiring network. Ground connection lines may also extend from outside the stack 1 (e.g., via additional wirebonds or tabs) to the middle die 1b and / or upper die 1c. In some embodiments, the first and / or second power supply lines may have a cross-sectional area that is greater than or equal to two times the average cross-sectional area of ​​the TSVs, greater than or equal to four times the average cross-sectional area of ​​the TSVs, greater than or equal to ten times the average cross-sectional area of ​​the TSVs, or greater than or equal to twenty times the average cross-sectional area of ​​the TSVs.

[0023] The wiring structures 9, 10 are shown as multi-layer structures integral with the die located below them, similar to a redistribution layer (RDL) and including multiple deposited and patterned metal layers separated by deposited dielectric layers and connected by vias. Inorganic dielectric layers, such as those described above, can advantageously facilitate hybrid direct bonding. As will be appreciated by those skilled in the art, while the illustrated wiring structures are deposited and patterned layers integral with the die located below them, in other embodiments the wiring structures distributing power from external power supply lines to the die need not be so formed. For example, in some embodiments the wiring structures may be integral with the undersides of the overlying dies (front surface 4 of middle die 1b and top die 1c). In still other embodiments, the distribution of externally supplied power can be achieved within the metallization layer 3 (e.g., BEOL) of the die itself. However, whether the illustrated separate wiring structures 9,10 between the dies of the stack are laterally coextensive with the overlying die or laterally coextensive with the underlying die, they can advantageously provide a more conductive path for power distribution compared to most BEOL lines. Those skilled in the art will appreciate that the wiring structures 9,10 can further include insulating features between ground and power / voltage domains and / or between voltage domains. For example, capacitor and / or inductor structures can be provided within the wiring structures between power distribution layers or between laterally separate voltage domains for separate power distribution.

[0024] As shown in FIG. 2, the stack may have a stepped profile 14 that provides a ledge for wire bond connections. Thus, the die stack may consist of different sized dies. For example, a larger die, e.g., a processor die, may be located on the bottom of the stack, whereas smaller dies are provided for the middle and / or top dies. The edges of the dies in the die stack may be laterally offset relative to each other to provide the ledge. In other embodiments, the stack may consist of dies of the same size, and the dies may be laterally offset to provide the ledge. In some embodiments, different voltages are provided for the different dies belonging to the die stack. Furthermore, although only one bond wire 7,8 is shown in the schematic cross-section of FIG. 2 at each die level for the middle / top die, one skilled in the art will appreciate that more than one power source may be provided to each die through multiple external power supply lines at the same level (e.g., multiple wire bonds at each wiring structure 9,10). Thus, multiple power / voltage domains may be provided at each level. In some embodiments, the external power supply line delivers power to the intermediate die through the back side of the intermediate die. For example, the top wire bond (second supply line) may be coupled to the second wiring structure to provide power to the intermediate die through the back side of the intermediate die. In other embodiments, the external power supply line delivers power to the intermediate die through the front side of the intermediate die. For example, the bottom wire bond (first supply line) may be coupled to the first PDN adjacent the front side of the intermediate die to provide power to the front side of the intermediate die. As mentioned above, in some embodiments, there may be no TSVs delivering power through a portion of the die stack. In other embodiments, additional internal power supply lines may be provided through the power TSVs that extend through the first and / or second die.

[0025] Although the die stack 1 of Figure 2 includes three dies, in other embodiments, the die stack can have multiple intermediate dies between the upper and lower die, such that the die stack has a total of four or more dies. In some embodiments, separate external power supply lines may be provided for each of the intermediate dies. In other embodiments, separate power supply lines are provided for some of the intermediate dies, while internal power supply lines (e.g., power TSVs) are provided for others of the intermediate dies.

[0026] The bottom die 1a may be attached to the carrier 2 in any suitable manner. In the illustrated embodiment, the bottom die 1a is direct hybrid bonded to the carrier, thereby providing a reliable mechanical link from the die to the carrier and allowing reliable low resistance connections for signals, ground and any internal power sources. However, in other embodiments, the bottom die may be bonded to the carrier by another bonding technique, such as thermocompression bonding (TCB), solder bonding, etc. The middle die 1b may be bonded to the bottom die 1a in any suitable manner, and the top die 1c may be bonded to the middle die 1b in any suitable manner. In some embodiments, the middle die 1b is direct hybrid bonded to the bottom die 1a and the top die 1c is direct hybrid bonded to the middle die 1b via intervening wiring structures 9, 10, respectively. Thus, the relevant surfaces of the die and / or wiring structures 9, 10 may include an inorganic dielectric that is pretreated for direct bonding, including extensive polishing and activation / termination, as described below. In other embodiments, one or more of the die may be bonded by another bonding technique, such as TCB, solder bonding, etc.

[0027] FIG. 3 illustrates another embodiment of a stacked electronic device 15. Unless otherwise noted, the components in FIG. 3 are the same or nearly the same as those in FIG. 2, and the variations described above with reference to FIG. 2 are equally applicable to the embodiment of FIG. 3. Unlike FIG. 2, where the external power supply lines are made of bonds or tab bonds, in the embodiment of FIG. 3, the external power supply lines are made of one or more edge traces 12 (sometimes also referred to as sidewall traces) along the sidewalls 16 of the die stack 1. In some embodiments, the edge traces 12 are made of a hardened conductive paste. In some embodiments, the edge traces 12 are made of a plated metal, such as copper. As with the wiring structures 9, 10 described above with reference to FIG. 2, the edge traces 12 may be made of multiple patterned metal layers separated by dielectric layers and connected by vias, and may include insulation between ground and power traces or levels, and / or between traces or levels representing different voltage domains. In various embodiments, the edge trace 12 may be substantially similar to the edge trace described in U.S. Pat. No. 8,461,673, which is incorporated by reference and incorporated herein in its entirety for all purposes.

[0028] Figure 4 illustrates another embodiment of a stacked electronic device 27. Unless otherwise noted, the components in Figure 4 are the same or substantially the same as those in Figure 2, and the variations discussed above with reference to Figure 2 are similarly applicable to the embodiment of Figure 3. In addition, although the external power supply lines in Figure 4 are shown as wire bonds 7 similar to the wire bonds in Figure 2, the power supply lines in Figure 4 could instead take the form of edge traces substantially similar to the edge traces in Figure 3.

[0029] In FIG. 4, the stacked electronic device 27 includes a die stack 19 attached to a carrier 2, such as another larger die, an interposer, a base device, a package substrate (e.g., a printed circuit board, a ceramic substrate, etc.), another base device, or a system board. The die stack may include at least two interconnected dies. The dies may include a first lower die 19a and a second upper die 19b. A through substrate via (TSV) 13 or multiple through substrate vias (TSVs) 13, each including a dielectric layer 13a and a dielectric material 13b, may be provided through at least the first lower die 19a to enable signal transfer to the dies in the stack 19. As described for the embodiments of FIGS. 2 and 3, the TSVs 13 may provide only signal transfer or may additionally provide ground or reference voltages, and in some embodiments, the TSVs 13 may also provide a subset of power sources. 4, a first external power supply line 7 (shown as a first wire bond or tab bond) may be configured to provide power to devices in at least the first die 19a. The external power supply line 7 may provide power to the lower die 19a from a board (e.g., the illustrated carrier 2) located below the lower die 19a, such that the supply line 7 bypasses the lower die 19a.

[0030] In FIG. 4, the lower die 19a is attached face down (e.g., active front surface 4 is the bottom surface) to the carrier, and the upper die 19b is attached face down (e.g., active front surface 4 is the bottom surface) to the lower die 19a. In some embodiments, the back surface 6 may be free of active circuitry. As shown, the back surface 6 of the lower die 19a includes a first wiring structure 9 having a first PDN configured to distribute power from a first external power supply line 7 (wirebond in the illustrated embodiment) to the lower die 19a. In addition, the back surface 6 of the lower die 19a may further include a ground wiring network. Ground connection lines may also extend from outside the stack 19 to the lower die 19a and / or the upper die 19b (e.g., via additional wirebonds or tabbonds), just as additional external power supply lines may be coupled to the wiring structure 9. A number of TSVs 18, including a dielectric liner layer 18a and conductive material 18b, may extend through at least the substrate of the lower die 19a to enable power to be provided from the top surface (wiring structure 9) to the devices of the lower die 19a. Because the TSVs 18 extend only through a portion of the substrate of the lower die 19a and not through metallization layer 3 (all of metallization layer 3), the TSVs 18 may be considered "nanoTSVs." Advantageously, power is provided through at least the power supply lines 7. The power supply does not need to be routed through the dense metallization layer 3 (e.g., BEOL) of the lower die 19a. In some embodiments, the upper die 19b can also receive a power supply from the first wiring structure 9 having a first PDN, and additional middle or upper dies may be provided deposited on the illustrated die stack 19. The dies may be direct hybrid bonded to each other, and the lower die 19a may also be direct hybrid bonded to the carrier 2.

[0031] FIG. 5 is an expanded view of the wiring layer 9, which in one embodiment is comprised of multiple separate metal layers. For example, as shown in FIG. 5, the multiple separate metal layers may further include a ground plane 21 and a power plane 22. A plurality of vias 20 are configured to connect the separate layers in the wiring layer 9 to each other and / or to an upper and / or lower die in the die stack. A power pad 25 allows a connection from the via 20 connected to the power layer 22 to the die, and a ground pad 24 allows a connection from the ground plane 21 to the die. The wiring layer 9 further includes a plurality of signal pads 23, each of which allows a connection from the die through the wiring layer 9 (not shown) to a TSV configured to send a signal to another conductive trace. In some embodiments, multiple power layers may be provided, each of which provides power from a single power source for a single voltage domain and is coupled to an upper or lower die in the die stack through a separate power pad 25. In one embodiment, a first power layer may be provided to provide a first voltage and a second power layer may be provided to provide a second voltage, where the first and second voltages may be the same or different. In another embodiment, a single power layer may be patterned to deliver multiple power supplies for multiple voltage domains, where each voltage domain is configured to provide an independent voltage. In one embodiment, a first power layer may be provided having a first voltage domain to provide a first voltage and a second voltage domain to provide a second voltage, where the first voltage of the first voltage domain may be the same or different from the second voltage of the second voltage domain. As mentioned above, insulating structures, such as capacitors and / or inductors, may also be provided between ground and power traces or levels and / or between voltage traces for different voltage domains.

[0032] FIG. 6 illustrates another embodiment showing a die stack 15 with an overlying element disposed on the top of the die and not associated with power delivery. In the illustrated embodiment, the overlying element may be a heat sink 28, which may be directly bonded to the top (e.g., back) surface of the top die 1c or to an intervening wiring structure (not shown). Such a heat sink may be omitted if power must be delivered from the top surface of the stack 15, rather than from the back surface as shown. In the illustrated embodiment, edge traces 12 provide power to the middle die 1b, and these edge traces may also provide power to the bottom die 1a and the top die 1c. Additionally, power, ground and / or other traces in the edge traces 12 may provide a thermal path from the bottom and middle die 1a, 1b to the heat sink 28. The intervening wiring structures 9, 10 can also help extract heat from the die and route the heat from the illustrated edge traces 12 to the heat sink 28. Additionally or alternatively, a thermal path from the die stack 15 can be provided by TSVs 29 including dielectric layers 29a and conductive layers 29b, which can be stacked TSVs for each die, similar to TSV 13, or via-last TSVs through the die stack 15 including the wiring structures 9, 10. Such TSVs can help extract heat to the heat sink 28. The illustrated TSVs 29 can also help carry power, ground, or signals if they are thermally coupled to the heat sink 28 without electrical connection (e.g., through an electrically insulating but thermally conducting intervening layer). In some embodiments, the heat sink 28 can also be grounded, which is electrically connected to the ground plane of the die stack 15. Because power is delivered to the backside of the die from side traces located outside the die stack 15, the heat sink 28 does not interfere with the power delivery to the backside.

[0033] Examples of direct bonding methods and directly bonded structures Various embodiments disclosed herein relate to a direct bonded structure in which two or more elements can be directly bonded together without an intervening adhesive. The two or more elements can be directly bonded together at a bond interface without an intervening adhesive. Two or more microelectronic elements (e.g., semiconductor elements including integrated device dies, wafers, passive devices, and individual active devices such as power switches) can be stacked or bonded together to form a bonded structure. A conductive feature (e.g., a contact pad, an exposed end of a via (e.g., TSV), or a through-substrate electrode) of one element can be electrically connected to a corresponding conductive feature of another element. Any suitable number of elements can be stacked in the bonded structure. For example, a third element can be stacked on a second element, a fourth element can be stacked on a third element, and so on. Additionally or alternatively, one or more additional elements can be stacked laterally adjacent to one another along the first element. In some embodiments, the laterally stacked additional elements can be smaller than the second element. In some embodiments, the additional element stacked laterally may be 1 / 2 the size of the second element.

[0034] In some embodiments, the elements are directly bonded to each other without adhesive. In various embodiments, a non-conductive field region comprising a non-conductive or dielectric material may serve as a first bonding layer of the first element, and the first bonding layer may be directly bonded to a corresponding non-conductive field region comprising a non-conductive or dielectric material that serves as a second bonding layer of the second element without adhesive. The non-conductive bonding layer may be provided on a front surface of each of the device portions, e.g., semiconductor (e.g., silicon) portions of the element. Active devices and / or circuits may be patterned and / or otherwise provided in or on the device portions. The active devices and / or circuits may be provided at or near the front surface of the device portion and / or at or near the opposite back surface of the device portion. A bonding layer may be provided on the front surface and / or back surface of the element. The non-conductive material may be referred to as a non-conductive bonding region or bonding layer of the first element. In some embodiments, the non-conductive bonding layer of the first component may be directly bonded to the corresponding non-conductive bonding layer of the second component using a dielectric-to-dielectric bonding technique. For example, the dielectric-to-dielectric bond may be formed without adhesive using a direct bonding technique as disclosed in at least U.S. Patent Nos. 9,564,414, 9,391,143, and 10,434,749, each of which is incorporated by reference and incorporated herein in its entirety for all purposes. It should be understood that in various embodiments, the bonding layer may be comprised of a non-conductive material, such as a dielectric, such as silicon oxide, or an undoped semiconductor material, such as undoped silicon. Suitable dielectric bonding surfaces or materials for direct bonding include, but are not limited to, inorganic dielectrics such as silicon oxide, silicon nitride, silicon oxynitride, or may include materials containing carbon, such as silicon carbide, silicon oxycarbonitride, low-k dielectrics, SiCOH dielectrics, silicon carbonitride, or diamond-like carbon or diamond surfaces.Such carbon-containing ceramic materials may be considered inorganic despite the presence of carbon. In some embodiments, the dielectric does not include a polymeric material, such as an epoxy, resin, or molding compound.

[0035] In some embodiments, the device portions may have significantly different coefficients of thermal expansion (CTE) that define a heterogeneous structure. The difference in CTE between the device portions, especially between the bulk semiconductor, typically single crystal portions of the device portions, may be greater than 5 ppm, or greater than 10 ppm. For example, the difference in CTE between the device portions may be in the range of 5 ppm to 100 ppm, 5 ppm to 40 ppm, 10 ppm to 100 ppm, or 10 ppm to 40 ppm. In some embodiments, one of the device portions may be made of optoelectronic single crystal materials (including perovskite materials) useful for opto-piezoelectric or pyroelectric applications, while the other of the device portions is made of more conventional substrate materials. For example, the device portion may be made of lithium tantalate (LiTaO3) or lithium niobate (LiNbO3), and the other of the device portions may be made of silicon (Si), quartz, fused silica glass, sapphire, or glass. In other embodiments, one of the device portions may be made of a single III-V semiconductor material, such as gallium arsenide (GaAs) or gallium nitride (GaN), and the other of the device portions may be made of a non-III-V semiconductor material, such as silicon (Si), or other material with a similar CTE, such as quartz, fused silica, sapphire, or glass.

[0036] In various embodiments, the direct hybrid bond can be formed without an intervening adhesive. For example, the non-conductive bonding surface can be polished to a high degree of smoothness. For example, chemical mechanical polishing (CMP) can be used to polish the non-conductive bonding surface. The polished bonding surface can have a roughness of less than 30 Å rms. For example, the bonding surface can have a roughness in the range of about 0.1 Å rms to 15 Å rms, 0.5 Å rms to 10 Å rms, or 1 Å rms to 5 Å rms. The bonding surfaces can be cleaned and exposed to plasma and / or etchants to activate the surfaces. In some embodiments, the surfaces can be terminated with chemical species after or during activation (e.g., during the plasma and / or etch process). Without being bound by theory, in some embodiments, an activation process may be performed to break chemical bonds at the bonding surface, and a termination process may provide one or more additional chemical species at the bonding surface that improves the bonding energy during direct bonding. In some embodiments, activation and termination may be provided in the same step, for example, the surface may be activated and terminated using a plasma. In other embodiments, the bonding surface may be terminated in a separate process to provide additional chemical species for direct bonding. In various embodiments, the termination chemical species may include nitrogen. For example, in some embodiments, the bonding surface may be exposed to a nitrogen-containing plasma. Additionally, in some embodiments, the bonding surface may be exposed to fluorine. For example, one or multiple fluorine peaks may be generated at or near the bond interface between the first and second elements. Thus, in a direct bonded structure, the bond interface between two non-conductive materials (e.g., bonding layers) can comprise a very smooth interface with a high nitrogen content and / or fluorine peak at the bond interface.Additional examples of activation and / or end grouping treatments can be found throughout U.S. Patent Nos. 9,564,414, 9,391,143, and 10,434,749, each of which is incorporated by reference and incorporated herein in its entirety for all purposes. The roughness of the polished bonding surface may be slightly rough (e.g., about 1 Å rms to 30 Å rms, 3 Å rms to 20 Å rms, or in some cases rougher) after the activation process.

[0037] In various embodiments, the conductive features of the first element may also be directly bonded to the corresponding conductive features of the second element. For example, direct hybrid bonding techniques may be used to provide conductor-to-conductor direct bonds along bond interfaces that include covalently directly bonded non-conductor (e.g., dielectric-dielectric) surfaces that have been pretreated as described above. In various embodiments, conductor-to-conductor (e.g., conductive feature-to-conductive feature) direct bonds and dielectric-to-dielectric hybrid bonds may be formed using direct bonding techniques as disclosed in at least U.S. Patent Nos. 9,716,033 and 9,852,988, each of which is incorporated by reference herein in its entirety for all purposes. In the direct hybrid bonding embodiments described herein, the conductive features are provided within a non-conductive bonding layer, and both the conductive and non-conductive features are pretreated for direct bonding, for example, by planarization, activation and / or end group treatments as described above. Thus, a bonding surface that has been pretreated for direct bonding has both conductive and non-conductive features.

[0038] For example, non-conductive (dielectric) bonding surfaces (e.g., including inorganic dielectric surfaces) can be pretreated and directly bonded to one another without an intervening adhesive as described above. Conductive contact features (e.g., conductive features), which may be at least partially surrounded by a non-conductive dielectric field region in the bonding layer, can also be directly bonded to one another without an intervening adhesive. In various embodiments, the conductive features may include separate pads or traces at least partially embedded within the non-conductive field region. In some embodiments, the conductive contact features may comprise exposed contact surfaces of through-substrate vias (TSVs), e.g., through-silicon via TSVs. In some embodiments, the conductive features may be recessed below the dielectric field region or the outer surface (e.g., top surface) of the non-conductive bonding layer, respectively, such as by less than 30 nm, less than 20 nm, less than 15 nm, or less than 10 nm, e.g., in the range of 2 nm to 20 nm or in the range of 4 nm to 10 nm. In various embodiments, prior to direct bonding, the recesses of the opposing elements may be dimensioned such that the total gap between the opposing contact pads is less than 15 nm, or less than 10 nm. The non-conductive bonding layers may be directly bonded together at room temperature without adhesive, and the bonded structure may then be annealed. Upon annealing, the conductive features may expand and contact each other, thereby forming intermetallic direct bonds. Beneficially, the use of Direct Bond Interconnect, or DBI® technology, commercially available from Adeia, Inc., San Jose, Calif., may allow for high density conductive features to be connected across the direct bond interface (e.g., with small or fine pitch for regular arrays). In some embodiments, the pitch of the conductive features, e.g., conductive traces embedded within the bonding surface of one of the bonded elements, may be less than 100 microns, less than 10 microns, or even less than 2 microns.For some applications, the ratio of the pitch of the conductive features to one of the dimensions of the bond pad (e.g., diameter) is less than 20, less than 10, less than 5, less than 3, and in some cases desirably less than 2. In other applications, the width of the conductive trace embedded in the bonding surface of one of the bonded elements may range from 0.3 microns to 20 microns (e.g., 0.3 microns to 3 microns). In various embodiments, the conductive features may be made of copper or a copper alloy, although other metals may be suitable. For example, the conductive features disclosed herein may be made of a fine-grained metal (e.g., fine-grained copper).

[0039] Thus, in a direct bonding process, a first element can be directly bonded to a second element without an intervening adhesive. In some configurations, the first element can be a singulated element, such as a singulated integrated device die. In other configurations, the first element can be a carrier or substrate (e.g., a wafer) that includes a plurality (e.g., tens, hundreds, or more) of device regions that, when singulated, form a plurality of integrated device dies. Similarly, the second element can be a singulated element, such as a singulated integrated device die. In other configurations, the second element can be a carrier or substrate (e.g., a wafer). Thus, the embodiments disclosed herein can be applied to a wafer-to-wafer (W2W) bonding process, a die-to-die (D2D) bonding process, or a die-to-wafer (D2W) bonding process. In a wafer-to-wafer (W2W) process, two or more wafers can be directly bonded (e.g., direct hybrid bonding) to each other and then singulated using a suitable singulation process. After singulation, the side edges of the singulated structure (e.g., the side edges of the two bonded elements) may be substantially flush with one another and may include indicia indicative of a common singulation process for the bonded structure (e.g., saw marks if a saw singulation process is used).

[0040] As described herein, the first and second elements can be directly bonded together without adhesive, which is different from the deposition process and results in a structurally different interface compared to deposition. In one application, the width of the first element in the bonded structure is approximately the same as the width of the second element. In some other embodiments, the width of the first element in the bonded structure is different from the width of the second element. Similarly, the width or area of ​​the larger element in the bonded structure may be at least 10% larger than the width or area of ​​the smaller element. Thus, the first and second elements may be comprised of non-deposited elements. Furthermore, unlike deposited layers, the direct bonded structure may include defect areas along the bond interface where nanoscale voids (nanovoids) exist. The nanovoids may form due to activation (e.g., exposure to plasma) of the bonding surface. As mentioned above, the bond interface may include a concentration of material resulting from activation and / or the final chemical treatment process. For example, in an embodiment utilizing nitrogen plasma for activation, a nitrogen peak may form at the bond interface. The nitrogen peak can be detected using a secondary ion mass spectrometer. In various embodiments, for example, a nitrogen endgroup treatment (e.g., exposing the bonding layer to a nitrogen-containing plasma) can replace the hydrolyzed (OH-terminated) surface with NH2 molecules, resulting in a nitrogen-terminated surface. In embodiments that utilize oxygen plasma for activation, an oxygen peak may form at the bond interface. In some embodiments, the bond interface may be comprised of silicon oxynitride, silicon oxycarbonitride, or silicon carbonitride. As described herein, the direct bond includes a covalent bond, which is stronger than a van der Waals bond. The bonding layer may further have a polished surface that is planarized to a high degree of smoothness.

[0041] In various embodiments, the metal-to-metal bonds between the conductive features may be bonded such that the metal grains grow into one another across the bond interface. In some embodiments, the metal may be or include copper, which may have grains oriented along (111) crystallographic planes to enhance copper diffusion across the bond interface. In some embodiments, the conductive features may include a nano-twinned copper crystal structure, which may aid in the coalescence of the conductive features during annealing. The bond interface may extend substantially completely to at least a portion of the bonded conductive features, such that there are substantially no gaps between the non-conductive bonding layers at or near the bonded conductive features. In some embodiments, a barrier layer may be provided under or laterally surrounding the conductive features, which may include copper, for example. However, in other embodiments, there may not be a barrier layer underneath the conductive features 106a, 106b, as described, for example, in U.S. Pat. No. 11,195,748, the entire contents of which are incorporated herein by reference for all purposes.

[0042] Beneficially, the use of the hybrid bonding techniques described herein allows for very fine pitches of adjacent conductive features and / or small pad sizes. For example, in various embodiments, the pitch p between adjacent conductive features (i.e., edge-to-edge or center-to-center distance) may be in the range of 0.5 microns to 50 microns, 0.75 microns to 25 microns, 1 micron to 25 microns, 1 micron to 10 microns, or 1 micron to 5 microns. Furthermore, the major lateral dimensions (e.g., pad diameter) may also be small, e.g., in the range of 0.25 microns to 30 microns, 0.25 microns to 5 microns, or 0.5 microns to 5 microns.

[0043] As described above, the non-conductive bonding layers may be direct bonded together without an adhesive, and then the bonded structure may be annealed. During annealing, the conductive features may expand and contact one another, thereby forming intermetallic direct bonds. In some embodiments, the materials of the conductive features may interdiffuse during the annealing process.

[0044] Exemplary embodiments of power distribution for stacked electronic devices In one aspect, an apparatus has a die stack including at least three interconnected dies, including a lower die, an upper die, and a middle die between the lower die and the upper die, the apparatus further having a number of through-substrate vias (TSVs) enabling signal transmission to the dies in the die stack, and a power supply line configured to provide power to the middle die without passing power through the lower die.

[0045] In some embodiments, the lower die is mounted with its active surface facing down and the middle die is mounted with its active surface facing down over the lower die, with the back surface of the lower die including a power distribution network configured to distribute power from the power supply line to the middle die. In some embodiments, the back surface of the lower die further includes a ground wiring network. In some embodiments, the device can further include a capacitor disposed between the power distribution network and the ground wiring network and the middle die. In some embodiments, the device can further include a second power supply line providing power from outside the die stack to the upper die in the die stack, with the back surface of the middle die including a second power distribution network providing power from the second power supply line to the upper die. In some embodiments, the device can further include a ground connection line from outside the die stack to the middle die. In some embodiments, the power supply line has a cross-sectional area that is at least two times the average cross-sectional area of ​​the TSVs. In some embodiments, the power supply line has a cross-sectional area that is at least four times the average cross-sectional area of ​​the TSVs. In some embodiments, the power supply line comprises a wire bond. In some embodiments, the apparatus may further comprise a ground wire bond that allows a ground connection for the intermediate die. In some embodiments, the die stack has a stepped profile that provides a step for the wire bond connection. In some embodiments, the die stack includes dies of different sizes. In some embodiments, the die stack includes dies of the same size. In some embodiments, edges of the dies in the die stack are laterally offset relative to one another to provide the step. In some embodiments, the power supply line has edge traces along the sidewalls of the die stack. In some embodiments, the edge traces include a hardened conductive paste. In some embodiments, the edge traces include a plated metal. In some embodiments, the plated metal is copper. In some embodiments, different voltages are provided for different dies in the die stack. In some embodiments, the power supply line delivers power to the intermediate die via a back surface of the intermediate die.In some embodiments, the power supply line delivers power to the intermediate die via a front surface of the intermediate die. In some embodiments, the apparatus may further include an additional internal power supply line passing through the power TSV. In some embodiments, the die stack includes multiple intermediate dies between the upper die and the lower die, and a separate power supply line is provided for each of the intermediate dies. In some embodiments, the die stack includes multiple intermediate dies, and a separate power supply line is provided for some of the intermediate dies without passing through the lower die, and an internal power supply line is provided for other of the intermediate dies. In some embodiments, the separate power supply lines provide different power to different ones of the intermediate dies. In some embodiments, at least two dies of the die stack are directly hybrid bonded to each other. In some embodiments, the dies of the die stack are directly hybrid bonded to each other. In some embodiments, the power supply line provides power to the intermediate die from a die or board located below the lower die and bypasses the lower die. In some embodiments, the power supply lines provide power to the middle die from a power supply source located above the top die and bypass the top die.

[0046] In another aspect, a device may have a stack of multiple stacked dies that include signal through-substrate vias (TSVs) and bond wires or edge traces that provide power to one or more dies above the bottom die in the stack.

[0047] In some embodiments, the multiple stacked dies include a lower die, an upper die, and an intermediate die between the lower die and the upper die, and bond wires or edge traces provide power to the intermediate die via a power distribution network provided on a back surface of the lower die.

[0048] In another aspect, a method for manufacturing an electronic module may include mechanically and electrically bonding at least three die in a stack, the bonding step including enabling signal connections between the die via through-substrate vias (TSVs), and the method may further include providing power connection paths to a middle die in the stack without conducting power through the TSVs.

[0049] In some embodiments, the method may further include providing a power distribution network between the intermediate die and the die located below, and connecting the power connection lines to the power distribution network. In some embodiments, the method may further include forming a capacitor disposed between the power distribution network and the intermediate die. In some embodiments, the method may further include providing separate power supply lines to each of the intermediate dies. In some embodiments, the method may further include applying separate voltages to separate dies of the stack. In some embodiments, the method may further include providing a separate power distribution network below each intermediate die, which has its own separate power supply line, and connecting the power supply lines to the power distribution network. In some embodiments, the step of providing the power supply lines includes wire bonding. In some embodiments, the method may further include wire bonding a ground connection for the intermediate die. In some embodiments, the step of mechanically and electrically connecting at least three dies of the stack includes positioning the dies to provide a step for wire bond connection. In some embodiments, providing the power supply lines includes forming edge traces along sidewalls of the stack. In some embodiments, forming the edge traces includes metal plating. In some embodiments, forming the edge traces includes copper plating. In some embodiments, the method may further include providing additional internal power supply lines through power TSVs. In some embodiments, the stack includes multiple intermediate dies, and the method further includes providing separate power supply lines for some of the intermediate dies and providing internal power supply lines through TSVs for other of the intermediate dies. In some embodiments, mechanically and electrically connecting at least three dies of the stack includes direct hybrid bonding the dies to each other.

[0050] In another aspect, an apparatus has a die stack including at least two interconnected dies, the dies including an upper die and a lower die having an active front surface and a rear surface, the upper die being attached to the rear surface of the lower die, the apparatus further having a plurality of through-substrate vias (TSVs) passing through the lower die, the TSVs enabling signal transmission to the upper die of the die stack, the apparatus further having power supply lines configured to provide power to the rear surface of the lower die, the lower die including power vias that conduct power from the rear surface to devices of the lower die without passing through all metallization levels of the lower die.

[0051] In some embodiments, the device may further include a wiring structure disposed between the upper die and the lower die, the wiring structure configured to distribute power from the power supply line to the lower die. In some embodiments, the wiring structure may further include a ground wiring network. In some embodiments, the device may further include a ground connection line from outside the die stack to the lower die. In some embodiments, the power supply line has a cross-sectional area that is at least two times the average cross-sectional area of ​​the TSVs. In some embodiments, the power supply line has a cross-sectional area that is at least four times the average cross-sectional area of ​​the TSVs. In some embodiments, the power supply line comprises a wire bond. In some embodiments, the device may further include a ground wire bond that enables a ground connection for the middle die. In some embodiments, the die stack has a stepped profile that provides a step for the wire bond connection. In some embodiments, the die stack includes dies of different sizes. In some embodiments, the die stack includes dies of the same size. In some embodiments, edges of the dies in the die stack are laterally offset relative to each other to provide a step. In some embodiments, the power supply lines have edge traces along the sidewalls of the die stack. The edge traces include a hardened conductive paste. In some embodiments, the edge traces include a plated metal. In some embodiments, the plated metal is copper. In some embodiments, multiple different voltages are provided for a die of the die stack by multiple power supply lines that do not pass through the lower die. In some embodiments, the power supply lines deliver power to the upper die via a back surface of the upper die. In some embodiments, the apparatus may further include additional internal power supply lines through the power TSVs. In some embodiments, the die stack includes multiple intermediate dies between the upper die and the lower die, with separate power supply lines provided for each of the intermediate dies. In some embodiments, the die stack includes multiple intermediate dies, with separate power supply lines provided for some of the intermediate dies and internal power supply lines provided for other of the intermediate dies.In some embodiments, separate power supply lines supply different power to different ones of the intermediate dies. In some embodiments, at least two dies of the die stack are direct hybrid bonded to each other. In some embodiments, the dies of the die stack are direct hybrid bonded to each other via a deposited wiring structure.

[0052] In another aspect, the die stack includes a plurality of stacked dies, at least a bottom die of the stacked dies having through-substrate vias (TSVs) extending from a bottom surface of the die to a top surface of the die, and the die stack further includes an external power supply line that provides power to at least one die of the die stack without passing power through the bottom die.

[0053] In some embodiments, the external power supply line provides power to the bottom die via a top surface of the bottom die. In some embodiments, the die stack may further include a wiring structure between the bottom die and the overlying die, the external power supply line being physically and electrically coupled to the wiring structure. In some embodiments, the external power supply line provides power to the bottom die via a top surface of the bottom die. In some embodiments, the external power supply line provides power to the overlying die via the wiring structure. In some embodiments, the external power supply line comprises a bond wire. In some embodiments, the external power supply line comprises an edge trace. In some embodiments, the stacked dies are connected to each other by direct hybrid bonding. In some embodiments, the bottom surface of the bottom die is further attached to the carrier. In some embodiments, the direct bonding between the dies of the die stack is performed via a wiring structure that includes a power distribution network.

[0054] In another aspect, an integrated circuit die has a semiconductor substrate portion having a front surface and a rear surface including at least some portion of an integrated device, and a back-end-of-line (BEOL) portion formed in a deposited state on the semiconductor substrate portion, the BEOL portion including metal interconnects, and the integrated circuit die further has a plurality of through-substrate vias (TSVs) extending through the BEOL portion and the semiconductor substrate portion, and a power supply via extending from the rear surface of the semiconductor substrate portion to the integrated device without extending through the entire BEOL portion.

[0055] Unless the context clearly requires otherwise, throughout the specification and claims, the terms "comprise", "comprising", "include", "including" and the like are to be construed in an inclusive sense, i.e., "including, but not limited to", as opposed to an exclusive or exhaustive sense. As used generally herein, the term "coupled" means two or more elements that are directly connected to each other or that are connected to each other through one or more intermediate elements. Similarly, as used generally herein, the term "coupled" means two or more elements that are directly connected to each other or that are connected to each other through one or more intermediate elements. In addition, the terms "herein," "above," "below," and words of similar import as used in the parent application refer to the application as a whole and not to any particular portion of the application. Furthermore, as used herein, when a first element is described as being located "on" or "over" a second element, the first element may be directly located on or over the second element such that the first element and the second element are in direct contact with each other, or the first element may be indirectly located on or over the second element such that one or more elements are interposed between the first element and the second element. Where the context permits, terms in the above detailed description using the singular or plural may include the plural or singular, respectively. The term "or" in reference to a list of two or more items includes all of the following interpretations of that term: any of the items in the list, all of the items in the list, and any combination of the items in the list.

[0056] Furthermore, conditional terms used in the specification, particularly "can," "could," "might," "may," "eg," "for example," "such as," and the like, unless expressly specified otherwise or understood otherwise within the context in which they are used, are generally intended to imply that certain embodiments include certain features, elements, and / or conditions and that other embodiments do not include certain features, elements, and / or conditions. Thus, such conditional terms are not generally intended to imply that features, elements, and / or conditions are present in any required manner for one or more embodiments.

[0057] Although certain embodiments have been described, these embodiments are provided by way of example only and are not intended to limit the scope of the invention. Indeed, the novel apparatus, methods, and systems described herein may be embodied in a variety of other forms, and furthermore, various omissions, substitutions, and modifications in the form of the methods and systems described herein may be made without departing from the scope of the invention. For example, although blocks are shown in a given arrangement, alternative embodiments may perform substantially the same functions with different components and / or circuit topologies, and some blocks may be deleted, moved, added, divided, combined, and / or modified. Each of these blocks may be embodied in a wide variety of ways. Any suitable combination of elements and acts of the various embodiments described above may be combined to provide further embodiments. The scope of the invention as set forth in the appended claims and equivalents thereto is intended to include such forms or modifications within the scope and spirit of the invention.

Claims

1. 1. An apparatus comprising: a die stack including at least three interconnected dies, the dies including a lower die, an upper die, and an intermediate die between the lower die and the upper die; a plurality of through-substrate vias (TSVs) extending through the lower die and enabling signal communication to dies in the die stack; An apparatus comprising: a power supply line configured to provide power to the middle die without passing power through the bottom die.

2. 2. The apparatus of claim 1, wherein the lower die is mounted with its active surface facing downward, the intermediate die is mounted with its active surface facing downward over the lower die, and a back surface of the lower die includes a power distribution network configured to distribute power from the power supply lines to the intermediate die.

3. 10. The apparatus of claim 1, further comprising a second power supply line that provides power from outside the die stack to an upper die in the die stack, the back surface of the middle die including a second power distribution network that provides power from the second power supply line to the upper die.

4. The apparatus of claim 1 further comprising a ground connection line from outside the die stack to the middle die.

5. The apparatus of claim 1 , wherein the power supply lines have a cross-sectional area that is at least twice the average cross-sectional area of ​​the TSVs.

6. The apparatus of claim 1 , wherein the power supply lines comprise wire bonds.

7. The apparatus of claim 1 , wherein the die stack has a stepped profile that provides steps for wire bond connections.

8. The apparatus of claim 2 , wherein the power supply lines have edge traces along sidewalls of the die stack.

9. The apparatus of claim 8 , wherein the edge trace comprises a hardened conductive paste.

10. The apparatus of claim 8 , wherein the edge trace comprises a plated metal.

11. The apparatus of claim 1 , wherein different voltages are provided for different dies in the die stack.

12. The apparatus of claim 1 , wherein multiple different voltages are provided for a die of the die stack by multiple power supply lines that do not pass through the bottom die.

13. The apparatus of claim 1 , wherein the die stack includes multiple intermediate dies between the upper die and the lower die, and a separate power supply line is provided for each of the intermediate dies.

14. 10. The apparatus of claim 1, wherein the die stack includes multiple intermediate dies, and wherein separate power supply lines are provided for some of the intermediate dies without passing through the lower die, and internal power supply lines are provided for other of the intermediate dies.

15. The apparatus of claim 1 , wherein at least two dies in the die stack are direct hybrid bonded to each other.

16. The apparatus of claim 1 , wherein the power supply lines provide power to the middle die from a power supply located above the top die and bypass the top die.

17. 1. An apparatus comprising: a stack of multiple stacked dies including a signal through-substrate via (TSV) passing through a lower die of the multiple stacked dies; and bond wires or edge traces that provide power to one or more dies positioned above the bottom die in the stack.

18. 20. The apparatus of claim 17, wherein the plurality of stacked dies include a lower die, an upper die, and an intermediate die between the lower die and the upper die, and the bond wires or edge traces provide power to the intermediate die via a power distribution network provided on a back surface of the lower die.

19. 1. An apparatus comprising: a die stack including at least two interconnected dies, the dies including an upper die and a lower die having an active front surface and a rear surface, the upper die being attached to the rear surface of the lower die; a plurality of through-substrate vias (TSVs) through the lower die, the TSVs enabling signal transmission to the upper die of the die stack; 1. An apparatus comprising: a power supply line configured to provide power to the back surface of the lower die, the lower die including power vias that conduct power from the back surface to devices on the lower die without passing through all metallization levels of the lower die.

20. 20. The apparatus of claim 19, further comprising a wiring structure disposed between the upper die and the lower die, the wiring structure configured to distribute power from the power supply lines to the lower die.

21. 20. The apparatus of claim 19, wherein the power supply lines deliver power to the upper die via a back surface of the upper die.

22. The apparatus of claim 19 , further comprising an additional internal power supply line passing through the power TSV.

23. A die stack comprising: a plurality of stacked dies, at least a bottom die of the plurality of stacked dies having through-substrate vias (TSVs) extending through at least a substrate portion of the bottom die; A die stack including an external power supply line that provides power to at least one die in the die stack without passing power through the bottom die.

24. 24. The die stack of claim 23, wherein the external power supply line provides power to the bottom die via a top surface of the bottom die.

25. 24. The die stack of claim 23, further comprising a wiring structure between said bottom die and an overlying die, said external power supply lines being physically and electrically coupled to said wiring structure.

26. 26. The die stack of claim 25, wherein the external power supply lines comprise bond wires.

27. The die stack of claim 25 , wherein the external power supply lines comprise edge traces.

28. The die stack of claim 23 , wherein the plurality of stacked dies are connected to each other by direct hybrid bonding.

29. 30. The die stack of claim 28, wherein the underside of the bottom die is attached to a carrier.

30. 30. The die stack of claim 28, wherein direct bonding between dies in the die stack is performed via a wiring structure that includes a power distribution network.

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