Wafer-Level Stacked Die Structure and Associated Systems and Methods

Abstract

This application relates to wafer-level stacked die structures and associated systems and methods. A stacked die structure for a semiconductor device generally includes a primary level having a first die formed in a wafer and a secondary level having a second die coupled to the first die. A third level includes a third die coupled to the second die. The levels respectively have conductive first, second, and third interconnects extending from the active sides of the dies and may be bonded before stacking the dies. The dies may be stacked relative to each other in offset or rotated positions such that the interconnects extend beyond each of the other dies to contact a redistribution layer that forms an electrical connection to an external component. In some configurations, a fourth level having a fourth die and a conductive fourth interconnect is coupled to the third die and positioned to be laterally offset from the third die such that the third interconnect extends beyond the fourth die.

Description

Technical Field

[0001] The present disclosure generally relates to semiconductor devices, and in some embodiments, more particularly, to wafer-level stacked die structures. Background Art

[0002] Microelectronic devices, such as memory devices, microprocessors, and light-emitting diodes, typically include one or more semiconductor dies mounted to a substrate and encapsulated in a protective cover. The semiconductor die includes functional features such as memory cells, processor circuitry, interconnect circuitry, etc. There is increasing pressure on semiconductor die manufacturers to reduce the volume occupied by the semiconductor die while increasing the capacity and / or speed of the resulting encapsulated component. To meet these and other needs, semiconductor die manufacturers typically stack multiple semiconductor dies vertically on top of each other to increase the capacity or performance of the microelectronic device within the limited volume on a circuit board or other component to which the semiconductor die is mounted. Individual or stacked semiconductor dies can be electrically coupled to the substrate using gold wire loops.

[0003] Conventional semiconductor device configurations have a semiconductor substrate that is electrically coupled to a component such as a printed circuit board (PCB) using one or more solder balls. The substrate carries semiconductor dies attached to each other via multiple die attach films to form a semiconductor device. Some conventional semiconductor devices have a first primary die and a second primary die that are electrically coupled to the semiconductor substrate using primary wire loops (such as bond wires). Additionally, the semiconductor device may also include a first secondary die and a second secondary die that are electrically coupled to the substrate using secondary wire loops. Due to the height limitations of the primary and / or secondary wire loops, the height of the semiconductor die stack is typically limited. Summary of the Invention

[0004] One aspect of the present disclosure relates to a semiconductor device including: a primary stage having a first die including a back side and an active side opposite the back side, and a conductive first interconnect extending from the active side; and a second stage having a second die including a back side and an active side opposite the back side, and a conductive second interconnect extending from the active side of the second die in a direction of the first interconnect, and the back side of the second die is mounted to the active side of the first die, wherein the second die is offset from the first die in a lateral direction along the active side of the first die such that the first interconnect extends beyond the active side of the mounted second die.

[0005] Another aspect of the present disclosure relates to a semiconductor die assembly in a stacked configuration, the assembly comprising: a primary having a first die including a back side and an active side opposite the back side, the first die being formed in a wafer, and the primary having a conductive first interconnect extending from the active side; a secondary having a second die including a back side and an active side opposite the back side and a conductive second interconnect extending from the active side of the second die in the direction of the first interconnect, and the back side of the second die being laterally offset and mounted to the active side of the first die such that a portion of the second die is mounted to the wafer and another portion of the second die is mounted to the active side of the first die, and such that the first interconnect extends beyond the active side of the second die; a molding material at least partially surrounding the second die and the first and second interconnects, the molding material having a surface on which the first and second interconnects are partially exposed; and a redistribution layer in electrical communication with the first and second interconnects.

[0006] Yet another aspect of the present disclosure relates to a method of assembling a semiconductor device, the method comprising: forming a first die in a semiconductor wafer, the first die having a back side and an active side opposite the back side; connecting a conductive first interconnect to the active side of the first die; connecting a conductive second interconnect to the active side of a second die, wherein the second die has a back side opposite the active side of the second die; and mounting the back side of the second die to the active side of the first die after the first and second interconnects are respectively connected to the first and second dies such that the first interconnect extends beyond the active side of the second die, wherein the second interconnect extends in the direction of the first interconnect. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1A is an enlarged front cross-sectional view and Figure 1B is an enlarged cross-sectional plan view showing a primary stage of forming a stacked die structure in accordance with the techniques of the present invention.

[0008] Figure 2A is an enlarged front cross-sectional view and Figure 2B is an enlarged cross-sectional plan view showing a secondary stage of forming a stacked die structure in accordance with the techniques of the present invention.

[0009] Figure 3A is an enlarged front cross-sectional view and Figure 3B is an enlarged cross-sectional plan view showing a third stage of forming a stacked die structure in accordance with the techniques of the present invention.

[0010] Figure 4A is an enlarged front cross-sectional view and Figure 4Bis an enlarged cross-sectional plan view and is the fourth stage of forming a stacked die structure according to the technology of the present invention.

[0011] Figures 5A to 5G is the use according to the technology of the present invention Figure 4A and 4B of the stacked die structure for the enlarged front cross-sectional views of the respective stages of forming a semiconductor device.

[0012] Figure 6 is an enlarged front cross-sectional view of a semiconductor device according to the technology of the present invention.

[0013] Figure 7 is a schematic diagram of a system including a semiconductor device configured according to an embodiment of the technology of the present invention. Detailed Description

[0014] The technology disclosed herein relates to semiconductor devices, systems having semiconductor devices, and related methods for manufacturing semiconductor devices. The term "semiconductor device" generally refers to a solid-state device that includes one or more semiconductor materials. Examples of semiconductor devices include logic devices, memory devices, and diodes, among others. Additionally, the term "semiconductor device" may refer to a finished device or a component or other structure at various processing stages prior to becoming a finished device.

[0015] Depending on its context of use, the term "substrate" may refer to a structure that supports an electronic component (e.g., a die), such as a wafer-level substrate, or a singulated die-level substrate, or another die for die stacking applications. One of ordinary skill in the relevant art will recognize that the appropriate steps of the methods described herein may be performed at the wafer level or at the die level. Additionally, unless the context otherwise indicates, conventional semiconductor manufacturing techniques may be used to form the structures disclosed herein. For example, materials may be deposited using chemical vapor deposition, physical vapor deposition, atomic layer deposition, spin coating, electroplating, and / or other suitable techniques. Similarly, for example, materials may be removed using plasma etching, wet etching, chemical mechanical planarization, or other suitable techniques.

[0016] The present inventive technique includes a stacked die structure packaging configuration. The figures and description herein relate to wafer-level packaging of stacked die structures, such as Package-on-Package (PoP), but the present inventive technique is suitable for use with other packaging levels. In contrast to the present inventive technique, conventional semiconductor die stacks using wire loop electrical connections have a limited configuration based on the length limitation of the gold material forming the wire loop. Gold wire loops generally cannot achieve reliable electrical connections between the substrate and the upper die in a die stack having more than two dies. In a conventional configuration, the use of gold wire loops may also limit manufacturing process options and may require additional time and specialized tools for handling. As the size and pitch of semiconductor packages become smaller and closer, embodiments of the present inventive technique allow for closer packaging pitches and greater die density in higher stacked configurations.

[0017] A semiconductor device formed in accordance with the present inventive technique may generally include a primary stage having a first die and a conductive first interconnect. The first die has a back side and an active side opposite the back side, and the first interconnect extends from the active side of the first die. The semiconductor device also has a secondary stage having a second die and a conductive second interconnect. The second die has an active side and a back side, and the second interconnect extends from the active side of the second die. The back side of the second die is mounted to the active side of the first die such that the second interconnect extends in the same direction as the first interconnect. The second die may be offset laterally along the active side of the first die from the first die such that the first interconnect extends beyond the active side of the mounted second die.

[0018] The semiconductor device may be assembled by forming the first die of the primary stage in a wafer and connecting the first interconnect to the first die such that the first interconnect extends from the active side of the first die. The second die may be formed separately, and the second interconnect is connected to the active side of the second die. After connecting the first and second interconnects to their respective dies, the back side of the second die is mounted to the active side of the first die such that the first interconnect extends beyond the active side of the second die. In the assembled configuration, the second conductive interconnect extends in the same direction as the first conductive interconnect. Manipulating and stacking the dies with the interconnects already connected to the dies may require less of a vacuum bond tip and / or gripping edge for dies that do not have interconnects.

[0019] The configuration of the present invention's technology is suitable for use with a variety of semiconductor die packages, including static random access memory (SRAM), dynamic random access memory (DRAM), "NAND" flash memory, application specific integrated circuits (ASICs), microcontrollers (uCs), and / or other memories and semiconductor devices. The present invention's technology can be used in ultra-thin die (typically having a wafer thickness of less than 50 micrometers (μm)) and ultra-fine bond wire (typically having a die attach film (DAF) with a bond thickness at or below 10 μm) multi-chip package applications and other applications. In some embodiments, the substrate for connection to a PCB or other component can be omitted to reduce the package size (about 80 to 100 μm) and / or save costs. Figures 1A to 6 The illustrated die stack configuration is an example of the present invention's technology, and the die shown and described can have different thicknesses, amounts, profiles, and aspect ratios to create the desired stack configuration. The illustrated conductive interconnect configuration is also an example and can have different amounts, lengths, and / or placements to electrically connect the die within the package.

[0020] The interconnect structure of the die described herein is typically a pillar or pin formed of a suitable conductive material such as copper (Cu) or gold (Au). The interconnect structure can be connected to a solder cap to form an electrical connection (such as a tin-silver (SnAg) solder cap). The interconnect structure can be electrically connected to a redistribution layer (RDL) by reflowing the solder cap using gang reflow, acoustic reflow, or other techniques. In some embodiments, the interconnect structure is formed before the die are stacked on each other, and can be formed using single or multiple mask processing techniques. Alternatively, the interconnect structure can be formed after the die are stacked (such as by using vertical copper wire bonding, etc.). The bond pads on the die to which the interconnect structure is connected are typically copper pads such that the copper pillar or pin is coupled to the bond pad using copper-to-copper bonding. In other embodiments, the interconnect structure can be formed of a material different from the bond pad, or it can be formed of a combination of materials.

[0021] Figure 1A and 1BShows a primary of a stacked die structure 100 according to an embodiment of the technology of the present invention. The primary of the stacked die structure 100 has a first die 110 each including an active side 114 and a back side 116. As shown, the first die 110 is formed in a common wafer 102 (e.g., a single semiconductor wafer). In other embodiments, any number of stacked die structures are formed in a single wafer in a suitable manner. In the following description, the stacked die structure 100 is an example of a multi-die structure formed according to an embodiment of the technology of the present invention. In other embodiments, adjacent stacked die structures on a wafer may have a stacked configuration different from each other, or a stacked configuration different from other dies on the wafer. The scribe lines between the first dies may be wider than conventional scribe lines to provide a cutting gap between the die stacks after assembly, and the scribe lines between the second, third, and fourth levels described below may have scribe lines of a conventional width on the same wafer or on a secondary wafer.

[0022] The first die 110 may include a conductive first interconnect 112 that extends from a surface (e.g., a bonding pad) formed on or otherwise connected to the active side 114 of the first die 110 before subsequent dies are stacked on the first die 110. The height of the first interconnect 112 may be greater than the stacked die height such that the first interconnect 112 will be exposed during processing of the stacked die structure 100, as will be described in more detail below. As noted, the first interconnect 112 may be formed as a pillar or a pin to electrically couple the first die 110 with other electrical components of the stacked die structure 100.

[0023] Figure 2A and 2B Shows the stacked die structure 100 with a second level stacked on the primary. The second level has a second die 210 having an active side 214 and a back side 216. The second level also has a conductive second interconnect 212 that extends from a surface (e.g., a bonding pad) formed on the active side 214 of the second die 210. The second die 210 to which the second interconnect 212 has been attached is stacked on top of the first die 110 to which the first interconnect 112 has been attached. The back side 216 of the second die 210 faces the active side 114 of the first die 110. The second die 210 may be attached to the first die 110 and the wafer 102 using a die attach film 220. As shown, the second die 210 may have an orientation rotated by about 180° from the orientation of the first die 110. In this regard, the second interconnect 212 is positioned near an edge of the stacked die structure 100 opposite the first interconnect 112. To accommodate the first interconnect 112 formed prior to stacking, the second die 210 may be laterally shifted relative to the first die 110. The degree of lateral shift may be any suitable offset that provides a clearance for the first interconnect 112.

[0024] Figure 3A and3B Disclosed is a stacked die structure 100, where a third level is stacked on a second level. The third level has a third die 310 with an active side 314 and a back side 316, and a conductive third interconnect 312 extending from a surface (such as a bonding pad) formed on the active side 314 of the third die 310. The third die 310 to which the third interconnect 312 is attached is stacked on top of the second die 210 to which the second interconnect 212 is attached. The back side 316 of the third die 310 faces the active side 214 of the second die 210. The third die 310 can be attached to the second die 210 using a die attach film 320. As shown, the third die 310 can have an orientation rotated by about 90° from the orientations of the first die 110 and the second die 210. In this regard, the third interconnect 312 is positioned near an adjacent edge of the stacked die structure 100 that is perpendicular to the first interconnect 112 and the second interconnect 212.

[0025] To accommodate the extensions of the first interconnect 112 and the second interconnect 212 beyond the third die 310, the third die 310 can be narrower (e.g., in width) than the first die 110 and the second die 210 formed before stacking. The size of the third die 310 can be adjusted to provide a clearance for the first interconnect 112 and the second interconnect 212 that are laterally positioned outside the third die 310 when assembled into the stacked die structure 100.

[0026] Figure 4A and 4B Disclosed is the stacked die structure 100 after a fourth level is stacked on the third level. The fourth level has a fourth die 410 with an active side 414 and a back side 416, and a conductive fourth interconnect 412 extending from a surface (such as a bonding pad) formed on the active side 414 of the fourth die 410. The fourth die 410 to which the fourth interconnect 412 is attached is stacked on top of the third die 310 to which the third interconnect 312 is attached. The back side 416 of the fourth die 410 faces the active side 314 of the third die 310. The fourth die 410 can be attached to the third die 310 using a die attach film 420. As shown, the fourth die 410 can have an orientation rotated by about 90° from the orientations of the first die 110 and the second die 210 and rotated by about 180° from the orientation of the third die 310. In this regard, the fourth interconnect 412 is positioned near an adjacent edge of the stacked die structure 100 that is perpendicular to the first interconnect 112 and the second interconnect 212 and opposite to the third interconnect 312.

[0027] Similar to the third die 310, the fourth die 410 can be narrower (e.g., in width) than the first die 110 and the second die 210 to accommodate the extensions of the first interconnect 112 and the second interconnect 212 that extend beyond the fourth die 410. The size of the fourth die 410 can be adjusted to provide a clearance for the first interconnect 112 and the second interconnect 212 that are laterally positioned outside the fourth die 410 when assembled into the stacked die structure 100. To accommodate the third interconnect 312 that can be formed prior to stacking, the fourth die 410 can be laterally shifted relative to the third die 310. The degree of lateral shift can be any suitable offset that provides a clearance for the third interconnect 312.

[0028] Figures 5A to 5G Showing a further stage of fabricating the stacked die structure 100 from the state shown in Figure 4A and 4B In Figures 5A to 5G for clarity, the reference numerals for the primary, secondary, tertiary, and quaternary die and interconnect structures and the corresponding die attach films are not shown. In this regard, unless otherwise indicated, the arrangement of the reference numerals for these components in Figure 4A and 4B can be inferred from Figures 5A to 5G As Figure 5A shown, after assembling the dies, the active sides 114, 214, 314, and 414 all face the same direction, and the interconnects 112, 212, 312, and 412 extend from the active sides 114, 214, 314, and 414 in a common direction, respectively. In some embodiments, the interconnects 112, 212, 312, and 412 extend straight (i.e., perpendicular) from the active sides 114, 214, 314, and 414.

[0029] The components of the stacked die structure 100 can be covered in a molding material 104 to encapsulate and protect the stacked die structure 100. The molding material 104 can be a resin, an epoxy resin, a silicone-based material, a polyimide, and / or any other suitable encapsulant. After deposition, the molding material 104 can be cured by UV light, a chemical hardener, heat, or other suitable curing methods. Generally, the molding material 104 can encapsulate the components of the stacked die structure 100 such that the components are sealed within the molding material 104 after curing.

[0030] Figure 5B Showing the stacked die structure 100, where a portion of the molding material 104 has been trimmed and removed to expose one or more of the interconnects of the stacked die structure 100. As shown, at least some of the interconnects can be bisected during the removal step such that the exposed ends of the interconnects are flat. The portion of the molding material 104 can be removed by a grinder, a saw, or other tools. In the illustrated embodiment, along Figure 5AThe scribe line 5B shown removes the molding material 104 to expose the surface of the interconnects of the stacked die structure 100. In other embodiments, the molding material 104 is removed and / or removed in a non-planar configuration at any location along the height of the stacked die structure 100.

[0031] Figure 5C A redistribution layer 106 is shown formed on or otherwise coupled to the surface created when the molding material 104 is removed along the scribe line 5B. The redistribution layer 106 is electrically coupled to the interconnect structures 112, 212, 312, and 412 to make the interconnect structures available at other locations on the redistribution layer 106 of the stacked die structure 100 to accommodate the layout of a PCB or other component, and / or to improve access to the connections depending on the configuration of the stacked die structure 100. The redistribution layer 106 can have traces, vias, and pads that provide circuitry to spread the arrangement of the interconnects to a larger pad array.

[0032] Figure 5D A stacked die structure 100 is shown having a connector 108 that electrically connects the stacked die structure 100 to a PCB or other external component. In some embodiments, the connector 108 is a solder ball coupled to a conductive region (e.g., a pad) on the redistribution layer 106. Depending on the layout of the dies and interconnects of the stacked die structure 100, and / or the configuration of the component on which the stacked die structure 100 will be assembled, the connector 108 can be arranged at any location on the redistribution layer 106.

[0033] Figure 5E A stacked die structure 100 is shown after removing a portion of the wafer 102 along the scribe line 5E shown in Figure 5D to further thin the stacked die structure 100. Similar to the trimming of the molding material 104 in Figure 5B a portion of the wafer 102 can be removed using a grinder, saw, or other tool. After thinning the wafer 102, the first die 110 can have a thickness of less than 50 μm (e.g., an ultra-thin die thickness). In other embodiments, after thinning the wafer 102, the first die 110 has a thickness of 40 μm or less.

[0034] Figure 5F A layer of dicing tape 107 is shown applied to the surface of the stacked die structure 100 created when removing a portion of the wafer 102 along the scribe line 5E. The dicing tape 107 is configured to maintain the arrangement and spacing of the stacked die structure 100 during package separation.

[0035] Figure 5GShows a configuration of a package of the separated stacked die structure 100. The stacked die structure 100 can be separated along a first die street 502, a second die street 504, and a third die street 506, which cut through the redistribution layer 106, the molding material 104, the die 102, and partially into the dicing tape 107. Similar die streets can be arranged in a direction parallel to the page and Figure 5G to surround the packaged stacked die structure 100 for individual removal.

[0036] Figure 6 Shows the completed packaged stacked die structure 100. The stacked die structure 100 is packaged and configured to be electrically connected to an external component, such as a PCB, through a connector 108. Laser package markings can be applied to the exposed surfaces of the primary die 110 and / or the die 102. As shown, after the package separation in Figure 5G , a portion of the die 102 can be retained, which extends laterally from at least one side of the primary die 110. In embodiments having an extended portion of the die 102, the secondary die 210 is partially supported by the extended portion. In other embodiments, the primary die 110 is larger than the secondary die 210 to sufficiently support the backside 216 such that the extended portion of the die 102 is omitted.

[0037] The wafer-level package of the present inventive technique is expected to provide several advantages over conventional die stacking techniques using gold wire loops. In some embodiments, the interconnect material is copper, which can improve signal transmission compared to gold wire loops. Compared to conventional die stacking techniques, the present inventive technique omits an interposer or other types of additional substrates to reduce the package footprint, height, and cost, among other advantages. In this regard, the substrate-less stacked die structure of the present inventive technique has a footprint that generally conforms to the size of the total footprint of the primary and secondary dies (e.g., laterally offset as shown herein) in the stacked configuration. In other aspects, the redistribution layer can allow the stacked die structure to utilize a fine trace pitch and a fine ball pitch configuration. The direct exposure of the backside 116 of the first die 110 (in the orientation shown in Figure 6 ) - as opposed to such surfaces being under the molding material - can improve heat dissipation. The illustrated embodiments depict several examples of semiconductor devices using the stacked die configuration of the present inventive technique; however, other device configurations having stacked dies are also within the scope of the present inventive technique. Forming the interconnects before stacking the dies can provide more manufacturing options (e.g., mask processing techniques) and improved efficiency.

[0038] Figure 7 Is a block diagram of a system incorporating a semiconductor device according to an embodiment of the present inventive technique. Having the above reference Figures 1A to 6Any of the semiconductor devices described herein may be incorporated into any of a number of larger and / or more complex systems, representative examples of which are the systems 700 schematically shown in Figure 7 System 700. System 700 may include a processor 702, a memory 704 (e.g., SRAM, DRAM, flash, and / or other memory devices), an input / output device 706, and / or other subsystems or components 708. The semiconductor components, devices, and device packages described above with reference to Figures 1A to 6 may be included in any of the elements shown in Figure 7 The resulting system 700 may be configured to perform any of a wide variety of suitable computing, processing, storage, sensing, imaging, and / or other functions. Accordingly, representative examples of system 700 include, but are not limited to, computers and / or other data processors, such as desktop computers, laptop computers, network appliances, handheld devices (e.g., palmtop computers, wearable computers, cellular or mobile phones, personal digital assistants, music players, etc.), tablet computers, multi-processor systems, processor-based or programmable consumer electronics devices, network computers, and minicomputers. Additional representative examples of system 700 include lights, cameras, vehicles, etc. In these and other examples, system 700 may be housed in a single unit or distributed over multiple interconnected units, e.g., via a communication network. Accordingly, the components of system 700 may include local and / or remote memory storage devices and any of a wide variety of suitable computer-readable media.

[0039] As used in the foregoing description, given the orientations shown in the figures, the terms "vertical," "lateral," "upper," and "lower" may refer to the relative directions or positions of features in a semiconductor device. For example, "upper" or "uppermost" may refer to a feature positioned closer to the top of the page than another feature. However, these terms should be interpreted broadly to include semiconductor devices having other orientations, such as inverted or tilted orientations, where top / bottom, above / below, higher / lower, up / down, left / right, and distal / proximal may be interchanged depending on the orientation. Additionally, for ease of reference, throughout this disclosure, the same reference numerals are used to identify like or similar components or features, but the use of the same reference numeral does not imply that the features should be understood as the same. In fact, in many of the examples described herein, the features with the same number have multiple embodiments that are different in structure and / or function from each other. Further, unless specifically noted herein, the same shading may be used to indicate materials that may be compositionally similar in cross-section, but the use of the same shading does not imply that the materials should be understood as the same.

[0040] The foregoing disclosure may also refer to quantities and numbers. Unless otherwise specified, these quantities and numbers should not be considered restrictive, but rather as examples of possible quantities or numbers related to the new technology. Additionally, in this regard, the present disclosure may use the term "plurality" to refer to a quantity or number. In this regard, the term "plurality" means greater than one, for example, any number such as two, three, four, five, etc. For the purposes of the present disclosure, the phrase "at least one of A, B, and C" means, for example, (A), (B), (C), (A and B), (A and C), (B and C), or (A, B, and C), including all further possible permutations when listing more than three elements.

[0041] It should be understood from the foregoing that specific embodiments of the new technology have been described herein for purposes of illustration, but various modifications may be made without departing from the present disclosure. Accordingly, the invention is not limited except as by the appended claims. Additionally, certain aspects of the new technology described in the context of a particular embodiment may also be combined or removed in other embodiments. Moreover, although advantages associated with certain embodiments of the new technology have been described in the context of those embodiments, other embodiments may also exhibit such advantages, and not all embodiments need to exhibit such advantages to fall within the scope of the present disclosure. Accordingly, the present disclosure and the associated technology may cover other embodiments not expressly shown or described herein.

Claims

1. A semiconductor device, comprising: A primary stage having a first die including a back side and an active side opposite the back side, and a conductive first interconnect extending from the active side; A secondary stage having a second die including a back side and an active side opposite the back side, and a conductive second interconnect extending from the active side of the second die in the direction of the first interconnect, and the back side of the second die being mounted to the active side of the first die, wherein the second die is offset from the first die along the active side of the first die in a lateral direction such that the first interconnect extends beyond the active side of the mounted second die, wherein the second die is rotated approximately 180° relative to the first die, and wherein the first interconnect is positioned near a first edge of the semiconductor device, and the second interconnect is positioned near a second edge of the semiconductor device opposite the first edge; And A tertiary stage having a third die including a back side and an active side opposite the back side, and a conductive third interconnect extending from the active side of the third die in the direction of the first interconnect and the second interconnect, wherein the third die is rotated approximately 90° relative to the second die, and the back side of the third die is mounted to the active side of the second die between the first interconnect and the second interconnect, wherein the third interconnect is positioned near a third edge between the first edge and the second edge of the semiconductor device, wherein the width of the third die is less than the width of the first die and the width of the second die such that the first interconnect and the second interconnect extend beyond the active side of the mounted third die.

2. The semiconductor device according to claim 1, further comprising a quaternary stage having a fourth die including a back side and an active side opposite the back side, the fourth die having a conductive fourth interconnect extending from the active side of the fourth die in the direction of the first, second, and third interconnects, and the back side of the fourth die being mounted to the active side of the third die, wherein the fourth die has a width such that the first and second interconnects extend beyond the active side of the mounted fourth die.

3. The semiconductor device according to claim 2, wherein the fourth die is offset from the third die along the active side of the third die in a lateral direction such that the third interconnect extends beyond the active side of the mounted fourth die.

4. The semiconductor device according to claim 3, wherein the fourth interconnect is positioned near a fourth edge of the semiconductor device between the first and second edges and opposite the third edge.

5. The semiconductor device according to claim 2, wherein the fourth die has an orientation rotated approximately 90° from the orientations of the first die and the second die and rotated approximately 180° from the orientation of the third die.

6. The semiconductor device according to claim 1, further comprising a molding material that at least partially surrounds the second and third dies and the first, second, and third interconnects, wherein the molding material is cut to define a trim surface and to partially expose the first, second, and third interconnects on the trim surface at the same distance as the back side of the first die, and wherein the back side of the first die defines an external surface of the semiconductor device.

7. The semiconductor device according to claim 6, further comprising a redistribution layer coupled to the trim surface and in electrical communication with the first, second, and third interconnects.

8. The semiconductor device according to claim 7, further comprising solder balls coupled to the redistribution layer and in electrical communication with at least one of the first, second, and third interconnects.

9. The semiconductor device according to claim 1, wherein the second die is mounted to the active side of the first die by a die attach film, and wherein the third die is mounted to the active side of the second die by a die attach film.

10. The semiconductor device according to claim 1, wherein the first die further comprises a wafer material that extends laterally from an edge of the first die to support a portion of the mounted second die.

11. A semiconductor die assembly in a stacked configuration, the assembly comprising: a primary having a first die including a back side and an active side opposite the back side, the first die being formed in a wafer, and the primary having a conductive first interconnect extending from the active side; a secondary having a second die including a back side and an active side opposite the back side and a conductive second interconnect extending from the active side of the second die in a direction of the first interconnect, and the back side of the second die being laterally offset and mounted to the active side of the first die such that a portion of the second die is mounted to the wafer and another portion of the second die is mounted to the active side of the first die, and such that the first interconnect extends beyond the active side of the second die, wherein the second die is rotated approximately 180° relative to the first die, wherein the first interconnect is positioned near a first edge of the assembly, and the second interconnect is positioned near a second edge of the assembly opposite the first edge; A third level having a third die including a back side and an active side opposite the back side, and a conductive third interconnect extending from the active side of the third die in a direction of the first interconnect and the second interconnect, wherein the third die is rotated approximately 90° relative to the second die, and the back side of the third die is mounted to the active side of the second die between the first interconnect and the second interconnect, wherein the third interconnect is positioned near a third edge between a first edge and a second edge of the assembly, and wherein a width of the third die is less than a width of the first die and a width of the second die such that the first interconnect and the second interconnect extend beyond the active side of the mounted third die; A molding material at least partially surrounding the second die and the first and second interconnects, the molding material having a surface on which the first and second interconnects are partially exposed; And A redistribution layer in electrical communication with the first and second interconnects.

12. The assembly of claim 11, further comprising a fourth level having a fourth die including a back side and an active side opposite the back side, and a conductive fourth interconnect extending from the active side of the fourth die in a direction of the first, second, and third interconnects, the back side of the fourth die being mounted to the active side of the third die, wherein the fourth die has a width such that the first and second interconnects extend beyond the active side of the mounted fourth die.

13. The assembly of claim 12, wherein the fourth die is positioned offset laterally from the third die along the active side of the third die such that the third interconnect extends beyond the active side of the mounted fourth die.

14. The assembly of claim 13, wherein the fourth interconnect is positioned near a fourth edge of the assembly between the first and second edges and opposite the third edge.

15. The assembly of claim 11, wherein the back side of the first die defines an outer surface of the assembly.

16. The assembly of claim 11, further comprising solder balls coupled to the redistribution layer and in electrical communication with the first and second interconnects.

17. The assembly of claim 11, wherein the second die is mounted to the active side of the first die by a die attach film, and wherein the third die is mounted to the active side of the second die by a die attach film.

18. A method of assembling a semiconductor device, the method comprising: Forming a first die in a semiconductor wafer, the first die having a back side and an active side opposite the back side; Connecting a conductive first interconnect to a first peripheral edge region of the active side of the first die; Connecting a conductive second interconnect to a second peripheral edge region of an active side of a second die, wherein the second die has a back side opposite the active side of the second die; After connecting the first interconnect and the second interconnect to the first die and the second die, respectively, the back side of the second die is mounted to the active side of the first die such that the first interconnect extends beyond the active side of the second die and the second peripheral edge region of the second die overhangs an edge of the first die opposite the first peripheral edge region, wherein the second interconnect extends in the direction of the first interconnect, and wherein, during assembly, the second die is rotated approximately 180° relative to the first die, and the first interconnect is positioned near a first edge of the semiconductor device and the second interconnect is positioned near a second edge of the semiconductor device opposite the first edge; Connecting a conductive third interconnect to the active side of a third die, wherein the third die has a back side opposite the active side of the third die, and the width of the third die is less than the width of the first die and the width of the second die; and After connecting the third interconnect to the third die, mounting the back side of the third die to the active side of the second die such that the third die is rotated approximately 90° relative to the second die and positioned between the first interconnect and the second interconnect such that the first interconnect and the second interconnect extend beyond the active side of the third die, wherein the third interconnect extends in a direction between the first interconnect and the second interconnect, and wherein, during assembly, the third interconnect is positioned near a third edge between the first edge and the second edge of the semiconductor device.

19. The method of claim 18, further comprising mounting the back side of the second die to the semiconductor wafer such that a portion of the second die is mounted to the semiconductor wafer and another portion of the second die is mounted to the active side of the first die.

20. The method of claim 18, further comprising: Applying a molding material at least partially around the second die, the third die, the first interconnect, the second interconnect, and the third interconnect; Curing the molding material; And Trimming a surface of the molding material to at least partially expose the first interconnect, the second interconnect, and the third interconnect.

21. The method of claim 20, further comprising: Placing a redistribution layer on the trimmed surface of the molding material; And Electrically connecting the first interconnect, the second interconnect, and the third interconnect to the redistribution layer.

22. The method of claim 18, further comprising: Connecting a conductive fourth interconnect to the active side of a fourth die, wherein the fourth die has a back side opposite the active side of the fourth die; After connecting the fourth interconnect to the fourth die, the back side of the fourth die is mounted to the active side of the third die such that the first, second, and third interconnects extend beyond the active side of the fourth die, wherein the fourth interconnect extends in the direction of the first, second, and third interconnects.

23. The method of claim 22, wherein, in assembly, the fourth interconnect is positioned near a fourth edge of the semiconductor device that is between the first and second edges and opposite the third edge.

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