This disclosure relates generally to wafer fabrication methods, and more specifically, but not exclusively, to backside power distribution networks (PDNs) and fabrication techniques thereof.
One technique to reduce the size of integrated circuits is to use a backside power distribution network (PDN), in which through substrate vias (TSVs) are used to supply power through the wafer substrate, i.e., from the back side of the substrate to devices on the front side of the substrate.
However, the thickness of the substrate 100 is large compared to the diameter of a typical TSV 202, which results in a TSV 202 with a high aspect ratio, causing high contact resistance and creating a narrow margin for process defects. For example, a TSV 202 with a typical diameter of 100 nm has a 30:1 aspect ratio.
Accordingly, there is a need for systems, apparatus, and methods that overcome the deficiencies of conventional backside PDN processing, including the methods, system and apparatus provided herein.
The following presents a simplified summary relating to one or more aspects and/or examples associated with the apparatus and methods disclosed herein. As such, the following summary should not be considered an extensive overview relating to all contemplated aspects and/or examples, nor should the following summary be regarded to identify key or critical elements relating to all contemplated aspects and/or examples or to delineate the scope associated with any particular aspect and/or example. Accordingly, the following summary has the sole purpose to present certain concepts relating to one or more aspects and/or examples relating to the apparatus and methods disclosed herein in a simplified form to precede the detailed description presented below.
In accordance with the various aspects disclosed herein, at least one aspect includes a semiconductor die with a through substrate via (TSV) structure having improved electrical characteristics suitable for backside power distribution networks (PDNs). The semiconductor die includes a substrate having a front side and a back side and includes a TSV extending from the back side of the substrate towards the front side of the substrate. The TSV includes a first portion extending from the back side of the substrate towards the front side of the substrate and having a first cross sectional area. The TSV also includes a second portion extending from the first portion towards the front side of the substrate and having a second cross sectional area smaller than the first cross sectional area. A conductor is disposed within the TSV. According to some aspects, the first portion of the TSV is trench structure.
In accordance with the various aspects disclosed herein, at least one aspect includes, a method for fabricating a semiconductor die with a TSV structure having improved characteristics suitable for PDNs. The method includes providing a substrate having a front side and a back side. The method also includes providing a TSV extending from the back side of the substrate towards the front side of the substrate. The TSV includes a first portion extending from the back side of the substrate towards the front side of the substrate and having a first cross sectional area. The TSV includes and a second portion extending from the first portion towards the front side of the substrate and having a second cross sectional area smaller than the first cross sectional area. A conductor is disposed within the TSV. According to some aspects, the first portion of the TSV is trench structure.
Other features and advantages associated with the apparatus and methods disclosed herein will be apparent to those skilled in the art based on the accompanying drawings and detailed description.
A more complete appreciation of aspects of the disclosure and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings which are presented solely for illustration and not limitation of the disclosure.
In accordance with common practice, the features depicted by the drawings may not be drawn to scale. Accordingly, the dimensions of the depicted features may be arbitrarily expanded or reduced for clarity. In accordance with common practice, some of the drawings are simplified for clarity. Thus, the drawings may not depict all components of a particular apparatus or method. Further, like reference numerals denote like features throughout the specification and figures.
Aspects of the present disclosure are illustrated in the following description and related drawings directed to specific embodiments. Alternate aspects or embodiments may be devised without departing from the scope of the teachings herein. Additionally, well-known elements of the illustrative embodiments herein may not be described in detail or may be omitted so as not to obscure the relevant details of the teachings in the present disclosure.
In certain described example implementations, instances are identified where various component structures and portions of operations can be taken from known, conventional techniques, and then arranged in accordance with one or more exemplary embodiments. In such instances, internal details of the known, conventional component structures and/or portions of operations may be omitted to help avoid potential obfuscation of the concepts illustrated in the illustrative embodiments disclosed herein.
The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises,” “comprising,” “includes,” and/or “including,” when used herein, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.
In order to fully illustrate aspects of the design of the present disclosure, methods of fabrication are presented. Other methods of fabrication are possible, and the discussed fabrication methods are presented only to aid understanding of the concepts disclosed herein.
As can be seen in
It will be appreciated that the foregoing fabrication process was provided merely as general illustration of some of the aspects of the disclosure and is not intended to limit the disclosure or accompanying claims. Further, many details in the fabrication process known to those skilled in the art may have been omitted or combined in summary process portions to facilitate an understanding of the various aspects disclosed without a detailed rendition of each detail and/or all possible process variations.
According to some aspects, the conductor 414 is part of a backside PDN. According to some aspects, the first portion 410 of the TSV is a trench structure. According to some aspects, the conductor 414A is electrically coupled to a metallization layer, such as BPR 404, for example, embedded within the substrate 402. According to some aspects, the second portion 412 of the TSV extends to or beyond the front side of the substrate. According to some aspects, the conductor 414B is electrically coupled to a metal layer 408 located on or above the front side of the substrate 402. According to some aspects, such as in a damascene process, the conductor 414 is separated from the substrate 402 by an isolation layer 416. According to some aspects, the conductor 414 contains copper. According to some aspects the semiconductor die 400 is incorporated into an apparatus such as, but not limited to, a music player, a video player, an entertainment unit, a navigation device, a communications device, a mobile device, a mobile phone, a smartphone, a personal digital assistant, a fixed location terminal, a tablet computer, a computer, a wearable device, an Internet of things (IoT) device, a laptop computer, a server, and a device in an automotive vehicle.
Semiconductor die 400 provides several technical advantages, including but not limited to the following. Using a trench structure for the first portion 410 of the TSV has at least two benefits: the trench structure has a larger cross-sectional area 500 than the cross-sectional area 502 of the etched nano-TSV, which lowers the resistance of the first portion 410; and the length L of the second portion 412 of the TSV is much less than T, which means that the aspect ratio of the second portion 412 of the TSV is much lower than for conventional TSVs 202, resulting in lower resistance for the entire TSV compared to conventional TSVs 202. Moreover, the first portion 410 may be creating using any technique that results in a larger cross-sectional area 500 compared to the cross-sectional area 502 of conventional etched TSV structures. Furthermore, in the example illustrated in
In some aspects,
In a particular aspect, where one or more of the above-mentioned blocks are present, processor 602, display controller 616, memory 612, CODEC 618, and wireless controller circuits 624 can be included in a system-in-package or system-on-chip device, including but not limited to semiconductor die 400, which may be implemented in whole or part using the techniques disclosed herein. Input device 628 (e.g., physical or virtual keyboard), power supply 630 (e.g., battery), display 614, input device 628, speaker 620, microphone 622, wireless antenna 626, and power supply 630 may be external to system-on-chip device and may be coupled to a component of system-on-chip device, such as an interface or a controller.
It should be noted that although
The foregoing disclosed packages, devices, and functionalities may be designed and configured into computer files (e.g., RTL, GDSII, GERBER, etc.) stored on computer-readable media. Some or all such files may be provided to fabrication handlers who fabricate devices based on such files. Resulting products may include semiconductor wafers that are then cut into semiconductor die and packaged into a flip-chip or other package. The packages may then be employed in devices described herein.
It will be appreciated that various aspects disclosed herein can be described as functional equivalents to the structures, materials and/or devices described and/or recognized by those skilled in the art. For example, in one aspect, an apparatus may comprise a means for performing the various functionalities discussed above. It will be appreciated that the aforementioned aspects are merely provided as examples and the various aspects claimed are not limited to the specific references and/or illustrations cited as examples.
One or more of the components, processes, features, and/or functions illustrated in
As used herein, the terms “user equipment” (or “UE”), “user device,” “user terminal,” “client device,” “communication device,” “wireless device,” “wireless communications device,” “handheld device,” “mobile device,” “mobile terminal,” “mobile station,” “handset,” “access terminal,” “subscriber device,” “subscriber terminal,” “subscriber station,” “terminal,” and variants thereof may interchangeably refer to any suitable mobile or stationary device that can receive wireless communication and/or navigation signals. These terms include, but are not limited to, a music player, a video player, an entertainment unit, a navigation device, a communications device, a smartphone, a personal digital assistant, a fixed location terminal, a tablet computer, a computer, a wearable device, a laptop computer, a server, an automotive device in an automotive vehicle, and/or other types of portable electronic devices typically carried by a person and/or having communication capabilities (e.g., wireless, cellular, infrared, short-range radio, etc.). These terms are also intended to include devices which communicate with another device that can receive wireless communication and/or navigation signals such as by short-range wireless, infrared, wireline connection, or other connection, regardless of whether satellite signal reception, assistance data reception, and/or position-related processing occurs at the device or at the other device. In addition, these terms are intended to include all devices, including wireless and wireline communication devices, that are able to communicate with a core network via a radio access network (RAN), and through the core network the UEs can be connected with external networks such as the Internet and with other UEs. Of course, other mechanisms of connecting to the core network and/or the Internet are also possible for the UEs, such as over a wired access network, a wireless local area network (WLAN) (e.g., based on IEEE 802.11, etc.) and so on. UEs can be embodied by any of a number of types of devices including but not limited to printed circuit (PC) cards, compact flash devices, external or internal modems, wireless or wireline phones, smartphones, tablets, tracking devices, asset tags, and so on. A communication link through which UEs can send signals to a RAN is called an uplink channel (e.g., a reverse traffic channel, a reverse control channel, an access channel, etc.). A communication link through which the RAN can send signals to UEs is called a downlink or forward link channel (e.g., a paging channel, a control channel, a broadcast channel, a forward traffic channel, etc.). As used herein the term traffic channel (TCH) can refer to either an uplink/reverse or downlink/forward traffic channel.
The wireless communication between electronic devices can be based on different technologies, such as code division multiple access (CDMA), wide-band CDMA (W-CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal frequency division multiplexing (OFDM), global system for mobile communications (GSM), the third generation partnership project (3GPP) long term evolution (LTE), fifth generation (5G) new radio (NR), Bluetooth (BT), Bluetooth low energy (BLE), IEEE 802.11 (WiFi), and IEEE 802.15.4 (Zigbee/Thread) or other protocols that may be used in a wireless communications network or a data communications network. Bluetooth low energy (also known as Bluetooth LE, BLE, and Bluetooth Smart) is a wireless personal area network technology designed and marketed by the Bluetooth Special Interest Group intended to provide considerably reduced power consumption and cost while maintaining a similar communication range. BLE was merged into the main Bluetooth standard in 2010 with the adoption of the Bluetooth Core Specification Version 4.0 and updated in Bluetooth 5.
The word “exemplary” is used herein to mean “serving as an example, instance, or illustration.” Any details described herein as “exemplary” is not to be construed as advantageous over other examples. Likewise, the term “examples” does not mean that all examples include the discussed feature, advantage or mode of operation. Furthermore, a particular feature and/or structure can be combined with one or more other features and/or structures. Moreover, at least a portion of the apparatus described hereby can be configured to perform at least a portion of a method described hereby.
It should be noted that the terms “connected,” “coupled,” or any variant thereof, mean any connection or coupling, either direct or indirect, between elements, and can encompass a presence of an intermediate element between two elements that are “connected” or “coupled” together via the intermediate element unless the connection is expressly disclosed as being directly connected.
Any reference herein to an element using a designation such as “first,” “second,” and so forth does not limit the quantity and/or order of those elements. Rather, these designations are used as a convenient method of distinguishing between two or more elements and/or instances of an element. Also, unless stated otherwise, a set of elements can comprise one or more elements.
Those skilled in the art will appreciate that information and signals may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.
Nothing stated or illustrated depicted in this application is intended to dedicate any component, action, feature, benefit, advantage, or equivalent to the public, regardless of whether the component, action, feature, benefit, advantage, or the equivalent is recited in the claims.
Further, those of skill in the art will appreciate that the various illustrative logical blocks, modules, circuits, and algorithm actions described in connection with the examples disclosed herein may be implemented as electronic hardware, computer software, or combinations of both. To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and actions have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present disclosure.
Although some aspects have been described in connection with a device, it will be understood that these aspects also constitute a description of the corresponding method, and so a block or a component of a device should also be understood as a corresponding method action or as a feature of a method action. Analogously thereto, aspects described in connection with or as a method action also constitute a description of a corresponding block or detail or feature of a corresponding device. Some or all of the method actions can be performed by a hardware apparatus (or using a hardware apparatus), such as, for example, a microprocessor, a programmable computer or an electronic circuit. In some examples, some or a plurality of the method actions can be performed by such an apparatus.
In the detailed description above it can be seen that different features are grouped together in examples. This manner of disclosure should not be understood as an intention that the claimed examples have more features than are explicitly mentioned in the respective claim. Rather, the disclosure may include fewer than all features of an individual example disclosed. Therefore, the following claims should hereby be deemed to be incorporated in the description, wherein each claim by itself can stand as a separate example. Although each claim by itself can stand as a separate example, it should be noted that-although a dependent claim can refer in the claims to a specific combination with one or a plurality of claims-other examples can also encompass or include a combination of said dependent claim with the subject matter of any other dependent claim or a combination of any feature with other dependent and independent claims. Such combinations are proposed herein, unless it is explicitly expressed that a specific combination is not intended. Furthermore, it is also intended that features of a claim can be included in any other independent claim, even if said claim is not directly dependent on the independent claim.
It should furthermore be noted that methods, systems, and apparatus disclosed in the description or in the claims can be implemented by a device comprising means for performing the respective actions and/or functionalities of the methods disclosed.
Furthermore, in some examples, an individual action can be subdivided into a plurality of sub-actions or contain a plurality of sub-actions. Such sub-actions can be contained in the disclosure of the individual action and be part of the disclosure of the individual action.
While the foregoing disclosure shows illustrative examples of the disclosure, it should be noted that various changes and modifications could be made herein without departing from the scope of the disclosure as defined by the appended claims. The functions and/or actions of the method claims in accordance with the examples of the disclosure described herein need not be performed in any particular order. Additionally, well-known elements will not be described in detail or may be omitted so as to not obscure the relevant details of the aspects and examples disclosed herein. Furthermore, although elements of the disclosure may be described or claimed in the singular, the plural is contemplated unless limitation to the singular is explicitly stated.