This disclosure relates generally to containers (e.g., housings) for semiconductor devices. More specifically, disclosed embodiments relate to containers that may reduce the likelihood that at least some types of radiation (e.g., neutron radiation, proton radiation) may otherwise produce deleterious effects in semiconductor devices, such as, for example, bit flipping in memory devices and/or radiation-induced alteration of current-voltage characteristics of trench FET commercial power MOSFETS.
Shielding materials may conventionally be deployed to contain harmful radiation, such as neutron radiation, within the environment where a radiation source is located. For example, shielding materials may be interposed between a nuclear fuel source and any people or sensitive equipment to reduce the likelihood that radiation emitted by the nuclear fuel source would irradiate those people or sensitive equipment. The shielding materials may at least substantially contain the radiation within an enclosed space defined by the shielding materials.
While this disclosure concludes with claims particularly pointing out and distinctly claiming specific embodiments, various features and advantages of embodiments within the scope of this disclosure may be more readily ascertained from the following description when read in conjunction with the accompanying drawings. In the drawings:
It has been established that certain types of radiation, for example, neutron and proton radiation, may cause degradation of semiconductor devices. For example, certain semiconductor-based components of integrated circuits are more or less susceptible to neutron-induced performance degradation. Included are such component devices as bipolar transistors, JFETs, MOSFETS, diodes, operational amplifiers, voltage comparators, TTL and EDL gates, and CMOS gates and, of course, integrated circuits including combinations of such component devices.
Radiation damage mechanisms include two primary types: displacement damage and ionization damage. The former occurs when incident radiation displaces semiconductor (e.g., silicon) atoms from their sites in the silicon lattices, altering electronic characteristics of the crystal. The latter occurs when energy absorbed by electronic ionization in insulating layers, such as SiO2, liberates charge carriers which, in turn, diffuse or drift to other locations where they are trapped and lead to concentrations of charge and parasitic fields.
While it has been proposed to fabricate integrated circuits from component devices and combinations of component devices configured for radiation resistance, such approaches limit the utility of such circuits and drive up complexity and cost. Other conventional approaches to radiation shielding involve relatively thick, bulky and heavy shielding materials such as concrete or lead, which approaches are impractical if not impossible for many applications where radiation-induced degradation is of concern.
Disclosed embodiments relate generally to containers that may reduce the likelihood that at least some types of radiation may otherwise produce deleterious effects in semiconductor devices. For example, containers in accordance with this disclosure may be positioned, and may have sufficient radiation shielding characteristics, to reduce (e.g., eliminate) the likelihood that radiation from outside the containers will induce damage in semiconductor devices located at least partially within the containers. More specifically, containers in accordance with this disclosure may have one or more panels including radiation absorbing and/or reflecting material in sufficient quantities to inhibit radiation (e.g., proton and/or neutron radiation) at an exterior of the container from passing through the relevant panel to the interior of the container. As a specific, nonlimiting example, containers of this disclosure may reduce (e.g., eliminate) radiation-induced bit flipping in memory devices and radiation-induced alteration of current-voltage characteristics of trench FET commercial power MOSFETS.
In some embodiments, the containers for supporting semiconductor devices in accordance with this disclosure may be configured as storage containers, shipping containers, housings for installed configurations, server racks, and building constructions that may at least partially enclose semiconductor devices. The containers may include shielding materials positioned to reduce or eliminate the likelihood that radiation from the ambient environment exterior to a container will enter a volume where the semiconductor devices are located. For example, the shielding materials may be incorporated into one or more walls of a housing at least partially enclosing semiconductor devices during storage, shipping, and potentially when installed in a system. As another example, the shielding materials may be incorporated into one or more walls of a server rack supporting the semiconductor devices, or into one or more construction materials for the building housing the semiconductor devices. Providing shielding materials at least partially around semiconductor devices may reduce the likelihood that radiation (e.g., neutron radiation) may flip any bits in memory devices (e.g., dynamic random access memory (DRAM)) or induce alteration of current-voltage characteristics of trench FET commercial power MOSFETS. Such a reduction in the phenomenon of radiation-induced bit flipping and/or other radiation-induced damage in semiconductor devices may reduce the error rate in operating semiconductor devices, and reduce the need to re-test and verify the functionality of semiconductor devices after shipping and after spending time in storage.
As used herein, the terms “substantially” and “about” in reference to a given parameter, property, or condition means and includes to a degree that one of ordinary skill in the art would understand that the given parameter, property, or condition is met with a degree of variance, such as within acceptable manufacturing tolerances. For example, a parameter that is substantially or about a specified value may be at least about 90% the specified value, at least about 95% the specified value, at least about 99% the specified value, or even at least about 99.9% the specified value.
The term “semiconductor device,” as used herein, means and includes microelectronic devices formed utilizing doped regions of a semiconducting material. For example, semiconductor devices include processors, memory devices, and systems on a chip, and may be provided in the form of a singulated device region of a semiconductor wafer.
The term “semiconductor wafer,” as used herein, means and includes substrates including semiconducting material. For example, semiconductor wafers may include bulk wafers of undoped semiconducting material or device wafers having discrete regions of doped semiconducting material forming device regions separated by streets, forming a grid.
The term “semiconductor device package,” as used herein, means and includes a semiconductor device in the form of a singulated device region of a semiconductor wafer having protective material surrounding at least a portion of the semiconductor device and an interface structure for integrating the semiconductor device package with higher level packaging. For example, semiconductor device packages include encapsulated semiconductor chips having input and output structures (e.g., pads, balls, bumps, pillars, columns, lead fingers) of electrically conductive material, and may be supported on, and electrically connected to, higher level packaging (e.g., a printed circuit board (PCB), a bread board).
The terms “memory” and “memory device,” as used herein, include microelectronic devices exhibiting, but not limited to, memory functionality, but exclude embodiments encompassing transitory signals. For example, a system on a chip (SoC) is encompassed in the meaning of “memory device.” By way of non-limiting example, memory devices may generally include packaged semiconductor devices having shielding material configurations as described herein, unless otherwise specified.
The illustrations presented in this disclosure are not meant to be actual views of any particular container, semiconductor device, support structure, or component thereof, but are merely idealized representations employed to describe illustrative embodiments. Thus, the drawings are not necessarily to scale.
The container 100 may include, for example, walls 102 sized, shaped, and positioned to at least partially surround a semiconductor device within the container. Though the container 100 shown in
At least one of the walls 102 may include a radiation-shielding material. For example, those walls 102 to be positioned between relevant portions of any semiconductor devices at least partially supported within the walls 102 and a source of radiation may include the radiation-shielding material. More specifically, those walls 102 intended for positioning above any semiconductor devices, laterally proximate to any semiconductor devices, and optionally below any semiconductor devices at least partially supported within the container 100 may include or be formed from a radiation-shielding material. As specific, nonlimiting examples, each of the walls 102 may include the radiation-shielding material, or each of the walls 102 other than a wall 102 positioned and configured to face a floor when the container 100 is placed on the floor may include the radiation-shielding material, and the wall 102 positioned to face the floor may lack the radiation-shielding material.
The radiation-shielding material of the wall 102 or walls 102 may be configured to reduce the likelihood that certain types of radiation will alter a state of a silicon lattice in any semiconductor devices supported within the container 100. For example, the radiation-shielding material of the wall 102 or walls 102 may be configured to inhibit one or more types of radiation (e.g., neutron radiation, proton radiation) from altering the state of the silicon lattice in any of the semiconductor devices within the walls 102 in a way that would affect the operation, reliability, or longevity of the semiconductor devices. More specifically, the radiation-shielding material of a given wall 102 may be configured to absorb, deflect, reflect, and/or otherwise mitigate radiation of one or more types (e.g., neutron radiation, proton radiation) to reduce the risk of radiation-induced damage in semiconductor devices (e.g., bit flipping in memory devices, radiation-induced alteration of current-voltage characteristics of trench FET commercial power MOSFETS) within the walls 102 of the container 100.
The radiation-shielding material may be or include, for example, low atomic number elements having scattering cross sections or elements having capturing cross sections. More specifically, the radiation-shielding material may be or include hydrogen, carbon, oxygen, lead, bismuth, tungsten, boron, cadmium, and/or gadolinium. As specific, nonlimiting examples, the radiation-shielding material may be or include at least one material selected from the group consisting of borated polyethylene, boron carbide (e.g., B4C), a boron aluminum alloy. In embodiments where the container 100 is used for shipping, borated polyethylene may be particularly suitable at least in part because of its lower density than other radiation-shielding materials, resulting a lower-weight container 100 with suitable radiation shielding capabilities.
In some embodiments, one or more of the walls 102 may include multiple sheets 106 of, or including, the radiation-shielding material. For example, two or more sheets 106 may be provided in layers to form at least a portion of at least one of the walls 102 of the container 100. More specifically, at least some, and up to each, of the walls 102 intended to provide radiation shielding capabilities to the container 100 may include two or more of the sheets 106 (e.g., 2, 3, 4, etc.) mutually secured to one another to form the respective wall 102. Providing the radiation-shielding material in sheets 106 may enable selective deployment of a desired level of radiation shielding by adding or removing layers of the sheets 106 when forming the associated wall 102. In other embodiments, one or more of the walls 102 may include a single sheet 106 of or including the radiation-shielding material, and the degree of radiation shielding may be altered by modifying the thickness 110 of the sheet 106, as measured in a direction parallel to a shortest distance between the interior volume 104 and the exterior of the container 100. Suitable sheets 106 including or of radiation-shielding materials are commercially available from, for example, MarShield Custom Radiation Shielding Products of 4140 Morris Dr., Burlington, Ontario, L7L 5L6, Canada, and Apex Industries of 12670 SW Hall Blvd, Igard, Oreg. 97223, USA.
A degree of radiation shielding provided by a given wall 102 of the container 100 may be sufficient to inhibit radiation of certain types of radiation at an exterior of the container 100 from passing through the relevant wall 102 to the interior of the container 100. For example, a quantity of the radiation-shielding material in the wall 102 may be between about 1% and 20% by weight of the wall 102, and a thickness of the wall 102, as measured in a shortest direction from the exterior of the container 100 to the interior, may be between about 0.5 inch and about 12 inches. More specifically, the wall 102 may include between about 1.5% and about 15% by weight of a radiation-shielding element, and the thickness of the wall 102 may be between about 1 inch and about 6 inches. As a specific, nonlimiting example, the wall 102 may include between about 2% and about 10% (e.g., about 5%) boron by weight (e.g., in the form of borated polyethylene), and the thickness of the wall 102 may be between about 2 inches and about 5 inches (e.g., about 3 inches). When compared to enclosures that may be used to contain radiation within the enclosure, rather than keeping environmental radiation out of the container 100, containers 100 in accordance with this disclosure may include thinner walls 102. This comparative thinness may enable the containers 100 to be used in a greater variety of situations, such as, for example, during shipping, short-term storage, medium- to long-term storage, and in installed, operating configurations.
A weight of the container 100 may be low, particularly when compared to enclosures that may be used to contain radiation within the enclosure. For example, the container 100 may weigh about 100 pounds or less. More specifically, the container 100 may weigh between about 1 pound and about 25 pounds. As a specific, nonlimiting example, the container 100 may weigh between about 2 pounds and about 15 pounds (e.g., about 5 pounds, about 10 pounds). This comparative lightness may similarly enable the containers 100 to be used in a greater variety of situations, such as, for example, during shipping, short-term storage, medium- to long-term storage, and in installed, operating configurations.
In some of the embodiments where the walls 102 include adjacent sheets 106 of, or including, the radiation-shielding material, the walls 102 may be joined to one another proximate vertexes 108 of the container 100 utilizing a stair-step configuration. For example, innermost sheets 106 may have a smallest longitudinal length 112, and the longitudinal length 112 of each successive sheet 106 as distance to the exterior decreases may be progressively greater, forming a stair-step shape at a periphery of the wall 102. The stair-step-shaped peripheries of walls 102 oriented perpendicular to one another may be brought into mating contact with one another, forming the associated vertex 108. Adjacent walls 102 may be secured to one another, and adjacent sheets 106 of a given wall 102 may be secured to one another, utilizing a mechanical connector (e.g., nails, screws, bolts), adhesive material (e.g., glue, epoxy), mechanical interference (e.g., a snap fit, a friction fit), or other suitable connection. In some embodiments, a sealing member (e.g., an elastomeric sealing ring) may be positioned between adjacent walls 102 to form or improve the quality of a seal between the walls 102.
At least a portion of at least one of the walls 102 may be displaceable to enable a user to selectively access an interior of the container 100. For example, one of the walls 102 may be removable, rotatable, or otherwise displaceable with respect to the other walls 102 to enable a user to access the interior volume 104 of the container 100 and to subsequently close the container 100 to at least partially restrict access to the interior volume 104 of the container 100. More specifically, one of the walls 102 (e.g., the top wall 102 when the container 100 is supported on a floor) may form a lid that is removable entirely or is hinged to an adjacent wall 102 to grant selective access to the interior volume 104 of the container 100. As another example, a portion of one of the walls 102 may be removable, rotatable, or otherwise displaceable with respect to the remainder of that wall 102, and to the other walls 102, to enable a user to access the interior volume 104 of the container 100 and to subsequently close the container 100 to at least partially restrict access to the interior volume 104 of the container 100. More specifically, one or more of the walls 102 may include an opening 116 extending through a portion of the wall 102 and a plug 114 to selectively obstruct the opening 116. As a specific, nonlimiting example, one of the walls 102 may include a plug 114 configured as a door having a wall 102 and a hinge 118, enabling a user to selectively displace the plug 114 from within the opening 116 to access the interior volume 104 and to replace the plug 114 into the opening 116 to place the container 100 in a closed state. The wall 102, portion of the wall 102, or plug 114 may be securable in place relative to a remainder of the container 100 (e.g., utilizing a latch, a snap fit, a pin, etc. and optionally including a sealing member to form a seal) to temporarily fix the container 100 in the closed state.
The container 100 may be sized, shaped, and configured to support one or more semiconductor devices configured as semiconductor wafers, semiconductor device packages, or a substrates supporting one or more semiconductor device packages therein. The size and shape of the container 100, as well as the size and shape of the interior volume 104 and any access openings for the container 100, may be adapted for the desired application for the container 100.
The support structure 302 may be adapted to support semiconductor devices 304 having different form factors, depending on the intended application for the container 300. For example, the support structure 302 may be sized, shaped, and configured to support a semiconductor device configured as a semiconductor die, a semiconductor device package, or a module comprising a substrate supporting one or more semiconductor device packages thereon. In the embodiment of
The method 200 may also involve placing the semiconductor devices 304 and the support structure 302 within the walls 102 of the container 300, as indicated at act 204. At least one of the walls 102 may include a radiation-shielding material, as discussed previously in connection with
As a summary, containers for supporting one or more semiconductor devices therein in accordance with some embodiments may include walls positioned to at least partially surround a semiconductor device. At least one of the walls may include a radiation-shielding material. A support structure may be shaped, positioned, and configured to support the semiconductor device within the walls.
In other embodiments, methods of protecting one or more semiconductor devices may involve supporting a semiconductor device on a support structure. The semiconductor device and the support structure may be placed within walls of a container. At least one of the container walls may include a radiation-shielding material.
The semiconductor devices 404 of
The container 400 may be used to protect the semiconductor devices 404 from at least certain forms of radiation in desired situations, such as, for example, during shipping, short-term storage, and/or long-term storage. For example, the container 400 may be used to inhibit neutron and/or proton radiation from altering a state of a silicon latter in the semiconductor devices 404 utilizing the radiation-shielding material of the walls 102. More specifically, the container 400 may be used to reduce the likelihood that radiation from outside the container 400 will induce damage in a given semiconductor device 404 (e.g., that a bit of a memory device of a given semiconductor device 404 will flip, that radiation will induce alterations of current-voltage characteristics of trench FET commercial power MOSFETS) within the walls 102 utilizing the radiation-shielding material.
The semiconductor devices 504 of
The container 500 may be used to protect the semiconductor devices 504 from at least certain forms of radiation in desired situations, such as, for example, during shipping, short-term storage, and/or long-term storage. For example, the container 500 may be used to inhibit neutron and/or proton radiation from altering a state of a silicon latter in the semiconductor devices 504 utilizing the radiation-shielding material of the walls 102. More specifically, the container 500 may be used to reduce the likelihood that radiation from outside the container 500 will damage a given semiconductor wafer 506 (e.g., that a bit of a memory device of a given semiconductor wafer 506, that radiation will alter current-voltage characteristics of trench FET commercial power MOSFETS) within the walls 102 utilizing the radiation-shielding material.
The container 600 may be configured as, for example, a case for positioning around a majority of the semiconductor device 606 after the semiconductor device 606 has been installed (e.g., a PC case). For example, the container 600 may include two clamshell portions rotatable with respect to one another about a hinge 602 and a latch (e.g., a snap-fit, a pinned connection) to secure the clamshell portions to one another on a side opposite the hinge 602 when the container 600 is in a closed state.
To install the semiconductor device 606 and the container 600, the semiconductor device 606 may first be installed into the relevant socket 610, connecting the semiconductor device 606 to another system 614 (e.g., a motherboard, an expansion card). The container 600 may then be installed around the semiconductor device 606, with a connector portion of the semiconductor device 606 extending through the port 612 in the container 600 for communication with higher level packaging exterior to the container, and a remainder of the semiconductor device 606 being located within the interior volume 104 of the container 600.
The container 600 may be used to protect the semiconductor devices 606 from at least certain forms of radiation in desired situations, such as, for example, after installation and during operation. For example, the container 600 may be used to inhibit neutron and/or proton radiation from altering a state of a silicon latter in the semiconductor devices 606 utilizing the radiation-shielding material of the walls 102. More specifically, the container 600 may be used to reduce the likelihood that radiation from outside the container 600 will damage a given semiconductor device 606 (e.g., that a bit of a memory device of a given semiconductor device 606 will flip, that radiation will alter current-voltage characteristics of trench FET commercial power MOSFETS) within the walls 102 utilizing the radiation-shielding material.
The semiconductor devices 706 may be configured as, for example, hot-swappable components for deployment in server racks 704. More specifically, the semiconductor devices 706 may be configured as hot-swappable memory devices for deployment in server racks 704.
In some embodiments, the radiation-shielding material may be selected to reduce the likelihood that neutron radiation will alter a state of a silicon lattice in the semiconductor device. For example, the radiation-shielding material may be selected to include at least one material selected from the group consisting of borated polyethylene, boron carbide, and a boron aluminum alloy, or any of the other materials described previously in connection with
In some embodiments, defining the recess utilizing the walls may involve layering sheets of the radiation-shielding material in layers to form at least a portion of the at least one of the walls, as described in connection with
In summary, methods of making containers for supporting one or more semiconductor devices therein may involve providing a support structure shaped, positioned, and configured to support a semiconductor device. A recess sized and shaped to receive the support structure and the semiconductor device may be defined therein utilizing walls of the container. A material of at least one walls may be selected to include a radiation-shielding material.
Embodiments of containers in accordance with this may reduce the likelihood that at least some types of radiation may otherwise produce deleterious effects in semiconductor devices, such as, for example, bit flipping in memory devices and/or radiation-induced alteration of current-voltage characteristics of trench FET commercial power MOSFETS. Such containers may be particularly useful in situations where radiation is more likely to be encountered, such as, for example, when shipping by air, in aerospace applications (e.g., black boxes, control systems), at high altitudes, and in nuclear facilities. Such containers may also find application in situations where reliability is important, such as, for example, in autonomous control systems implicating the safety of humans (e.g., self-driving cars, autopilots for airplanes, autopilots for other aerospace systems, defense systems) and voting systems. Radiation-shielding containers in accordance with this disclosure may also reduce the need to re-test and verify the functionality of semiconductor devices after shipping and after spending time in storage.
While certain illustrative embodiments have been described in connection with the figures, those of ordinary skill in the art will recognize and appreciate that the scope of this disclosure is not limited to those embodiments explicitly shown and described in this disclosure. Rather, many additions, deletions, and modifications to the embodiments described in this disclosure may be made to produce embodiments within the scope of this disclosure, such as those specifically claimed, including legal equivalents. In addition, features from one disclosed embodiment may be combined with features of another disclosed embodiment while still being within the scope of this disclosure.