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US Government Funds Fabs of Radiation-Resistant Chips Used in Nuclear Weapons, Space

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The U.S. government is putting money into radiation-resistant chips. It's investing the MESA (Microsystems, Engineering, Science and Applications) fabrication facility that makes such chips for usage in nuclear weapons, as reported by the Institute of Electrical and Electronics Engineers' magazine IEEE Spectrum today.

MESA is located at the U.S. Energy Department’s Sandia National Laboratories in New Mexico. The government is also investing another $170 million to improve the radiation-hardened chip line of SkyWater Technology Foundry, in Bloomington, Minn., for other U.S. Department of Defense (DoD) needs.

Overdue for an Upgrade

The MESA fab has been making radiation-resistant chips for the U.S.’ nuclear arsenal for decades. However, although the chips are advanced enough to work reliably without being damaged by radiation, they are still using a highly antiquated 350nm process technology that was used for consumer chips for the first time back in 1994. 

The facility was also making 150mm wafers, which are just about as old the the process node. The most advanced fabs currently make 300mm wafers, and there is also a thriving supply for 200mm wafers.

But the feds aren't interested in upgrading the MESA fab just because the tech was more than two decades old. Rather, the upgrades are about how difficult it's become to source the parts and raw materials for tools used to make the 150mm wafers.

MESA has already completed the first step in a four-step process that will allow the facility to make 200mm wafers. The conversion involves rebuilding chemical recipes, adjusting hundreds of process parameters and extensive testing. The upgrade should be completed by July 2021.

The facility will also upgrade to a 180nm process in parallel, which will double the transistor density of nuclear weapon chips. 

Michael Holmes, senior manager of microfabrication at MESA said, that although their primary goal is to build radiation-hardened chips, it’s also important to scale the technology to provide denser and more complex logic function.

Enhancements to SkyWater Technology Foundry

The DoD is also providing $170 million SkyWater Technology Foundry to develop a 90nm process for radiation-hardened chips and copper interconnects. SkyWater should be able to build chips with this “newer” process node because the radiation-hardening requirements are not as stringent as they are for Sandia’s MESA facility. SkyWater’s chips are meant to be used in DoD’s military gear and in space.

SkyWater’s radiation-hardening process relies on silicon-on-insulator (SOI) technology, which uses a silicon wafer with a layer of oxide buried below the transistor layer. SOI chips are inherently more tolerant of radiation than regular silicon chips because ordinary silicon chips create charges that interfere with the chip’s operation when they are hit by radiation. Alternatively, in a SOI chip the oxide layer prevents the radiation-caused charge from reaching the transistor layer. 

SkyWater will also replace its use of aluminum in interconnects with copper, a move that the consumer chip industry made about 15 years ago. The use of copper interconnects combined with support for the 65nm and 45nm process technology in the near future means that SkyWater will be able to build chips that resemble modern consumer chips. As such, the company will be able to make high-end mixed signal chips for the Internet of Things, chiplets and silicon interposers.

The U.S. government will fund the first phase of SkyWater’s facility upgrade with $80 million, with the rest to come in the next phases.

  • NightHawkRMX
    I never knew CPUs were susceptible to radiation damage.
    Reply
  • genz
    They aren't, but the radiation passing through them causes single-bit 'style' errors because it's basically handing electrons to whatever it hits and thus flipping bits from 0 to 1. You can't even build a heavy lead shield around an existing CPU (which for space is dumb anyway 'cause you're paying about $40,000 per kilo to get stuff into orbit)... any spike in radiation that overcomes this will lead will junk your data. Same to all other bits of the machine. Drives have to be Faraday caged but most of the time it's better to just transmit them instantly down to earth.

    I know a bit about the DoD microprocessor in satellites. It makes ancient look new, and I think the fastest they ever made was like 150Mhz, but the large process node means that it takes more electrical energy to disrupt them (just as a new 10TB HDD needs a weaker magnet to wipe as the individual 1s and 0s take a lower amount of space on the disk, and are designed to just need less power per bit in the first place).

    So you have to make a CPU with the equivalent of RAM ECC on all it's processing units. Then you have to ECC the ECC lol.
    Reply
  • Mirkoskji
    Ehm.
    So They need to upgrade radiation-resistance for processing units in their nuclear arsenal? Are they building nuclear arsenal? Is US planning to dump some new shit in the atmosphere which is clearly not their property? Or are they planning to democratise the world in the next few decades? Or is this just for scientific purposes?
    What's the real need? this leaves more questions than answers. #thefuq
    Reply
  • TJ Hooker
    genz said:
    They aren't, but the radiation passing through them causes single-bit 'style' errors because it's basically handing electrons to whatever it hits and thus flipping bits from 0 to 1.
    It looks like radiation can cause permanent damage to ICs, not just data corruption.
    https://en.wikipedia.org/wiki/Radiation_hardening#Radiation_effects_on_electronics

    Mirkoskji said:
    Ehm.
    So They need to upgrade radiation-resistance for processing units in their nuclear arsenal? Are they building nuclear arsenal? Is US planning to dump some new shit in the atmosphere which is clearly not their property? Or are they planning to democratise the world in the next few decades? Or is this just for scientific purposes?
    What's the real need? this leaves more questions than answers. #thefuq
    They have an existing nuclear arsenal. I would assume that arsenal requires maintenance, including part replacement. It's becoming difficult to source the tools required to make those antiquated parts, so they're investing in new tools to make new parts. That's my take on it based on what's stated in the article.
    Reply
  • NightHawkRMX
    Russia actually has a larger nuclear arsonal than the us.
    Reply