[HN Gopher] Iris (Infra-Red, in Situ) Silicon Verification Proje...
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Iris (Infra-Red, in Situ) Silicon Verification Project Updates
Author : pabs3
Score : 68 points
Date : 2024-03-10 09:52 UTC (13 hours ago)
(HTM) web link (www.bunniestudios.com)
(TXT) w3m dump (www.bunniestudios.com)
| peter_d_sherman wrote:
| From the earlier blog post:
|
| https://www.bunniestudios.com/blog/?p=6712
|
| >"This post introduces a technique I call "Infra-Red, In Situ"
| (IRIS) inspection. It is founded on two insights: first, that
| silicon is transparent to infra-red light; second, that
|
| _a digital camera can be modified to "see" in infra-red, thus
| effectively "seeing through" silicon chips._
|
| We can use these insights to inspect an increasingly popular
| family of chip packages known as Wafer Level Chip Scale Packages
| (WLCSPs) by shining infrared light through the back side of the
| package and detecting reflections from the lowest layers of metal
| using a digital camera. This technique works even after the chip
| has been assembled into a finished product. However, the
| resolution of the imaging method is limited to micron-scale
| features."
|
| This seems to be a set of ideas that is on the right track -- it
| would be interesting to know the minimum size of chip features
| that Infrared Light will work on, and upon knowing this, to try
| to improve upon that by using other wavelengths (i.e., UV, EUV,
| ?), types of light (i.e., infrared or other wavelength laser),
| and/or other beam lensing/focusing/detecting techniques...
|
| Perhaps in the future, IC shells will be made of materials that
| not only perform the functions that they do now (heat
| dissipation, etc.) -- but are also friendly to different types of
| EM wavelengths (i.e., higher wavelengths to allow scanning of
| smaller feature sizes) that could be used for
| visualization/verification of the underlying electronic
| components and circuits...
|
| Anyway, this set of ideas will probably be refined and expanded
| upon in the future...
|
| The ultimate future goal would be a device which could read the
| internal circuitry of any chip at any time with absolute fidelity
| -- regardless of how tiny the components and circuits of that
| chip might be...
| kurthr wrote:
| Cameras similar to this have been around for decades, but they
| weren't as automated, and they were more expensive since they
| had longer Depth of Field for research purposes. But
| fundamentally, putting an IR back (or front) illuminator on a
| microscope with IR lenses and a CCD was necessary and available
| for wafer stacking decades ago (I used them in the early 90s).
| This looks like it has a motion stage and automated scanning,
| which is important for doing the verification!
|
| I don't think you're going to get crazy high resolution. The
| minimum wavelength of light that goes through silicon at even
| 0.5% (it's >50% down to 1.2um) is ~0.9um. There are specialized
| techniques (top illumination) for super-resolution like
| confocal microscopy that can get quarter-eighth wavelength
| ~120nm as described below, but that's about it. A bigger issue
| will be that, if there is too high a density of metal, you just
| won't be able to see through. However, you will almost
| certainly be able to see the large features, the structural
| areas (RAM/Logic/Serial) for identification, and the Through
| Silicon Vias (TSV) used for aligning die together for MCM, but
| not the underlying logic.
|
| https://www.tydexoptics.com/materials1/for_transmission_opti...
|
| https://www.photometrics.com/learn/spinning-disk-confocal-mi...
|
| The resolutions needed for reverse engineering will still rely
| on layer etching/removal and SEM.
| nonrandomstring wrote:
| What a super important project! Very well done to the
| researchers and I really, really hope you get funding and/or
| people joining and taking this all the way. Please keep it
| up!
|
| Been involved with a physical supply-chain assurance
| technology project and this is the first time I heard of this
| kind of IR chip scanning.
|
| For those that don't understand; securing the provenance of
| physical hardware is the foundation of all other
| cybersecurity.
|
| VCs and money people... this is where you should be placing
| your bets!
|
| It doesn't actually matter if/that it's not terribly
| effective at the moment. Keep building and roll it out. Get
| people using cheap scanners and publish open hash databases.
| Even with false positives it becomes like "effective security
| theatre" and is a _massive_ deterrent to anyone attempting
| implants or stealth logic modification at silicon or board
| level.
| kurthr wrote:
| That's "bunnie" Andrew Huang. He's great and been working
| on this for a long time!
| s0rce wrote:
| Isn't the idea with IR that you can transmit through the
| silicon and part of the package. There are slightly higher
| resolution options like IR confocal microscopes
| https://www.wdidevice.com/products/ and X-ray can do some
| similar stuff.
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