[HN Gopher] Silicon Zoo: Tiny artwork on CPU dies
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Silicon Zoo: Tiny artwork on CPU dies
Author : michaelt
Score : 171 points
Date : 2022-04-22 11:44 UTC (11 hours ago)
(HTM) web link (micro.magnet.fsu.edu)
(TXT) w3m dump (micro.magnet.fsu.edu)
| tverbeure wrote:
| Second story!
|
| A former manager used to work for the Vax silicon team. For the
| youngster: the Vax was a very popular mini computer in the
| eighties. It was also copied by the evil communists on the other
| side of the iron curtain.
|
| So the engineers put a message on the die, in Cyrillic: "Vax,
| when you care enough to steal the very best."
|
| When they found out about it, management wasn't totally happy
| about it, but it didn't go any further than "do don't this
| again."
|
| https://micro.magnet.fsu.edu/creatures/pages/russians.html
| tverbeure wrote:
| Story time!
|
| 28 years ago, I worked for Mietec, a company that had a fab that
| is now owned by OnSemi.
|
| The mask preparation team told me the following:
|
| One time they received the GDS2 file with the mask layers (that's
| the golden file that gets created when you do a tape-out) from a
| customer, did their usual preparation and design rule checks, and
| sent it to the mask maker.
|
| A few days later, they received an email stating that they
| couldn't process the file due to "the presence of twitty birds
| and Christmas trees." And, indeed, upon closer inspection, the
| design contained these elements.
|
| However the metal vias to make those images were only on one
| layer, and not connected to others.
|
| The resulting issue was one of "floating vias". (That's the exact
| wording that I remember all these years later, but Google doesn't
| turn up anything.) For some reason, these unconnected vias
| couldn't be held in place during some steps of either the mask
| masking process or the actual silicon production step, and that's
| why the mask maker rejected it.
|
| A new guideline was issued by my company that designs should not
| have these kind of graphic elements and logos to avoid wasting
| engineering resources on something frivolous.
|
| What I don't understand is why this issue wasn't detected during
| design rule checking at the customer's site or at our mask making
| preparation stage. But that's a different story.
|
| Either way: I've worked on a lot of chips and for a bunch of
| different companies, and I'm not aware of there being any
| graphical elements in them either. Masks were moderately
| expensive 28 years ago (something like $25k), they're insanely
| expensive today (millions.) You don't want to risk anything...
| jjoonathan wrote:
| I've been out of touch for a while -- what's the driving factor
| in mask expense these days? Time in the mask writer? Something
| about only being able to pack so many simultaneous electron
| beams next to each other before they fuzz out?
| stormbrew wrote:
| It's really wild to me that there isn't a market out there
| for smaller chip manufacturers at larger feature scales to
| still do production orders in that price range or cheaper
| even. Or, if there are, they're hard to find and get access
| to.
|
| Lots of chips in use today are still not anywhere near the
| tiny end of the scale, and they're clearly still being
| manufactured somewhere, but it's like economies of scale have
| somehow worked against price in IC manufacturing in some ways
| (but obviously not others: per-feature-count is obviously
| much more cost effective now).
| tverbeure wrote:
| I can't offer you any more insights other than "it's
| expensive to make things that are just a few nanometer in
| size..."
| jecel wrote:
| Just adding processing steps requires more masks. Moving from
| visible light to smaller wavelengths requires more and more
| sophisticated materials for the masks with smaller and
| smaller imperfections.
|
| To push a technology like DUV (deep ultra violet) further and
| further requires multi-patterning, which means several masks
| for a single processing step.
|
| For EUV (extreme ultra violet) no material is transparent so
| the masks are actually mirrors. With 40 alternating silicon
| and molybdenum layers, each the exact thickness to match the
| 13.5nm wavelength, you can reflect enough of the EUV beam to
| get the job done. Making such a mask is a lot more expensive
| than one that is basically a glass photographic plate.
|
| The time to actually write a mask has gone up by a large
| factor, as you mentioned.
|
| The combination of all the factors increases the cost of the
| masks from a few thousand dollars for 1970s technology to
| many millions today.
| gitgud wrote:
| This resolution must be orders of magnitudes better now, maybe
| they're just harder to find...
| timw4mail wrote:
| I think there's just less room for extra stuff on a die.
| michaelt wrote:
| We fit more stuff on dies than ever before - If a
| ThreadRipper has space for 64 cores and 256 MB of L3 cache,
| it has room for a microscopic picture of a bird.
| timw4mail wrote:
| You are kind of proving my point: room for artwork can't be
| at the expense of the stuff that actually does work.
| jaguar1878 wrote:
| I think it has more to do with design rules for metal layers.
| Between the rules for: min area, max area, min density, max
| density, and density gradient it can be tough to get artwork
| to be manufacturable, even if you have the space for it. No
| one wants to risk poor yields because of the art.
| Linda703 wrote:
| boredumb wrote:
| RIP
| sibrahim wrote:
| Sometimes these are officially sanctioned and even required! Most
| notably, including logos/other embellishments are a form of "trap
| street" where the idea is to have something to point to that
| trivially proves someone is using your mask design if it comes to
| it.
| spijdar wrote:
| Are there any recent examples of chip art like this? I'm not
| seeing anything from the 2000s or 2010s, and it's a little sad to
| think it died out.
| Pathogen-David wrote:
| The RP2040 released last year has a little Raspberry Pi logo
| https://blog.adafruit.com/2021/01/29/die-shots-of-the-raspbe...
| ranma42 wrote:
| I know of at least one GDDR5 memory chip that should have chip
| art of a snake on the die.
| boothby wrote:
| Sadly, the chip art I'm responsible for is not public. But
| yeah, folks still do this.
| verdverm wrote:
| When I worked at an IBM Fab, I remember seeing these during
| inspection under the 1000000x microscope. There were many, I
| wondered if each engineer had their own they'd embed.
|
| Both were impressive!
| timw4mail wrote:
| Now I want to know if there is artwork corresponding to CPU code
| names: Bulldozer and Piledriver, while not the best performing
| chips, certainly have a clear visual image to their names.
| rjsw wrote:
| Intel could just do a map of the location of each code name
| within the outline of whichever state it is from.
| mauriciolange wrote:
| My first thought was that the site has died (gone off-line)
| zarzavat wrote:
| Title is a Garden path sentence
| https://en.wikipedia.org/wiki/Garden-path_sentence
| ismaildonmez wrote:
| You have the best nick ever, hats off
| victorbstan wrote:
| Learned something today.
| [deleted]
| [deleted]
| Wildgoose wrote:
| I'm fascinated by your comment because I mentally parsed it
| correctly from the start. I presume you hadn't heard of a CPU
| die before? I'm not sure how else this could be misunderstood
| on an initial read.
| mauriciolange wrote:
| I am well aware of CPU dies. But as I wrote that first
| sentence I read it "bad" from your perspective! I correlate
| much stronger "dies" with death than with a die.
| samstave wrote:
| ....except when I see it literally next to the term,
| CPU....
| nonameiguess wrote:
| They might actually both be true. A sibling comment seems
| to indicate they don't do this any more and the main
| gallery page hasn't been updated in four years. It's
| possible that the project to put artwork on CPU dies has
| died, though the webpage hosting the gallery has clearly
| not died.
| nothatscool wrote:
| Most of the posts here with "dies" in the title are about
| public figures who have died. If you are used to those and
| are scanning through the posts it is easy to read "dies" in
| that context first and then the rest of the sentence.
| colejohnson66 wrote:
| If you're a visual learner, Tom Scott made a great video
| about these "Crash Blossoms":
| https://www.youtube.com/watch?v=ldT2g2qDQNQ
| gcheong wrote:
| Mine was of some kind of simulation running that "died". Like a
| Tamagochi or something.
| (https://en.m.wikipedia.org/wiki/Tamagotchi)
| kgwxd wrote:
| Mine was that the practice of putting art on CPUs has died.
| jhgb wrote:
| The comment by tverbeure justifies your belief.
| fortran77 wrote:
| Maybe we should have the black bar up on hacker news today.
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