Silicon Zoo: Tiny artwork on CPU dies

https://micro.magnet.fsu.edu/creatures/index.html

by michaelt • 4 years ago

189 37 4 years ago

micro.magnet.fsu.edu

mauriciolange2• 4 years ago

My first thought was that the site has died (gone off-line)

zarzavat• 4 years ago

Title is a Garden path sentence https://en.wikipedia.org/wiki/Garden-path_sentence

victorbstan• 4 years ago

Learned something today.

Wildgoose• 4 years ago

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.

colejohnson66• 4 years ago

If you're a visual learner, Tom Scott made a great video about these "Crash Blossoms": https://www.youtube.com/watch?v=ldT2g2qDQNQ

ismaildonmez• 4 years ago

You have the best nick ever, hats off

fortran77• 4 years ago

Maybe we should have the black bar up on hacker news today.

gcheong• 4 years ago

Mine was of some kind of simulation running that “died”. Like a Tamagochi or something. (https://en.m.wikipedia.org/wiki/Tamagotchi)

kgwxd• 4 years ago

Mine was that the practice of putting art on CPUs has died.

jhgb• 4 years ago

The comment by tverbeure justifies your belief.

DavidSJ• 4 years ago

Mine was that the art itself had died.

gitgud• 4 years ago

This resolution must be orders of magnitudes better now, maybe they're just harder to find...

timw4mail3• 4 years ago

I think there's just less room for extra stuff on a die.

michaelt• 4 years ago

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.

jaguar1878• 4 years ago

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.

boredumb• 4 years ago

RIP

timw4mail3• 4 years ago

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• 4 years ago

Intel could just do a map of the location of each code name within the outline of whichever state it is from.

spijdar• 4 years ago

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• 4 years ago

The RP2040 released last year has a little Raspberry Pi logo https://blog.adafruit.com/2021/01/29/die-shots-of-the-raspbe...

ranma42• 4 years ago

I know of at least one GDDR5 memory chip that should have chip art of a snake on the die.

boothby• 4 years ago

Sadly, the chip art I'm responsible for is not public. But yeah, folks still do this.

tverbeure4• 4 years ago

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• 4 years ago

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?

tverbeure4• 4 years ago

I can't offer you any more insights other than "it's expensive to make things that are just a few nanometer in size..."

stormbrew• 4 years ago

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).

jecel• 4 years ago

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.

userbinator• 4 years ago

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.

They can cause damage due to static accumulation during the processing steps. It's hard to find good references to this due to the secretive nature of IC manufacturing in general, but here's some discussion:

https://www.edaboard.com/threads/question-about-metal-fillin...

tverbeure4• 4 years ago

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

sibrahim• 4 years ago

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.

verdverm• 4 years ago

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!

Silicon Zoo: Tiny artwork on CPU dies

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