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I have a synthesized design, obtained the GDS file...
# general
d
I have a synthesized design, obtained the GDS file using OpenROAD with a 45nm technology and I would like to have it taped out. Can anyone walk me through the process?
v
45nm pdk from OpenROAD? do you mean fabrication?
t
You used FreePDK45 ? That's not a manufacturable process, it's just for "fun" (ok academic / research ) basically, you can't make chips out of it.
If you want to actually tape out something in a 45nm process, you need to pick a foundry, select one of their process, then talk to them, give them a lot of $$$ and sign NDA and everything so that you can get their PDK for that specific process, and then you can start designing your chip for that specific process.
d
Oh, I see. If I want to submit and get a tape out then what can I do? I mane what are the technology nodes that I need to synthesize?
t
What's the application ... what are the requirements ... and what's your budget ?
d
Budget is can be around $200 ( I am not sure if this too much, or too low) application is Tensor Processing Unit.
t
You realize a tapeout in 45 nm would cost ... millions of dollars.
d
Geezzz,..! Should I switch to sky water 130 ? Or anything supported by Open lane such as tsmc65?
t
For 200$ you can try tinytapeout.com but that's more for learning / academic / playing around, you're not going to get any "production" type chip.
The only manufacturable process supported by open tools are Sky130, Global foundries GF180 and iHP SG13G2. Oh those, sky130 is the most "supported / mature" one and has the most manufacturing option : • Chip ignite from efabless directly, you get 10 mm^2 of area and you get 100 chips back for 10k$ • Tiny Tapeout for which you get a much smaller area as part of a chip ( like 0.03 mm^2 ) and you only get one chip, for 200$
GF180 and iHP SG13G2 have some manufacturing MPW runs from europractice also in the 10~20 kEUR range IIRC. Tinytapeout will also have support for SG13G2 around mid-2025.
d
This is insightful. Thanks, @tnt I will look more into it and keep in touch with you for further details or doubts. I very much appreciate you for your time in clarification regarding this matter.
a
A couple notes: • A 45nm tapeout wouldn't cost millions, you could do an MPW for <$100k USD. But yes, still orders of magnitude more than 200 • OpenROAD supports down to 12nm technologies and is verified to work the GF12, Intel16, TSMC65, as well as the ones mentioned. The main issue from there would be porting the DRC decks because there are no (public) open-source versions
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t
• wrt to cost, Yes, you can actually browser europractice for some MPW prices, I was more referring to "full tapeout" (i.e. you get the whole wafer).
• wrt to OpenROAD do the foundry provide the required OpenROAD config files for those processes if you sign their NDA ?
d
If I want to submit my design to tiny tapeout or anyone else out there, what would you suggest me to do? I can re-synthesize the design using OpenROAD and obtain GDS files.
t
@Deepak Vungarala It's a bit dependent of who you want to submit to ...
d
Can I use any technology listed above?
t
Tiny tapeout is sky130 only.
d
Oh I see, sorry to bother everyone with a ton of questions. But, I'm very much interested in this.
t
And just because OpenROAD can build designs for GF12, Intel16, TSMC65 doesn't mean you can have them made. (1) you'd still need to get their PDK and (2) you need to find a MPW run for those tech and in the best of cases thi is in the 10~20k$ range.
a
There is some tuning required to get the best performance out of each of those processes, but the setup is not significant for an experienced designer. It is no more setup than you would do for a commercial tool.
t
Looking at https://europractice-ic.com/schedules-prices-2024/ GF12 would be like 300kEUR minimum, TSMC65 you could probably minimal area for 5 kEUR (I'm surprised by that actually, I would have tought more).
a
I definitely think that there is no reason for a beginner to tape out in an expensive, advanced node, but for anyone else reading this thread I just wanted to add those notes
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a
Sylvain, I think you can tapeout in GF22FDX for around 140K but you need to have your own tools and an NDA for the PDK from GF or a service provider. Most foundry technologies are not supported by OS PDKs and most of the foundries do not allow PDK sharing outside of direct NDA control.
t
@Andrew Wright But that's a MPW right ? Not a full wafer ? I was mostly referencing what it would cost to get a "true" production tapeout, not a shared run.
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