All the details we have about the layout can be found at the following links;

• https://github.com/google/skywater-pdk-sky130-raw-data/tree/main/docs/sky130-testtile-proprietary
• https://bit.ly/sky130-testtile-edit
• https://bit.ly/sky130-mpw1-testtile-notes

It would be best to publish the simulation results and let people help debug what is going on.

Hi,
using DMT we managed to obtain simulation results fairly similar to the measurements, at least in DC.

Here is the link to the repo: https://gitlab.com/dmt-development/skywater130-pdk-dutlib

Until now, it only covers the first set of measurements. But in general we had the same issues (for especially the missing layout) as you, that's why we did not integrate all new batches to this DutLib.

@mithro I have reviewed all of these documents before and I did that again to double check. But some of the information that I'm looking for can't be found or missing. It would be better to get the actual GDS file to be able to measure any missing information that we would like to get from the layout directly. That would be really helpful.

One of the most important parameters that we are looking for is temperature. At what temperature did they measure this? I was never able to find that. Also, Do they have temperature controlled setup? Please point me to the document that might have that information if it's available.

We are planning to release all our work here as a PR later. We have created an interactive plot measurement vs simulation for all the nfet_01v8 sizes in the test structure as an example in Jupyter Notebook. But code could be generalized for all devices easily.

I'm waiting until we have done our due diligence of review and finding any issues that we might have missed on our side. Because we are seeing differences for some devices and we want to understand why they are different from the simulation?

@akinakturk Thanks for the info. GDS file would be extremely helpful we could measure any information we need from the layout directly rather than speculation how did you layout the device?

@miesli We just found out about this git repo yesterday. We have seen you have done some assumptions there that we are not sure where did you get that information? We are trying to replicate that. Also, you only took a smaller subset of the devices.

Thanks @akinakturk.

Could you share the GDS as well?

Yes, we just made the assumptions and wanted to see how far we can get. But also we only had limited time to spend on that project, which was only a proof of concept.
As we proved the concept, we are basically able to add all measurements and simulations of all devices relatively quickly. Adding the other devices is a matter of adding a few lines of script.

Doing this, would only require more assumptions and already from the simple example one can already see that the model approximates the DC drain current with a visible error. In #4 and #9 we discussed the naming of the measurements and were looking for more information.

Our conclusion was to wait for the new test chip with an available layout and new measurements. There, a model verification (which was our initial goal) makes much more sense in our opinion.

That's great news @akinakturk Looking forward to getting that data.

@mithro Could you check with Skywaters to see if they can share the GDS file?

The GDS cannot be shared. That's an unfortunate limitation of the Skywalker test tile

@QuantamHD I'll share our results in the next few days. But simulation results are way off the measurements. The first thing that came to my mind that we missed something. Anyhow, I'll share everything for more scrutiny from the community. I hope we are wrong.

@QuantamHD is correct that we can not share the GDS for the SkyWater original test tile.

This is why @msaligane has been working with NIST to create a fully open source test tile - see https://github.com/google/skywater-pdk-sky130-raw-data/tree/main/docs/sky130-testtile-open -- We are still waiting to get these back from manufacturing.

@QuantamHD and @mithro I'll close this ticket as it's addressed at #26