open-source-silicon.dev

How do you paint the `tunm`  ( SONOS ) in magic ?

<@U016HU5HK8V> Does painting `nsonos` over the gate (diffusion - poly intersection) work?

<@U017X0NM2E7> Nope, that's what I tried but it doesn't seem to do anything and I get nothing in the resulting GDS either.

スクリーンショット 2024-11-29 12.09.16.png

<@U016HU5HK8V> this is what I did.
1. paint ndiffusion
2. paint polysilicon
That gave me an nfet

スクリーンショット 2024-11-29 12.11.16.png

3. `Layers` -> `Unlock base layers`
4. set the box to the exact nfet region
5. paint `nsonos`
That changed the nfet to nsonos.

スクリーンショット 2024-11-29 12.12.52.png

I then did a `gds write test.gds` and opened the file in klayout. It’s not pretty, but the `tunm` layer is there.

<@U017X0NM2E7> Ah yes, I was missing "Unlock base layers" !   Thanks !

BTW, the command for that is `tech unlock *` or in this case just `tech unlock nsonos` will do.  I try not to lock layers but in a few cases the layers are very obscure, are used in very specific vendor-approved layouts, and locking the layer helps discourage people from using the layer unless they really know what they're doing.