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Preparing an MPW Run 50 submission (SOI 220 nm)

CORNERSTONE's 50th call is a 220 nm SOI passive run, and cspdk.si220 matches its standard-component library. This page covers what a design needs before you upload it. Everything here comes from the 50th-call design guideline; read the guideline itself for the full rules and the services' costs.

Deadlines: sign-up by 14/10/2026, design submission by 11/11/2026, both at 13:00 UK time.

1. Lay out the design on a die

The design area is either a full cell (11470 x 4900 µm) or a half cell (5500 x 4900 µm), drawn as the cell outline on layer 99/0. Use one of the die cells:

  • die(): the full cell outline;
  • die_half(): the half cell outline;
  • die_with_pads(): the full-cell packaging template, with 16 grating couplers per side (the outermost pair joined by a loopback) and 31 pads per side.

Name the top cell Cell0_<Name of Institution>, and keep every shape inside the outline:

import gdsfactory as gf
from cspdk.si220 import PDK, cells

PDK.activate()

c = gf.Component("Cell0_MyUniversity")
c << cells.die()
mzi = c << cells.mzi_heater_loop()
gc = c << cells.grating_coupler_rectangular()
gc.dmove((1000, 0))
c.write_gds("Cell0_MyUniversity.gds")

2. Check the file

cspdk.si220.submission.check_submission checks the submission rules in the guideline that aren't geometric design rules; DRC covers those in step 3. It checks that:

  • the file is GDSII or OASIS (section 5.5);
  • there is exactly one top cell, named Cell0_<Name of Institution> (section 8);
  • only designated GDS layers are used (section 5.2 and Table 6);
  • the layout is on the 1 nm manufacturing grid (section 5.5);
  • the layer 99/0 cell outline is one full or half design area, and nothing extends outside it (section 5.1).
from cspdk.si220.submission import check_submission

problems = check_submission("Cell0_MyUniversity.gds")
print(problems or "OK")

Or from the command line, which exits with status 1 if any file has a problem:

python -m cspdk.si220.submission Cell0_MyUniversity.gds

Every cspdk.si220 cell draws only on designated layers, so problems usually come from your own shapes or from the die setup.

3. Run DRC with GDSFactory+

The geometric design rules are minimum feature sizes, gaps, overlaps and exclusion zones (section 5.3 and Table 6). Check them with GDSFactory+'s DRC. For cspdk.si220 it runs CORNERSTONE's SOI 220 nm passive rules, including the 50th call's graphene rules, with nothing to configure.

Run DRC from the GDSFactory+ extension in VS Code, or from the command line:

gfp check drc Cell0_MyUniversity.gds --pdk cspdk.si220

Inside a GDSFactory+ project for cspdk.si220 you can leave out --pdk.

The results are saved as a KLayout report database (.lyrdb). DRC runs on the GDSFactory+ service, so it needs a GDSFactory+ API key (gfp configure).

You can also cross-check with CORNERSTONE's own KLayout pre-DRC script, from the live calls page. CORNERSTONE's team runs a full DRC after submission, and the guideline offers 20-minute one-to-one drop-in sessions to review a layout before the deadline; the booking link is in the guideline.

4. Optional services

The guideline describes three add-on services, each with its own cost and longer delivery time:

  • Bonded photodiodes: use the photodiode and photodiode_integrated cells.
  • An integrated C-band laser: use the laser_full* and laser_half* design templates.
  • Hybrid graphene integration: use the graphene_* cells.

Photodiode and laser integration both require the access cost with heaters. Graphene integration can't be combined with laser or photodiode integration.

5. Submit

Upload the GDSII or OASIS file and a purchase order through CORNERSTONE's mask submission form, linked from the guideline, before the deadline. You must have signed up for the call first.