Run a design-rule check before you expose

A design-rule check (DRC) catches geometry your process can't actually make — a gap too narrow to resolve, a feature too thin to survive etch — before you commit to exposing it. In Glyph, that's a per-layer rule table plus one keyboard shortcut, F7.

Time: ~10 min You'll need: a Glyph document with at least one drawn layer — see Design your first photomask if you don't have one yet.

1. Open the rule table. In Glyph, go to Verify → Design rules…. You get one row per layer, with columns for min width and min spacing (both in µm) and min area (nm²). Leave a cell blank to skip that particular check on that layer.
2. Set rules for your process, or use a one-click writer preset — laser (1.5 µm), e-beam (200 nm), or BEAM (500 nm) — to set the min-width floor on every layer at once, then adjust individual layers from there.
3. Run the check. Press F7 (or Verify → Run design-rule check). Glyph expands every SREF/AREF in the active cell before checking, so a spacing violation between two instances of the same cell — which only exists once they're placed near each other in the parent — is still caught, not hidden by checking the un-expanded cell.
4. Step through the violations. Each violation appears as a numbered marker on the canvas. Press F2 / Shift+F2 to jump from one to the next; the view zooms to each marker with enough surrounding geometry to see what's wrong.
5. Fix each one with your normal editing tools — widen a boundary, nudge two shapes apart, or delete a sliver — and re-run F7 to confirm it's clear.
6. Clear the markers once you're done via Verify → Clear violations, or just leave them — they don't affect export either way.

DRC in Glyph is strictly read-only: it never touches your drawing or the undo stack, and it runs in a background worker with a Cancel button so a dense layer doesn't freeze the UI. Rules are remembered per browser, not per document — they describe the process you intend to fabricate with, not the specific file, so the same rule table follows you across documents. What's checked is boundaries and boxes; paths, cross-layer enclosure/overlap, and connectivity are not, and Glyph tells you explicitly when a checked layer contains paths rather than silently reporting clean.

What you built

A layout that's been checked against your process's real geometric limits — minimum width, minimum spacing, minimum area — with every instance expanded so hierarchy can't hide a violation. That's the check worth running right before you export the final .gds for exposure.

For the full rule reference and what each check does and doesn't cover, see Design-rule check (DRC) in the docs. Once your layout is clean, head back to Glyph to export it.

Next steps

A clean DRC result tells you the geometry is manufacturable — it doesn't expose anything by itself. Next: choose a resist for your process, then expose the mask you just checked. See the photoresist glossary for resist basics, or go straight to maskless lithography to see how a checked design gets exposed without a physical photomask.