GDS Tapeout Checklist is the comprehensive signoff validation process that verifies every aspect of a chip design is correct, complete, and foundry-compliant before submitting the final GDSII (or OASIS) layout file for mask fabrication, representing the point of no return where any remaining error becomes a multi-million-dollar silicon respin.

The term "tapeout" dates from when designs were shipped on magnetic tape. Today it means the final GDS file submission to the foundry. For advanced nodes, mask sets cost $10-50M+ and fabrication takes 3-6 months — making tapeout the highest-stakes milestone in chip development.

Signoff Categories:

Pre-Tapeout Verification Checklist:

1. DRC clean — zero unwaived violations on the foundry-certified DRC deck 2. LVS clean — layout matches schematic with all devices extracted correctly 3. ERC clean — no floating gates, missing well taps, or ESD path gaps 4. Antenna clean — no antenna ratio violations that could damage gates during fabrication 5. Timing signoff — met at all PVT corners (process, voltage, temperature) in all modes 6. IR drop signoff — static and dynamic IR drop within budget at worst-case activity 7. EM signoff — no electromigration violations at worst-case current density and temperature 8. Formal LEC — RTL-to-netlist equivalence proven 9. CDC/RDC clean — all clock and reset domain crossings properly synchronized 10. DFT signoff — stuck-at coverage >99%, transition coverage >95% 11. Fill insertion — metal fill meets density requirements, re-verified with DRC 12. Seal ring and pad verification — chip boundary structures complete and correct

Release Process: The tapeout review meeting brings together teams from design, verification, DFT, physical implementation, and project management. Each team presents signoff status against the checklist. Any open items are classified as tapeout-blocking (must be resolved) or non-blocking (acceptable risk with waiver). The project decision-maker authorizes GDS submission.

GDS tapeout is the culmination of months to years of chip design effort — the checklist distills thousands of engineering decisions into a binary go/no-go determination, and the discipline of rigorous signoff separates first-pass silicon success from costly respins.