Posttapeout

Posttapeout is the phase in semiconductor design that follows the tapeout of a chip design—the point at which the final mask data is sent to a foundry for fabrication. During this phase, teams move from design verification to physical verification, manufacturing, and silicon debugging. Posttapeout encompasses wafer fabrication, packaging, and the systematic testing of their first silicon runs, as well as the preparation of data needed for subsequent revisions if defects are found.

Key activities include fabrication planning and mask set finalization by the foundry, die probing and binning, and the execution of extensive test programs to verify functionality, timing, power, and reliability on actual silicon. Functional and parametric tests are performed to confirm that the manufactured devices meet the intended specifications and to identify yield issues. Design-for-test improvements may be implemented in the silicon through post-silicon workarounds, test pattern development, and firmware or microcode updates.

Posttapeout also involves silicon bring-up and debugging, where engineers validate interfaces, memory timing, voltage rails, thermal behavior, and real-world workloads. If issues are uncovered, the project may enter a silicon re-spin (rev) cycle, producing a revised set of masks and new silicon to address the defects and improve yield and performance.

The term contrasts with pre-tapeout verification, which occurs entirely in virtual environments. Posttapeout is a critical bridge to production, influencing yield, time-to-market, and overall reliability of the final product. In practice, the phase spans from the first silicon wafer test through yield ramp and eventual production release.