Tape-out

In the field of integrated circuit (IC) design, tape-out refers to the final stage of the design process where the completed design database is sent to a manufacturing facility (fab) for fabrication. This database contains all the information necessary to physically create the integrated circuit on a silicon wafer. It represents the culmination of all design, verification, and layout activities.

The term "tape-out" is a historical artifact. In earlier eras of IC design, the design information was physically recorded on magnetic tape before being sent to the fabrication facility. While magnetic tape is no longer used for this purpose, the term has persisted.

The tape-out marks a critical milestone because it signifies the transition from the design phase to the manufacturing phase. After tape-out, the design is essentially "frozen," and any errors discovered afterward are extremely costly to correct, often requiring a complete redesign and another tape-out. Therefore, rigorous verification and validation are essential before reaching this stage.

The database transmitted during tape-out typically includes:

• Layout data: This describes the physical arrangement of transistors, interconnects, and other components on the chip, usually in formats like GDSII or OASIS.
• Mask data: This defines the patterns to be etched onto the silicon wafer during fabrication.
• Process parameters: These specify the manufacturing process details required by the fab.
• Documentation: This includes relevant design specifications and instructions for the fabrication facility.

Successful tape-out is followed by wafer fabrication, testing, and packaging, ultimately resulting in functional integrated circuit chips. A failed tape-out, on the other hand, can lead to significant delays, cost overruns, and reputational damage.