The term
tapeout currently is used to describe the creation of the photomask itself from the final approved electronic CAD file. Designers may use this term to refer to the writing of the final file to disk or CD and its subsequent transmission to the
semiconductor foundry; however, in current practice, the foundry will perform checks and make modifications to the mask design specific to the manufacturing process before actual tapeout. These modifications of the
mask data include: •
Chip finishing which includes custom designations and structures to improve
manufacturability of the layout. Examples of the latter are a seal ring and filler structures. • Producing a
reticle layout with test patterns and alignment marks. •
Layout-to-mask preparation that enhances layout data with graphics operations and adjusts the data to mask production devices. This step includes
resolution enhancement technologies (RET), such as
optical proximity correction (OPC) which corrects for the wave-like behavior of light when etching the nano scale features of the most modern integrated circuits. A modern
integrated circuit has to go through a long and complex design process before it is ready for tape-out. Many of the steps along the way use software tools collectively known as
electronic design automation (EDA). The design must then go through a series of verification steps collectively known as "
signoff" before it can be taped-out. Tape-out is usually a cause for celebration by everyone who worked on the project, followed by trepidation awaiting the
first article, the first physical samples of a chip from the manufacturing facility (
semiconductor foundry). First tapeout is rarely the end of work for the design team. Most chips will go through a series of iterations, called "spins", in which errors are detected and fixed after testing the first article. Many different factors can cause a spin, including: • The taped-out design fails final checks at the foundry due to problems manufacturing the design itself. • The design is successfully fabricated, but the first article fails functionality tests. == Naming ==