Physically detectable id introduced by lithography sraf insertion for heterogeneous integration

Abstract

A system and method of leveraging sub-resolution assist feature (SRAF) to intentionally distort a feature of a pattern for identification and security purposes. A method of forming an identifier on a semiconductor structure includes: receiving, at a semiconductor manufacturing foundry, a specification of an identifier including a pattern comprising a combination of main features; designing a lithographic mask structure based on the received identifier specification, the lithographic mask structure including mask features corresponding to the specified main features and at least one sub-resolution assist feature (SRAF) structure in a geometrical relationship with a corresponding mask feature for forming, using a lithography process, a uniquely modified identifier pattern comprising a combination of modified main features; and then subsequently lithographically exposing, employing the mask structure, photoresist layers at an optical condition and subsequently developing the photoresist layers to transfer the uniquely modified identifier pattern to a surface of a semiconductor wafer.

Dependencies are inferred from the claim text.