IDENTIFICATION DATA DESCRIBING SILICON SUBSTRATE AND ITS MANUFACTURE

摘要

PROBLEM TO BE SOLVED: To individually manage a silicon wafers and small semiconductor chips by forming a two-dimensional(2D) code capable of recording a large amount of data on the surface of a hard and transparent silicon wafer. SOLUTION: Semispherical recessed parts 5 are worked by having the surface of a silicon wafer 1 irradiated with laser beams to form round dots 12 circularly formed on a plane, plural round dots 12 are vertically and horizontally arranged in a matrix form to form unit cells 4a of bright patterns. Smooth surfaces which are not irradiated with laser beams are formed as unit cells 4b of dark patterns, and these bright and dark unit cells 4a, 4b are combined to form a 2D code 3 consisting of a matrix of bright and dark patterns.