Wafer serialization manufacturing process for read/write heads using photolithography and selective reactive ion etching

Abstract

A serialization process presents an efficient method of creating serial numbers on a ceramic-like semiconductor wafer by forming a non-rigid photomask that incorporates character specifications for the serial numbers. The non-rigid photomask is retained in a rigid, optically transparent photomask holder that enables the photomask to be handled as a rigid structure. Upon preparation of the wafer, the serial numbers are created onto wafer dies using a combined process involving photolithography, and a reactive ion etching process with a selective etch rate. The serialization process enables a rapid creation of serial numbers, with the selective RIE process substantially increasing the optical contrast of the characters without the need for deep trenches and without generation of excessive debris.