US 6,806,035 B1 · 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.

Claims27

Dependent claims

A serialization process for creating serial numbers on a semiconductor wafer that is subdivided into dies, comprising:

forming a non-rigid photomask that incorporates character specifications for the serial numbers;
retaining the non-rigid photomask in a photomask holder to enable handling of the photomask as a rigid structure;
preparing the wafer;
creating serial numbers onto the dies using a combined process involving photolithography, and a reactive ion etching process with a selective etch rate;
wherein the wafer is formed of at least two compounds;
and
wherein creating the serial numbers comprises using the reactive ion etching process to selectively etch the at least two compounds at different rates for creating a phase change between the at least two compounds, in order to provide improved visual contrast between the serial numbers and surrounding areas of the dies.

4 more elements

Dependencies are inferred from the claim text.

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

Life of this patent

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

Life of this patent

Abstract

Claims27