Lucent Technologies Inc.

At+t Corp.

At&t Bell Laboratories

Barbara J Sapjeta

Karrie Jo Hanson

Ken M Takahashi

Barry Irwin Miller

Akshay V Shah

The linewidth in patterns produced by etching copper layers is more easily maintained using a specific etching medium. In particular, this medium includes aqueous hydrofluoric acid, copper chloride, and an additional chloride salt. The etching medium is also particularly useful for bilayer metal constructions such as the copper/titanium structure found in many multichip modules.

Etching of copper-containing devices

A process for removing titanium from a device is disclosed. The titanium is etched at a controllable rate. The etchant oxidizes the titanium, and the oxidized titanium forms a complex in the etchant. When the concentration of this complex in the etchant nears its solubility limit, it precipitates and forms a film on the titanium metal surface. This film reduces the rate of the etch, enabling the amount of titanium removed by the etchant to be controlled.

Process for etching titanium at a controllable rate

Growing community of inventors

Parsippany, NJ, United States of America

Barbara J Sapjeta