Bell Telephone Laboratories

At&t Bell Laboratories

Catherine Wolowodiuk

Paul A Kohl

Yutaka Okinaka

Frederick W Ostermayer, Jr

Joseph Anthony Abys

Lucian Arthur D'Asaro

Edward J Laskowski

Reginald R Buckley

Virginia T Eckert

A process is described for electroplating palladium and palladium alloys. The process involves the use of an alkyl hydroxyamine as complexing agent and is particularly good for palladium alloys such as palladium-nickel and palladium-cobalt.

Palladium alloy plating process

A photoelectrochemical etching process is described for n-type and semi-insulating III-V semiconductor compounds that contain aluminum or indium (AlGaAs, InGaAs) in which a non-aqueous electrolyte is used. High etch rates are achieved without harm to exposed metallization or p-layers. An exemplatory application is the separation of chips (e.g., LED chips) after wafer processing.

Semiconductor etching process

A process is described for plating gold on metal surfaces electrically attached to a compound semiconductor. The procedure is particularly valuable where gold is to be in small holes or crevices in semiconductor structure since electroplating on the semiconductor surface is avoided. The process is useful for providing low inductance electrical connection to various parts of semiconductor devices such as to the source in gallium arsenide field-effect transistors.

Photoelectrochemical gold plating process

A process is described for photoelectrochemically etching n-type indium phosphide and closely related compound semiconductors such as indium gallium arsenide and indium gallium arsenide phosphide. Such a process is advantageous because the etching is confined to where light is incident to the surface of the semiconductor. In addition, the shape of the configuration etched out of the semiconductor can be controlled by the light incident on the surface of the semiconductor. For example, undercutting can be minimized by use of parallel rays incident on the surface of the semiconductor to be etched.

Photoelectrochemical processing of InP-type devices

The gold content of a gold plating bath is replenished by circulating the plating solution through an AuCN containing vessel. The plating solution contains sufficient free cyanide to render the gold soluble by producing the soluble Au(CN).sub.2.sup.- ion.

Method of replenishing gold/in plating baths

Certain reducible species are found in gold electroplating solutions which interfere with efficient electroplating of gold and make uncertain gold thickness predictions based on current throughput. A gold electroplating process is described which minimizes formation of undesirable reducible species. This process uses an anode of titanium having a coating of the oxides of ruthenium, iridium, rhodium, titanium or mixtures thereof. In addition, a procedure is described for removing such chemical species from the gold plating bath which does not adversely affect the gold electroplating solution.

Growing community of inventors

Chatham Township, NJ, United States of America

Catherine Wolowodiuk