International Business Machines Corporation

Gunars M Ozols

Bryant N Zingerman

James R Kitcher

George T Chiu

William H Ma

Rudolf G Frieser

Robert R Joseph

A cathode for reactive ion etching is provided which improves the etch rate and the uniformity of etching on the object etched. The cathode has a quartz plate with a series of recesses having disks therein of the same material as the object to be etched and a ring of that same material around the outer edge of the plate. In a preferred embodiment a cathode for etching silicon wafers has silicon disks recessed in a quartz plate at each wafer holding position and a ring of silicon around the outer edge of the plate.

Cathode for etching

Aluminum/copper alloy conductors are made by forming a patterned layer of copper on a layer of aluminum. The portion of the aluminum layer which is not protected by the copper layer is removed by reactive ion etching and the resulting structure is then heated to cause the copper to diffuse into, and alloy with the aluminum layer.

Method of forming aluminum/copper alloy conductors

Chromium is etched in a glow discharge without attack on Al/Cu, Si, SiO.sub.2, and Si.sub.3 N.sub.4 layers by etching in a low pressure ambient atmosphere containing a polychlorinated organic compound such as CCl.sub.4, water, and a material selected from the group consisting of the noble gases and oxygen.

Glow discharge etching process for chromium

Metal layers, for example; chromium and titanium-tungsten, used in conductive metallurgies as adhesion or barrier layers for integrated circuit devices which are formed in silicon semiconductor substrates, are selectively etched without significant attack on either the silicon substrate or aluminum conductor layers. The metal layers are exposed to a glow discharge formed by imposing an RF voltage across two spaced electrodes in an ambient atmosphere comprising a gaseous mixture of from about 5 to about 20 percent by volume of a polychlorinated organic compound containing one to two carbon atoms, for example, CCl.sub.4 or C.sub.2 HCl.sub.3 and about 80 to about 95 percent by volume of oxygen at a pressure in the range of about 5 to 50 milli-torr.

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Wappingers Falls, NY, United States of America

Gunars M Ozols