International Business Machines Corporation

Joseph J Gajda

Kris V Srikrishnan

Paul A Totta

Francis G Trudeau

An integrated circuit chip including a first and a higher second surface levels with an abrupt sidewall step transition therebetween, and having a first layer of a first conductive material disposed over the first surface level and over the second surface level, but terminating on the first surface level in a first end portion which extends up to but does not touch the sidewall. This end portion comprises a conductive material which has been converted to an insulator. A second layer of a second conductive material is disposed on top of the first conductive layer with essentially no conductive material conversion to insulator therein adjacent to the abrupt sidewall transition. In a preferred embodiment, the conductive material is an alloy of aluminum and the end portion is aluminum oxide.

Chip contacts without oxide discontinuities

Controlling Al.sub.2 Cu precipitation in copper doped aluminum by evaporating the aluminum metallurgy containing 3 to 4% copper at about 210.degree. C. on SiO.sub.2 coated semiconductor devices. In multilevel metallurgy sintering can be optionally performed at 400.degree. C. for 75 minutes to cause intermetal diffusion at vias between the metallurgy levels.

Aluminum-copper alloy evaporated films with low via resistance

An etchant comprising a solution of hydrogen fluoride dissolved in an organic solvent such as glycerine. The solution is substantially free of unbound water and ammonium fluoride. The etchant is particularly suitable for removing silicon dioxide disposed atop a metallic silicide formed in a silicon semiconductor where the silicon may be exposed.

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Wappingers Falls, NY, United States of America

Joseph J Gajda