The reliability, electromigration resistance, adhesion, and electrical contact resistance of planarized, in-laid metallization patterns, eg, of copper, are enhanced by a process comprising selectively depositing on the planarized, upper surfaces of the metallization features at least one thin layer comprising at least one passivant element for the metal of the features, reacting the at least one passivant element to chemically reduce any deleterious oxide layer present at the upper surfaces of the metallization features, and diffusing the at least one passivant element for a distance below the upper surface to form a passivated top interface The passivated top interfaces advantageously exhibit reduced electromigration and improved adhesion to overlying metallization with lower ohmic contact resistance Planarization, as by CMP, may be performed subsequent to reaction/diffusion to remove any elevated, reacted and/or unreacted portions of the at least one thin layer The invention finds particular utility in “back-end” metallization processing of high-density integrated circuit semiconductor devices having sub-micron dimensioned metallization features

Selective Deposition Process For Passivating Top Interface Of Damascene-Type Cu Interconnect Lines

The purposed of this paper is to improve the corrosion resistance of connector application by plating ultrathin Ni-W film by reverse pulse current. Method of reverse pulse plating Ni-W alloy in the solution without Ni ion as well as the electrochemical behaviors of the plated thin film have been investigated. The results indicates that the corrosion resistance of the Ni layer is enhanced by the reverse pulse plating in W plating solution, even though the accurate content of W was not detected. For comparison, Ni-W alloys were also plated in ultralow Ni ions concentration bath (0.01M) by direct current in order to get the similar composition of RPC-Ni-W film.

Reverse pulse current (RPC) electrodeposition of anti-corrosive nickel-tungsten ultrathin film for connector application

PROBLEM TO BE SOLVED: To improve corrosion and deterioration resistances by bringing a tungsten alloy electroplate into contact with a specified amount of CrO 3 in an aq. soln. in a bath having a specified pH to passivate the tungsten alloy electroplate. SOLUTION: A tungsten alloy electroplate is brought into contact with CrO 3 in an amount effective for passivation such as about 1.8 - about 45 g/liter in a bath having a definite parameter, pH of about 3.5 - about 8. At this time, a bath temp is preferably about 38 - about 82°C. As an origin of CrO 3 , there may be cited chromic acid, potassium dichromate, sodium dichromate, sodium chromate, potassium chromate and their mixtures. Control of pH in the bath can be carried out by adding a hydroxyl ion origin, sodium hydroxide, ammonium hydroxide, carbonate and their mixtures. COPYRIGHT: (C)1996,JPO

Robert A Tremmel

Papers

Passivate for tungsten alloy electro-plating