Patent Number: 6,251,787

Title: Elimination of photo-induced electrochemical dissolution in chemical mechanical polishing

Abstract: Eliminating exposure of PN junctions to light capable of invoking a photovoltaic effect and/or inhibiting the oxidation and reduction reactions induced by the photovoltaic effect prevents the electrochemical dissolution of metal components on semiconductor devices by electrolysis. A darkened enclosure for use on tools for wafer CMP, brush cleaning, unloading, and rinsing will eliminate exposure. Alternatively, illumination of a semiconductor wafer can be limited to wavelengths of light that do not provide enough energy to induce a photovoltaic effect. An inhibitor in the CMP slurry and/or post-CMP water rinse blocks the oxidation and/or reduction reactions. A blocking agent, such as a high molecular weight surfactant, will interfere with both the oxidation and reduction reactions at the metal surface. Also, a poisoning agent will impede the reduction portion of electrolysis.

Inventors: Edelstein; Daniel C. (New Rochelle, NY), Horkans; Wilma J. (Ossining, NY), Luce; Stephen E. (Underhill, VT), Lustig; Naftall E. (Croton on Hudson, NY), Pope; Keith R. (Danbury, CT), Roper; Peter D. (Clinton Corners, NY)

Assignee: International Business Machines Corporation

International Classification: B24B 37/04 (20060101); B24B 49/12 (20060101); H01L 21/02 (20060101); H01L 21/321 (20060101); H01L 21/00 (20060101); H01L 021/00 ()

Expiration Date: 06/26/2018