Method for chemical-mechanical polishing of layers made from metals from the platinum group

• Main Authors: MAINKA GERD, SAENGER ANNETTE, BEITEL GERHARD, SCHNABEL RAINER FLORIAN
• Format: Patent
• Language: English
• Published: 15.05.2003
• Edition: 7
• Subjects: ADHESIVES; BASIC ELECTRIC ELEMENTS; CHEMICAL SURFACE TREATMENT; CHEMISTRY; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATIONOR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING MATERIAL WITH METALLIC MATERIAL; COATING METALLIC MATERIAL; DIFFUSION TREATMENT OF METALLIC MATERIAL; DYES; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION INGENERAL; METALLURGY; MISCELLANEOUS APPLICATIONS OF MATERIALS; MISCELLANEOUS COMPOSITIONS; MULTI-STEP PROCESSES FOR SURFACE TREATMENT OF METALLICMATERIAL INVOLVING AT LEAST ONE PROCESS PROVIDED FOR IN CLASSC23 AND AT LEAST ONEPROCESS COVERED BY SUBCLASS C21D OR C22F OR CLASS C25; NATURAL RESINS; NON-MECHANICAL REMOVAL OF METALLIC MATERIAL FROM SURFACE; PAINTS; POLISHES; POLISHING COMPOSITIONS OTHER THAN FRENCH POLISH; SEMICONDUCTOR DEVICES; SKI WAXES

The invention discloses a method for the chemical-mechanical polishing of layers composed of metals of the group of platinum metals, particularly iridium. In the CMP process, high erosion rates for iridium and a high selectivity relative to silicon oxide are achieved upon employment of a polishing fluid that contains 1 through 6% by weight abrasive particles, 2 through 20% by weight of at least one oxidation agent selected from the group comprising Ce(IV) salts, salts of chloric acid, salts of peroxodisulfuric acid and hydrogen peroxide as well as the salts thereof, and 97 through 74% by weight water. This enables the structuring of iridium layers with the assistance of an oxide mask and a CMP process.