Methods for planarization of group VIII metal-containing surfaces using oxidizing gases

Abstract

A planarization method includes providing a second and / or third Group VIII metal-containing surface (preferably, a platinum-containing surface) and positioning it for contact with a polishing surface in the presence of a planarization composition that includes an oxidizing gas.

Description

FIELD OF THE INVENTION [0001] The present invention relates to methods for planarization of Group VIII metal-containing (preferably, platinum-containing) surfaces, particularly in the fabrication of semiconductor devices. BACKGROUND INVENTION [0002] Films of metals and metal oxides, particularly the heavier elements of Group VIII, are becoming important for a variety of electronic and electrochemical applications. This is at least because many of the Group VIII metal films are generally unreactive, resistant to oxidation or retard the diffusion of oxygen, and are good conductors. Oxides of certain of these metals also possess these properties, although perhaps to a different extent. [0003] Thus, films of Group VIII metals, their alloys, and metal oxides, particularly the second and third row metals (e.g., Ru, Os, Rh, Ir, Pd, and Pt) have suitable properties for a variety of uses in integrated circuits. For example, they can be used in integrated circuits for barrier materials, for e...

AI Technical Summary

Benefits of technology

[0009] The present invention provides methods that overcome many of the problems associated with the planarization of a surface that includes platinum and / or another of the Group VIII second or third row metals (i.e., Groups 8, 9, and 10, preferably, Rh, Ru, Ir, Pd, and Pt). Such a surface is referred to herein as a platinum-containing surface, or more generally, a Group VIII metal-containing surface. A “Group VIII metal-containing surface” refers to an exposed region having a Group VIII metal (particularly, platinum) preferably present in an amount of at least about 10 atomic percent, more preferably at least about 20 atomic percent, and most preferably at least about 50 atomic percent, of the composition of the region, which may be provided as a layer, film, coating, etc., to be planarized (e.g., via chemical-mechanical or mechanical planarization or polishing) in accordance with the present invention. The surface preferably includes one or more Group VIII metals in elemental form or an alloy thereof (with each other and / or one or more other metals of the Periodic Table), as well as oxides, nitrides, and silicides thereof. More preferably, the surface includes (and most preferably, consists essentially of) one or more Group VIII metals in elemental form or an alloy of Group VIII metals only.

Problems solved by technology

Many surfaces that result during the formation of Group VIII metal-containing films, particularly in the wafer fabrication of semiconductor devices, do not have uniform height, and therefore, the wafer thickness is also non-uniform.

Further, surfaces may have defects such as crystal lattice damage, scratches, roughness, or embedded particles of dirt or dust.

Unfortunately, mechanical polishing tends to cause the formation of defects (e.g., scratches and particles), both of which can be detected optically, rather than the clean removal of the platinum.

Also, many commercially available abrasive slurries do not effectively planarize platinum or other Group VIII metal-containing surfaces either because no material is removed (which results in no change in resistance of the wafer) or the resultant surface has defects therein.

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