Chemical-mechanical polishing composition and method for using the same

Abstract

The invention provides a chemical-mechanical polishing composition comprising: (a) an abrasive comprising α-alumina, (b) about 0.05 to about 50 mmol / kg of ions of at least one metal selected from the group consisting of calcium, strontium, barium, and mixtures thereof, based on the total weight of the polishing composition, and (c) a liquid carrier comprising water. The invention also provides a chemical-mechanical polishing composition comprising: (a) an abrasive selected from the group consisting of α-alumina, γ-alumina, δ-alumina, θ-alumina, diamond, boron carbide, silicon carbide, tungsten carbide, titanium nitride, and mixtures thereof, (b) about 0.05 to about 3.5 mmol / kg of ions of at least one metal selected from the group consisting of calcium, strontium, barium, magnesium, zinc, and mixtures thereof, based on the total weight of the polishing composition, and (c) a liquid carrier comprising water. The invention further provides methods of polishing a substrate using each of the above-described chemical-mechanical polishing compositions.

Description

FIELD OF THE INVENTION [0001] This invention pertains to a chemical-mechanical polishing composition and a method of polishing a substrate using the same. BACKGROUND OF THE INVENTION [0002] In the fabrication of integrated circuits and other electronic devices, multiple layers of conducting, semiconducting, and dielectric materials are deposited onto or removed from a substrate surface. Thin layers of conducting, semiconducting, and dielectric materials may be deposited onto the substrate surface by a number of deposition techniques. Deposition techniques common in modem microelectronics processing include physical vapor deposition (PVD), also known as sputtering, chemical vapor deposition (CVD), plasma-enhanced chemical vapor deposition (PECVD), and electrochemical plating (ECP). [0003] As layers of materials are sequentially deposited onto and removed from the substrate, the uppermost surface of the substrate may become non-planar and require planarization. Planarizing a surface, ...

AI Technical Summary

Problems solved by technology

As layers of materials are sequentially deposited onto and removed from the substrate, the uppermost surface of the substrate may become non-planar and require planarization.

As the demand for ever smaller storage devices capable of storing ever larger amounts of information increases, electronics manufacturers have begun to manufacture increasingly complicated integrated circuits utilizing exotic materials.

While the use of noble metals can provide increased performance in such devices, the use of noble metals can—and often does—present unique manufacturing challenges.

This mechanical hardness and relative chemical resistance make noble metals much more difficult to efficiently polish using conventional chemical-mechanical polishing compositions and techniques.

While each of the aforementioned chemical-mechanical polishing compositions might be capable of polishing noble metals more efficiently than conventional chemical-mechanical polishing compositions, the compositions also can produce defects on the surface of the substrate that can negatively impact the performance of any integrated circuit later manufactured from the substrate.

Furthermore, the halogen- and sulfur-containing compounds utilized in the aforementioned polishing compositions can be highly toxic (which can complicate the polishing process by requiring specialized handling equipment and / or procedures), expensive to produce, and / or expensive to properly dispose of in accordance with environmental regulations.