BACKGROUND

1. Field of the Disclosure

The present disclosure provides chemical mechanical polishing (CMP) slurry that is advantageous for polishing ruthenium materials, at a high selectivity with respect to copper. In particular, the CMP slurries of the present disclosure comprise, in part, a synergistic combination of a hydroxide pH adjustor, an oxygenated halogen compound, which may be a perhaolgenate or a halogen peroxy acid, and a halogen alkyl benzotriazole.

2. Description of the Related Art

In back-end-of-line (BEOL) applications in the semiconductor industry, ruthenium is often used as a liner material. Unlike some other materials, such as cobalt, ruthenium is relatively chemically stable and thus does not deteriorate. It also has favorable deposition properties. However, ruthenium can be hard to remove during CMP processes. Further, ruthenium is often used in conjunction with copper, which is a relatively soft material and thus easy to remove. Copper is essential to the function of many semiconductor devices, so if a CMP slurry is used that too easily strips away or damages copper layers or inlays, it can adversely affect the performance of the finished device.

There is a need for a CMP slurry that balances the ability to remove ruthenium at sufficiently high rates, while still protecting any copper in the same semiconductor device.

SUMMARY

In one embodiment, the present disclosure provides a CMP slurry that comprises a combination of an alkali hydroxide, an oxygenated halogen compound (e.g., a perhaolgenate or a halogen peroxy acid), and a halogen alkyl benzotriazole. The slurry may also comprise abrasives, acids, stabilizers, and removal rate enhancers.

In another aspect, embodiments disclosed herein relate to polishing slurry concentrates for use on ruthenium and copper materials, including: an alkali hydroxide; an oxygenated halogen; a halogen alkyl benzotriazole; an abrasive; and an acid, wherein the slurry exhibits a polishing selectivity ratio of ruthenium to copper that is greater than about 1.2.

In yet another aspect, embodiments disclosed herein relate to polishing slurry concentrates for use on ruthenium and copper materials, including: potassium hydroxide, present in an amount of about 0.01 wt % to about 10 wt %, based on the total weight of the slurry; hydrogen periodate, present in an amount of about 0.01 wt % to about 10 wt %, based on the total weight of the slurry; chloro methyl benzotriazole, present in an amount of about 0.001 wt % to about 10 wt %, based on the total weight of the slurry; silica, present in an amount of about 0.01 wt % to about 12 wt %, based on the total weight of the slurry; and malonic acid, present in an amount of about 0.01 wt % to about 10 wt %, based on the total weight of the slurry, wherein the slurry exhibits a polishing selectivity ratio of ruthenium to copper that is greater than 2.5.

In yet another aspect, embodiments disclosed herein relate to polishing slurry concentrates for use on ruthenium and copper materials, including: a pH adjuster; a ruthenium oxidizer; a copper corrosion inhibitor; an abrasive; and a removal rate enhancer, wherein the slurry exhibits a polishing selectivity ratio of ruthenium to copper that is greater than about 1.2.

In yet another aspect, embodiments disclosed herein relate to methods for polishing and removing ruthenium from a semiconductor device including: applying a chemical mechanical polishing slurry concentrate to said layered semiconductor device, said slurry including: a pH adjuster; a ruthenium oxidizer; a copper corrosion inhibitor; an abrasive; and a removal rate enhancer, wherein the slurry exhibits a polishing selectivity ratio of ruthenium to copper that is greater than about 1.2; and polishing said semiconductor device with a rotating polishing pad.

