Alkali Wet Chemicals for Ru with Advanced Semiconductor Technology Nodes

Abstract:

Wet chemicals for ruthenium (Ru) etching are required for the formation of reliable Ru interconnects in advanced semiconductor technology nodes. In the present study, a novel alkali wet etchant, referred to as TK-1, has been developed in order to overcome issues with conventional Ru etchants, such as a low etch rate and the formation of toxic RuO₄ gas. Regardless of the Ru deposition process, TK-1 exhibits a high Ru etching selectivity of greater than 100 relative to dielectric and liner materials. It also suppresses the production of RuO₄ during the etching process. TK-1 has potential applications for Ru recess etching during fully self-aligned via fabrication.

• Periodical: Solid State Phenomena (Volume 346)
• Pages: 325-330
• DOI: https://doi.org/10.4028/p-08cHSp
• Online since: August 2023
• Authors: Yuki Kikkawa*, Yuzan Suzuki, Kohei Saito, Hiroto Yarimizu, Satoko Kanamori, Tomoaki Sato, Toru Nagashima
• Keywords: Backside Cleaning, Bevel Cleaning, Recess Process, RuO₄ Gas, Ruthenium, Surface Roughness, Wet Etching

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