(Invited) Plasma-Enhanced Atomic Layer Etching for Metals and Dielectric Materials

Abstract

The critical dimensions of semiconductor devices are continuously shrinking with 3D device structure and are approaching to nanometer scale. The demand for dimension control in angstrom level is drastically increasing also in etching processes. Atomic layer etching (ALE) processes are being actively studied and developed for various semiconductor, dielectric materials as well as metals. In this talk, various plasma-enhanced ALE (PEALE) processes will be discussed for isotropic and anisotropic patterning of metals and dielectric materials such as molibdenum, ruthenium, cobalt, titanium nitride, tantalum nitride, halfnium oxide, zirconium oxides.[1-7] Typical ALE processes consist of surface modification step and removal step. For the surface modification, various fluorination, chlorination and oxidation schemes are applied through fluorocarbon deposition, halogenation, oxidation with radicals generated plasmas. For the removal or etching step, various schemes were applied including ion-bomardment, heating, ligand volatilization, ligand exchange, and halogenation. The surface characteristics and requirements of plasma-enhanced ALE will be also discussed.1) K. Koh, Y. Kim, C.-K. Kim, H. Chae, J. Vac. Sci. Technol. A, 36(1), 10B106 (2017)2) Y. Cho, Y. Kim, S. Kim, H. Chae, J. Vac. Sci. Technol. A, 38(2), 022604 (2020)3) Y. Kim, S. Lee, Y. Cho, S. Kim, H. Chae, J. Vac. Sci. Technol. A, 38(2), 022606 (2020)4) D. Shim, J. Kim, Y. Kim, H. Chae, J. Vac. Sci. Technol. B., 40(2) 022208 (2022)5) Y. Lee, Y. Kim, J. Son, H. Chae, J. Vac. Sci. Technol. A., 40(2) 022602 (2022)6) J. Kim, D. Shim, Y. Kim, H. Chae, J. Vac. Sci. Technol. A., 40(3) 032603 (2022)7) Y. Kim, S. Chae, H. Ha, H. Lee, S. Lee, H. Chae, Appl. Surf. Sci. 619, 156751 (2023)