[18p-A31-1~19] 8.2 Plasma deposition of thin film, plasma etching and surface treatment

4:15 PM - 4:30 PM JST(7:15 AM - 7:30 AM UTC)Presentation by Applicant for JSAP Young Scientists Presentation Award

[18p-A31-11] Etching of tungsten-based mask materials by CF₃⁺ ion irradiation

〇Hojun Kang¹, Shunta Kawabata¹, Nicolas A. Mauchamp¹, Tomoko Ito¹, Erin Joy Capdos Tinacba¹, Song-Yun Kang², Jiwon Son², Dongkyu Lee², Kazuhiro Karahashi¹, Satoshi Hamaguchi¹ (1.Osaka Univ., 2.Samsung Electronics)

Keywords:

etching,tungsten,fluorocarbon

To address the increasing demand for high-density memory devices driven by advancements in smartphones, data centers, and AI technologies, it has become essential to develop efficient fabrication techniques for the etching complicated structures of DRAM and 3D NAND devices. This requires improving plasma etching capabilities using high-energy ions and developing mask materials that resist erosion under high-energy ion irradiation.This study investigates the CF₃⁺ ion etching characteristics of tungsten-based hard masks. Using a mass-selected ion beam system, ions were irradiated onto W and WSi, and the etching yields were measured. It was demonstrated that at low energies, CF₃⁺ ions are suppressed by tungsten-carbon mixed layer, while at high energies, they are promoted by fluorine through chemical etching.