[17a-Z03-1~10] 8.2 Plasma deposition of thin film, plasma etching and surface treatment

△ [17a-Z03-5] Behavior of active species in gas modulation cycle process using Ar/C₄F₈/SF

〇(M1)Taito Yoshie¹, Yasufumi Miyoshi², Takayoshi Tsutsumi¹, Katsuhisa Kugimiya², Kenji Ishikawa¹, Masaru Hori¹ (1.Nagoya Univ., 2.Sony Semiconductor Solutions Corp.)

Keywords:plasma, semiconductor, etching

In the gas modulation cycle process, the deposition of the side wall protective film using C₄F₈ and the anisotropic etching using Ar and SF₆ are alternately performed to enable high aspect ratio Si etching with few shape abnormalities. However, the behavior of ions and radicals in the plasma and the reaction mechanism inside the hole have not been elucidated. In this study, we focused on the behavior of C₂ in the deposition process and measured the time course of emission intensity of Ar and C₂ using optical emission spectroscopy. As a result, it was found that the emission intensity of both Ar and C₂ was significantly reduced when C₄F₈ was introduced. This indicates that there is a correlation between the C₂ emission intensity and the Ar emission intensity, and it is considered that the formation of C₂ is due to the reactive ion etching of the deposited fluorocarbon film by Ar ions and CF_x radicals.