Remote plasma enhanced cyclic etching of a cyclosiloxane polymer thin film

Autor: Xianglin Wang, Xinyu Luo, Weiwei Du, Yuanhao Shen, Xiaocheng Huang, Zheng Yang, Junjie Zhao
Jazyk: angličtina
Rok vydání: 2024
Předmět:
Zdroj: International Journal of Extreme Manufacturing, Vol 6, Iss 5, p 055101 (2024)
Druh dokumentu: article
ISSN: 2631-7990
DOI: 10.1088/2631-7990/ad57a1
Popis: The continuous evolution of chip manufacturing demands the development of materials with ultra-low dielectric constants. With advantageous dielectric and mechanical properties, initiated chemical vapor deposited (iCVD) poly(1,3,5-trimethyl-1,3,5-trivinyl cyclotrisiloxane) (pV _3 D _3 ) emerges as a promising candidate. However, previous works have not explored etching for this cyclosiloxane polymer thin film, which is indispensable for potential applications to the back-end-of-line fabrication. Here, we developed an etching process utilizing O _2 /Ar remote plasma for cyclic removal of iCVD pV _3 D _3 thin film at sub-nanometer scale. We employed in-situ quartz crystal microbalance to investigate the process parameters including the plasma power, plasma duration and O _2 flow rate. X-ray photoelectron spectroscopy and cross-sectional microscopy reveal the formation of an oxidized skin layer during the etching process. This skin layer further substantiates an etching mechanism driven by surface oxidation and sputtering. Additionally, this oxidized skin layer leads to improved elastic modulus and hardness and acts as a barrier layer for protecting the bottom cyclosiloxane polymer from further oxidation.
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