Isotropic silicon etch characteristics in a purely inductively coupled SF6 plasma

Panduranga, Parashara; Abdou, Aly; Ren, Zhong; H. Pedersen, Rasmus; P. Nezhad, Maziar

Abstract

The characteristics of isotropic etching of silicon in a purely inductively coupled SF plasma are quantitatively studied. Since the etch results are strongly dependent on mask features, the authors investigated both large area and narrow trench etch characteristics. Circles of diameter 500 m were used as a proxy for unpatterned surfaces and etched for different durations to establish the material etch rate and surface roughness. The average etch rate using the chosen recipe was found to be 2.27 m/min. Arrays of narrow trenches ranging from 8 to 28 m were also etched to analyze the effect of trench size on etch rate and degree of anisotropy. The etch rate of the trenches was found to strongly decrease with decreasing trench width. The results demonstrate that isotropic SF etch can be readily used as a replacement for more exotic silicon vapor phase etch chemistries such as XeF⁠.

Citation

Panduranga, P., Abdou, A., Ren, Z., H. Pedersen, R., & P. Nezhad, M. (2019). Isotropic silicon etch characteristics in a purely inductively coupled SF6 plasma. Journal of Vacuum Science and Technology B, 37(6), https://doi.org/10.1116/1.5116021

• Journal Article Type: Article
• Acceptance Date: Oct 14, 2019
• Publication Date: Nov 4, 2019
• Deposit Date: Aug 21, 2024
• Journal: Journal of Vacuum Science & Technology B, Nanotechnology and Microelectronics: Materials, Processing, Measurement, and Phenomena
• Print ISSN: 2166-2746
• Publisher: AIP Publishing
• Peer Reviewed: Peer Reviewed
• Volume: 37
• Issue: 6
• DOI: https://doi.org/10.1116/1.5116021