Plasma Etching of SiO2 Contact Holes Using Hexafluoroisopropanol and C4F8

You, Sanghyun; Lee, Yu Jong; Chae, Heeyeop; Kim, Chang‐Koo

doi:10.3390/coatings12050679

Cited by 6 publications

(2 citation statements)

References 17 publications

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“…The precise measurement of the radicals density is a great challenge in plasma processing. Several studies used optical emission spectroscopy [ 27 , 28 ] and a quadrupole mass spectrometer [ 2 , 29 ] for estimating radicals densities, but its accuracy remains questionable. Alternatively, a volume-averaged model was used for analyzing plasma chemistry in a complex gas mixture [ 30 , 31 , 32 ].…”

Section: Experiments Setup Measurement Methods and Volume-ag Plasma M...mentioning

confidence: 99%

Contribution of Ion Energy and Flux on High-Aspect Ratio SiO2 Etching Characteristics in a Dual-Frequency Capacitively Coupled Ar/C4F8 Plasma: Individual Ion Energy and Flux Controlled

et al. 2023

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As the process complexity has been increased to overcome challenges in plasma etching, individual control of internal plasma parameters for process optimization has attracted attention. This study investigated the individual contribution of internal parameters, the ion energy and flux, on high-aspect ratio SiO2 etching characteristics for various trench widths in a dual-frequency capacitively coupled plasma system with Ar/C4F8 gases. We established an individual control window of ion flux and energy by adjusting dual-frequency power sources and measuring the electron density and self-bias voltage. We separately varied the ion flux and energy with the same ratio from the reference condition and found that the increase in ion energy shows higher etching rate enhancement than that in the ion flux with the same increase ratio in a 200 nm pattern width. Based on a volume-averaged plasma model analysis, the weak contribution of the ion flux results from the increase in heavy radicals, which is inevitably accompanied with the increase in the ion flux and forms a fluorocarbon film, preventing etching. At the 60 nm pattern width, the etching stops at the reference condition and it remains despite increasing ion energy, which implies the surface charging-induced etching stops. The etching, however, slightly increased with the increasing ion flux from the reference condition, revealing the surface charge removal accompanied with conducting fluorocarbon film formation by heavy radicals. In addition, the entrance width of an amorphous carbon layer (ACL) mask enlarges with increasing ion energy, whereas it relatively remains constant with that of ion energy. These findings can be utilized to optimize the SiO2 etching process in high-aspect ratio etching applications.

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Section: Experiments Setup Measurement Methods and Volume-ag Plasma M...mentioning

confidence: 99%

Contribution of Ion Energy and Flux on High-Aspect Ratio SiO2 Etching Characteristics in a Dual-Frequency Capacitively Coupled Ar/C4F8 Plasma: Individual Ion Energy and Flux Controlled

et al. 2023

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“…Furthermore, Lim et al compared the etch results with a low-GWP precursor, C 6 F 12 O, to those with the conventional precursor, CF 4 [ 25 ]. Although many papers, including the aforementioned ones, have documented the development of alternative low-GWP precursors in the field of semiconductor manufacturing [ 26 , 27 , 28 , 29 , 30 ], there are still numerous potential precursors that need to be investigated regarding their qualification as promising alternatives to conventional high-GPW precursors.…”

Section: Introductionmentioning

confidence: 99%

Characterization of SiO2 Plasma Etching with Perfluorocarbon (C4F8 and C6F6) and Hydrofluorocarbon (CHF3 and C4H2F6) Precursors for the Greenhouse Gas Emissions Reduction

et al. 2023

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This paper proposes the use of environmentally friendly alternatives, C6F6 and C4H2F6, as perfluorocarbon (PFC) and hydrofluorocarbon (HFC) precursors, respectively, for SiO2 plasma etching, instead of conventional precursors C4F8 and CHF3. The study employs scanning electron microscopy for etch profile analysis and quadrupole mass spectrometry for plasma diagnosis. Ion bombardment energy at the etching conditions is determined through self-bias voltage measurements, while densities of radical species are obtained using quadrupole mass spectroscopy. The obtained results compare the etch performance, including etch rate and selectivity, between C4F8 and C6F6, as well as between CHF3 and C4H2F6. Furthermore, greenhouse gas (GHG) emissions are evaluated using a million metric ton of carbon dioxide equivalent, indicating significantly lower emissions when replacing conventional precursors with the proposed alternatives. The results suggest that a significant GHG emissions reduction can be achieved from the investigated alternatives without a deterioration in SiO2 etching characteristics. This research contributes to the development of alternative precursors for reducing global warming impacts.

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Heptafluoroisopropyl Methyl Ether as a Low Global Warming Potential Alternative for Plasma Etching of SiC

You,

Sun,

Hwang

et al. 2024

Korean J. Chem. Eng.

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Hepta uoroisopropyl methyl ether (HFE-347mmy) was used for SiC etching to evaluate low-GWP (global warming potential) hydro uoroether as an alternative to SF 6 . SiC was etched in the HFE-347mmy/O 2 /Ar and SF 6 /O 2 /Ar plasmas, and the etching characteristics were compared at various bias voltages. The etch rates of SiC in the HFE-347mmy/O 2 /Ar plasma were higher than those in the SF 6 /O 2 /Ar plasma at low bias voltages (lower than −500 V), whereas those in the SF 6 /O 2 /Ar plasma were higher than those in the HFE-347mmy/O 2 /Ar plasma at high bias voltages (higher than −600 V). The relative amounts of F and O radicals in both plasmas imply that F is a major contributor to SiC etching at low bias voltages (lower than −500 V), whereas O is a major contributor at high bias voltages (higher than −600 V) in the HFE-347mmy/O 2 /Ar and SF 6 /O 2 /Ar plasmas. AFM measurements showed that the SiC etched in the HFE-347mmy/O 2 /Ar plasma exhibited smoother surfaces than that etched in the SF 6 /O 2 /Ar plasma.

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Plasma Etching of SiO2 Contact Holes Using Hexafluoroisopropanol and C4F8

Cited by 6 publications

References 17 publications

Contribution of Ion Energy and Flux on High-Aspect Ratio SiO2 Etching Characteristics in a Dual-Frequency Capacitively Coupled Ar/C4F8 Plasma: Individual Ion Energy and Flux Controlled

Contribution of Ion Energy and Flux on High-Aspect Ratio SiO2 Etching Characteristics in a Dual-Frequency Capacitively Coupled Ar/C4F8 Plasma: Individual Ion Energy and Flux Controlled

Characterization of SiO2 Plasma Etching with Perfluorocarbon (C4F8 and C6F6) and Hydrofluorocarbon (CHF3 and C4H2F6) Precursors for the Greenhouse Gas Emissions Reduction

Heptafluoroisopropyl Methyl Ether as a Low Global Warming Potential Alternative for Plasma Etching of SiC

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