Nanostructured ruthenium etching in three-component Cl2 /O2/Ar plasma

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Abstract

Using spectral and probe diagnostic methods for the radical composition and electronic component of the removed plasma of an RF discharge in a mixture of 50 ٪Ar/Сl2 /O2, low-energy (Ei ~80 eV) etching of a nanometer-thick Ru film was studied depending on pressure, RF power, and relative content of Сl2 /O2. With a 10–30 percent chlorine content in the plasma, a wide maximum of the Ru etching rate is observed. In a plasma of this composition, using an array of amorphous silicon nanoconuses as a mask, vertical nanoconded Ru structures with a height of 35 nm and a distance between them of 10–20 nm were obtained. The mechanism of Ru etching in plasma of 50 ٪Ar/Сl2 /O2 is discussed.

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About the authors

I. I. Amirov

National Research Center “Kurchatov Institute”

Author for correspondence.
Email: ildamirov@yandex.ru

The Center for Scientific and Information Technologies – Yaroslavl of the K.A. Valiev Department of Physico-Technological Research

Russian Federation, Yaroslavl

M. O. Izyumov

National Research Center “Kurchatov Institute”

Email: ildamirov@yandex.ru

The Center for Scientific and Information Technologies – Yaroslavl of the K.A. Valiev Department of Physico-Technological Research

Russian Federation, Yaroslavl

D. V. Lopaev

Lomonosov Moscow State University

Email: ildamirov@yandex.ru

Skobeltsyn Institute of Nuclear Physics

Russian Federation, Moscow

T. V. Rakhimova

Lomonosov Moscow State University

Email: ildamirov@yandex.ru

Skobeltsyn Institute of Nuclear Physics

Russian Federation, Moscow

A. N. Kropotkin

Lomonosov Moscow State University

Email: ildamirov@yandex.ru

Skobeltsyn Institute of Nuclear Physics

Russian Federation, Moscow

D. G. Voloshin

Lomonosov Moscow State University

Email: ildamirov@yandex.ru

Skobeltsyn Institute of Nuclear Physics

Russian Federation, Moscow

A. P. Palov

Lomonosov Moscow State University

Email: ildamirov@yandex.ru

Skobeltsyn Institute of Nuclear Physics

Russian Federation, Moscow

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Supplementary files

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2. Fig. 1. Schematic diagram of the RF inductive discharge remote plasma reactor

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3. Fig. 2. Typical etching pattern of a Ru film on Si in 50% Ar/Сl2 /O2 plasma

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4. Fig. 3. Dependences on the plasma pressure in a 35Cl2 /15O2 /50Ar mixture, W = 800 W: (a) concentrations of Cl2 molecules (curve 1), Cl atoms (curve 2), and O atoms (curve 3), the Ru etching rate (curve 4); (b) concentrations of ions

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5. Fig. 4. Dependences on the RF power in a 35Cl2 /15O2 /50Ar mixture, P = 0.6 Pa: (a) concentrations of Cl2 molecules (curve 1), Ru etching rates (curve 2), Cl atoms (curve 3), and O atoms (curve 4); (b) concentrations of ions

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6. Fig. 5. Dependence of the Ru etching rate (1) and the concentration of Ni ions (2 – experiment, 3 – calculation) on the addition of oxygen to the 50% Ar/O2 /Cl2 plasma. P = 0.6 Pa, W = 800 W, Ei = 80 eV

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7. Fig. 6. Dependence of the proportion of ion fluxes (a): 1 – Cl2+, 2 – O2+, 3 – Ar+, 4 – Cl+, 5 – O+ and the concentration of neutral radical components (b): calculation 1–4, experiment 1e–3e: 1 and 1e – Cl2; 2 and 2e – Cl; 3 and 3e – O, 4 – ClO on the mixture composition. P = 0.6 Pa, W = 800 W

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8. Fig. 7. Dependence of the etching rate of Ru on the ion energy in 50% Ar/Сl2 /O2 plasma at the concentration of О2 = 15% (2) and 90% (1); Р = 0.6 Pa, W = 800 W

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9. Fig. 8. View of Ru nanocolumnar structures obtained by etching in 50% Ar/10Сl2 /40O2 plasma at the ion energy of 80 eV

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