Experiments of inductive Ar/CF 4 , Ar/NF 3 , and Ar/SF 6 discharges with a Langmuir probe and optical emission spectroscopy are carried out in the total pressure range of 8 -30 mTorr, changing the ratio of the partial pressure of reactive gas to the total pressure (the fraction of the reactive gas) from 0 to 30%. The structure of the measured electron energy probability functions (EEPFs) deviates from the Maxwellian distribution owing to the large depletion of high-energy electrons at any reactive gas fraction. The electron density markedly decreases with increasing reactive gas fraction in the fraction range below 10%, whereas the electron temperature gradually increases. The density of the ground state fluorine atoms in the Ar/SF 6 and Ar/ NF 3 discharges is about 5 times higher than that in the Ar/CF 4 discharges. The effects of oxygen addition on the plasma parameters in those discharges are also investigated. The plasma parameters, such as electron density and temperature, do not depend on the fraction of oxygen for the fixed fraction of Ar. On the other hand, the dependence of the fluorine atom density on the fraction of oxygen differs among the inductive Ar/CF 4 , Ar/NF 3 , and Ar/SF 6 discharges.
Measurements using a Langmuir probe and optical emission spectroscopy combined with actinometry are carried out in inductively coupled CF 4 /O 2 /Ar discharges at total pressures lower than 30 mTorr for Ar contents ranging from 10 to 90%. The measured structure of the electron energy probability functions can be changed from being Druyvesteyn-like to being Maxwellian-like as Ar content decreases. The electron density measured at each fixed Ar content gradually decreases with increasing O 2 content, whereas the measured electron temperature is not sensitive to O 2 content. The atomic fluorine density measured at each fixed Ar content reaches its maximum when the ratio (R OC ) of O 2 content to the sum of CF 4 and O 2 contents is around 0.2, beyond which it decreases with increasing R OC . The atomic fluorine density measured at R OC ¼ 0:2 remains constant for Ar contents lower than 60%, beyond which it monotonically decreases with increasing Ar content. These results are shown to be in reasonably good agreement with the predictions of the global model for electronegative plasma.
The properties of inductively coupled Ar/C 4 F 8 /O 2 and Ar/CF 4 /O 2 plasmas are investigated at two total pressures of 15 and 30 mTorr. Measurements using a Langmuir probe and optical emission spectroscopy are carried out, while varying the ratio of the oxygen fraction to the sum of fluorocarbon and oxygen fractions (R OC ) at an Ar fraction higher than 70%. The measured electron energy probability functions slightly deviate from the Maxwellian distribution owing to the depletion of electrons with an energy higher than 10 eV. The electron density measured in the Ar/C 4 F 8 /O 2 plasmas gradually decreases with increasing R OC and reaches a minimum at R OC 0:3, whereas that in the Ar/CF 4 /O 2 plasmas does not strongly depend on R OC . The density of CF 2 radicals in the Ar/C 4 F 8 /O 2 plasmas markedly decreases in the range of 0:2 R OC 0:4, whereas that of oxygen atoms in the Ar/C 4 F 8 /O 2 plasmas more sharply increases with increasing R OC compared with that of oxygen atoms in the Ar/CF 4 /O 2 plasmas. The density of fluorine atoms measured in the Ar/C 4 F 8 /O 2 plasmas reaches a minimum at R OC 0:3 { 0:4 and then starts to increase again, whereas that in the Ar/CF 4 /O 2 plasmas has a maximum at R OC 0:2 { 0:3.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.