International Journal of Physics | Vol. 4, No. 3, March 2013 | pp. 17–24
DOI: 10.46882/2013/IJP/000035
Research Article
Title: Characterization of Plasma Chemistry and Ion Energy Distributions in Low-Pressure Carbon Tetrafluoride Discharges
Names of Authors: L. K. Rousseau¹, M. A. Al-Hussaini²
Authors’ Affiliations: ¹Laboratoire de Physique des Plasmas, École Polytechnique, 91128 Palaiseau, France; ²Department of Physics, Faculty of Science, Kuwait University, Safat 13060, Kuwait
Abstract: Carbon tetrafluoride (CF4) plasmas are extensively utilized for precise oxide etching within industrial semiconductor fabrication processes. This paper evaluates the internal plasma chemistry and measures the corresponding ion energy distributions (IEDs) within a low-pressure inductively coupled plasma reactor. The system was operated at an excitation frequency of 13.56 MHz under gas pressures varying from 0.5 Pa to 5.0 Pa. We integrated a mass spectrometer with an energy analyzer directly into the grounded substrate electrode to capture real-time flux parameters. The experimental findings indicate that the CF3+ ion dominates the total positive ion flux across all tested configurations. It accounts for more than 70.0% of the total ion concentration. As the radio-frequency power increased from 100.0 W to 500.0 W, the average ion energy shifted from 34.2 eV to 58.5 eV. This shift occurred alongside a narrowing of the IED full-width at half-maximum from 12.4 eV down to 4.1 eV. Numerical simulations using a zero-dimensional global model match the observed neutral radical densities within a minor ±8.0% margin. These simulations show that electron-impact dissociation of CF4 is the primary pathway generating reactive fluorine atoms. This work provides critical kinetic tracking data necessary for refining thin-film etching profiles on sub-22 nm node architectures.
Keywords: Plasma chemistry; carbon tetrafluoride; ion energy distribution; mass spectrometry; semiconductor etching; inductively coupled plasma
Manuscript Timeline: Received: December 14, 2012; Revised: January 22, 2013; Accepted: February 09, 2013; Published: March 15, 2013
Citation: Rousseau, L. K., & Al-Hussaini, M. A. (2013). Characterization of Plasma Chemistry and Ion Energy Distributions in Low-Pressure Carbon Tetrafluoride Discharges. International Journal of Physics, 4(3), 17–24.
Subscribe to read the full article: https://internationalscholarsjournals.org/subscribe-to-read