c-C sub(4)F sub(8) Plasmas for the Deposition of Fluorinated Carbon Films

• Published in: Plasma processes and polymers 2014-03, Vol.11 (3), p.289-299
• Main Authors: Terriza, Antonia, Macias-Montero, Manuel, Lopez-Santos, Maria C, Yubero, Francisco, Cotrino, Jose, Gonzalez-Elipe, Agustin R
• Format: Article
• Language: English
• Subjects: Carbon; Deposition; Diamond-like carbon films; Fluorination; Fluorine; Parallel plates; Plasmas; Synthesis
• ISSN: 1612-8850; 1612-8869
• DOI: 10.1002/ppap.201300129

Highly fluorinated polymeric (CF sub(X)), fluorine containing diamond-like carbon (F-DLC) and, for comparison, diamond-like carbon (DLC) films have been plasma deposited in a RF parallel plate reactor by using c-C sub(4)F sub(8) as fluorine precursor and different mixtures of argon, C sub(2)H sub(2), and H sub(2). Plasmas have been characterized by optical emission spectroscopy, mass spectrometry, and Langmuir probe measurements. Differences in the film composition and structure have been related with the type of species formed in the plasma and with the self-bias potential developed at the deposition electrode. Additional experiments using CF sub(4) have confirmed that the formation in the plasmas of neutral or ionized C sub(x)F sub(y) species with x>2 is a critical factor for the synthesis of fluorine rich films. This work addresses the use of c-C sub(4)F sub(8) as plasma precursor for the synthesis of fluorinated carbon films, from fluorinated DLC to polymeric-like CFx, with different compositions and properties. A clue for their tailored synthesis in a RF parallel plate reactor is the plasma formation of C sub(x)F sub(y) (x>2) fragments and their dependence on the self-bias potential and plasma gas composition.