Structural Characterization of γ-Terpinene Thin Films Using Mass Spectroscopy and X-Ray Photoelectron Spectroscopy

Understanding the polymerization mechanism of a precursor is indispensable to enhance the requisite material properties. In situ mass spectroscopy and X-ray photoelectron spectroscopy is used in this study to understand the RF plasma polymerization of γ-terpinene. High-resolution mass spectra positive ion mass spectrometry data of the plasma phase demonstrates the presence of oligomeric species of the type [M+H]⁺ and [2M+H]⁺, where M represents a unit of the starting material. In addition, there is abundant fragmented species, with most dominant being [M⁺] (136 m/z), C₁₀H₁₃⁺ (133 m/z), C₉H₁₁⁺ (119 m/z), and C₇H₉⁺ (93 m/z). The results reported in this manuscript enables to comprehend the relationship between the degree of incorporation of oxygen and the rate of deposition with the input RF power.