1：Experimental Design and Method Selection:

A homemade asymmetric RF CCP source operating at

2：56 MHz was used to deposit a-C:

H films from pure C2H2 plasma. The films were deposited at different powers (100-600 W) and a gas pressure of 40 mTorr. The study aimed to correlate plasma electrical and optical measurements with film properties, utilizing the plasma series resonance (PSR) effect to enhance ionization and control film transformation from polymeric to graphitic a-C:H.

3：Sample Selection and Data Sources:

Glass substrates were used for film deposition. Plasma species were characterized using optical emission spectroscopy (OES), and films were analyzed using SEM, EDS, Raman spectroscopy, FTIR, and UV-Vis spectrophotometry.

4：List of Experimental Equipment and Materials:

RF CCP source (homemade, 13.56 MHz, 1 kW), matching network (π type with variable air gap capacitors and air variable coil), derivative probe for current measurement, Ocean Optics USB4000 Spectrometer for OES, SEM (Quanta EFI 250, Philips, Netherlands) with EDS, Raman spectrometer (Bruker Senterra, 532 nm laser), FTIR spectrometer (VERTEX 70/70V, Bruker Optics, Germany), UV-Vis spectrophotometer (Jasco V-630, Japan). Materials included acetylene gas, glass substrates, and cooling water.

5：56 MHz, 1 kW), matching network (π type with variable air gap capacitors and air variable coil), derivative probe for current measurement, Ocean Optics USB4000 Spectrometer for OES, SEM (Quanta EFI 250, Philips, Netherlands) with EDS, Raman spectrometer (Bruker Senterra, 532 nm laser), FTIR spectrometer (VERTEX 70/70V, Bruker Optics, Germany), UV-Vis spectrophotometer (Jasco V-630, Japan). Materials included acetylene gas, glass substrates, and cooling water. Experimental Procedures and Operational Workflow:

4. Experimental Procedures and Operational Workflow: The chamber was evacuated, and C2H2 gas was injected. Films were deposited at varying powers (100-600 W) and 40 mTorr pressure. OES was performed near the substrate surface. Current waveforms were measured, and FFT was applied to study PSR effects. Films were characterized post-deposition using SEM, EDS, Raman, FTIR, and UV-Vis absorption.

6：Data Analysis Methods:

OES data analyzed intensities of species like C4H2+, CH, C2, and Hα. Raman spectra were fitted with Breit-Wigner-Fano (BWF) and Lorentzian functions to extract G peak position, ID/IG ratio, and sp3 content. FTIR spectra were analyzed for CH and C=C vibrations. EDS data quantified carbon content. Optical band gaps were estimated from absorption spectra.