Effect of Sulfuric Acid Immersion on Electrical Insulation and Surface Composition of Amorphous Carbon Films
Abstract
:1. Introduction
2. Materials and Methods
2.1. Deposition Conditions for Amorphous Carbon Films
2.2. Spectroscopic Ellipsometric Analysis
2.3. Sulfuric Acid Immersion Conditions
2.4. Surface Morphology Analysis
2.5. Structural Analysis
2.6. Surface Composition Analysis
2.7. Electrical Insulation Evaluation
3. Results
3.1. Classification of Amorphous Carbon Films Based on Optical Constants
3.2. Surface Morphology of Amorphous Carbon before and after Sulfuric Acid Immersion
3.3. Effect of Sulfuric Acid Immersion on the Structure of Amorphous Carbon Films
3.4. Effect of Sulfuric Acid Immersion on the Surface Composition of Amorphous Carbon Films
3.5. Effect of Sulfuric Acid Immersion on the Electrical Insulation Properties of Amorphous Carbon Films
3.6. Optical Classification of Amorphous Carbon Films According to Their Electrical Insulation Properties
4. Conclusions
Author Contributions
Funding
Institutional Review Board Statement
Informed Consent Statement
Data Availability Statement
Acknowledgments
Conflicts of Interest
References
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Sample No. | Deposition Method | Precursor | Substrate Bias Voltage [kV] | Target Voltage [kV] | |
---|---|---|---|---|---|
1 | CVD | RF-PCVD | hydrogenated gas (C6H6) | 1.5 | - |
2 | Pulsed DC-PCVD | hydrogenated gas (C6H6) | 1.5 | - | |
3 | PVD | Ionized evaporation | hydrogenated gas (C6H6) | 1.0 | - |
4 | HiPIMS | graphite solid target + Ar | - | 0.75 | |
5 | HiPIMS | graphite solid target + Ar | −0.05 | 0.90 |
Sample No. | χ2 | Film Thickness (nm) | n | k | Type | Optical Surface Roughness (nm) |
---|---|---|---|---|---|---|
λ = 550 nm | ||||||
1 | 0.19 | 90 | 1.94 | 0.04 | PLC | 11 |
2 | 0.16 | 129 | 2.02 | 0.28 | GLC-A | 4 |
3 | 0.12 | 107 | 2.25 | 0.33 | a-C:H | 19 |
4 | 0.06 | 197 | 1.70 | 0.39 | GLC-B | 17 |
5 | 0.19 | 170 | 1.91 | 0.47 | GLC-C | 7 |
Sample No. | Sulfuric Acid Immersion | Surface Roughness (nm) | D-Peak Position [cm−1] | G-Peak Position [cm−1] | ID/IG Intensity Ratio |
---|---|---|---|---|---|
1 (PLC) | Without | 0.39 ± 0.04 (n = 3) | 1311.6 ± 2.4 | 1523.8 ± 0.4 | 0.31 |
With | 0.12 ± 0.01 (n = 3) | 1309.1 ± 2.5 | 1523.1 ± 0.4 | 0.31 | |
2 (GLC-A) | Without | 0.33 ± 0.04 (n = 3) | 1369.1 ± 2.9 | 1541.3 ± 0.2 | 0.52 |
With | 0.22 ± 0.01 (n = 3) | 1369.1 ± 3.0 | 1540.8 ± 0.2 | 0.52 | |
3 (a-C:H) | Without | 0.16 ± 0.05 (n = 3) | 1387.8 ± 3.5 | 1554.3 ± 0.2 | 0.60 |
With | 0.12 ± 0.02 (n = 3) | 1387.4 ± 3.5 | 1555.0 ± 0.2 | 0.63 | |
4 (GLC-B) | Without | 3.54 ± 0.01 (n = 3) | 1366.9 ± 0.8 | 1581.2 ± 0.3 | 1.00 |
With | 2.90 ± 0.02 (n = 3) | 1369.0 ± 0.8 | 1582.0 ± 0.3 | 1.00 | |
5 (GLC-C) | Without | 3.21 ± 0.36 (n = 3) | 1367.2 ± 0.9 | 1581.9 ± 0.3 | 1.10 |
With | 2.66 ± 0.12 (n = 3) | 1374.6 ± 0.9 | 1582.8 ± 0.3 | 1.10 |
Sample No. | Sulfuric Acid Immersion | O1s/C1s Ratio | C1s Curve Fitting Area | ||||
---|---|---|---|---|---|---|---|
C–C sp2 | C–C sp3 | C–O | C=O | O=C–O | |||
1 (PLC) | Without | 0.14 | 0.64 | 0.26 | 0.08 | 0.02 | 0.00 |
With | 0.19 | 0.54 | 0.34 | 0.10 | 0.03 | 0.00 | |
2 (GLC-A) | Without | 0.12 | 0.49 | 0.34 | 0.12 | 0.03 | 0.02 |
With | 0.15 | 0.48 | 0.34 | 0.13 | 0.03 | 0.02 | |
3 (a-C:H) | Without | 0.11 | 0.40 | 0.39 | 0.15 | 0.05 | 0.02 |
With | 0.13 | 0.39 | 0.39 | 0.15 | 0.05 | 0.02 | |
4 (GLC-B) | Without | 0.21 | 0.44 | 0.24 | 0.16 | 0.11 | 0.04 |
With | 0.21 | 0.43 | 0.25 | 0.17 | 0.11 | 0.04 | |
5 (GLC-C) | Without | 0.21 | 0.47 | 0.15 | 0.21 | 0.10 | 0.06 |
With | 0.21 | 0.46 | 0.17 | 0.20 | 0.10 | 0.07 |
Sample No. | Sulfuric Acid Immersion | Electrical Insulation (n = 5) | |
---|---|---|---|
Insulation Voltage (V) | Electrical Insulation (kV/mm) | ||
1 (PLC) | Without | 40 ± 1 | 444 ± 11 |
With | 42 ± 3 | 467 ± 33 | |
2 (GLC-A) | Without | 39 ± 2 | 302 ± 16 |
With | 36 ± 1 | 279 ± 8 | |
3 (a-C:H) | Without | 52 ± 3 | 486 ± 28 |
With | 53 ± 2 | 495 ± 19 | |
4 (GLC-B) | Without | 13 ± 0 | 66 ± 0 |
With | 13 ± 0 | 66 ± 0 | |
5 (GLC-C) | Without | 16 ± 4 | 94 ± 24 |
With | 14 ± 3 | 82 ± 29 |
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Kanasugi, K.; Ichijo, E.; Hiratsuka, M.; Hirakuri, K. Effect of Sulfuric Acid Immersion on Electrical Insulation and Surface Composition of Amorphous Carbon Films. Coatings 2024, 14, 1023. https://doi.org/10.3390/coatings14081023
Kanasugi K, Ichijo E, Hiratsuka M, Hirakuri K. Effect of Sulfuric Acid Immersion on Electrical Insulation and Surface Composition of Amorphous Carbon Films. Coatings. 2024; 14(8):1023. https://doi.org/10.3390/coatings14081023
Chicago/Turabian StyleKanasugi, Kazuya, Eito Ichijo, Masanori Hiratsuka, and Kenji Hirakuri. 2024. "Effect of Sulfuric Acid Immersion on Electrical Insulation and Surface Composition of Amorphous Carbon Films" Coatings 14, no. 8: 1023. https://doi.org/10.3390/coatings14081023