Microwave sheath-voltage combination plasma（MVP）is high-density plasma generated in the substrate vicinity. Plasma Chemical vaper deposition（CVD）with MVP enables deposit of a-C:H:Si film at much higher deposition rates than with conventional plasma CVD employing DC and RF plasmas. Nevertheless, the friction property of a-C:H:Si films deposited using MVP, where deposition rates are typically higher than 100 μm/h, have not been elucidated. Therefore, for this study, ball-on-disc friction tests of a-C:H:Si films deposited by MVP were conducted, where a steel ball（SUJ2, JIS）is slid against a coated steel disk（S25C or SCM415, JIS）at a normal load of 9.8 N and sliding speed of 0.157 m/s under dry conditions in ambient air. The MVP-synthesized a-C:H:Si films with Si contents of 5.5-19.6 at% showed a friction coefficient of 0.025-0.12, indicating a friction coefficient of around 0.05, which has been reported often for conventional a-C:H:Si films, is possible by a-C:H:Si films deposited by MVP. A conventional a-C:H:Si film with silicon content of 7.2 at%, which was deposited using a commercial DC plasma CVD for comparison, showed a friction coefficient of 0.12 from the same test. For these films, the friction coefficient decreased with the hydrogen content in the film detected using Rutherford backscattering spectroscopy（RBS）- Elastic recoil detection analysis（ERDA）. This tendency was not reported for conventional a-C:H:Si films. Compared to the hydrogen content, carbon and silicon contents in the film were detected using RBS-ERDA. The oxygen detected at the film surface using X-ray photoelectron spectroscopy（XPS）did not clearly correlate with the friction coefficient. Additionally, results show that the specific wear rate of a-C:H:Si film increases monotonically with the film's Si content. This result is similar to a tendency reported already for conventional a-C:H:Si films.
An in-situ imaging channel flow double electrode（CFDE）was used to investigate the dissolution current and dissolution area of copper during anodic polarization. The CFDE is a useful method to investigate the anodic dissolution mechanisms of various metals and alloys because the oxidation state of the metal ions dissolved from the metal working electrode（WE）can be detected by arranging a detecting electrode（DE）downstream of the WE. In-situ imaging CFDE provides video recording of the WE surface during measurement of the anodic current of WE and the detection current related to the oxidation or reduction of metal ions at DE. For this study, the copper and glassy carbon were used, respectively, as the WE and the DE. Video images of the WE surface during anodic polarization revealed that initiation of the dissolution site on the copper surface corresponded to the increase of the anodic current in the polarization curve and that the dissolution site area increased with increasing polarization potential. The detection current associated with oxidation of cuprous ions to cupric ions was measured at DE when the dissolution site was observed on the copper surface. The dissolution current of cuprous ions increased with increasing area of the dissolution site. Results confirmed that the increase of the dissolution current of cuprous ions is correlated with the increase of the dissolution area on the copper surface during anodic polarization.
The transmission speed of printed circuit boards designed for high-speed transmission exceeds 10 GHz（20 Gbps）, but the need increases for additional efforts to realize ultra-high-speed transmission. Selection of low dielectric constant materials and skin effects of wiring conductors are important for improvement of high-speed signal transmission characteristics. To date, to cope with skin effects during formation of the wiring conductor, attention has been devoted to reducing the roughness of the matted surface of the copper foil. Therefore, efforts to smooth the surface side of the wiring conductor had not been assigned priority. As described herein, related to the skin effect, we investigated the influence of the four-side surface roughness of the wiring conductor and wiring dimension parameters on the transmission loss in the ultra-high-speed region. Therefore, we examined factors for producing high-speed circuit wiring.