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Plasma copolymerization of hexamethyldisiloxane (HMDSO, (CH3)3-Si-O-Si-(CH3)3) and tetrafluoroethylene (CF2=CF2) was performed using an RF plasma enhanced chemical vapor deposition method, for its application to low dielectric constant intermetal dielectrics. Film structure was investigated by X-ray photoelectron spectroscopy and Fourier transform infrared (FT-IR) spectroscopy. Film composition was controlled gradually from that of fluorinated carbon to organic siloxane by changing the HMDSO mixing ratio. The films possessed a dielectric constant of less than 2.5 for an HMDSO mixing ratio of less than 10%. Thermal treatment of the films revealed that the C-Fn, Si-O-Si, Si-(CH3)nand Si-(CH2)n-Si bonds were stable to 400°C, but the C-H2bonds were not. In situgas-phase FT-IR spectroscopy was also performed on the plasma, and the reaction mechanisms are discussed.

Changes of surface states of a substrate during diamond nucleation in a bias-enhanced microwave plasma have been monitored and analyzed by ellipsometry. In order to enable monitoring, a surface-wave-excited microwave plasma was applied, and it has been demonstrated that the generation of high-density diamond nuclei by appropriate negative-bias application and subsequent diamond growth are possible in the plasma. Evolution of the ellipsometric parameters was compared with a simulated calculation, and carbonization, incubation and nuclei growth stages have been distinguished.

Simple hexagonal Coulomb crystals have been observed near a deformed plasma sheath boundary in a dusty plasma. It seems that particle rows, which are found in the direction perpendicular to an electrode in the Coulomb crystal, are formed due to not only Coulomb repulsive forces but also some attractive forces. In this study, experiments using the deformed sheath revealed that the rows were bent along the direction of electric fields and ion flows in a plasma. The result shows that sheath structures and shapes affect Coulomb crystal structures in dusty plasmas. In this paper, the formation of the particle rows are discussed, where balances of forces on particles in a dusty plasma are taken into account under the assumption that wake potentials related to ion flows exist in the sheath region.

Bias-enhanced nucleation (BEN) of oriented diamond on Si(100) substrates was investigated by ellipsometric monitoring using hot-filament chemical vapor deposition (HF-CVD). A plasma was observed above the substrate on the Mo holder by a glow discharge during the BEN process. We confirm that this plasma plays a critical role in the BEN process. A diamond film growth boundary was present when the initial bias voltage was below -250 V. The results of the ellipsometric monitoring indicate that the BEN process includes the following stages: carbonization, incubation, nucleation, nuclei growth and film growth. A scanning electron micrograph showed that biasing for too long induces twinned crystals. It is showed that the biasing time is a very important factor in oriented nucleation.

Stable F-doped SiO2(SiOF) films have been deposited using a simple conventional capacitively coupled RF plasma-enhanced chemical vapor deposition method using H-free tetraisocyanatesilane (Si(NCO)4: TICS) diluted with oxygen, and tetrafluorosilane (SiF4) having Si-F bonds in itself. The SiO2films deposited only with TICS have poor water resistivity, which originates in the inclusion of the SiNCO structure in the films. This property has been improved by mixing O2with the source gases. Although F atoms at the top surface of films desorbed upon air exposure, SiOF films deposited with TICS, SiF4and O2exhibit excellent water resistivity. A film with F concentration of 6 at.% exhibited a dielectric constant of 3.3, a resistivity of 3.6×1015?cm and a break-down electric field of 7.7 MV/cm. These values are comparable to or better than the reported values for films prepared using tetraethylorthosilicate. These results indicate that the TICS, SiF4and O2system can be used to deposit high quality SiOF films using a much simpler method than those requiring complex high density plasma sources.

A bias-enhanced nucleation (BEN) technique in hot-filament chemical vapor deposition (HF-CVD) has been applied to single-crystalline 6H-SiC substrates for the deposition of oriented diamond films. The results of scanning electron microscopy (SEM) showed that on the (000\overline1) face not only oriented diamond films with the relationship (111) Dia.//(000\overline1) 6H-SiC and <110> Dia. // <11\overline20> 6H-SiC, but also that high nucleation density (\symbol"3E109cm-2) has been achieved. In the case of deposition on the (0001) face of the 6H-SiC under the same experimental conditions, although the nucleation density of diamond was enhanced (above 109cm-2), however, oriented diamond was not observed. The diamond nucleation density is greater on the (0001) face than on the (000\overline1) face. The differences in oriented nucleation and nucleation density on these two faces are attributed to the difference of their specific free surface energy and chemical bonds.

A bias-enhanced nucleation (BEN) technique in hot-filament chemical vapor deposition (HF-CVD) has been applied to singlecrystalline 6H-SiC substrates for diamond nucleation. The oriented diamond film has been grown on a 6H-SiC substrate. The experimental results have shown that the 6H-SiC substrate surfaces are etched by the reactive hydrogen species during the BEN process, and many inclined-pyramid crystals with {01\overline14} type faces are formed on the substrate surface. The array direction of the inclined-pyramid crystals is determined by the diffusion direction of the reactive hydrogen species existing in the plasma sheath and the specific free surface energy of the substrate. Diamonds nucleate on the top of the inclined-pyramid crystals. Diamond nucleation density is higher on the (0001)face than on the (000\overline1)face. The relationship between the inclined-pyramid crystals and the diamond nuclei is investigated using scanning electron microscopy.