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A two-step process consisting of an initial nucleation stage with hydrogen followed by a growth stage without hydrogen is used to examine the role of hydrogen in ultrananocrystalline diamond deposition in Ar-rich microwave plasmas. An addition of 5% of [H.sub.2] to Ar-rich/C[H.sub.4] in the initial stage increases the nucleation density (up to [10.sup.9] [cm.sup.-2]) and the mean grain size (around 10 nm), accompanied by some improvement of crystallinity. However, an addition of [H.sub.2] above 10% suppresses nucleation by the etching of nucleation sites. The introduction of hydrogen atoms promotes the termination and stabilization of diamond grain surfaces toward [sp.sup.3] configuration, which are responsible for enhancing nucleation and crystallization. In contrast, Ar promotes renucleation by increasing the production of [C.sub.2] radicals in the plasma, which causes the degradation of the stabilization on the growing surfaces. Index Terms--Chemical vapor deposition (CVD), hydrogen, microwave plasma, nanocrystalline diamond, nucleation, optical emission, surface.

The lowest threshold energy of ion bombardment for cubic boron nitride (cBN) film deposition, which is prepared on positively biased Si (100) substrates from boron trifluoride gas in the high-density source region of inductively coupled plasma with mean ion impact energies from 45 down to a few eV or less, is presented. The findings have shown the existence of a way to deposit cBN films through quasistatic chemical processes under ultralow-energy ion impact.

Axial distributions of plasma parameters towards a positively biased substrate in an electron cyclotron resonance (ECR) plasma are measured as a function of substrate dc bias and pressure. It is observed that the pretreatment with low ion impact energy of around 10 eV produced a clean and smooth surface with minimal structural damage by high flux ion irradiation.

Research is presented concerning the control of the ion-to-adatom flux ration through the insertion of a grid mesh as a dual-bias into the front of a substrate. The deposition of crystalline materials is discussed.

A new study uses vacuum ultraviolet absorption spectroscopy to measure the decay rate of C atom density in inductively coupled plasmas.

A quadrupole mass spectrometer is used to study the precursor species of fluorocarbon film growth at the reactor wall irradiated by an electron cyclotron resonance C4F8 plasma. The study shows that the fluxes of CFx radicals and positive ions incident upon the wall are shown to be comparable with the net condensed carbon flux derived from the growth rate and in contrast, the trends in the amount of polymeric neutrals are not well correlated to the growth rate.

Diamond growth at pressures under 20m Torr was analyzed by employing inductively coupled plasma (ICP) enhanced chemical vapor deposition. ICP is favored for diamond growth because it offers high electron density of even at pressures under 100m Torr. Plasma diagnostics were conducted using Langmuir probe techniques optical emission spectroscopy. To control the incident ion energy, deposits were obtained employing positive substrate bias. The results are discussed.

Nitrogen-incorporated carbon nanowalls are prepared by microwave plasma-enhanced chemical vapor deposition by using acetylene and methane and n-type conduction in the nanowalls is confirmed by Hall- and Seebeck-effect measurements. The high conductivity is ascribed to the global increase in the [sp.sup.2] cluster size and crystallinity, which has increased delocalization of defect states associated with [pi] bonding and quasimetallic character.

The properties of nitrogen-doped nanodiamond films are analyzed as a function of deposition temperature ([T.sub.D]). The studies have shown that the high conductivity at high [T.sub.D] is because of the amount and crystallinity of [sp.sup.2] carbon, rather than the nitrogen concentration.

Plasma diagnostics and kinetic rate analysis for radicals is used for studying the role of neutral radicals and charged ions in a low pressure limit diamond chemical vapor deposition in CO-CH(sub 4)-H(sub 2) plasmas, which are coupled inductively. The results show radical fluxes limit the nucleation and modify the dynamic effects of energetic ions.

A low-input capacitance emissive probe heated by a CO2 laser is used to investigate frequency-modulated electric potentials in a radio-frequency (rf) glow discharge plasma. The results were found consistent with a one-dimensional model for potential and electric field distribution in the sheath region.

The ion-to-CH3 flux ratio, ion energy and ionic composition in a low-pressure inductively coupled plasma (ICP) is examined by mass spectrometry with absolute calibration techniques. The specific surface process which is dominated by energetic ions is discussed.

A simple low-pressure condition at 80 mTorr is employed to study he kinetics and role of C, O, and OH in diamond growth by using inductively coupled CO/CH(sub 4)/H(sub 2)n and O2/CH4/H2 plasmas. The findings support the growth chemistry of diamond from H-hybridized carbon radicals fragmented from CH4 rather than from H-stripped carbon radicals.