Organic polymer thin films deposited on silicon and copper by plasma-enhanced chemical vapor deposition method and characterization of their electrochemical and optical properties J. Vac. Sci. Technol. A 23, 875 (2005); 10.1116/1.1946714 Surface modification of silicon-containing fluorocarbon films prepared by plasma-enhanced chemical vapor deposition J.Optical and compositional study of silicon oxide thin films deposited in a dual-mode (microwave/radiofrequency) plasma-enhanced chemical vapor deposition reactorIn situ Fourier-transform infrared measurements have been carried out to study the effects of H atoms on removing impurities in Cu thin films during plasma enhanced metal organic chemical vapor deposition ͑PEMOCVD͒ using bis͑hexafluoroacetylacetonato͒ copper ͑II͒, Cu͑hfac͒ 2 as a source material. The results show that H atoms are very effective in removing impurities in the film, as well as on its surface. Based on such knowledge regarding the effects of H atoms, a PEMOCVD reactor equipped with an H atom source is developed to control both densities of H atoms and Cu-contained radicals independently. High purity ͑Ϸ100%͒ Cu films of a low resistivity of 2 ⍀ cm can be deposited for a H 2 gas volume fraction of 50%-67% by using the H atom source, while the high purity films were obtained only for a very high H 2 gas volume fraction above about 90% in the case of no H atom source as reported previously. This feature opens up a possibility of deposition of high quality Cu films at a high rate using the reactor equipped with the H atom source, since a gas volume fraction of Cu metal organic material can be increased by more than five times.

The new superconductors discovered after MgB 2 are discussed. Two serious claims have been made so far. The first claim concerns a graphite-sulfur composite undergoing a transition at 35 K. Since the magnetic transition clearly has the characteristics of a superconducting shielding effect, it would be worthwhile to investigate the possibility of increasing the sample volume responsible for this transition. However, there is no zero-resistance transition and the authors suggest that the superconductivity could be due to a surface effect. Carbon in this sample has the same structure as boron in MgB 2 . The second claim is more modest, but it is really a superconduting transition at 1 K. The sample is a single crystal of Cd 2 Re 2 O 7 . The Re cations could be in a mixed valence state, but the charges do not seem to localize by lowering the temperature. The importance of these results is the discovery of a new oxide structure such as the pyrochlore, which can host a superconducting state.

The temporal saturation effects of the critical dimensions of nanoscale contact holes are investigated by a two-dimensional reaction-diffusion simulator for the chemical shrink techniques of nanolithography. Models included with the simulator are the crosslinking reaction of water-soluble polymers and crosslinkers, the diffusion of photoacids, and the inactivation of photoacids. Within the the statistical errors of the experimental data, the simulation critical dimensions agree with the experiment for baking temperatures over 105 C and for all baking times. It is found that the temporal saturation of the contact holes' critical dimensions can be explained by the photoacid inactivating reaction included in the simulator.

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The bias-enhanced nucleation (BEN) method is well known as a pretreatment method for nucleation, and the nucleus is generated in the plasma sheath region during the BEN process. To utilize high-density nucleation at low pressure and to expand the nucleation region in hot-filament chemical vapor deposition (HFCVD), the BEN method was applied under a low-pressure condition in which the plasma and plasma sheath expanded. Some substrates were treated in hydrogen plasma or activated hydrogen before nucleation. The purpose of this study is to confirm the characteristics of nucleation at low pressure and to determine the condition for realizing uniform, high-density and large-area nucleation. By using emitted electrons, bias voltage and current were controlled to be steady at the low pressure of 0.1 Torr. The nucleation density increased and the width of the nucleation area expanded when the substrate surface was treated in hydrogen plasma or activated hydrogen before nucleation. It was proposed that the nucleation mechanism is as follows. (1) A substrate surface was treated by H ions and H radicals, (2) a nucleation site was formed on the treated position and (3) nucleation occurred on the nucleation site. To achieve high-density and large-area nucleation, it is necessary to obtain the treated substrate surface and to generate carbon-containing cations, H ions and H radicals with appropriate ratios and density distributions in the nucleation phase.