The temperature vs. gas composition phase diagram of solid carbon deposition in atmospheric oxyacetylene flame is calculated. The phase diagram, which is composed of a diamond growth region, a gas phase region, and a nondiamond carbon growth region, is identical with the reported experimental data. So the suitable ranges of substrate temperature and O2=C2H2 ratio for diamond synthesis in oxyacetylene flames can be theoretically predicted. When the substrate temperature is between 1000K and 1250K, the corresponding O2=C2H2 ratio range is about between 0:8 and 1:1. The suitable range of substrate temperature is widest for O2=C2H2 ratio close to unity and is narrowed rapidly when the flow ratio deviates from unity.

Amorphous SiCOF films with high carbon concentration are prepared by PECVD (plasma-enhanced CVD) with TEOS/C4F8/O2. The dielectric constant of (α-SiCOF film is reduced to 2.6 and other electric properties are improved remarkably. The moisture resistibility of the film is also improved. Through FTIR and XPS analyses, the chemical construction of α-SiCOF film is investigated. The mechanism of improvements in electrical properties and stability in moisture is further discussed. It is found that the ionic polarization and orientational polarization decrease in α-SiCOF films and contribute a lot to the reduction in dielectric constant. In addition, because of the hydrophobicity of incorporated C−F bonds, the moisture resistibility of α-SiCOF film is improved.

Amorphous fluoropolymer (AF) thin films have been prepared from Teflon AF 1600 solution by spin-coating. Scanning electron micrograph (SEM) observations reveal that the film has planar and compact surface without any pinhole, and there are many pores in the matrix. By capacitance-voltage (C-V) and current-voltage (I-V) measurements, the dielectric constant of the AF film is equal to 1.57 at 1 MHz, and breakdown strength is 2.07MV cm−1. The Fourier transform infrared spectroscopy (FTIR) spectra and X-ray diffraction (XRD) patterns of the films show that the films have excellent thermal stability below 400℃, and thermal treatment does not change amorphous nature of the films. X-ray photoelectron spectroscopy (XPS) spectra reveal decomposition of CF3 groups due to annealing at 400℃, leading to a remarkable increase in CF2 groups. Possible decomposition mechanisms of AF film are also discussed.

The interactions between magnetron-sputtered Cu and plasma-enhanced chemical-vapour-deposited a-SiCOF film have been investigated via x-ray photoelectron spectroscopy (XPS), Auger electron spectroscopy (AES) and scanning electron microscopy (SEM). High-resolution C 1s, Cu 2p, O 1s, Si 2p and F 1s XPS spectra for the samples before and after annealing are collected. The results show that the C-Cu bond is not observed at the interface of Cu/a-SiCOF before or after the annealing. Moreover, the annealing causes the obvious shifts of Cu 2p3/2, C 1s, O 1s and Si 2p photoelectron peaks toward higher binding energy, and the underlying reasons are discussed in detail. The AES spectra of Cu L3M4, 5M4, 5 with the etching time reveal that some chemical reactions take place at the interface during the sputtering deposition of copper on the a-SiCOF film, and possible reaction mechanisms are also presented. The Cu 2p3/2 XPS spectra and the SEM graphs demonstrate that the annealing enhances the interdiffusion between Cu and a-SiCOF film.

As ultra large scale integration devices scale to smaller feature sizes and larger die dimensions, the resistance-capacitance (RC) delay of the metal interconnections will increasingly limit the performance of high speed logic chips. In order to reduce the RC delay, the introduction of low dielectric constant (k) materials (k<3) for the interlayer dielectric and/or low-resistivity conductors, such as copper, is required. [1] In order to reduce the interconnection capacitance, many low k materials have been developed using different methods, such as CVD, spin coating, liquid-phase deposition, porous film formation techniques, and air bridge techniques. [2] Of particular interest are CVD techniques, which have the advantage of being able to completely fill narrow features with a high aspect ratio better than other deposition techniques, and are also generally considered compatible with damascene process flows. Furthermore, a layered structure that promotes adhesion can be easily fabricated by changing the source compounds, so the deposition of low k thin films by CVD appears promising. As Dorfman suggested, [3] in atomicscale composites the highest physical limits of mechanical and electronic "sensor" properties can be combined, leading to the creation of "smart" construction materials. For instance, diamond-like atomic-scale composites (a-C:H/a-Si:O) and metal-containing, diamond-like nanocompos-

The preparation of a-SiOCF films from Si (OC2H5) 4, C4F8 and/or Ar using a plasma-enhanced chemical vapour deposition method is reported. The chemical bonding structures of the films are analysed by high-resolution x-ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FTIR) spectroscopy. The results show that the films contain F-Si-O-Si, Si-OH, Si-O-Si, C-CF and C-F configurations. However, as for the film deposited from the feeding gases with Ar, a C-C configuration is also included in addition to the above-mentioned configurations. This indicates that the existence of Ar in the plasma leads to the formation of a fluorocarbon structure with a high degree of cross-linking. No evidence reveals the presence of a Si-C bond in the film, so it is believed that the fluorocarbon is perhaps embedded into the matrix of SiOF.

The reaction mechanisms of ZrCl4 adsorption and dissociation on Ge/Si (100)-(2

pper atoms or clusters penetrating in to the SiCOF film and cleaving Si-O bonds. Additionally, the anncaling at 400℃ in high pure N2 leads to the formation of Cu2O phase at the full expense of Cu phase, subsequently, CuO phase comes into being logether with a decrease in Cu2O phase after annealing at 500℃. Possible reason is that annealing at different temperatures causes a special ratio of Cu/O in some special diffusion area; which determines the formation of reactive production between Cu and SiCOF. Furthermore, C-Cu bond is not formed during sputtering deposition of copper, and even after the annealing.

We have investigated adsorption and dissociation of water and HfCl4 on Ge/Si(100)-(231) surface with density functional theory. The Si-Ge heterodimer and Ge-Ge homodimer are employed to represent the Si1−xGex surface. The activation energy for adsorption of water on Ge-Ge homodimer is much higher than that on Si-Ge heterodimer. No net activation barrier exists during the adsorption of HfCl4 on both SiGe surface dimers. The differences in the potential energy surface between reactions on Si-Ge and Ge-Ge dimers are due to different bond strengths. It should also be noticed that the activation energy for HfCl4 is quite flat, thus HfCl4 adsorbs and dissociates on Ge/Si (100)-(231) easily.

Atomic-layer-deposited Al2O3-HfO2-Al2O3 dielectrics have been investigated to replace conventional silicon oxide and nitride for radio frequency and analog metal-insulator-metal capacitors applications. In the case of 1-nm-Al2O3, sufficiently good electrical performances are achieved, including a high dielectric constant of～17, a small dissipation factor of 0.018 at 100 kHz,an extremely low leakage current of 7.8×10−9 A/cm2 at 1 MV/cm and 125℃, perfect voltage coefficients of capacitance (74ppm/V2 and 10ppm/V). The quadratic voltage coefficient of capacitance decreases with the applied frequency due to the change of relaxation time with different carrier mobility in insulator, and correlates with the dielectric composition and thickness, which is of intrinsic property owing to electric field polarization. Furthermore, the conduction mechanism of the AHA dielectrics is also discussed, indicating the Schottky emission dominated at room temperature.