When a gold film is vacuum evaporated at around 50 °C onto a clean surface of single-crystal silicon substrate, the adhesion of the film to the substrate is very strong, which suggests that some chemical reaction has taken place at the interface. Present study by Auger electron spectroscopy (AES) concludes the occurrence of the above reaction which induces a diffuse interface region in order to relax (or minimize) the interface energy. For the relaxation of silicon (110) and (111) interfaces, at least 45 and 20 monolayers of gold are necessary, respectively. The phase of the thus-formed interface is concluded to be similar to that of the nonequilibrium solid alloy obtained by quenching from a solid Si–Au eutectic liquid.

Using a laser-induced fluorescence (LIF) technique, SiF2 and CF2 radicals are detected during the downstream etching of silicon with a discharge of CF4 gas. It is confirmed that SiF2 radical is desorbed from the surface in the etching of silicon by fluorine atom. Addition of O2 gas to the CF4 discharge enhances the LIF intensity of SiF2 radical and extinguishes that of CF2. Mechanism of the increase of etching rate of silicon by addition of O2 is discussed on the basis of the results of LIF measurements. The etching rate of silicon is proportional to the LIF intensity of SiF2, when the microwave power of the discharge is changed. The relationship between the intensity of chemiluminescent continuum and the concentration of SiF2 is revealed, which suggests that the chemiluminescence is attributed to the emission of SiF*3 which is produced by the reaction between SiF2 and fluorine atoms in the gas phase. There is no signal of SiF2 during the etching of either SiO2 or SiNx.

Using a laser-induced fluorescence technique, SiH radicals were detected in the rf glow discharge of SiH4 gas during CVD of amorphous silicon. The pressure, flow rate, and rf power dependencies of the relative concentration of SiH radicals were obtained. The spatial distribution of SiH radicals between rf and ground electrodes was also revealed. It was found that the behaviors of the concentration of SiH in the ground electronic state are different from those of SiH in the excited state. The latter was obtained from measurement of the spontaneous emission in the discharge. The rotational temperature of SiH radicals was derived from the laser excitation spectra with computer simulations. The obtained temperature reflects the translational temperature of the parent molecules (SiH4). The rotational energies of SiH radicals in the discharge are thermalized with surroundings by collisions during their lifetimes.

The transport properties of the convective fluid motion in a MOCVD reactor are investigated using a numerical method. For the purpose of a uniform deposition rate on a substrate with a diameter of 3 inches, a combinatorial optimization was carried out concerning the pressure, the mass-flow rate and the reactor's geometry. Under the optimal condition, a deposition uniformity within ±0.6% is attainable. The results also reveal a variety of flow configurations, depending on the relative magnitudes of the forced and natural convections. When the volumetric velocity of the supplied gas decreases, a recirculating vortex appears on the upstream side of the deposition surface. The numerical results suggest that the appearance of the vortex is governed by F r/R e when R e<R e c and by F r when R e>R e c.

Thin vapor−quenched films of Si−Au (Ag, Cu) alloys were studied by using Auger electron spectroscopy (AES). In these films, when the concentration of the noble metal was more than a critical value (∼70 at.%), the Si (LVV) Auger spectrum had double peaks at 90 and 95 eV; these peak energies were all the same for Si−Au, Si−Ag, and Si−Cu. However, with smaller noble−metal concentrations, the Si (LVV) spectrum was nothing but that of pure Si having a single peak at 92 eV. These results are explained by the statement that the double−peaked spectrum reflects the metallic state of Si quenched from the liquid state and some amount of metal is necessary to stabilize the metallic Si.