Viscosity measurements of GaInSn eutectic alloys were performed in a homebuilt device for low (9%) and high (95%) relative humidity for shorter (450 min) and longer (1800 min) time periods. At constant exposure time a characteristic increase of viscosity is observed with increasing humidity. For high humidity, high viscosity is obtained after a short time.Assuming that the measured viscosity change is strongly related to the absorption of oxygen, XPS was applied to the chemical and quantitative analysis of differently prepared samples. In all cases, Ga is predominantly oxidized at the surface whereas Ga atoms in the metallic state are located deeper inside. Besides Ga 2 O 3 (the most stable oxide phase), the less stable Ga 2 O is detected. Indium and tin are almost stable in their metallic state. With increasing humidity the thickness of the oxide film increases in our case from about 19Å to 25Å, assuming a layer-by-layer model. The presented results confirm our assumption of the increase in viscosity of the GaInSn system as a consequence of the preferential oxidation of gallium in the near-surface region.

Silicon carbide can be reproducibly grown on (111)Si below 600 °C by carbonization using an elemental solid carbon source in molecular beam epitaxy. The initial stages were observed by in situ reflection high-energy electron diffraction. Prior to silicon carbide growth, the continuous carbon flux lead to a transition from the (7×7) reconstruction of clean (111)Si to a carbon-induced (∛×∛)R30° structure. Above 660 °C, the silicon carbide growth starts directly on the silicon surface via three-dimensional nucleation. Below 660 °C, first a thin silicon–carbon alloy was formed by diffusion of carbon into the surface near the region with a concentration exceeding the bulk solubility in silicon.

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