Wetting angles and surface tension of Ge1-xSix melts on different substrate materials

The wetting angles and surface tension of Ge1-xSix melts (0.02<x<0.13) have been measured on various substrate materials using the sessile drop technique. Fused quartz, sapphire, SiC, glassy carbon, pBN, AlN, and Si3N4 were used as substrates. The highest and most stable wetting angles were found for pBN substrates with 164+/-8degrees, either under forming gas with an additional carbon getter in the system or under active vacuum. The surface tension measurements resulted in a value of +2.2 x 10(-3) N/m at% Si for the concentration dependence partial derivativegamma/partial derivativeC. For the composition range measured, the temperature dependence partial derivativegamma/partial derivativeT showed values similar to those of pure Ge, on average -0.07 x 10(-3) N/mK. (C) 2002 Elsevier Science B.V. All rights reserved.