To prepare a silicon-germanium bulk crystal with uniform composition distribution, it is necessary to supply solute component to the growth interface and to control the growth interface temperature. The multicomponent zone melting method with the feedback system of the growth interface temperature which we established fulfills these necessary conditions. The homogeneous bulk crystal with the length of 20 mm over was successfully grown by this method. This paper provides an overview of this growth method and related in-situ techniques to measure position and temperature of growth interface during the crystal growth. To grow high quality crystals, it is also necessary to control supercooling and supersaturation in the solution. We also introduce an in-situ observation technique for supersaturation.
