A step forward to the growth and characterization of compositionally homogeneous InxGa1-xAs bulk crystal

A possibility of tunable lattice matching makes bulk In_xGa_1-xAs crystal an excellent substrate material for InGaAs-based optical communication devices. However, due to convection in the melt caused by the gravity, it is very difficult to grow a compositionally homogeneous In_xGa_1-xAs single crystal on ground using the conventional growth techniques. Considering the shortcomings of the conventional growth methods, we have developed a novel growth technique, named as the traveling liquidus-zone method, which can be used to grow compositionally homogeneous In_xGa_1-xAs single crystals in space, under the micro-gravity conditions. This new technique, which has some specific requirements about the starting material and the growth temperature profile, has been used on ground to carry out some preliminary growths. Since a precise evaluation of compositional profile is inevitable, the starting materials as well as the preliminarily grown crystals have been non-destructively characterized.