Abstract: An apparatus is provided for fabricating a semiconductor device by thermal gradient zone melting, whereby metal-rich droplets such as aluminum migrate through a semiconductor wafer such as silicon to create conductive paths. One surface of the wafer is placed directly on a heating surface to establish a high and uniform thermal gradient through the wafer. Heat in the wafer is removed from the other wafer surface. The apparatus for fabricating semiconductor devices utilizing temperature gradient zone melting comprises a base, heating means and heat sink means. Heating means comprises a platform having a generally planar heating surface adapted to receive the entire area of the one surface of at least one wafer. The heat sink means is spaced away from the other wafer surface to form a space therebetween, the space being adapted to receive a high heat conductive gas. The heat sink means and the gas cooperatively remove the heat in the wafer to enhance the establishment of the thermal gradient.