Semiconductor device manufacture

DETAILED DESCRIPTION We claim as our invention: 1.
An improved method for migrating a melt of metal-rich semiconductor material through a solid body of the semiconductor material including the process steps of: a.
selecting a body of single crystal semiconductor material having two major opposed surfaces comprising the top and bottom surfaces thereof, a predetermined type conductivity, a predetermined level of resistivity, a preferred diamond cubic crystal structure, a preferred planar crystal orientation for at least one of the major surfaces, a vertical axis substantially perpendicular to the opposed major surfaces, and a first preferred crystal axis substantially parallel with the vertical axis and substantially perpendicular to the opposed major surfaces; b.
vapor depositing a layer of metal on the major surface having a preferred planar crystal orientation, the layer having a preferred width and a preferred thickness and so oriented as to form at least one metal wire having a longitudinal axis substantially aligned parallel with a second preferred crystal axis of the crystal structure of the material of the body; c.
heating the body and the layer of metal to an elevated temperature for a predetermined period of time sufficient to alloy the metal of the layer to at least that portion of the semiconductor material of the major surface of the body in contact therewith; d.
heating the body and the alloyed metal wire to a predetermined elevated temperature sufficient to form a melt of metal-rich semiconductor material on the surface of the body; e.
establishing a temperature gradient substantially parallel to the vertical axis of the body and the first axis of the crystal structure; and f.
migrating the melt of metal-rich semiconductor material through the solid body, substantially aligned with the first axis of the crystal structure, to a predetermined depth beneath that major surface to form a planar region of recrystallized material of the body having solid solubility of the metal of the layer therein