Migration of fine lines for bodies of semiconductor materials having a (100) planar orientation of a major surface

An improved method for the migration of a molten zone through a solid body of semiconductor material to form a region comprising the process steps of:

• a. selecting a body of single crystal semiconductor material having two major opposed surfaces being respectively the top and bottom surface thereof;
• a preferred crystallographic structure;
• a planar orientation of (100) for which at least the top surface thereof, a first selective type conductivity;
• a selected level of resistivity, and a vertical axis substantially aligned with the <
• 100 >
• axis of the crystal structure and which is also substantially perpendicular to the top surface;
• b. depositing at least one mass of metal on the top surface of the body;
• c. heating the body and the deposited metal to a preselected elevated temperature sufficient to form a melt of a metal-rich semiconductor material therein;
• d. establishing a temperature gradient substantially parallel to the vertical axis of the body and the <
• 100 >
• axis of the crystal structure, the surface on which the melt is formed being at the lower temperature, and
• e. migrating each melt of metal-rich semiconductor material as a molten zone through the solid body of semiconductor material for a sufficient period of time to reach a predetermined depth in the body from the top surface and to form a region of recrystallized semiconductor material of the body having solid solubility of the deposited metal therein, a substantially uniform cross-sectional area and a substantially uniform level of resistivity throughout the entire region.