SEMICONDUCTORS HAVING DEFECT DENUDED ZONES

摘要

This invention relates to a process for preparing a semiconductor substrate having a defect-free region therein. The method includes providing a semiconductor substrate in which oxygen is concentrated in the substrate region adjacent to the substrate surface. The trench is formed in the substrate surface. After the trench formation, within the area comprises the step of reducing the oxygen concentration. ; oxygen reducing step reduces the oxygen concentration within the region to heat the substrate. A trench forming step forms a trench through the region, the oxygen reduction step is to reduce the oxygen concentration in a portion of the lower region of the trench bottom. Oxygen reducing step is to heat the substrate to reduce the oxygen concentration within the portion of the lower region of the trench bottom. Reducing the oxygen concentration occurs in the first portion of the first area prior to forming the trench, and this first section is positioned in contact with the substrate. In this way, the side walls and the base of the trench is exposed to the oxygen reduction process to form a defect-free region immediately adjacent (contact) on this side wall and the base, and whereby the topography-aligned DZ (i.e., DZ follows the trench shape ) forms.