METHOD OF FILLING TRENCHES IN A SUBSTRATE

摘要

A laterally insulated buried zone of increased conductivity is fabricated in a semiconductor substrate. First, a reference layer is formed on a substrate with a buried zone of increased conductivity. Then the reference layer is patterned. A trench is produced in the substrate, and the insulation material used for filling the trench is applied to the structure thus produced. A planar surface is thereby formed in that the growth rate in the trench is faster than the growth rate on the reference layer adjacent the trench. Here, the reference layer is chosen such that the growth rate of the insulation material on the reference layer is at least a factor of two less than the growth rate of the insulation material on the surface of the trench which is to covered. This trench surface to be covered will usually be composed of substrate material. However, intermediate layers may also be provided.