摘要 |
<p>To completely isolate an island of silicon, a trench is cut into an epitaxial layer to provide access to a differently doped buried layer. While suspending the portion of the epitaxial layer surrounded by the trench by means of an oxide bridge, the underlying region of the buried layer is etched away to form a cavity under the active area. This cavity, as well as the surrounding trench, is then filled with a suitable insulating material to isolate the active island from the substrate.</p> |