Process for device isolation

摘要

A novel process for isolating devices on a semiconductor substrate is disclosed. An isolation layer is first formed over the semiconductor substrate and patterned into at least two isolation mesas on the substrate. Next, a blanket semiconductor layer is formed over the substrate with a thickness sufficient to cover the isolation mesas. The semiconductor layer is subjected to planarization until the isolation mesas are exposed, thus resulting in a semiconductor region between the two isolation mesas to serve as an active region for semiconductor devices.