Method and structure for isolating semiconductor devices after transistor formation

摘要

A method for isolating semiconductor devices comprising providing a semiconductor substrate. The semiconductor substrate includes a first pair of source/drain regions on either side of a first channel region and a second pair of source/drain regions on either side of a second channel region. One of the first pair of source/drain regions is proximal to one of the second pair of source/drain regions. First and second laterally displaced MOS transistors are formed partially within the semiconductor substrate. An isolation trench is formed through the proximal source/drain regions and the trench is filled with a trench dielectric material such that the proximal source/drain regions are electrically isolated whereby the first transistor is electrically isolated from the second transistor.