Semiconductor structure with isolation region including combination of deep and shallow trench isolation structures and method

Abstract

Disclosed is a semiconductor structure and method of forming the semiconductor structure. Specifically, the semiconductor structure can include a first semiconductor fin extending from a semiconductor substrate. The semiconductor structure can further include an isolation region on the semiconductor substrate adjacent to a lower portion of the first semiconductor fin. The first semiconductor fin can, for example, be incorporated into a single-fin fin-type semiconductor device, such as a single-fin fin-type field effect transistor (FINFET). The isolation region can include at least one shallow trench isolation (STI) structure positioned laterally between and immediately adjacent to sections of a deep trench isolation (DTI) structure. With this alternating DTI-STI-DTI configuration, overall shrinkage of isolation material of the isolation region during anneals is reduced and, thus, so are stress-induced crystalline defects in the first semiconductor fin. Also disclosed are methods for forming such a semiconductor structure.