Determining the relationship between local lattice strain and slip systems of dislocations around shallow trench isolation by convergent-beam electron diffraction

We clarified the generation of process-induced dislocations around a shallow trench isolation (STI) by using convergent-beam electron diffraction. Comparing the resolved shear strain (RSS) of 12 slip systems, we found that at the trench bottom corner the RSS on slip systems (1 −1 1)[0 1 1] and (1 −1 1)[1 0 −1] was largest in all slip systems. In fact, the dislocations of slip systems (1 −1 1)[0 1 1] and (1 −1 1)[1 0 −1] were observed around the trench bottom corner more often than those of any other slip systems. We also found that the large RSS at the trench bottom corner may be due to the corner shape or the intrinsic stress induced during oxidation. Therefore, to control dislocation around STI, the oxidation-induced stress at the trench bottom corner must be reduced, and the shape of the bottom corner must be controlled.