Corner-parasitics-free low-cost trench isolation

In this work, we present results on a novel low-cost, corner-parasitics-free trench isolation process. Regarding process complexity, this approach is almost as simple as LOGOS isolation, since the isolation oxide is deposited selectively within the trench. Due to the self-planarizing nature of the fill oxide, the global planarization sequence is largely simplified. With respect to scalability, this approach offers all the advantages of trench isolation with its abrupt transition of active area to isolation. However, in contrast to previous trench isolation schemes, corner-parasitic effects are eliminated by means of the extended trench isolation gate technology (EXTIGATE) device geometry. As a result, excellent narrow width characteristics and subthreshold curves without kink effect are obtained.