Dimensional characterisation of poly buffer LOCOS in comparison with suppressed LOCOS

The main disadvantage when using a LOCOS isolation technique is the formation of the so called bird´s beak and its geometric dependence. In this paper we demonstrate that for Poly Buffer LOCOS (PBLOCOS), in comparison with Suppressed LOCOS (SLOCOS), the bird´s beak is not only smaller, but is also less dependent on geometry. The comparison between PBLOCOS and SLOCOS will be focussed on four geometric configurations.