Abstract: A method of forming an isolation region is provided that in one embodiment substantially reduces divot formation. In one embodiment, the method includes providing a semiconductor substrate, forming a first pad dielectric layer on an upper surface of the semiconductor substrate and forming a trench through the first pad dielectric layer into the semiconductor substrate. In a following process sequence, the first pad dielectric layer is laterally etched to expose an upper surface of the semiconductor substrate that is adjacent the trench, and the trench is filled with a trench dielectric material, wherein the trench dielectric material extends atop the upper surface of the semiconductor substrate adjacent the trench and abuts the pad dielectric layer.

Abstract: A semiconductor body includes a substrate, a buried zone having a first conductivity type that is formed in the substrate, a first zone having the first conductivity type that is above the buried zone, a second zone having a second conductivity type that is different from the first conductivity type and above the first zone, and a third zone having the first conductivity type that is above the second zone. The buried zone includes first and second implantation regions that are formed via first and second implantations that are performed using a mask. The buried zone, the first zone, the second zone and the third zone are parts of a first transistor structure.