TRENCH-BASED DEVICE WITH IMPROVED TRENCH PROTECTION

摘要

A semiconductor device includes a semiconductor substrate having a first type of conductivity. A first layer is formed on the substrate having the first type of conductivity and is more lightly doped than the substrate. At least one trench is formed in the first layer. A dielectric layer lines the bottom surface and the sidewalls of the trench. A conducting material fills the trench. A lightly doped region is formed in the first layer having the second conductivity type. The lightly doped region is disposed below the bottom surface of the trench. A metal layer is disposed over the first layer and the conducting material. A first electrode is formed over the metal layer and a second electrode is formed on a backside of the substrate.