Trench gate high voltage transistor for embedded memory

Abstract

Various embodiments of the present application are directed to an IC, and associated forming methods. In some embodiments, the IC comprises a memory region and a logic region integrated into a substrate. A memory cell structure is disposed on the memory region. A plurality of logic devices is disposed on the logic region. A first logic device comprises a first logic gate electrode separated from the substrate by a first logic gate dielectric. The first logic gate dielectric is disposed along surfaces of a logic device trench of the substrate, and the first logic gate electrode is disposed on the first logic gate dielectric within the logic device trench. By arranging the first logic gate electrode within the logic device trench, metal layer loss and the resulted sheet resistance and threshold voltage variations and mismatch issues caused by the subsequent planarization process can be improved.