TRENCH GATE HIGH VOLTAGE TRANSISTOR FOR EMBEDDED MEMORY

Various embodiments of the present application are directed to an IC, and associated forming methods. In some embodiments, the IC is manufactured by forming a plurality of deep trenches including an isolation trench and a logic device trench from a top surface of a substrate, filling an isolation material in the isolation trench and the logic device trench, removing the isolation material from the logic device trench, forming a first logic device by filling a first logic gate dielectric and a first logic gate electrode in the logic device trench, and forming first and second source/drain regions in the substrate on opposite sides of the logic device trench. The isolation material is kept in the isolation trench to form an isolation structure.