High voltage trench transistor

摘要

A method of forming a device is disclosed. A substrate defined with a device region is provided. A gate having a gate electrode, first and second gate dielectric layers is formed in a trench. The trench has an upper trench portion and a lower trench portion. A field plate is formed in the trench. First and second diffusion regions are formed. The gate is displaced from the second diffusion region.

主权项

1. A method of forming a device comprising:
providing a substrate defined with a device region; forming a gate in the substrate, wherein forming the gate comprises
forming a first trench, wherein the first trench defines an upper trench portion,forming a first gate dielectric layer on the upper trench portion, wherein the first gate dielectric layer lines the upper trench portion without filling the trench, andforming a gate electrode layer on the substrate, wherein the gate electrode layer fills the upper trench portion; forming a second trench through the gate, wherein the second trench extends below the upper trench portion and forms a lower trench portion; forming a second gate dielectric layer in the second trench, wherein the second gate dielectric layer lines the second trench without filling the trench; forming a field plate in the second trench, the field plate fills the trench, wherein the field plate is disposed adjacent to the gate; and forming first and second diffusion regions, wherein the gate is displaced from the second diffusion region.