Semiconductor device and manufacturing method thereof

摘要

A semiconductor device and its manufacturing method are disclosed. The semiconductor device comprises a gate, and source and drain regions on opposite sides of the gate, wherein a portion of a gate dielectric layer located above the channel region is thinner than a portion of the gate dielectric layer located at the overlap region of the drain and the gate. The thicker first thickness portion may ensure that the device can endure a higher voltage at the drain to gate region, while the thinner second thickness portion may ensure excellent performance of the device.

主权项

1. A method of manufacturing a semiconductor device, comprising the following steps:
providing a semiconductor substrate, forming a patterned dielectric layer on the substrate, the patterned dielectric layer having an opening therein exposing a portion of an upper surface of the substrate; forming a first gate dielectric layer and a mask layer of dielectric material on the first gate dielectric layer, said first gate dielectric layer and said mask layer conforming with the patterned dielectric layer and the opening on the substrate; etching the mask layer to retain at least a portion of the mask layer on the first gate dielectric layer within the opening so that a residual of the mask layer is located within the opening and is attached to the first gate dielectric layer at a sidewall of the opening; etching the first gate dielectric layer using the residual of the mask layer of dielectric material to expose a portion of the substrate within the opening; and forming a second gate dielectric layer on the exposed substrate portion, wherein the thickness of the second gate dielectric layer is less than that of the first gate dielectric layer.