Semiconductor device with a step gate dielectric structure

摘要

A semiconductor device and a method for forming the same are disclosed. The semiconductor device includes an isolation structure formed in a substrate to define an active region of the substrate. The active region has a field plate region therein. A step gate dielectric structure is formed on the substrate in the field plate region. The step gate dielectric structure includes a first layer of a first dielectric material and a second layer of the dielectric material, laminated vertically to each other. The first and second layers of the first dielectric material are separated from each other by a second dielectric material layer. An etch rate of the second dielectric material layer to an etchant is different from that of the second layer of the first dielectric material. A method for forming a semiconductor device is also disclosed.

主权项

1. A semiconductor device, comprising:
an isolation structure formed in a substrate to define an active region of the substrate, wherein the active region has a field plate region therein; a step gate dielectric structure formed on the substrate in the field plate region, wherein the step gate dielectric structure comprises:
a first layer of a first dielectric material and a second layer of the first dielectric material, laminated vertically to each other; anda second dielectric material layer, wherein the first and second layers of the first dielectric material are separated from each other by the second dielectric material layer, and an etch rate of the second dielectric material layer to an etchant is different from that of the second layer of the first dielectric material to the etchant; and a gate dielectric layer on the substrate in the active region, extended to cover a portion of the active region adjacent to the step gate dielectric structure to a top surface of the step gate dielectric structure, wherein the top surface of the step gate dielectric structure and the gate dielectric layer have an overlapping region therebetween and a non-overlapping region in which the top surface of the step gate dielectric structure and the gate dielectric layer do not contact, wherein the top surface of the step gate dielectric structure is on an opposite side of the step gate dielectric structure from the substrate.