Aligned gate-all-around structure

摘要

Among other things, a semiconductor device comprising an aligned gate and a method for forming the semiconductor device are provided. The semiconductor device comprises a gate formed according to a multi-gate structure, such as a gate-all-around structure. A first gate portion of the gate is formed above a first channel of the semiconductor device. A second gate portion of the gate is formed below the first channel, and is aligned with the first gate portion. In an example of forming the gate, a cavity is etched within a semiconductor layer formed above a substrate. A dielectric layer is formed around at least some of the cavity to define a region of the cavity within which the second gate portion is to be formed in a self-aligned manner with the first gate portion. In this way, the semiconductor device comprises a first gate portion aligned with a second gate portion.

主权项

1. A semiconductor device, comprising:
a semiconductor layer disposed on a substrate, wherein at least one of:
at least some of a first channel of the semiconductor device;at least some of a source region of the semiconductor device; orat least some of a drain region of the semiconductor device, are disposed on the semiconductor layer; a dielectric layer disposed on the substrate and wherein a first portion of the dielectric layer underlies at least some of the source region and a second portion of the dielectric layer underlies at least some of the drain region, wherein the dielectric layer includes an oxide of a semiconductor material of the semiconductor layer; and a gate having:
a first gate portion of the gate including a gate dielectric and a gate electrode disposed above the first channel; anda second gate portion including a gate dielectric and a gate electrode of the gate disposed between the substrate and the first channel and aligned with the first gate portion, wherein the second gate portion interposes the first and second portions of the dielectric layer.