Semiconductor device having buried gate structure and method for fabricating the same
AssigneeSK hynix Inc.
InventorSeong-Wan Ryu
Life of this patent
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Abstract
A semiconductor device includes: a substrate; a first source/drain region and a second source/drain region spaced apart from each other by a trench in the substrate; and a gate structure in the trench, wherein the gate structure includes: a gate dielectric layer formed on a bottom and sidewalls of the trench; a first gate electrode positioned in a bottom portion of the trench over the gate dielectric layer; a second gate electrode positioned over the first gate electrode; and a dipole inducing layer formed between the first gate electrode and the second gate electrode and between sidewalls of the second gate electrode and the gate dielectric layer.
Claims14
A method for fabricating a semiconductor device, comprising:
- forming a trench in a substrate;
- forming a gate dielectric layer on a surface of the trench;
- forming a first gate electrode over the gate dielectric layer to fill a bottom portion of the trench;
- forming a sacrificial layer including a dipole inducing chemical species over the first gate electrode and the gate dielectric layer;
- exposing the sacrificial layer to a thermal treatment to diffuse the dipole inducing chemical species from the sacrificial layer into a portion of the gate dielectric layer and an upper portion of the first gate electrode;
- removing the sacrificial layer;
- and forming a second gate electrode over the first gate electrode in contact with the dipole inducing chemical species.
A method for fabricating a semiconductor device, comprising:
- forming a trench in a substrate;
- forming a gate dielectric layer on a surface of the trench;
- forming a first gate electrode over the gate dielectric layer to fill a bottom portion of the trench;
- forming an anti-oxidation barrier over the first gate electrode;
- forming a sacrificial layer including a dipole inducing chemical species over the anti-oxidation barrier layer and the gate dielectric layer;
- exposing the sacrificial layer to a thermal treatment to diffuse the dipole inducing chemical species from the sacrificial layer into a portion of the gate dielectric layer and the anti-oxidation barrier layer;
- removing the sacrificial layer;
- and forming a second gate electrode over the anti-oxidation barrier layer.
Dependencies are inferred from the claim text.