Semiconductor component and method for fabricating the same
A semiconductor component, which includes a substrate, an interfacial layer disposed on the substrate, a first metal gate structure and a second metal gate structure disposed on the substrate. The first metal gate structure includes a first high-k dielectric layer disposed on the interfacial layer, and a first metal gate layer disposed on the first high-k dielectric layer. The second metal gate structure includes a second high-k dielectric layer disposed on the interfacial layer, a third high-k dielectric layer disposed on the second high-k dielectric layer, and a second metal gate layer disposed on the third high-k dielectric layer.
1. A semiconductor component, comprising:
a substrate;
a first metal gate structure disposed on the substrate, comprising:
a first high-k dielectric layer disposed on the substrate; and
a first metal gate layer disposed on the first high-k dielectric layer; and
a second metal gate structure disposed on the substrate, comprising:
a second high-k dielectric layer disposed on the substrate;
a third high-k dielectric layer disposed on and in contact with the second high-k dielectric layer, wherein the second high-k dielectric layer is between the third high-k dielectric layer and the substrate, and a dielectric constant of the first high-k dielectric layer is different from a dielectric constant of the third high-k dielectric layer; and
a second metal gate layer disposed on the third high-k dielectric layer.
2. The semiconductor component of claim 1 , wherein a dielectric constant of the second high-k dielectric layer is greater or less than that of the third high-k dielectric layer.
3. The semiconductor component of claim 1 , wherein the first high-k dielectric layer and the second high-k dielectric layer are made of same material.
4. The semiconductor component of claim 1 , further comprising a first work function metal layer disposed on the first high-k dielectric layer.
5. The semiconductor component of claim 4 , further comprising a barrier layer disposed between the first high-k dielectric layer and the first work function metal layer.
6. The semiconductor component of claim 1 , further comprising a second work function metal layer disposed on the third high-k dielectric layer.
7. The semiconductor component of claim 6 , further comprising a barrier layer disposed between the third high-k dielectric layer and the second work function metal layer.
8. The semiconductor component of claim 1 , further comprising a pair of spacers disposed in contact with side surfaces of the first metal gate structure.
9. The semiconductor component of claim 1 , further comprising a pair of spacers disposed in contact with side surfaces of the second metal gate structure.
10. A semiconductor component, comprising:
a first device comprising:
a first source;
a first drain; and
a first metal gate structure disposed between the first source and the first drain, the first metal gate structure comprising:
an interfacial layer;
a first high-k dielectric layer in contact with the interfacial layer;
a first barrier layer in contact with the first high-k dielectric layer; and
a first metal gate layer disposed on the first barrier layer; and
a second device comprising:
a second source;
a second drain; and
a second metal gate structure disposed between the second source and the second drain, the second metal gate structure comprising:
a second high-k dielectric layer;
a third high-k dielectric layer disposed on the second high-k dielectric layer, wherein a dielectric constant of the first high-k dielectric layer is different from a dielectric constant of the third high-k dielectric layer;
a second barrier layer in contact with the third high-k dielectric layer; and
a second metal gate layer disposed on the second barrier layer.
11. The semiconductor component of claim 10 , wherein a threshold voltage of the first device is different from that of the second device.
12. The semiconductor component of claim 10 , wherein the first device and the second device are FinFET devices.
13. The semiconductor component of claim 10 , wherein a material of the first high-k dielectric layer is the same as that of the second high-k dielectric layer.
14. The semiconductor component of claim 10 , wherein a material of the first high-k dielectric layer is different from that of the third high-k dielectric layer.
15. A method for fabricating a semiconductor component, comprising:
forming a first high-k dielectric layer on a substrate;
forming a second high-k dielectric layer directly on a first part of the first high-k dielectric layer such that a second part of the first high-k dielectric layer is entirely uncovered by the second high-k dielectric layer, wherein the first part of the first high-k dielectric layer is between the second high-k dielectric layer and the substrate; and
forming a metal gate layer on the second high-k dielectric layer and on the second part of the first high-k dielectric layer.
16. The method of claim 15 , wherein a dielectric constant of the first high-k dielectric layer is greater than that of the second high-k dielectric layer.
17. The method of claim 15 , wherein a dielectric constant of the first high-k dielectric layer is less than that of the second high-k dielectric layer.
18. The method of claim 15 , wherein the first high-k dielectric layer and the second high-k dielectric layer are made of different materials.
19. The method of claim 15 , further comprising forming a first work function metal layer on the second part of the first high-k dielectric layer before forming the metal gate layer.
20. The method of claim 15 , further comprising forming a second work function metal layer on the second high-k dielectric layer before forming the metal gate layer.