Gate structures in semiconductor devices
A semiconductor device with different configurations of gate structures and a method of fabricating the same are disclosed. The method includes forming a fin structure on a substrate, forming a gate opening on the fin structure, forming an interfacial oxide layer on the fin structure, forming a first dielectric layer over the interfacial oxide layer, forming a dipole layer between the interfacial oxide layer and the first dielectric layer, forming a second dielectric layer on the first dielectric layer, forming a work function metal (WFM) layer on the second dielectric layer, and forming a gate metal fill layer on the WFM layer. The dipole layer includes ions of first and second metals that are different from each other. The first and second metals have electronegativity values greater than an electronegativity value of a metal or a semiconductor of the first dielectric layer.
1. A semiconductor device, comprising:
a substrate;
a fin structure disposed on the substrate;
a first metal oxide layer disposed on the fin structure;
a second metal oxide layer disposed on the first metal oxide layer, wherein the second metal oxide layer is different from the first metal oxide layer;
a first dielectric layer disposed on the second metal oxide layer, wherein metals of the first and second metal oxide layers have electronegativity values greater than an electronegativity value of a metal or a semiconductor of the first dielectric layer; and
a gate metal fill layer on the first dielectric layer.
2. The semiconductor device of claim 1 , further comprising a second dielectric layer disposed on the first dielectric layer.
3. The semiconductor device of claim 1 , further comprising first and second dipoles disposed between the fin structure and the first metal oxide layer, wherein the first and second dipoles are different from each other.
4. The semiconductor device of claim 1 , further comprising:
a first concentration of first dipoles disposed between the fin structure and the first metal oxide layer; and
a second concentration of second dipoles disposed between the fin structure and the first metal oxide layer, wherein:
the first and second dipoles are different from each other; and
the first and second concentrations are different from each other.
5. The semiconductor device of claim 1 , further comprising first and second dipoles disposed between the fin structure and the first metal oxide layer, wherein the first dipole comprises a metal atom of the first metal oxide layer and the second dipole comprises a metal atom of the second metal oxide layer.
6. The semiconductor device of claim 1 , further comprising first and second dipoles disposed between the fin structure and the first metal oxide layer, wherein the first dipole comprises an ion of a transition metal and the second dipole comprises an ion of a metal from group 13 of the periodic table.
7. The semiconductor device of claim 1 , wherein the first metal oxide layer comprises an oxide of a transition metal.
8. The semiconductor device of claim 1 , wherein the second metal oxide layer comprises an oxide of a metal from group 13 of the periodic table.
9. The semiconductor device of claim 1 , wherein the first and second metal oxide layers have oxygen areal densities greater than an oxygen areal density of the first dielectric layer.
10. The semiconductor device of claim 1 , wherein a thickness of the first metal oxide layer is greater than a thickness of the second metal oxide layer.
11. A semiconductor device, comprising:
a substrate;
a fin structure disposed on the substrate;
a first dielectric layer disposed on the fin structure, wherein the first dielectric layer comprises first and second metal dopants different from each other, and wherein a first peak of a concentration profile of the first metal dopant is closer to a bottom surface of the first dielectric layer than a second peak of a concentration profile of the second metal dopant;
a second dielectric layer disposed on the first dielectric layer; and
a gate metal fill layer on the second dielectric layer.
12. The semiconductor device of claim 11 , wherein the first and second metal dopants have electronegativity values greater than an electronegativity value of a metal or a semiconductor of the first dielectric layer.
13. The semiconductor device of claim 11 , wherein the first metal dopant comprises a transition metal, and wherein the second metal dopant comprises a metal from group 13 of the periodic table.
14. The semiconductor device of claim 11 , wherein the first metal dopant comprises zinc, and wherein the second metal dopant comprises gallium.
15. The semiconductor device of claim 11 , further comprising first and second dipoles disposed between the fin structure and the first dielectric layer, wherein the first and second dipoles are different from each other.
16. The semiconductor device of claim 11 , further comprising first and second dipoles disposed between the fin structure and the first dielectric layer, wherein the first dipole comprises an ion of a transition metal and the second dipole comprises an ion of a metal from group 13 of the periodic table.
17. A method, comprising:
forming a fin structure on a substrate;
depositing a first dielectric layer on the fin structure;
forming a dipole layer between the first dielectric layer and the fin structure, wherein the dipole layer comprises ions of first and second metals that are different from each other;
depositing a second dielectric layer on the first dielectric layer; and
depositing a gate metal fill layer on the second dielectric layer.
18. The method of claim 17 , wherein forming the dipole layer comprises doping the first dielectric layer with first and second metal dopants different from each other.
19. The method of claim 17 , wherein forming the dipole layer comprises depositing, on the first dielectric layer, first and second dopant source layers different from each other.
20. The method of claim 17 , further comprising depositing, on the first dielectric layer, first and second metal oxide layers different from each other.