Method of manufacturing semiconductor device including ferroelectric layer having columnar-shaped crystals
In a method of manufacturing a negative capacitance structure, a ferroelectric dielectric layer is formed over a first conductive layer disposed over a substrate, and a second conductive layer is formed over the ferroelectric dielectric layer. The ferroelectric dielectric layer includes an amorphous layer and crystals.
1. A method of manufacturing a negative capacitance structure, the method comprising:
forming a first ferroelectric dielectric layer including columnar-shaped crystals over a first conductive layer disposed over a substrate;
forming a second dielectric layer, which is an amorphous layer over the first ferroelectric dielectric layer; and
forming a second conductive layer over the second dielectric layer, wherein:
the amorphous layer and the columnar-shaped crystals are made of a same material including HfO 2 and an oxide of a metal element, where the metal element is one or more selected from the group consisting of La, Y, Gd and Sr, and
the columnar-shape crystals comprise an orthorhombic phase crystal.
2. A method of manufacturing a negative capacitance structure, the method comprising:
forming an epitaxial layer over a semiconductor substrate;
forming, by an epitaxial growth method, a first ferroelectric dielectric layer including columnar-shaped crystals directly on the epitaxial layer;
forming a second dielectric layer, which is an amorphous layer over the first ferroelectric dielectric layer; and
forming a first conductive layer over the second dielectric layer,
wherein the columnar-shaped crystals extend along a film stack direction,
wherein the columnar-shape crystals comprise an orthorhombic phase crystal of hafnium oxide.
3. The method of claim 2 , wherein the columnar-shaped crystals are made of HfO 2 and ZrO 2 .
4. The method of claim 3 , wherein an average diameter of the columnar-shaped crystals is in a range from 0.5 nm to 5 nm.
5. The method of claim 3 , wherein an average length of the columnar-shaped crystals is in a range from 1 nm to 5 nm.
6. The method of claim 1 , the columnar shape crystals extends along a film stack direction.
7. The method of claim 1 , wherein an average diameter of the columnar-shape crystals is in a range from 0.5 nm to 5 nm.
8. The method of claim 1 , wherein an average lengrth of the columnar-shape crystals is in a range from 1 nm to 5 nm.
9. The method of claim 2 , wherein the epitaxial layer is made of SiGe.
10. A method of manufacturing a negative capacitance structure, the method compri sing:
forming, by an epitaxial growth method, a first ferroelectric dielectric layer including columnar-shaped crystals over a semiconductor layer;
forming a second dielectric layer, which is an amorphous layer, over the first ferroelectric dielectric layer; and
forming a second conductive layer on and in direct contact with the second dielectric layer, which is an amorphous layer,
wherein the columnar-shape crystals comprise an orthorhombic phase crystal of hafnium oxide.
11. The method of clam 10 , wherein the first and second dielectric layers are made of HfO 2 and ZrO 2 .
12. The method of claim 10 , wherein an average diameter of the columnar-shape crystals is in a range from 0.5 nm to 5 nm.
13. The method of claim 10 , wherein an average length of the columnar-shape crystals is in a range from 1 nm to 5 nm.
14. The method of claim 1 , wherein the columnar-shape crystals further comprise one of a monolithic phase crystal, a cubic phase crystal or a tetragonal phase crystal.
15. The method of claim 1 , wherein the columnar-shape crystals consist of an orthorhonibic phase crystal.
16. The method of claim 2 , wherein the columnar-shape crystals further comprise one of a monolithic phase crystal, a cubic phase crystal or a tetragonal phase crystal.
17. The method of claim 2 , wherein the columnar-shape crystals consist of an orthorhombic phase crystal.
18. The method of claim 10 , wherein the columnar-shape crystals further comprise one of a monolithic phase crystal, a cubic phase crystal or a tetragonal phase crystal.
19. The method of claim 10 , wherein the columnar-shape crystals consist of an orthorhombic phase crystal.
20. The method of claim 1 , wherein at least one of the columnar-shape crystals is in contact with an adjacent one of the columnar-shape crystals.