Method for manufacturing semiconductor device
View Patent ↗A method for manufacturing a semiconductor device includes at least forming a lower electrode comprising titanium nitride on a semiconductor substrate, forming a dielectric film comprising zirconium oxide as a primary constituent on the lower electrode, forming a first protective film comprising a titanium compound on the dielectric film, and forming an upper electrode comprising titanium nitride on the first protective film. The method can include a step of forming a second protective film on the lower electrode before the step of forming the dielectric film on the lower electrode.
1. A method for manufacturing a semiconductor device including a formation of a capacitor, the formation of the capacitor comprising:
forming a lower electrode comprising titanium nitride on a semiconductor substrate;
forming a dielectric film comprising zirconium oxide as a primary constituent on said lower electrode;
forming a first protective film comprising a titanium compound on said dielectric film; and
forming an upper electrode comprising titanium nitride on said first protective film,
wherein said forming a dielectric film is an operation of forming a dielectric film including at least a stacked structure of a first dielectric film comprising a zirconium oxide film, a second dielectric film comprising an amorphous aluminum oxide film on said first dielectric film, and a third dielectric film comprising a zirconium oxide film on said second dielectric film,
wherein said third dielectric film is formed by an atomic layer deposition (ALD) method, and
wherein said first protective film comprises a titanium compound and is formed on said third dielectric film without exceeding the film forming temperature of said third dielectric film over 70° C.
2. The method for manufacturing a semiconductor device according to claim 1 , wherein said first protective film comprises titanium oxide as a primary constituent.
3. The method for manufacturing a semiconductor device according to claim 1 , wherein said first protective film comprises titanium nitride as a primary constituent.
4. The method for manufacturing a semiconductor device according to claim 1 , wherein said first protective film is formed with a film thickness of not less than 0.4 nm and not more than 5.0 nm.
5. The method for manufacturing a semiconductor device according to claim 1 , wherein said dielectric film further comprises an aluminum oxide layer.
6. The method for manufacturing a semiconductor device according to claim 5 , wherein said dielectric film has a composite ratio of 0.8 or more, the composite ratio being indicated Z/(Z+M) where Z is the number of a zirconium atom and M is the number of an aluminum atom.
7. The method for manufacturing a semiconductor device according to claim 1 , wherein said dielectric film is formed in a film thickness of 5.0 nm to 8.0 nm.
8. The method for manufacturing a semiconductor device according to claim 1 , wherein said third dielectric film is formed as a zirconium oxide film with a microcrystalline state by said ALD method, and changes into a polycrystalline state through a secondary growth of crystal grains of zirconium oxide by heat treatment after the formation of said first protective film.
9. A method for manufacturing a semiconductor device including a formation of a capacitor, the formation of the capacitor comprising:
forming a lower electrode comprising titanium nitride on a semiconductor substrate;
forming a second protective film on said lower electrode;
forming a dielectric film comprising zirconium oxide as a primary constituent on said second protective film;
forming a first protective film on said dielectric film; and
forming an upper electrode comprising a titanium nitride on said first protective film,
wherein said forming a dielectric film is an operation of forming a dielectric film including at least a stacked structure of a first dielectric film comprising a zirconium oxide film, a second dielectric film comprising an amorphous aluminum oxide film on said first dielectric film, and a third dielectric film comprising a zirconium oxide film on said second dielectric film,
wherein said third dielectric film is formed by an atomic layer deposition (ALD) method, and
wherein said first protective film comprises a titanium compound and is formed on said third dielectric film without exceeding the film forming temperature of said third dielectric film over 70° C.
10. The method for manufacturing a semiconductor device according to claim 9 , wherein said second protective film is a film comprising titanium oxide as a primary constituent.
11. The method for manufacturing a semiconductor device according to claim 10 , wherein said second protective film is formed in a film thickness of 0.4 nm to 2.0 nm.
12. The method for manufacturing a semiconductor device according to claim 9 , wherein said first protective film comprises titanium oxide as a primary constituent.
13. The method for manufacturing a semiconductor device according to claim 9 , wherein said first protective film comprises titanium nitride as a primary constituent.
14. The method for manufacturing a semiconductor device according to claim 9 , wherein said first protective film formed in a film thickness of not less than 0.4 nm and not more than 5.0 nm.
15. The method for manufacturing a semiconductor device according to claim 9 , wherein said dielectric film further comprises an aluminum oxide layer.
16. The method for manufacturing a semiconductor device according to claim 15 , wherein said dielectric film has a composite ratio of 0.8 or more, the composite ratio being indicated Z/(Z+M) where Z is the number of a zirconium atom and M is the number of an aluminum atom.