Dielectric film, method of manufacturing the same, and semiconductor capacitor having the dielectric film

1. A ferroelectric substance, comprising:

a ferroelectric layer; and

a paraelectric layer disposed on a surface of the ferroelectric layer,

wherein the ferroelectric layer and the paraelectric layer are formed to a thickness at which a remnant polarization and a coercive field of the ferroelectric substance is larger than a remnant polarization and a coercive field of the ferroelectric layer, and a thickness of the paraelectric layer is smaller than a thickness of the ferroelectric layer.

2. The ferroelectric substance of claim 1 , wherein the ferroelectric layer comprises at least one material selected from the group consisting of Pb(Zr,Ti)O 3 (PZT), SrBi 2 Ta 2 O 9 (SBT), (Bi x ,La 1−x ) 4 Ti 3 O 12 (BLT), SrBi 2 (Ta,Nb)O 9 (SBTN), and Ba x Sr (1−x) TiO 3 (BST).

3. The ferroelectric substance of claim 1 , wherein the paraelectric layer comprises at least one material selected from the group consisting of aluminum oxide (Al 2 O 3 ), hafnium oxide (HfO 2 ), titanium oxide (TiO 2 ), zirconium oxide (ZrO 2 ), tantalum oxide (Ta 2 O 5 ), and niobium oxide (Nb 2 O 5 ).

4. A method of manufacturing a ferroelectric substance, comprising:

forming a ferroelectric layer; and

forming a paraelectric layer on a surface of the ferroelectric layer,

wherein a thickness of the ferroelectric layer and a thickness of the paraelectric layer are set so that a remnant polarization and a coercive field of the ferroelectric substance is larger than a remnant polarization and a coercive field of the ferroelectric layer and the paraelectric layer is formed so that a thickness of the paraelectric layer is smaller than a thickness of the ferroelectric layer.

5. The method of claim 4 , wherein the ferroelectric layer is formed by a sol-gel process or a sputtering process.

6. The method of claim 4 , wherein the paraelectric layer is formed by an ALD process.

7. The method of claim 4 , further comprising, prior to the forming of the pyroelectric layer, annealing the ferroelectric layer at 600-700° C. for 10-50 minutes so as to give crystallizing to the ferroelectric layer.

8. A semiconductor capacitor, comprising:

a lower electrode;

a ferroelectric substance film disposed on the lower electrode and comprising a ferroelectric layer and a paraelectric layer disposed on a surface of the ferroelectric layer to have a thickness that is smaller than a thickness of the ferroelectric layer; and

an upper electrode disposed on the ferroelectric substance film,

wherein the ferroelectric layer and the paraelectric layer are formed to a thickness at which a remnant polarization and a coercive field of the ferroelectric substance film is larger than a remnant polarization and a coercive field of the ferroelectric layer.

9. The semiconductor capacitor of claim 8 , wherein the ferroelectric layer comprises at least one material selected from the group consisting of Pb(Zr,Ti)O 3 (PZT), SrBi 2 Ta 2 O 9 (SBT), (Bi x ,La 1−x ) 4 Ti 3 O 12 (BLT), SrBi 2 (Ta,Nb)O 9 (SBTN), and Ba x Sr (1−x) TiO 3 (BST).

10. The semiconductor capacitor of claim 9 , wherein the ferroelectric layer has a thickness ranging from approximately 500 Å to approximately 10,000 Å.

11. The semiconductor capacitor of claim 8 , wherein the paraelectric layer comprises at least one material selected from the group consisting of aluminum oxide (Al 2 O 3 ), hafnium oxide (HfO 2 ), titanium oxide (TiO 2 ), zirconium oxide (ZrO 2 ), tantalum oxide (Ta 2 O 5 ), and niobium oxide (Nb 2 O 5 ).

12. The semiconductor capacitor of claim 11 , wherein the paraelectric layer has a thickness ranging from approximately 5 Å to approximately 200 Å.

13. The semiconductor capacitor of claim 8 , wherein the ferroelectric layer is formed by a sol-gel process or a sputtering process, and the paraelectric layer is formed by an atomic layer deposition (ALD) process.