Semiconductor device and method for fabricating the same
A method for fabricating semiconductor device includes: forming a bottom electrode of a high aspect ratio; forming an interface layer by sequentially performing a first plasma process and a second plasma process onto a surface of the bottom electrode; forming a dielectric layer over the interface layer; and forming a top electrode over the dielectric layer.
1. A method for fabricating a semiconductor device, comprising:
forming a bottom electrode having a high aspect ratio;
forming an interface layer by sequentially performing a first plasma process and a second plasma process onto a surface of the bottom electrode;
forming a dielectric layer over the interface layer; and
forming a top electrode over the dielectric layer,
wherein the first plasma process is performed in an ion plasma-dominant atmosphere at a low pressure,
wherein the second plasma process is performed in a radical plasma-dominant atmosphere at a high pressure.
2. The method of claim 1 , wherein the second plasma process is performed at a higher pressure than at a pressure which the first plasma process is performed.
3. The method of claim 1 , wherein the second plasma process is performed at a pressure that is higher by approximately 1 Torr, and the first plasma process is performed at a pressure that is lower than approximately 100 mTorr.
4. The method of claim 1 , wherein the forming of the interface layer comprises;
performing the first plasma process in a nitrogen ion plasma-dominant atmosphere at a low pressure, and
performing the second plasma process in an oxygen radical plasma-dominant atmosphere at a high pressure.
5. The method of claim 1 , wherein the first plasma process includes a low-pressure plasma nitridation, and
the second plasma process includes a high-pressure plasma oxidation.
6. The method of claim 1 , wherein the bottom electrode includes a cylindrical shape having an aspect ratio of at least approximately 1:10 or higher.
7. The method of claim 1 , wherein the bottom electrode includes a pillar shape having an aspect ratio of at least approximately 1:10 or higher.
8. The method of claim 1 , wherein the bottom electrode includes a lower bottom electrode and an upper bottom electrode, and
the first plasma process locally nitridizes a surface of the upper bottom electrode, and
the second plasma process oxidizes the lower bottom electrode and the nitridized surface of the upper bottom electrode.
9. The method of claim 1 , wherein the bottom electrode includes a metal nitride.
10. The method of claim 1 , wherein the bottom electrode includes a titanium nitride or a tantalum nitride.
11. The method of claim 1 , wherein the interface layer includes a metal oxide.
12. The method of claim 1 , wherein the interface layer includes a titanium oxide or a tantalum oxide.
13. The method of claim 1 , wherein the dielectric layer includes ZAZ (ZrO 2 /Al 2 O 3 /ZrO 2 ) or HAH (HfO 2 /Al 2 O 3 /HfO 2 ).
14. A method for fabricating a semiconductor device, comprising:
forming a mold layer over a lower structure;
forming an opening by etching the mold layer;
forming a bottom electrode including a metal nitride inside the opening;
exposing the bottom electrode by removing the mold layer;
forming an interface layer over the bottom electrode by sequentially exposing the bottom electrode to a low-pressure plasma nitridation process and a high-pressure plasma oxidation process;
forming a dielectric layer over the interface layer; and
forming a top electrode over the dielectric layer.
15. The method of claim 14 , wherein the low-pressure plasma nitridation process is performed in a nitrogen ion plasma-dominant atmosphere at a low pressure, and
the high-pressure plasma oxidation process is performed in an oxygen radical plasma-dominant atmosphere at a high pressure.
16. The method of claim 14 , wherein the high-pressure plasma oxidation process is performed at a pressure that is higher by approximately 1 Torr, and the low-pressure plasma nitridation process is performed at a pressure that is lower than approximately 100 mTorr.
17. The method of claim 14 , wherein the bottom electrode includes a cylindrical shape or a pillar shape having an aspect ratio of at least approximately 1:10 or higher.
18. The method of claim 14 , wherein the bottom electrode includes a titanium nitride or a tantalum nitride.
19. The method of claim 14 , wherein the interface layer includes a titanium oxide or a tantalum oxide.