Capacitor with high work function interface layer
A method for fabricating a capacitor includes: forming a bottom electrode; forming a dielectric layer on the bottom electrode; forming a metal oxide layer including a metal having a high electronegativity on the dielectric layer; forming a sacrificial layer on the metal oxide layer to reduce the metal oxide layer to a metal layer; and forming a top electrode on the sacrificial layer to convert the reduced metal layer into a high work function interface layer.
1. A capacitor, comprising:
a bottom electrode;
a dielectric layer formed on the bottom electrode;
a high work function interface layer formed on the dielectric layer; and
a top electrode formed on the high work function interface layer,
wherein the high work function interface layer includes a silicide having a high electronegativity, and
wherein the top electrode is formed of a silicon germanium layer.
2. The capacitor of claim 1 , wherein the high work function interface layer includes a metal silicide or a metal-rich metal silicide.
3. The capacitor of claim 1 , wherein the high work function interface layer includes a nickel silicide or a nickel-rich nickel silicide.
4. The capacitor of claim 1 , wherein the high work function interface layer includes a cobalt silicide, a cobalt-rich cobalt silicide, a tungsten silicide, or a tungsten-rich tungsten silicide.
5. The capacitor of claim 1 , wherein the top electrode includes a boron-doped silicon germanium layer.
6. The capacitor of claim 1 , wherein the dielectric layer includes a zirconium oxide, an aluminum oxide, or a combination thereof.
7. The capacitor of claim 1 , wherein the bottom electrode has a cylindrical shape or a pillar shape.
8. The capacitor of claim 1 , wherein the bottom electrode includes a titanium nitride.
9. The capacitor of claim 1 , wherein the dielectric layer includes ZAZA (ZrO 2 /Al 2 O 3 /ZrO 2 /Al 2 O 3 ) stack.
10. The capacitor of claim 1 , wherein the dielectric layer includes ZAZ (ZrO 2 /Al 2 O 3 /ZrO 2 ) stack, HAH (HfO 2 /Al 2 O 3 /HfO 2 ) stack, TiO 2 /ZrO 2 /Al 2 O 3 /ZrO 2 stack, TiO 2 /HfO 2 /Al 2 O 3 /HfO 2 stack, Ta 2 O 5 /ZrO 2 /Al 2 O 3 /ZrO 2 stack or Ta 2 O 5 /HfO 2 /Al 2 O 3 /HfO 2 stack.
11. The capacitor of claim 1 , wherein the high work function interface layer has a work function of 4.9 eV or higher.
12. A capacitor, comprising:
a bottom electrode;
a dielectric layer formed on the bottom electrode;
a high work function interface layer formed on the dielectric layer; and
a top electrode formed on the high work function interface layer,
wherein the high work function interface layer includes a metal silicide having a high electronegativity, and
wherein the top electrode is formed of a non-metal material.
13. The capacitor of claim 12 , wherein the top electrode includes a silicon germanium layer.
14. The capacitor of claim 12 , wherein the top electrode includes a boron-doped silicon germanium layer.
15. The capacitor of claim 12 , wherein the high work function interface layer includes a nickel silicide or a nickel-rich nickel silicide.
16. The capacitor of claim 12 , wherein the high work function interface layer includes a cobalt silicide, a cobalt-rich cobalt silicide, a tungsten silicide, or a tungsten-rich tungsten silicide.