Semiconductor device and method for fabricating the same
A semiconductor layer stack includes a first conductive layer, a dielectric layer including a high-k material, which is formed on the first conductive layer, a second conductive layer formed on the dielectric layer, and an interface control layer formed between the dielectric layer and the second conductive layer and including a leakage blocking material, a dopant material, a high bandgap material and a high work function material.
1. A memory cell comprising:
a semiconductor substrate including a first impurity region, a second impurity region, and a word line trench formed between the first impurity region and the second impurity region;
a buried word line formed in the word line trench;
a bit line coupled to the first impurity region; and
a capacitor coupled to the second impurity region,
wherein the capacitor includes:
a bottom electrode;
a dielectric layer including a high-k material, which is formed on the bottom electrode;
a top electrode formed on the dielectric layer; and
an interface control layer formed between the dielectric layer and the top electrode, and including a leakage blocking material, a dopant material, a high bandgap material and a high work function material that are sequentially stacked on top of one another.
2. The memory cell of claim 1 , wherein the high work function material includes a conductive material having a higher work function than the top electrode.
3. The memory cell of claim 1 , wherein the high bandgap material includes a material having a higher bandgap than the dopant material.
4. The memory cell of claim 1 , wherein each of the leakage blocking material and the high bandgap material is thinner than the dopant material.
5. The memory cell of claim 1 , wherein the dopant material includes a material having a higher dielectric constant than the high-k material, the leakage blocking material and the high bandgap material.
6. The memory cell of claim 1 , wherein each of the leakage blocking material and the high bandgap material includes an aluminum oxide or a silicon oxide.
7. The memory cell of claim 1 , wherein the dopant material includes a titanium oxide.
8. The memory cell of claim 1 , wherein the high work function material includes a titanium aluminum nitride or a titanium silicon nitride.
9. The memory cell of claim 1 , wherein a dielectric layer, leakage blocking material, dopant material and high bandgap material stack in which the dielectric layer, the leakage blocking material, the dopant material and the high bandgap material are sequentially stacked includes a ZAZATA (ZrO2/Al2O3/ZrO2/Al2O3/TiO2/Al2O3) stack, a ZAZATS (ZrO2/Al2O3/ZrO2/Al2O3/TiO2/SiO2) stack, an HAHATA (HfO2/Al2O3/HfO2/A2O3/TiO2/A2O3) stack, an HAHATS (HfO2/Al2O3/HfO2/Al2O3/TiO2/SiO2) stack or an HSHSTS (HfO2/SiO2/HfO2/SiO2/TiO2/SiO2) stack.