Semiconductor device with adjustment layers and method for fabricating the same
The present application discloses a semiconductor device with adjustment layers and a method for fabricating the semiconductor device with the adjustment layers. The semiconductor device includes a substrate, an interconnection structure positioned on the substrate, a contact positioned penetrating the interconnection structure, two adjustment layers positioned on sidewalls of the contact, a contact barrier layer positioned between the interconnection structure and the contact and between the substrate and the contact, wherein the two adjustment layers are positioned between the contact and the contact barrier layer. A bottom segment of the contact barrier layer is positioned between the substrate and the contact, and bottom most points of the two adjustment layers contact the bottom portion of the contact barrier layer.
1. A semiconductor device, comprising:
a substrate having an impurity region formed therein;
an interconnection structure positioned on the substrate, wherein the interconnection structure has a contact opening extended therethrough from top to bottom and having a width gradually reduced from top to bottom, wherein the impurity region is exposed through the contact opening;
a contact positioned penetrating the interconnection structure through the contact opening, wherein a width of the contact is gradually reduced toward the substrate;
an adjustment layer having two side sections positioned on sidewalls of the contact; and
a contact barrier layer positioned between the interconnection structure and the contact and between the substrate and the contact, wherein the two side sections of the adjustment layer are positioned between the contact and the contact barrier layer;
wherein a bottom segment of the contact barrier layer is positioned between the substrate and the contact, and bottom most points of the two side sections of the adjustment layer are in contact with the bottom segment at a position above a bottom surface of the contact barrier layer;
wherein the contact barrier layer has two side segments extended from the bottom segment, wherein a distance between the side segments of the contact barrier layer is gradually reduced toward the bottom segment thereof, wherein the side sections of the adjustment layer are extended along the side segments of the contact barrier layer;
wherein the contact barrier is disposed in the contact opening at a position that the side segments of the contact barrier are formed on sidewalls of the contact opening respectively while the bottom segment of the contact barrier is in direct contact with the impurity region of the substrate, such that the bottom segment of the contact barrier is sandwiched between the contact and the impurity region of the substrate.
2. The semiconductor device of claim 1 , wherein a thickness of each of the side sections of the adjustment layer gradually decreases toward the bottom most point thereof.
3. The semiconductor device of claim 1 , wherein a thickness of each of the side sections of the adjustment layer at a top end thereof is between about 1 angstrom and about 30 angstroms, wherein the side sections of the adjustment layer are extended along the side segments of the contact barrier layer to contact with the bottom segment thereof.
4. The semiconductor device of claim 1 , wherein an aspect ratio of the contact is between about 1:3 and about 1:15.
5. The semiconductor device of claim 1 , wherein a thickness of the contact barrier layer is between about 10 angstroms and about 15 angstroms.
6. The semiconductor device of claim 5 , wherein the interconnection structure comprises a first liner layer positioned on the substrate to cover the impurity region, a first insulating layer positioned on the first liner layer, a second liner layer positioned on the first insulating layer, and a second insulating layer positioned on the second liner layer, and the contact positioned penetrating the second insulating layer, the second liner layer, the first insulating layer, and the first liner layer, wherein top ends of the two side sections of the adjustment layer are coplanar with a top surface of the second insulating layer and are coplanar with a top surface of the contact barrier layer, wherein the contact opening is extended through the second insulating layer, the second liner layer, the first insulating layer, and the first liner layer to expose the impurity region.
7. The semiconductor device of claim 6 , wherein the interconnection structure comprises a third insulating layer positioned on the second insulating layer, wherein the third insulating layer has a capacitor trench formed therethrough to expose at least a portion of a top surface of the contact structure, wherein the bottom most points of the two side sections of the adjustment layer are at a vertical level lower than a vertical level of the second liner layer, wherein a top surface of the contact is coplanar with the top surface of the second insulating layer, wherein the top ends of the two side sections of the adjustment layer, the top surface of the contact barrier layer, and the top surface of the contact are covered by the third insulating layer, wherein the bottom surface of the contact is located within the first liner layer.
8. The semiconductor device of claim 6 , wherein a dielectric constant of the first insulating layer is equal to or less than 3.0.
9. The semiconductor device of claim 6 , wherein the first insulating layer is porous.
10. The semiconductor device of claim 9 , wherein a porosity of the first insulating layer is between about 15% and about 50%.
11. The semiconductor device of claim 6 , wherein the two adjustment layer is formed of metal oxide, metal nitride, or metal carbide.
12. The semiconductor device of claim 6 , wherein an angle between a top surface of the contact and one of the sidewalls of the contact is between about 83 degrees and about 90 degrees.