Semiconductor structure having self-aligned conductive structure and method for forming the semiconductor structure

1 . A method for making a semiconductor structure, comprising:

providing a substrate with a conductive structure thereon;

forming a conductive layer on the substrate;

forming a patterned mask layer on the conductive layer;

patterning the conductive layer by using the patterned mask layer as a mask to form a patterned conductive layer that includes a conductive feature and a recess adjoining the conductive feature, the conductive feature being electrically connected to the conductive structure;

forming a first dielectric layer over the patterned mask layer and filling the recess with the first dielectric layer;

patterning the first dielectric layer to form an opening;

selectively forming a blocking layer in the opening over the conductive feature;

after forming the blocking layer, forming an etch stop layer to cover the first dielectric layer and exposing the blocking layer;

removing the blocking layer after forming the etch stop layer;

forming a second dielectric layer on the etch stop layer;

patterning the second dielectric layer to form a through hole and exposing the conductive feature; and

filling the through hole with an electrically conductive material to form an interconnect which is electrically connected to the conductive feature.

2 . The method as claimed in claim 1 , wherein, in forming the etch stop layer, the etch stop layer is formed to be separated from the patterned conductive layer by the first dielectric layer.

3 . The method as claimed in claim 2 , wherein the etch stop layer is separated from the patterned conductive layer by a distance ranging from 2 nm to 10 nm.

4 . The method as claimed in claim 1 , wherein the etch stop layer has a horizontal cross section that is complementary in shape to that of the blocking layer.

5 . The method as claimed in claim 1 , wherein the blocking layer is made of a self-assembling monolayer material that includes a head group containing phosphorus, sulfur, or a combination thereof.

6 . The method as claimed in claim 5 , wherein the head group of the self-assembling monolayer material includes phosphonic acid, thiol, benzotriazole, or combinations thereof.

7 . A method for making a semiconductor structure, comprising:

providing a substrate with a conductive structure thereon;

forming a metal layer on the substrate;

forming a mask layer on the metal layer;

patterning the mask layer to form a patterned mask layer;

patterning the metal layer by using the patterned mask layer as a mask to form a patterned metal layer that includes a first conductive feature and a recess adjoining the first conductive feature, the first conductive feature being covered by the patterned mask layer and being electrically connected to the conductive structure;

covering the patterned mask layer with a first dielectric layer and filling the recess with the first dielectric layer;

patterning the first dielectric layer to expose the patterned mask layer on the first conductive feature;

selectively covering the patterned mask layer on the first conductive feature with a self-assembling monolayer material to form a blocking layer on the patterned mask layer disposed on the first conductive feature;

forming an etch stop layer to cover the first dielectric layer and exposing the blocking layer;

removing the blocking layer to expose the patterned mask layer on the first conductive feature;

forming a second dielectric layer to cover the etch stop layer and the patterned mask layer on the first conductive feature;

patterning the second dielectric layer to form a through hole from which the patterned mask layer on the first conductive feature is exposed;

removing the patterned mask layer on the first conductive feature to expose the first conductive feature; and

filling the through hole with an electrically conductive material to form an interconnect which is electrically connected to the first conductive feature.

8 . The method as claimed in claim 7 , wherein:

the patterned metal layer further includes a second conductive feature that adjoins the recess, that is separated from the first conductive feature, and that is covered by the patterned mask layer; and

in patterning the first dielectric layer, the patterned mask layer on the second conductive feature is not exposed from the first dielectric layer.

9 . The method as claimed in claim 7 , wherein:

the patterned metal layer further includes a second conductive feature that adjoins the recess, that is separated from the first conductive feature, and that is covered by the patterned mask layer;

in patterning the first dielectric layer, the first dielectric layer aligned with the second conductive feature is removed to expose the patterned mask layer on the second conductive feature;

in the selective covering step, the blocking layer is formed on the patterned mask layer on the second conductive feature;

in removing the blocking layer, the blocking layer aligned with the second conductive feature is removed to expose the patterned mask layer on the second conductive feature; and

in forming the second dielectric layer, the patterned mask layer on the second conductive feature is covered by the second dielectric layer.

10 . The method as claimed in claim 7 , wherein, in forming the etch stop layer, the etch stop layer is formed to be separated from the patterned metal layer by the first dielectric layer.

11 . The method as claimed in claim 10 , wherein the etch stop layer is separated from the patterned metal layer by a distance ranging from 2 nm to 10 nm.

12 . The method as claimed in claim 7 , wherein the etch stop layer has a horizontal cross section that is complementary in shape to that of the blocking layer.

13 . The method as claimed in claim 7 , wherein the blocking layer is made of a self-assembling monolayer material that includes a head group including phosphorus, sulfur, or combinations thereof.

14 . The method as claimed in claim 13 , wherein the head group of the self-assembling monolayer material includes phosphonic acid, thiol, benzotriazole, or combinations thereof.

15 . A method for making a semiconductor structure, comprising:

providing a substrate with a conductive structure thereon;

forming a conductive layer disposed on the substrate, the conductive layer including a first conductive feature, the first conductive feature being electrically connected to the conductive structure;

forming a first dielectric layer adjoining the first conductive feature;

patterning the first dielectric layer to form an opening;

selectively forming a blocking layer in the opening over the first conductive feature;

after forming the blocking layer, forming an etch stop layer over the blocking layer to cover the first dielectric layer and exposing the blocking layer;

removing the blocking layer after forming the etch stop layer;

forming a second dielectric layer on the etch stop layer; and

forming an interconnect in the second dielectric layer, the interconnect being electrically connected to the first conductive feature.

16 . The method as claimed in claim 15 , wherein:

the conductive layer further includes a second conductive feature that is separated from the first conductive feature by the first dielectric layer; and

the method further comprises forming a mask layer disposed on and in direct contact with the second conductive feature.

17 . The method as claimed in claim 15 , wherein the etch stop layer has a first sub-layer that is formed on a top surface of the first dielectric layer, and a second sub-layer that is formed on an inner lateral side of the first dielectric layer.

18 . The method as claimed in claim 15 , wherein the etch stop layer is separated from the first conductive feature of the conductive layer by a distance ranging from 2 nm to 10 nm.

19 . The method as claimed in claim 15 , wherein:

the etch stop layer is made of a material selected from metal nitride, metal oxide, metal carbide, silicon nitride, silicon oxide, silicon carbide, and combinations thereof; and

the metal is selected from aluminum, zirconium, yttrium, hafnium, zinc, and combinations thereof.

20 . The method as claimed in claim 15 , wherein the etch stop layer has a horizontal cross section that is complementary in shape to that of the first conductive feature.