Method of fabricating interconnection structure of semiconductor device

1. A method of fabricating an interconnection structure of a semiconductor device comprising the steps of:

successively depositing an etch-stop layer and an intermetal insulating layer on a semiconductor substrate;

forming a sacrificial insulating layer on the intermetal insulating layer, wherein a thickness ratio of said etch-stop layer to said sacrificial insulating layer is in an inclusive range of 2:1 through 1:1;

forming a photoresist pattern on the sacrificial insulating layer to define a trench formation region;

etching the intermetal insulating layer using a photoresist pattern as a mask to form a trench and expose a portion of the etch-stop layer; and

etching the portion of the etch-stop layer and the sacrificial insulating layer.

2. The method of claim 1 , wherein the step of forming the sacrificial insulating layer includes using nitride series materials.

3. The method of claim 1 , wherein the thickness ratio is in an inclusive range of 1.2:1 through 1:1.

4. The method of claim 1 , wherein the step of forming the intermetal insulating layer includes forming plural layers using oxide series materials.

5. The method of claim 1 , further comprising the steps of:

forming a diffusion barrier on the intermetal insulating layer including the trench after the entire etch-stop layer is removed;

depositing a conductive layer on the diffusion barrier to fill the trench;

annealing the conductive layer; and

polishing the conductive layer and the diffusion baffler by chemical mechanical polishing until an upper surface of the intermetal insulating layer is exposed and planarized.

6. The method of claim 5 , wherein the step of depositing a conductive layer includes depositing copper.

7. A method of fabricating an interconnection structure of a semiconductor device comprising the steps of:

successively depositing an etch-stop layer and an intermetal insulating layer on a semiconductor substrate;

forming a sacrificial insulating layer on the intermetal insulating layer, wherein a thickness ratio of said etch-stop layer to said sacrificial insulating layer is in an inclusive range of 2:1 through 1:1;

forming a first photoresist pattern on the sacrificial insulating layer to define a via hole formation region;

forming a second photoresist pattern on the sacrificial insulating layer to define a trench formation region;

selectively etching an exposed portion of the intermetal insulating layer using the second photoresist pattern as a mask to form a dual damascene pattern; and

etching an entire exposed portion of the etch-stop layer.

8. The method of claim 7 , wherein the step of forming a sacrificial insulating layer includes using nitride series materials.

9. The method of claim 7 , the thickness ratio is in an inclusive range of 1.2:1 through 1:1.

10. The method of claim 7 , wherein the step of forming the intermetal insulating layer includes forming plural layers using oxide series materials.

11. The method of claim 7 , wherein the selective etching step of the partial intermetal insulating layer using a mask of the second photoresist pattern to form a dual damascene pattern step comprises the steps of:

filling the via hole with a non-photoresist material to protect the etch-stop layer;

etching the exposed portion of the intermetal insulating layer using a mask of the second photoresist pattern to form a trench; and

completely removing the non-photoresist material.

12. The method of claim 7 , further comprising the steps of:

forming a diffusion barrier on the intermetal insulating layer including the dual damascene pattern after the exposed portion of the etch-stop layer is removed;

depositing a conductive layer on the diffusion barrier to fill the trench;

annealing the conductive layer; and

polishing the conductive layer and the diffusion barrier by chemical mechanical polishing until the upper surface of the intermetal insulating layer is exposed and planarized.

13. The method of claim 12 , wherein the depositing step includes depositing copper.