Semiconductor devices and methods of manufacturing the same
View Patent ↗Shorting of a copper line with an adjacent line in a semiconductor device during chemical mechanical polishing may be prevented and thus reliability of the semiconductor device may be improved, when the semiconductor device includes a substrate, an interlayer insulating layer formed on the substrate and having a dual trench, and a copper line formed to fill the dual trench, wherein the dual trench includes a first trench inclined at a first angle with respect to the substrate, and a second trench connected to the first trench and inclined at a second angle that is smaller than the first angle with respect to the substrate.
1. A method of manufacturing a semiconductor device, comprising:
forming an insulating layer above a substrate;
forming a first photosensitive layer;
exposing and developing the first photosensitive layer to form a first photosensitive layer pattern exposing a plurality of predetermined regions of the insulating layer;
forming a plurality of first trenches each having a first sidewall with a first slope by etching the insulating layer using the first photosensitive layer pattern as a mask;
forming a second photosensitive layer pattern by exposing and developing the first photosensitive layer pattern;
forming a plurality of dual trenches by forming a second trench in each of the first trenches and aligned with the first trenches by etching the insulating layer using the second photosensitive layer pattern as a mask, each second trench having a second sidewall with a second slope that is smaller than the first slope of the first sidewall;
forming a copper layer on the insulating layer such that the plurality of dual trenches are filled thereby; and
chemical mechanical polishing the copper layer.
2. A method as defined in claim 1 , wherein the second photosensitive layer pattern has a narrower width than the first photosensitive layer pattern.
3. A method as defined in claim 1 , wherein the second sidewalls are inclined more toward the substrate than the first sidewalls are inclined toward the substrate.
4. A method as defined in claim 1 , wherein:
the second photosensitive layer pattern has a narrower width than the first photosensitive layer pattern; and
lateral sides of the second trenches are inclined more toward the substrate than lateral sides of the first trenches are inclined toward the substrate such that the dual trench becomes wider in an upward direction.
5. A method as defined in claim 4 , wherein forming the plurality of dual trenches prevents or reduces an incidence of a short circuit between adjacent copper lines.
6. A method as defined in claim 1 , wherein forming the first photosensitive layer pattern comprises forming a plurality of holes in the first photosensitive layer exposing the predetermined regions of the insulating layer.
7. A method as defined in claim 6 , wherein exposing and developing the first photosensitive layer pattern comprises widening the holes in the first photoresist layer to expose a surface of the insulating layer that was previously covered by the first photosensitive layer pattern.
8. A method as defined in claim 1 , wherein upper ends of the second trenches are wider than upper ends of the first trenches.
9. A method as defined in claim 1 , wherein the plurality of dual trenches are filled by the copper layer simultaneously.
10. A method as defined in claim 9 , wherein chemical mechanical polishing the copper layer removes substantially all of the copper layer from an upper, horizontal surface of the insulating layer, including an area of the insulating layer between adjacent dual trenches.
11. A method as defined in claim 10 , wherein adjacent dual trenches remain substantially filled with copper after the chemical mechanical polishing.
12. A method as defined in claim 9 , wherein forming the plurality of dual trenches prevents or reduces an incidence of a short circuit between adjacent copper lines.
13. A method as defined in claim 1 , wherein the insulating layer consists essentially of a single layer of insulating material.
14. A method as defined in claim 13 , wherein forming the plurality of dual trenches prevents or reduces an incidence of a short circuit between adjacent copper lines.
15. A method as defined in claim 1 , wherein forming the plurality of dual trenches prevents or reduces an incidence of a short circuit between adjacent copper lines.