Semiconductor device and method for manufacturing the same

1. A semiconductor device, comprising:

a substrate including a first region and a second region;

memory transistors on the first region;

a first interconnection layer on the memory transistors and having first interconnection lines; and

a second interconnection layer on the first interconnection layer and having second interconnection lines,

wherein the second interconnection lines on the first region include:

a first line extending along a first direction and spaced from the second region by a first distance along the first direction, and

a second line extending along the first direction, spaced from the first line along a second direction intersecting the first direction, and having a width smaller along the second direction than a width of the first line,

wherein the first line includes a protrusion extending along a third direction, intersecting the first and second directions, toward the substrate, and

wherein the protrusion is spaced from the second region by a second distance along the first direction, the second distance being greater than the first distance.

2. The semiconductor device as claimed in claim 1 , wherein:

the first line further includes a body portion on the protrusion, and

a sidewall of the first line has a stepped profile at a boundary between the protrusion and the body portion.

3. The semiconductor device as claimed in claim 1 , wherein a width of the protrusion is substantially equal to the width of the second line.

4. The semiconductor device as claimed in claim 1 , wherein a level of a bottom surface of the protrusion is higher than a level of top surfaces of the first interconnection lines.

5. The semiconductor device as claimed in claim 1 , wherein a level of a bottom surface of the protrusion is lower than a level of a bottom surface of the second line.

6. The semiconductor device as claimed in claim 1 , wherein the second interconnection lines further include a third line on the second region, wherein the third line is adjacent to an end of the first line and spaced apart from the protrusion by the second distance.

7. The semiconductor device as claimed in claim 6 , wherein a distance between the third line and the end of the first line is smaller than a distance between the third line and an end of the protrusion.

8. The semiconductor device as claimed in claim 1 , further comprising:

logic transistors on the second region.

9. The semiconductor device as claimed in claim 1 , wherein the memory transistors include:

first and second access transistors;

first and second pull-up transistors; and

first and second pull-down transistors,

wherein the first interconnection lines include a bit line and a power line on the memory transistors, and

wherein the first line is a word line and the second line is a ground line.

10. A semiconductor device, comprising:

a substrate including a memory cell region and a logic cell region;

memory transistors on the memory cell region;

logic transistors on the logic cell region;

an interconnection layer including interconnection lines on the memory transistors and the logic transistors; and

an interlayer insulating layer on the memory transistors and the logic transistors,

wherein the interconnection lines include:

a word line on the memory transistors and extending in a first direction in an upper portion of the interlayer insulating layer; and

a conductive line on the logic transistors and extending in a second direction intersecting the first direction in the upper portion of the interlayer insulating layer,

wherein the word line includes a protrusion extending along a third direction, intersecting the first and second directions, toward the substrate, and

wherein a distance in the first direction between the conductive line and the word line is smaller than a distance in the first direction between the conductive line and the protrusion.

11. The semiconductor device as claimed in claim 10 , wherein a level of a bottom surface of the protrusion is lower than a level of a bottom surface of the conductive line.

12. The semiconductor device as claimed in claim 10 , wherein:

the word line further includes a body portion on the protrusion, and

a sidewall of the word line has a stepped profile at a boundary between the protrusion and the body portion.

13. The semiconductor device as claimed in claim 10 ,

wherein a level of a bottom surface of the protrusion is higher than a level of a bottom surface of the interlayer insulating layer.

14. The semiconductor device as claimed in claim 10 , wherein:

the interconnection lines further include a ground line on the memory transistors that extends in the first direction,

a width of the ground line is smaller than a width of the word line, and

a level of a bottom surface of the protrusion is lower than a level of a bottom surface of the ground line.

15. The semiconductor device as claimed in claim 10 , wherein each of the memory and logic transistors includes:

an active pattern vertically protruding along the third direction from a device isolation layer on the substrate; and

a gate electrode intersecting the active pattern.

16. A semiconductor device, comprising:

a memory cell on a substrate;

an interlayer insulating layer on the memory cell; and

an interconnection layer including interconnection lines provided in an upper portion of the interlayer insulating layer,

wherein the memory cell includes:

first and second access transistors;

first and second pull-up transistors; and

first and second pull-down transistors,

wherein the interconnection lines include a first line and a second line extending along a first direction and spaced apart along a second direction intersecting the first direction, the second line having a width along the second direction smaller than a width of the first line,

wherein the first line includes a protrusion extending along a third direction, intersecting the first and second directions, toward the substrate,

wherein a level of a bottom surface of the protrusion is lower than a level of a bottom surface of the second line, and

wherein the level of the bottom surface of the protrusion is higher than a level of a bottom surface of the interlayer insulating layer.

17. The semiconductor device as claimed in claim 16 , wherein:

the first line is electrically connected to gates of the first and second access transistors, and

the second line is electrically connected to source/drains of the first and second pull-down transistors.

18. The semiconductor device as claimed in claim 16 , wherein:

the first line further includes a body portion on the protrusion,

a sidewall of the first line has a stepped profile at a boundary between the protrusion and the body portion, and

the body portion extends further in the first direction than the protrusion.