Lithography alignment marks

Patent metadata

Field	Value
Publication number	US-9823574-B2
Application number	US-201514868532-A
Country	US
Kind code	B2
Filing date	Sep 29, 2015
Priority date	Sep 29, 2015
Publication date	Nov 21, 2017
Grant date	Nov 21, 2017

Abstract

A device for semiconductor fabrication includes a substrate and a layer formed over the substrate, wherein the layer includes an alignment mark. The alignment mark includes a first plurality of elongated members that are oriented lengthwise along a first direction and are distributed along a second direction. The alignment mark further includes a second plurality of elongated members that are oriented lengthwise along a third direction perpendicular to the first direction and are distributed along the second direction, wherein the second direction is different from each of the first and third directions.

First claim

What is claimed is:

1. A device for semiconductor fabrication, comprising:
a substrate; and
a layer formed over the substrate, the layer having an alignment mark, wherein the alignment mark includes:
a first plurality of elongated members that are oriented lengthwise along a first direction, wherein middle points of the first plurality of elongated members are distributed along a second direction; and
a second plurality of elongated members that are oriented lengthwise along a third direction perpendicular to the first direction, wherein middle points of the second plurality of elongated members are distributed along the second direction, wherein the second direction is different from each of the first and third directions.

2. The device of claim 1 , wherein the first and second directions form a 45 degree angle.

3. The device of claim 1 , further comprising:
a third plurality of elongated members that are oriented lengthwise along the first direction, wherein middle points of the third plurality of elongated members are distributed along a fourth direction that is different from each of the first, second, and third directions; and
a fourth plurality of elongated members that are oriented lengthwise along the third direction, wherein middle points of the fourth plurality of elongated members are distributed along the fourth direction.

4. The device of claim 3 , wherein the third and fourth directions form a 45 degree angle.

5. The device of claim 3 , wherein:
the first and third pluralities are distributed along two sides of a first triangle and meet at a vertex of the first triangle; and
the second and fourth pluralities are distributed along two sides of a second triangle and meet at a vertex of the second triangle.

6. The device of claim 1 , wherein the first and second pluralities of elongated members are spaced away from each other.

7. The device of claim 1 , wherein:
the first plurality of elongated members are of a same length; and
the second plurality of elongated members are of a same length.

8. The device of claim 1 , wherein:
the first plurality of elongated members are of a first width;
the second plurality of elongated members are of a second width; and
the first width is greater than the second width.

9. The device of claim 1 , wherein:
the middle points of the first plurality are distributed with a first pitch defined in the third direction;
the middle points of the second plurality are distributed with a second pitch defined in the first direction; and
the first and second pitches are within 10% of each other.

10. The device of claim 9 , wherein:
each of the first plurality has a first width that is greater than half of the first pitch; and
each of the second plurality has a second width that is smaller than half of the second pitch.

11. The device of claim 1 , wherein the third direction is perpendicular to an electric field of a polarized light beam incident upon the layer during alignment.

12. The device of claim 11 , wherein the first and second pluralities of elongated members each include copper.

13. The device of claim 12 , wherein spaces between each of the first and second pluralities of elongated members are filled with an extreme low-k dielectric material.

14. The device of claim 13 , wherein the alignment mark is disposed in a scribe line region of the device.

15. A device for semiconductor fabrication, comprising:
a substrate; and
a layer formed over the substrate, the layer having an alignment mark, wherein the alignment mark includes:
a first plurality of elongated members that are oriented lengthwise along a first direction, wherein middle points of the first plurality of elongated members are distributed along a second direction;
a second plurality of elongated members that are oriented lengthwise along a third direction perpendicular to the first direction, wherein middle points of the second plurality of elongated members are distributed along the second direction, wherein the second direction is different from each of the first and third directions;
a third plurality of elongated members that are oriented lengthwise along the first direction, wherein middle points of the third plurality of elongated members are distributed along a fourth direction that is different from each of the first, second, and third directions; and
a fourth plurality of elongated members that are oriented lengthwise along the third direction, wherein middle points of the fourth plurality of elongated members are distributed along the fourth direction.

16. The device of claim 15 , wherein:
the middle points of the first and third pluralities are each distributed with a first pitch defined in the third direction;
the middle points of the second and fourth pluralities are each distributed with a second pitch defined in the first direction; and
the first and second pitches are within 10% of each other.

17. The device of claim 16 , wherein:
each of the first and third pluralities has a width that is greater than half of the first pitch; and
each of the second and fourth pluralities has a width that is smaller than half of the second pitch.

18. The device of claim 15 , wherein:
the substrate includes a semiconductor; and
the first, second, third, and fourth pluralities of elongated members each include copper.

19. The device of claim 15 , wherein:
the first and second directions form a 45 degree angle; and
the third and fourth directions form a 45 degree angle.

20. A device for semiconductor fabrication, comprising:
a semiconductor substrate; and
a layer formed over the semiconductor substrate, the layer having an alignment mark, wherein the alignment mark includes:
a first plurality of elongated members that are oriented lengthwise along a first direction, wherein middle points of the first plurality of elongated members are distributed along a second direction; and
a second plurality of elongated members that are oriented lengthwise along a third direction perpendicular to the first direction, wherein middle points of the second plurality of elongated members are distributed along a fourth direction, wherein each of the second and fourth directions is different from each of the first and third directions and the second direction is substantially parallel to the fourth direction.

Assignees

• Taiwan Semiconductor Mfg Co Ltd

Inventors

• Chen Ching-Huang
• Hsieh Hung-Chang
• Lu Kuei-Liang
• Chang Ya Hui
• Lin Spencer

Classifications

• H10P74/203

  Structural properties, e.g. testing or measuring thicknesses, line widths, warpage, bond strengths or physical defects · CPC title

• G03F9/7076 Primary

  Mark details, e.g. phase grating mark, temporary mark · CPC title

• G03F7/70141 Primary

  Illumination system adjustment, e.g. adjustments during exposure or alignment during assembly of illumination system · CPC title

• Y10S438/975

  Substrate or mask aligning feature · CPC title

• G03F7/70633

  Overlay, i.e. relative alignment between patterns printed by separate exposures in different layers, or in the same layer in multiple exposures or stitching · CPC title