Methods of fabricating dual fin structures

• US 7,902,057 B2
• Filed: 07/31/2007
• Issued: 03/08/2011
• Est. Priority Date: 07/31/2007
• Status: Active Grant

• Current Assignee: Micron Technology, Inc.
• Original Assignee: Micron Technology, Inc.
• Inventors: McDaniel, Terrence
• Primary Examiner(s): Smith; Zandra
• Assistant Examiner(s): Novacek; Christy L
• Application Number:
  US11/831,296
• Publication Number:
  US 20090032866A1
• Time in Patent Office: 1,316 Days
• Field of Search: 438/197, 438/241, 438/242, 438/589, 257/E21.023
• US Class Current: 438/589
• CPC Class Codes: H01L 29/66795 with a horizontal current flow in a vertical sidewall of a semiconductor body, e.g. FinFET, MuGFET
• CPC Class Codes: H01L 29/7854 with rounded corners

Abstract

Fin-FET devices and methods of fabrication are disclosed. The Fin-FET devices include dual fins that may be used to provide a trench region between a source region and a drain region. In some embodiments, the dual fins may be formed by forming a trench with fin structures on opposite sides in a protruding region of a substrate. The dual fins may be useful in forming single-gate, double-gate or triple-gate fin-FET devices. Electronic systems including such fin-FET devices are also disclosed.

Claims

1. A method for fabricating a semiconductor device, comprising:

forming a plurality of trenches in a substrate with at least one protruding region therebetween;

applying a mask material over the at least one protruding region without filling the plurality of trenches;

exposing a portion of an upper end of the at least one protruding region through the mask material; and

forming a pair of fins from the at least one protruding region by removing the exposed portion of the substrate at the upper end of the at least one protruding region to form a trench therein.

2. The method of claim 1, wherein exposing a portion of an upper end of the at least one protruding region through the mask material comprises rendering the mask material substantially coplanar with the upper end of the protruding region.

3. The method of claim 1, wherein exposing a portion of an upper end of the at least one protruding region through the mask material comprises polishing the mask material to a level substantially planar with the portion of the upper end of the at least one protruding region.

4. The method of claim 1, wherein forming a plurality of trenches in a substrate comprises selectively removing at least a portion of a silicon substrate.

5. The method of claim 1, wherein forming a plurality of trenches in a substrate with at least one protruding region therebetween comprises forming the at least one protruding region with a height of about 100 Å

to about 10,000 Å

from bases of the plurality of trenches.

6. The method of claim 1, wherein applying a mask material over the at least one protruding region comprises applying a dielectric material over the at least one protruding region without filling the plurality of trenches.

7. The method of claim 1, wherein applying a mask material over the at least one protruding region comprises applying a conductive material over the at least one protruding region without filling the plurality of trenches.

8. The method of claim 7, wherein applying a conductive material comprises applying at least one of titanium nitride, tungsten nitride, tungsten silicide, titanium silicide, platinum silicide, cobalt silicide, nickel silicide, tungsten, tantalum, and tantalum nitride.

9. The method of claim 7, wherein applying the mask material further comprises applying a dielectric material over the at least one protruding region without filling the plurality of trenches, and further comprising applying a conductive material over the dielectric material.

10. The method of claim 9, wherein applying the dielectric material over the at least one protruding region without filling the plurality of trenches comprises forming a gate dielectric over the pair of fins.

11. The method of claim 10, further comprising patterning the conductive material to define at least one conductive element of at least one transistor gate.

12. The method of claim 7, further comprising patterning the conductive material to define at least one conductive element.

13. A method for fabricating a semiconductor device, comprising:

forming a plurality of trenches in a substrate to form a plurality of protrusions therebetween;

applying a mask material over the substrate and over the plurality of protrusions;

exposing portions of upper ends of the plurality of protrusions by removing at least a portion of the mask material to render the remaining mask material substantially coplanar with the upper ends of the plurality of protrusions;

removing substrate material from the exposed portions of the upper ends of the plurality of protrusions to form recesses between fin structures;

applying a dielectric material over the substrate to form a lining on the sidewalls of the recesses;

applying a conductive material over the plurality of protrusions to fill the recesses; and

forming conductive lines on the fin structures on sides thereof opposite the recesses.

14. The method of claim 13, wherein forming a plurality of trenches in a substrate to form a plurality of protrusions therebetween comprises forming a plurality of trenches in a silicon substrate.

15. The method of claim 13, wherein forming a plurality of trenches in a substrate to form a plurality of protrusions therebetween comprises forming plurality of trenches with a depth of from about 100 Å

to about 10000 Å

.

16. The method of claim 13, wherein applying a conductive material over the plurality of protrusions to fill the recesses comprises applying a conductive material comprising at least one of titanium nitride, tungsten nitride, tungsten silicide, titanium silicide, platinum silicide, cobalt silicide, nickel silicide, tungsten, tantalum, and tantalum nitride.

17. The method of claim 13, wherein applying a conductive material over the plurality of protrusions comprises applying titanium nitride.

18. The method of claim 13, wherein exposing portions of the upper ends of the protrusions comprises chemical-mechanical polishing at least a portion of the mask material to render the remaining mask material substantially coplanar with the upper ends of the plurality of protrusions.

19. The method of claim 13, wherein removing substrate material from the exposed portions of the upper ends of the plurality of protrusions to form recesses between fin structures comprises forming the recesses extending below the bottoms of the plurality of trenches.

20. The method of claim 13, wherein removing substrate material from the exposed portions of the upper ends of the plurality of protrusions to form recesses between fin structures comprises forming the recesses having bottoms substantially coplanar with bottoms of the plurality of trenches.

21. The method of claim 13, wherein applying a conductive material to fill the recesses comprises applying a conductive material comprising at least one of titanium nitride, tungsten nitride, tungsten silicide, titanium silicide, platinum silicide, cobalt silicide, nickel silicide, tungsten, tantalum, and tantalum nitride.

22. The method of claim 13, wherein forming conductive lines on the fin structures on sides thereof opposite the recesses comprises removing at least a portion of the mask material to form the conductive lines on the sides of the fin structures.

23. The method of claim 13, wherein forming conductive lines on the fin structures on sides thereof opposite the recesses comprises depositing a conductive material over outer surfaces of the protrusions and removing portions thereof.

24. A method for fabricating a semiconductor device, comprising:

forming a plurality of trenches in a substrate with at least one protruding region therebetween;

applying a conductive material over the at least one protruding region;

exposing a portion of an upper end of the at least one protruding region through the conductive material to form a mask; and

forming a pair of fins from the at least one protruding region by removing the exposed portion of the substrate at the upper end of the at least one protruding region to form a trench therein.