Interconnections for semiconductor circuits

• US 6,081,033 A
• Filed: 07/29/1997
• Issued: 06/27/2000
• Est. Priority Date: 07/29/1997
• Status: Expired due to Fees

• Current Assignee: Micron Technology, Inc.
• Original Assignee: Micron Technology, Inc.
• Inventors: Clampitt, Darwin A.
• Primary Examiner(s): Arroyo, Teresa M.
• Application Number:
  US08/901,924
• Time in Patent Office: 1,064 Days
• Field of Search: 257/752, 257/758, 257/751, 257/773
• US Class Current: 257/758
• CPC Class Codes: H01L 23/5226 Via connections in a multilevel interconnection structure
• CPC Class Codes: H01L 23/5283 Cross-sectional geometry
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00

Abstract

Interconnections carrying the greatest currents within a semiconductor circuit are formed by an interconnect having at least one and commonly two or more ribs extending generally orthogonally from the interconnect line. The interconnect line is generally horizontal with the rib or ribs extending generally vertically downward from the interconnect line. The resulting interconnect occupies a surface area corresponding to that of the interconnect line yet includes the conductive material of both the interconnect line and the rib or ribs so that the interconnect has substantially less resistance than the interconnect line alone or the rib or ribs alone. The rib or ribs and interconnect line are produced from a conductive layer formed over an insulation layer after the insulation layer has been appropriately masked and etched. The rib or ribs can be formed over conductive plugs which are aligned with contact locations on a semiconductor structure and preformed through an insulation layer formed over the semiconductor structure. The rib or ribs and conductive plugs can also be formed together by forming a mask between two insulating layers to locate the conductive plugs. The top insulation layer is masked and etched to form trenches with openings through the bottom insulation layer being etched through the mask which prevents the bottom insulation layer from being etched other than to form openings for the conductive plugs. A layer of conductive material fills the conducive plug openings, corresponding openings in the mask and the trenches.

Claims

1. A semiconductor circuit comprising:

a semiconductor structure;

an insulation layer formed over said semiconductor structure;

at least one conductive rib extending through said insulation layer and coupled to at least one contact location on said semiconductor structure, said at least one conductive rib being substantially continuous along its entire length; and

a conductive contact line extending over said at least one conductive rib and being substantially coextensive in length therewith.

2. A semiconductor circuit as claimed in claim 1 wherein said at least one conductive rib is coupled to said at least one contact location on said semiconductor structure through a barrier layer.

3. A semiconductor circuit comprising:

a semiconductor structure;

a first insulation layer formed over said semiconductor layer;

conductive plugs extending through said first insulation layer and corresponding to contact locations on said semiconductor structure;

a second insulation layer formed over said first insulation layer;

a plurality of conductive ribs extending through said second insulation layer and coupled to said conductive plugs, said plurality of conductive ribs being substantially continuous along their entire length; and

a conductive contact line extending over said second insulation layer and interconnecting said plurality of conductive ribs, said conductive contact line being substantially coextensive in length with said plurality of conductive ribs.

4. A semiconductor circuit as claimed in claim 3 wherein said conductive ribs are coupled to said conductive plugs through a barrier layer.

5. A semiconductor circuit as claimed in claim 3 wherein at least two of said plurality of conductive ribs are substantially parallel to one another.

6. A semiconductor circuit as claimed in claim 5 wherein each of said plurality of conductive ribs are substantially parallel to one another.

7. A semiconductor circuit comprising:

a semiconductor structure;

an insulation layer formed over said semiconductor structure;

a plurality of conductive plugs extending from contact locations on said semiconductor structure into said insulation layer;

at least one conductive rib extending from said conductive plugs to an outer surface of said insulation layer, said at least one conductive rib being substantially continuous alone its entire length; and

a conductive contact line on said outer surface of said insulation layer connected to said at least one conductive rib and being substantially coextensive in length therewith.

8. A semiconductor circuit as claimed in claim 7 wherein said contact locations on said semiconductor structure comprise power contact locations on said semiconductor structure.

9. A semiconductor circuit as claimed in claim 7 further comprising a patterned mask embedded within said insulation layer.

10. A semiconductor circuit as claimed in claim 9 wherein said insulation layer is oxide and said patterned mask is nitride.

11. A semiconductor circuit comprising:

a semiconductor structure; and

a power bus comprising;

at least one generally vertical conductive rib coupled to at least one power contact location of said semiconductor structure, said at least one generally vertical conductive rib being substantially continuous along its entire length; and

a generally horizontal conductive contact line extending over and connected to said at least one generally vertical conductive rib and being substantially coextensive in length therewith.

12. An interconnect for a semiconductor circuit including a semiconductor structure, said interconnect comprising:

a conductive contact line; and

at least one conductive rib connected to and extending from said contact line and being coupled to at least one contact location of said semiconductor structure, said at least one conductive rib being substantially continuous along its entire length and being substantially coextensive in length with said conductive contact line.

13. An interconnect as claimed in claim 12 wherein said at least one contact location comprises at least one power contact location.

14. An interconnect for a semiconductor circuit including a semiconductor structure, said interconnect comprising:

a conductive contact line; and

a plurality of conductive ribs and connected to and extending from said power contact line, said plurality of conductive ribs being substantially continuous along their entire length and substantially coextensive in length with said conductive contact line.

15. An interconnect as claimed in claim 14 wherein at least two of said plurality of conductive ribs are substantially parallel to one another.

16. An interconnect as claimed in claim 15 wherein each of said plurality of conductive ribs are substantially parallel to one another.