Integrated capacitor with array of crosses

• US 8,207,592 B2
• Filed: 11/21/2008
• Issued: 06/26/2012
• Est. Priority Date: 11/21/2008
• Status: Active Grant

• Current Assignee: Xilinx, Inc. (Advanced Micro Devices, Inc.)
• Original Assignee: Xilinx, Inc. (Advanced Micro Devices, Inc.)
• Inventors: Quinn, Patrick J.
• Primary Examiner(s): Parker, Kenneth
• Assistant Examiner(s): Spalla, David
• Application Number:
  US12/276,296
• Publication Number:
  US 20100127349A1
• Time in Patent Office: 1,313 Days
• Field of Search: 257/307, 257/532, 257/534, 257/535, 257/E23.143, 257/E23.144, 257/E23.151, 257/E23.152, 257/E23.153
• US Class Current: 257/532
• CPC Class Codes: H01G 4/012 Form of non-self-supporting electrodes
• CPC Class Codes: H01G 4/33 Thin- or thick-film capacitors thin- or thick-film circuits H01L27/00; capacitors without a potential-jump or surface barrier specially adapted for integrated circuits, details thereof, multistep manufacturing processes therefor H01L28/40
• CPC Class Codes: H01L 23/5223 Capacitor integral with wiring layers
• CPC Class Codes: H01L 27/0207 Geometrical layout of the components, e.g. computer aided design; custom LSI, semi-custom LSI, standard cell technique
• CPC Class Codes: H01L 27/0805 Capacitors only
• CPC Class Codes: H01L 28/60 Electrodes
• 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
• CPC Class Codes: H01L 2924/3011 Impedance

Abstract

A capacitor in an integrated circuit (“IC”) has a first plurality of conductive crosses formed in a layer of the IC electrically connected to and forming a portion of a first node of the capacitor and a second plurality of conductive crosses formed in the metal layer of the IC. The conductive crosses in the second plurality of conductive crosses are electrically connected to and form a portion of a second node of the capacitor and capacitively couple to the first node.

Claims

1. A capacitor in an integrated circuit (“

IC”

) comprising;

a first plurality of conductive crosses formed in a first conductive layer of the IC, each of the first plurality of conductive crosses being electrically connected to and forming a first portion of a first node of the capacitor;

a second plurality of conductive crosses formed in the first conductive layer of the IC, each of the second plurality of conductive crosses being electrically connected to and forming a first portion of a second node of the capacitor and capacitively coupling to the first node;

an interconnection layer formed in a second conductive layer of the IC separated from the first conductive layer by a dielectric layer of the IC, the interconnection layer having a first plurality of staggered interconnect traces connected to the first plurality of conductive crosses alternating with a second plurality of staggered interconnect traces connected to the second plurality of conductive crosses, each staggered interconnect trace having wider sections alternating with narrower sections; and

a third conductive layer of the IC, the interconnection layer being between the third conductive layer and the first conductive layer, the third conductive layer having a third plurality of conductive crosses electrically connected to the first node through the first plurality of staggered interconnect traces and a fourth plurality of conductive crosses electrically connected to the second node through the second plurality of staggered interconnect traces.

2. The capacitor of claim 1 wherein each of the first plurality of conductive crosses is symmetrical.

3. The capacitor of claim 2 wherein each of the second plurality of conductive crosses is symmetrical.

4. The capacitor of claim 1 wherein the conductive crosses in the first plurality of conductive crosses are electrically isolated from each other within the first conductive layer by dielectric material.

5. The capacitor of claim 1 further comprising a first buss bar electrically connected to and forming a second portion of the first node and a second buss bar electrically connected to and forming a second portion of the second node, wherein each of the first plurality of conductive crosses is electrically connected to the first buss bar in the interconnection layer and each of the second plurality of conductive crosses is electrically connected to the second buss bar in the interconnection layer.

6. The capacitor of claim 1 wherein a first horizontal member of a first cross of the first plurality of conductive crosses overlaps a portion of a staggered interconnect trace of the first plurality of staggered interconnect traces, and further comprising a conductive via disposed at an end of the first horizontal member extending to the staggered interconnect trace.

7. The capacitor of claim 1 wherein the first conductive layer is a first metal layer of the IC, the interconnection layer is a second metal layer of the IC, and the third conductive layer is a third metal layer of the IC.

8. The capacitor of claim 1 wherein a staggered interconnect trace at least partially underlies and is connected to a first cross of the first plurality of conductive crosses and at least partially underlies and capacitively couples to a second cross of the second plurality of conductive crosses.

9. The capacitor of claim 8 wherein the first cross in the layer has a vertical element having a first width and each of the first plurality of staggered interconnector traces has a first portion having the first width and a second portion having a second width greater than the first width.