High capacitance structure in a semiconductor device

• US 5,208,725 A
• Filed: 08/19/1992
• Issued: 05/04/1993
• Est. Priority Date: 08/19/1992
• Status: Expired due to Term

• Current Assignee: Lonestar Inventions LP
• Original Assignee: Osman E. Akcasu
• Inventors: Akcasu, Osman E.
• Primary Examiner(s): GRIFFIN, DONALD
• Application Number:
  US07/932,425
• Time in Patent Office: 258 Days
• Field of Search: 361/311-313, 365/145, 357/51, 357/71
• US Class Current: 361/313
• CPC Class Codes: H01L 23/5223 Capacitor integral with wiring layers
• CPC Class Codes: H01L 27/0688 Integrated circuits having a three-dimensional layout
• CPC Class Codes: H01L 28/40 Capacitors
• CPC Class Codes: H01L 28/82 with an enlarged surface, e.g. formed by texturisation
• 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

The present invention provides for a capacitor structure on a semiconductor substrate with an enhanced capacitance. The structure has a first layer of conducting strips parallel to each other on the substrate and a second layer of conducting strips which are parallel to each other. The second layer strips overlie and are substantially congruent to the first layer conducting strips in a top view of the semiconductor substrate. The first layer conducting strips are alternately connected to a first node and a second node, and the second layer conducting strips are alternately connected to the first node and the second node in such a manner that each first layer conducting strip and a second layer conducting strip overlying the first layer conducting strip are connected to different nodes. The first and second nodes form two opposing nodes of the capacitor structure.

Claims

1. On a semiconductor substrate, a capacitor structure comprising

a first layer of conducting strips parallel to each other on said substrate;

and

a second layer of conducting strips parallel to each other, said second layer of conducting strips overlying, electrically separated from and substantially congruent to said first layer of conducting strips in a top view;

said first layer of conducting strips alternately connected to a first node and a second node, said second layer of conducting strips alternately connected to said first node and said second node in such a manner that each first layer conducting strip and a second layer conducting strip overlying said first layer conducting strip are connected to different nodes;

whereby said first and second nodes form two opposing nodes of an enhanced capacitor structure.

2. The capacitor structure of claim 1 wherein both first and second conducting layer strips comprise metal.

3. The capacitor structure of claim 1 wherein said first layer of conducting strips have substantially a width w, a height h, and are substantially separated from each other by said width w, said second layer of conducting strips having substantially the same dimensions and separation, said first layer of conducting strips being separated from said second layer of conducting strips by distance d, the relationship between w, h and d being

4. The capacitor structure of claim 1 further comprising

a third layer of conducting strips parallel to each other, said third layer of conducting strips overlying and

substantially congruent to said second layer of conducting strips in a top view;

said third layer of conducting strips alternately connected to said first and second nodes in such a manner that a third layer of conducting strip overlying said second layer of conducting strip are connected to different nodes.

5. The capacitor structure of claim 1 wherein said conducting strips of said first and second layers have first and second ends, said first layer of conducting strips being alternately connected at said first ends by a first base strip and at said second ends by a second base strip, said second layer of conducting strips connected at said first ends by a first base strip and at said second ends by a second base strip, said first base strip of said first layer being connected to said first base strip of said second layer and said second base strip of said first layer being connected to said second base strip of said second layer so that said conducting strips connected to said first base strip of said second conducting layer lie over said conducting strips connected to said second base strip of said first conducting layer and said conducting strips connected to said second base strip of said second conducting layer lie over said conducting strips connected to said first base strip of said first conducting layer.

6. The capacitor structure of claim 5 further comprising

a third layer of conducting strips parallel to each other, said third layer of conducting strips overlying and being substantially congruent to said second layer of conducting strips in a top view;

said third layer of conducting strips being alternatively connected to said first and second nodes in such a manner that third layer conducting strips overlying said second layer conducting strips are connected to different nodes.

7. The capacitor structure of claim 6 further comprising

a fourth layer of conducting strips parallel to each other, said fourth layer of conducting strips overlying and substantially congruent to said third layer of conducting strips in a top view;

said fourth layer of conducting strips alternately connected to said first and second nodes in such a manner that third layer conducting strips overlying said second layer conducting strips are connected to the same nodes.

8. The capacitor structure of claim 1 wherein the number of first conducting layer strips equal the number of second conducting layer strips, and the number of first conducting layer strips connected to said first node is equal to the number of first conducting layer strips connected to said second node.

9. The capacitor structure of claim 1 wherein said first and second layer of conducting strips are separated by an insulating layer of silicon dioxide.

10. The capacitor structure of claim 1 wherein said first and second layer of conducting strips are separated by an insulating layer of a ferro-electric ceramic having an extremely high dielectric constant.

11. The capacitor structure of claim 10 wherein said ferro-electric ceramic comprises PLZT.

12. The capacitor structure of claim 1 wherein said capacitor structure is formed as part of an integrated circuit formed on said semiconductor substrate.