METHOD AND APPARATUS FOR IMPLEMENTING A CO-AXIAL WIRE IN A SEMICONDUCTOR CHIP

• US 20060043541A1
• Filed: 08/26/2004
• Published: 03/02/2006
• Est. Priority Date: 08/26/2004
• Status: Active Grant

• Current Assignee: Bell Semiconductor, LLC (Hilco Inc. (d/b/a Hilco Global))
• Original Assignee: LSI Logic Corporation (Broadcom, Inc.)
• Inventors: Tetelbaum, Alexander
• Granted Patent: US 7,015,569 B1
• Time in Patent Office: Days
• US Class Current: 257/664
• CPC Class Codes: H01L 23/5225 Shielding layers formed together with wiring layers
• 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

A coaxial shield for a semiconductor chip includes: a top vertical shield wire formed in a top metal layer of a semiconductor chip wherein the top vertical shield wire has a selected length for providing a coaxial shield; a first side shield wire formed in an intermediate metal layer of the semiconductor chip; a first upper via formed in a first dielectric layer of the semiconductor chip that extends lengthwise parallel to the first side shield wire to electrically connect the first side shield wire to the top vertical shield wire along the selected length; a second side shield wire formed in the intermediate metal layer of the semiconductor chip having a length corresponding to the selected length wherein the second side shield wire extends lengthwise parallel to the first side shield wire; and a second upper via formed in the first dielectric layer that extends lengthwise parallel to the second side shield wire to electrically connect the second side shield wire to the top vertical shield wire along the length corresponding to the selected length.

Claims

1. A coaxial shield for a semiconductor chip comprising:

a top vertical shield wire formed in a top metal layer of a semiconductor chip wherein the top vertical shield wire has a selected length for providing a coaxial shield;

a first side shield wire formed in an intermediate metal layer of the semiconductor chip;

a first upper via formed in a first dielectric layer of the semiconductor chip that extends lengthwise parallel to the first side shield wire to electrically connect the first side shield wire to the top vertical shield wire along the selected length;

a second side shield wire formed opposite the first side shield wire in the intermediate metal layer of the semiconductor chip having a length corresponding to the selected length wherein the second side shield wire extends lengthwise parallel to the first side shield wire; and

a second upper via formed in the first dielectric layer that extends lengthwise parallel to the second side shield wire to electrically connect the second side shield wire to the top vertical shield wire along the length corresponding to the selected length.

2. The coaxial shield of claim 1 further comprising:

a bottom vertical shield wire formed in a bottom metal layer of the semiconductor chip;

a first lower via formed in a second dielectric layer of the semiconductor chip that extends lengthwise parallel to the first side shield wire to electrically connect the first side shield wire to the bottom vertical shield wire along the selected length; and

a second lower via formed in the second dielectric layer that extends lengthwise parallel to the second side shield wire to electrically connect the second side shield wire to the bottom vertical shield wire along the length corresponding to the selected length.

3. The coaxial shield of claim 1 further comprising a signal wire formed in the intermediate metal layer between the first shield wire and the second shield wire.

4. The coaxial shield of claim 3 wherein the signal wire extends lengthwise parallel to the first shield wire along the selected length.

5. The coaxial shield of claim 1 further comprising:

a third side shield wire formed in an additional intermediate metal layer of the semiconductor chip wherein the third side shield wire extends lengthwise parallel to the first side shield wire along the selected length;

a first lower via formed in a second dielectric layer of the semiconductor chip that extends lengthwise parallel to the third side shield wire to electrically connect the third side shield wire to the first side shield wire along the selected length;

a fourth side shield wire formed in the additional intermediate metal layer of the semiconductor chip wherein the fourth side shield wire extends lengthwise parallel to the second side shield wire along the length corresponding to the selected length; and

a second lower via formed in the second dielectric layer that extends lengthwise parallel to the second side shield wire to electrically connect the fourth side shield wire to the second side shield wire along the length corresponding to the selected length.

6. The coaxial shield of claim 5 further comprising:

a bottom vertical shield wire formed in a bottom metal layer of the semiconductor chip;

a third lower via formed in a third dielectric layer of the semiconductor chip that extends lengthwise parallel to the third side shield wire to electrically connect the third side shield wire to the bottom vertical shield wire along the selected length; and

a fourth lower via formed in the third dielectric layer that extends lengthwise parallel to the fourth side shield wire to electrically connect the fourth side shield wire to the bottom vertical shield wire along the length corresponding to the selected length.

7. The coaxial shield of claim 5 further comprising a signal wire formed in the intermediate metal layer between the first shield wire and the second shield wire.

8. The coaxial shield of claim 7 wherein the signal wire extends lengthwise parallel to the first shield wire along the selected length.

9. A method of shielding a volume in a semiconductor chip comprising steps of:

forming a top vertical shield wire in a top metal layer of a semiconductor chip wherein the top vertical shield wire has a selected length for providing a coaxial shield;

forming a first side shield wire in an intermediate metal layer of the semiconductor chip;

forming a first upper via in a first dielectric layer of the semiconductor chip that extends lengthwise parallel to the first side shield wire to electrically connect the first side shield wire to the top vertical shield wire along the selected length;

forming a second side shield wire in the intermediate metal layer of the semiconductor chip having a length corresponding to the selected length wherein the second side shield wire extends lengthwise parallel to the first side shield wire; and

forming a second upper via in the first dielectric layer that extends lengthwise parallel to the second side shield wire to electrically connect the second side shield wire to the top vertical shield wire along the length corresponding to the selected length.

10. The method of claim 9 further comprising steps of:

forming a bottom vertical shield wire in a bottom metal layer of the semiconductor chip;

forming a first lower via in a second dielectric layer of the semiconductor chip that extends lengthwise parallel to the first side shield wire to electrically connect the first side shield wire to the bottom vertical shield wire along the selected length; and

forming a second lower via in the second dielectric layer that extends lengthwise parallel to the second side shield wire to electrically connect the second side shield wire to the bottom vertical shield wire along the length corresponding to the selected length.

11. The method of claim 9 further comprising a step of forming a signal wire in the intermediate metal layer between the first shield wire and the second shield wire.

12. The method of claim 11 wherein the signal wire extends lengthwise parallel to the first shield wire along the selected length.

13. The method of claim 9 further comprising a steps of:

forming a third side shield wire in an additional intermediate metal layer of the semiconductor chip wherein the third side shield wire extends lengthwise parallel to the first side shield wire along the selected length;

forming a first lower via in a second dielectric layer of the semiconductor chip that extends lengthwise parallel to the third side shield wire to electrically connect the third side shield wire to the first side shield wire along the selected length;

forming a fourth side shield wire in the additional intermediate metal layer of the semiconductor chip wherein the fourth side shield wire extends lengthwise parallel to the second side shield wire along the length corresponding to the selected length; and

forming a second lower via in the second dielectric layer that extends lengthwise parallel to the second side shield wire to electrically connect the fourth side shield wire to the second side shield wire along the length corresponding to the selected length.

14. The method of claim 13 further comprising steps of:

forming a bottom vertical shield wire in a bottom metal layer of the semiconductor chip;

forming a third lower via in a third dielectric layer of the semiconductor chip that extends lengthwise parallel to the third side shield wire to electrically connect the third side shield wire to the bottom vertical shield wire along the selected length; and

forming a fourth lower via in the third dielectric layer that extends lengthwise parallel to the fourth side shield wire to electrically connect the fourth side shield wire to the bottom vertical shield wire along the length corresponding to the selected length.

15. The method of claim 13 further comprising forming a signal wire in the intermediate metal layer between the first shield wire and the second shield wire.

16. The method of claim 15 wherein the signal wire extends lengthwise parallel to the first shield wire along the selected length.