Method and pattern for reducing interconnect failures

• US 6,831,365 B1
• Filed: 05/30/2003
• Issued: 12/14/2004
• Est. Priority Date: 05/30/2003
• Status: Active Grant

• Current Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Original Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Inventors: Wan, Wen-Kai, Yao, Chih-Hsiang, Huang, Tai-Chun, Hsia, Chin-Chiu
• Primary Examiner(s): Thomas, Tom
• Assistant Examiner(s): Warren, Matthew E.
• Application Number:
  US10/448,656
• Publication Number:
  US 20040238959A1
• Time in Patent Office: 564 Days
• Field of Search: 257/758, 257/767, 257/773-775
• US Class Current: 257/758
• CPC Class Codes: H01L 23/5226 Via connections in a multilevel interconnection structure
• CPC Class Codes: H01L 23/528 Geometry or layout of the interconnection structure H01L27/0207 takes precedence; algorithms G06F30/00
• 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 method and a pattern for reducing interconnect failures are described. The method and pattern are used for a multilevel structure of metal/dielectric/metal. At least one assistant pattern is attached to one metal layer of the multilevel structure. A thermal stress gradient resulting from the assistant pattern can collect vacancies of the metal layer, so as to prevent stress-induced voids from generating at the bottom of a via plug which connects the two metal layers.

Claims

1. A pattern for reducing interconnect failures, the pattern for reducing interconnect failures comprising:

a first metal layer;

a second metal layer;

a dielectric layer, between the first metal layer and the second metal layer;

a first via plug in the dielectric layer, a first end of the first via plug is connected with the first metal layer, and a second end of the first via plug is connected with the second metal layer; and

at least one first line extension, attached to the first metal layer, wherein when the first via plug is connected with a second line extension attached to the first metal layer, the first line extension and the second line extension are on the same side of the first metal layer, and the first line extension collects vacancies of the first metal layer to prevent the vacancies of the first metal layer from being accumulated at a bottom of the first via plug and then forming voids.

2. The pattern for reducing interconnect failures of claim 1, wherein a material of the first via plug, the first metal layer, the second metal layer, and the first line extension is copper.

3. The pattern for reducing interconnect failures of claim 1, wherein a material of the dielectric layer is a low k material.

4. A pattern for reducing interconnect failures, the pattern for reducing interconnect failures comprising:

a first metal layer, having a line extension;

a second metal layer;

a dielectric layer, between the first metal layer and the second metal layer, and

a via plug in the dielectric layer, a first end of the via plug is connected with the line extension, and a second end of the via plug is connected with the second metal layer, wherein the line extension having at least one turning corner between the first metal layer and the via plug, the turning corner avoids vacancies in the first metal layer being driven to a bottom of the via plug.

5. The pattern for reducing interconnect failures of claim 4, wherein an angle of the turning corner is 90 degrees.

6. The pattern for reducing interconnect failures of claim 4, wherein a material of the via plug, the first metal layer, the second metal layer and the line extension is copper.

7. The pattern for reducing interconnect failures of claim 4, wherein a material of the dielectric layer is a low k material.

8. In an interconnect having a first via plug to connect a first metal layer and a second metal layer, an improvement thereto comprising:

at least one first line extension, attached to the first metal layer, wherein when the first via plug is connected with a second line extension attached to the first metal layer, the first line extension and the second line extension are on the same side of the first metal layer, and the first line extension collects vacancies of the first metal layer to prevent the vacancies of the first metal layer from being accumulated at a bottom of the first via plug and then forming voids.

9. The interconnect of claim 8, wherein a material of the first via plug, the first metal layer, the second metal layer, and the first line extension is copper.

10. In an interconnect having a via plug to connect a first metal layer and a line extension attached to a second metal layer, an improvement thereto comprising:

the line extension having at least one turning corner between the second metal layer and the via plug, wherein the turning corner avoids vacancies in the second metal layer being driven to a bottom of the via plug.

11. The interconnect of claim 10, wherein an angle of the turning corner is 90 degrees.

12. The interconnect of claim 10, wherein a material of the via plug, the first metal layer, the second metal layer and the line extension is copper.

13. A pattern for reducing interconnect failures, the pattern for reducing interconnect failures comprising:

a first metal layer;

a second metal layer;

a dielectric layer, between the first metal layer and the second metal layer;

a first via plug in the dielectric layer, a first end of the first via plug is connected with the first metal layer, and a second end of the first via plug is connected with the second metal layer; and

at least one second via plug in the dielectric layer, a first end of the second plug is connected with the first metal layer, wherein when the first via plug is connected to a line extension attached to the first metal layer, the first end of the second via plug is not connected to the line extension to avoid interrupting the line extension, and the second via plug collects vacancies of the first metal layer to prevent the vacancies of the first metal layer from being accumulated at a bottom of the first via plug and then forming voids.

14. The pattern for reducing interconnect failures of claim 13, wherein a material of the first via plug, the first metal layer, the second metal layer, and the second via plug is copper.

15. The pattern for reducing interconnect failures of claim 13, wherein a material of the dielectric layer is a low k material.

16. In an interconnect having a first via plug to connect a first metal layer and a second metal layer, an improvement thereto comprising:

at least one second via plug in the dielectric layer, a first end of the second plug is connected with the first metal layer, wherein when the first via plug is connected to a line extension attached to the first metal layer, the first end of the second via plug is not connected to the line extension to avoid interrupting the line extension, and the second via plug collects vacancies of the first metal layer to prevent the vacancies of the first metal layer from being accumulated at a bottom of the first via plug and then forming voids.

17. The interconnect of claim 16, wherein a material of the first via plug, the first metal layer, the second metal layer, and the second via plug is copper.