METAL EMBEDDED LOW-RESISTANCE BEOL ANTIFUSE

• US 20190326215A1
• Filed: 04/19/2018
• Published: 10/24/2019
• Est. Priority Date: 04/19/2018
• Status: Abandoned Application

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: REZNICEK, Alexander, YANG, Chih-Chao, WANG, Miaomiao
• Application Number:
  US15/956,919
• Publication Number:
  US 20190326215A1
• Time in Patent Office: Days
• CPC Class Codes: H01L 21/76805 the opening being a via or contact hole penetrating the underlying conductor
• CPC Class Codes: H01L 21/76831 in via holes or trenches, e.g. non-conductive sidewall liners
• CPC Class Codes: H01L 21/7684 Smoothing; Planarisation
• CPC Class Codes: H01L 21/76847 the layer being positioned within the main fill metal
• CPC Class Codes: H01L 21/76879 by selective deposition of conductive material in the vias, e.g. selective C.V.D. on semiconductor material, plating plating on semiconductors in general H01L21/288
• CPC Class Codes: H01L 21/76886 Modifying permanently or temporarily the pattern or the conductivity of conductive members, e.g. formation of alloys, reduction of contact resistances
• CPC Class Codes: H01L 23/5252 comprising anti-fuses, i.e. connections having their state changed from non-conductive to conductive

Abstract

A back-end-of-the-line (BEOL) anti-fuse of a BEOL structure is disclosed. The anti-fuse structure includes a metallization layer formed in a first insulator layer of the BEOL structure. The metallization layer has a trench formed therein. The trench has substantially vertical sidewalls and angled sidewalls formed underlying the vertical sidewalls, the angled sidewalls angled to meet at an apex. The anti-fuse structure further includes a second insulator formed on the vertical sidewalls and the angled sidewalls. The anti-fuse structure further includes a metallic via formed on the second insulator in the trench.

Claims

1. A method for manufacturing a back-end-of-the-line (BEOL) anti-fuse of a BEOL structure, comprising:

forming a trench in a metallization layer disposed in a first insulator layer of the BEOL structure, the trench having vertical sidewalls and angled sidewalls extending from underlying the vertical sidewalls, the angled sidewalls angled to meet at an apex;

forming a second insulator layer on the vertical sidewalls and the angled sidewalls; and

forming a metallic via on the second insulator layer in the trench to form the anti-fuse.

2. The method of claim 1, further comprising, before forming the trench in the metallization layer, forming a dielectric capping layer overlying the first insulator layer and the metallization layer.

3. The method of claim 2, further comprising forming a lower low-k dielectric layer overlying the dielectric capping layer and forming an upper low-k dielectric layer overlying the lower low-k dielectric layer.

4. The method of claim 3, further comprising forming a first portion of a second trench in the lower low-k dielectric layer selective to the metallization layer and a second wider portion of the second trench in the upper low-k dielectric layer overlying the lower low-k dielectric layer.

6. The method of claim 4, further comprising forming a liner layer overlying the first portion of the second trench, the second wider portion of the second trench, and the metallization layer underlying the first portion of the second trench.

7. The method of claim 6, wherein the liner layer is made of a metal that acts as a barrier layer to prevent diffusion of metal from the via past the liner layer into the lower low-k dielectric layer and the upper low-k dielectric layer.

8. The method of claim 6, further comprising performing directional ion bombardment with ions of the liner layer to extend the second trench to form the trench in the metallization layer.

10. The method of claim 1, wherein the second insulator layer is made of a high-k dielectric material.

11. The method of claim 1, wherein the second insulator layer is formed using a deposition process comprising at least one of chemical vapor deposition (CVD), plasma enhanced chemical vapor deposition (PECVD), atomic layer deposition (ALD), or physical vapor deposition (PVD).

12. The method of claim 1, further comprising performing a planarization process on the via to align a top portion of the via with a top portion of the remainder of the BEOL structure.

13. The method of claim 1, wherein the metallization layer is made of at least one of copper (Cu), aluminum (Al), or a Cu—

Al alloy.

14. The method of claim 1, wherein the metallic via is made of a metal selected from the group consisting of copper (Cu), Tungsten (W), Aluminum (Al), Cobalt (Co), or Ruthenium (Ru).

5. (canceled)

9. (canceled)

15. A back-end-of-the-line (BEOL) anti-fuse of a BEOL structure, comprising:

a metallization layer formed in a first insulator layer of the BEOL structure, the metallization layer having a trench formed therein, the trench having substantially vertical sidewalls and angled sidewalls formed underlying the vertical sidewalls, the angled sidewalls angled to meet at an apex;

a second insulator formed on the vertical sidewalls and the angled sidewalls; and

a metallic via formed on the second insulator in the trench to produce the anti-fuse.

16. The BEOL anti-fuse of claim 15, wherein the second insulator is made from a high-k material.

18. The BEOL anti-fuse of claim 15, wherein the first insulator layer is made of a low-k material.

19. The BEOL anti-fuse of claim 15, wherein the metallic via is made of a metal selected from the group consisting of include.

20. The BEOL anti-fuse of claim 15, wherein the second insulator underlies the entirety of the metallic via.

21. The BEOL anti-fuse of claim 15, further comprising a dielectric capping layer overlying the first insulator layer and a portion of the metallization layer that does not include the trench.

22. The BEOL anti-fuse of claim 21, further comprising a lower low-k dielectric layer formed overlying the dielectric capping layer and an upper low-k dielectric layer formed overlying the lower low-k dielectric layer.

23. The BEOL anti-fuse of claim 22, further comprising a liner layer made of a metal that acts as a barrier layer to prevent diffusion of metal from the via past the liner layer into the lower low-k dielectric layer and the upper low-k dielectric layer.

17. (canceled)