Back-end-of-the line capacitor

• US 10,497,519 B1
• Filed: 09/27/2018
• Issued: 12/03/2019
• Est. Priority Date: 09/27/2018
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Yang, Chih-Chao
• Primary Examiner(s): Nikmanesh, Seahvosh
• Application Number:
  US16/144,480
• Time in Patent Office: 432 Days
• CPC Class Codes: H01G 4/005 Electrodes
• CPC Class Codes: H01G 4/008 Selection of materials
• CPC Class Codes: H01G 4/018 Dielectrics
• CPC Class Codes: H01G 4/224 Housing; Encapsulation
• CPC Class Codes: H01G 4/30 Stacked capacitors H01G4/33 takes precedence
• 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 28/40 Capacitors
• CPC Class Codes: H01L 28/65 comprising a noble metal or a noble metal oxide, e.g. platinum (Pt), ruthenium (Ru), ruthenium dioxide (RuO2), iridium (Ir), iridium dioxide (IrO2)

Abstract

A back-end-of-the-line (BEOL) metal-insulator-metal (MIM) capacitor is provided that includes three electrode plates in which the first electrode plate of the MIM capacitor is an electrically conductive interconnect structure embedded in a first interconnect dielectric material layer. The other two electrode plates are located in a second interconnect dielectric material layer that is located above the first interconnect dielectric material layer. A first contact structure is present in the second interconnect dielectric material layer and contacts a surface of the first interconnect dielectric material layer, wherein the first contact structure passes through the second electrode plate. A second contact structure is also present in the second interconnect dielectric material layer and contacts a surface of the first electrode plate, wherein the second contact structure passes through the third electrode plate. Capacitor dielectric materials are located between each of the electrode plates.

Claims

1. A back-end-of-the-line (BEOL) metal-insulator-metal (MIM) capacitor comprising:

a first electrode plate comprising an electrically conductive interconnect structure embedded in a first interconnect dielectric material layer;

a first capacitor dielectric material located above the electrically conductive interconnect structure and embedded in a second interconnect dielectric material layer;

a second electrode plate located on the first capacitor dielectric material and embedded in the second interconnect dielectric material layer;

a second capacitor dielectric material located on the second electrode plate and embedded in the second interconnect dielectric material layer, wherein a surface of the second capacitor dielectric material contacts an outermost sidewall surface of the second electrode plate;

a third electrode plate located on the second capacitor dielectric material and embedded in the second interconnect dielectric material layer;

a first contact structure present in the second interconnect dielectric material layer and contacting a surface of the first interconnect dielectric material layer, wherein the first contact structure passes through the second electrode plate and the first capacitor dielectric material; and

a second contact structure present in the second interconnect dielectric material layer and contacting a surface of the first electrode plate, wherein the second contact structure passes through the third electrode plate and the second capacitor dielectric material.

2. The BEOL MIM capacitor of claim 1, further comprising a dielectric capping layer present between the first and second interconnect dielectric material layers.

3. The BEOL MIM capacitor of claim 1, further comprising a diffusion liner located on sidewall surfaces and a bottomost surface of each of the first contact structure and the second contact structure.

4. The BEOL MIM capacitor of claim 1, wherein the first and second capacitor dielectric materials are composed of a same capacitor dielectric material.

5. The BEOL MIM capacitor of claim 1, wherein the first capacitor dielectric material has outermost sidewall surfaces that are vertically aligned to outermost sidewall surfaces of the second electrode plate.

6. The BEOL MIM capacitor of claim 5, wherein the second capacitor dielectric material has outermost sidewall surfaces that are vertically aligned to outermost sidewall surfaces of the third electrode plate.

7. The BEOL MIM capacitor of claim 1, wherein each of the first capacitor dielectric material and the second capacitor dielectric material has a surface that directly contacts the first electrode plate.

8. The BEOL MIM capacitor of claim 1, wherein each of the third electrode plate and the second capacitor dielectric material overlaps a stack of the second electrode plate and the first capacitor dielectric material.

9. The BEOL MIM capacitor of claim 1, wherein the electrically conductive interconnect structure is composed of copper (Cu), aluminum (Al), tungsten (W), cobalt (Co) or alloys thereof.

10. The BEOL MIM capacitor of claim 9, wherein each of the second electrode plate and the third electrode plate is composed of tantalum (Ta), titanium (Ti), tungsten (W), copper (Cu), aluminum (Al), ruthenium (Ru), rhodium (Rh), cobalt (Co), titanium nitride (TiN) or tantalum nitride (TaN).

11. The BEOL MIM capacitor of claim 1, wherein each of the first capacitor dielectric material and the second capacitor dielectric material is composed of high-k material.

12. The BEOL MIM capacitor of claim 1, wherein the first contact structure has a topmost surface that is coplanar with a topmost surface of second contact structure and a topmost surface of the second interconnect dielectric material layer.