BEOL capacitor through airgap metallization

Patent metadata

Field	Value
Publication number	US-10475878-B2
Application number	US-201715856399-A
Country	US
Kind code	B2
Filing date	Dec 28, 2017
Priority date	Sep 1, 2016
Publication date	Nov 12, 2019
Grant date	Nov 12, 2019

Abstract

A backend-of-the-line (BEOL) semiconductor capacitor made by method, apparatus, or computer program product, through an airgap metallization process, patterning a first electrode by removing a portion of inter-layer dielectric for a desired capacitor area, depositing a dielectric for a capacitor insulator, filling the desired capacitor area to form a second electrode, polishing and capping the second electrode, and interconnecting the first electrode and the second electrode. The manufactured product has a bottom electrode, composed of a conductor, electrically connected to upward conductive prominences; a low-K layer, above and conjoined to the bottom layer and surrounding the prominences, composed of a low-K dielectric; an isolation layer, above the low-K layer and surrounding the prominences, composed of a high-K insulator material, where modulating its material and thickness controls the capacitance; and a top electrode, composed of a conductor and electrically connected to downward prominences, where the bottom and top electrodes are interconnected.

First claim

What we claim is:

1. A method comprising:
patterning a first array for a first electrode in a semiconductor capacitor;
removing a portion of inter-layer dielectric to achieve a desired capacitor area, wherein the removing comprises removing the portion of inter-layer dielectric from between metal lines to form trenches to create an interdigitated capacitor with a plurality of first prominences each having a first height and interconnected with a plurality of second prominences each having a second height, the first height being different from the second height;
depositing a dielectric for a capacitor insulator on the first prominences and on and under the second prominences, wherein variations in a material and/or thickness of the deposited dielectric determines a total capacitance of a structure formed;
filling the desired capacitor area to form a second electrode on the capacitor insulator;
polishing and capping the second electrode; and
interconnecting the first electrode and the second electrode.

2. The method of claim 1 , wherein the first electrode comprises conductive material.

3. The method of claim 1 , wherein the patterning uses a back end-of-the-line process of record.

4. The method of claim 1 , wherein the depositing comprises at least one existing high-K materials chemical vapor deposition process.

5. The method of claim 1 , wherein the second electrode comprises conductive material.

6. The method of claim 1 , wherein the depositing uses a back end-of-the-line process of record.

7. The method of claim 1 , wherein the polishing and capping uses a back end-of-the-line process of record.

8. The method of claim 1 , wherein the interconnecting uses a back end-of-the-line process of record.

9. A computer program product embodied on a non-transitory computer-readable medium in which a computer program is stored that, when being executed by a computer, is configured to provide instructions to control or carry out the method of claim 1 .

10. The method of claim 1 , wherein the removing of the portion of inter-layer dielectric comprises forming trenches that are wider on a bottom and narrower on a top.

11. The method of claim 10 , wherein depositing the dielectric to have variations in the material and/or thickness comprises depositing the dielectric to be thicker on the bottom of a wall of the trench and thinner on the top of the wall of the trench.

Assignees

• IBM

Inventors

• Bergendahl Marc A
• Demarest James J
• Penny Christopher J
• Waskiewicz Christopher

Classifications

• H10W20/496

  Capacitor integral with wiring layers · CPC title

• H01L28/92

  Electricity · mapped topic

• H01L28/90

  Electricity · mapped topic

• H01L28/60 Primary

  Electricity · mapped topic

• H10D1/716

  having vertical extensions · CPC title