Air gap semiconductor structure with selective cap bilayer

Patent metadata

Field	Value
Publication number	US-9305836-B1
Application number	US-201414536751-A
Country	US
Kind code	B1
Filing date	Nov 10, 2014
Priority date	Nov 10, 2014
Publication date	Apr 5, 2016
Grant date	Apr 5, 2016

Abstract

A semiconductor substrate including one or more conductors is provided. A first layer and a second layer are deposited on the top surface of the conductors. A dielectric cap layer is formed over the semiconductor substrate and air gaps are etched into the dielectric layer. The result is a bilayer cap air gap structure with effective electrical performance.

First claim

What is claimed is:

1. A semiconductor structure comprising:
a dielectric layer present on a semiconductor substrate;
one or more conductors within the dielectric layer, wherein the one or more conductors have a top surface;
a bilayer cap present on the one or more conductors, wherein the bilayer cap comprises a first layer and a second layer, and wherein the second layer comprises one or more of: CoCH, CoSiNCH, CoSi x , and a capping material including SiCH, SiCNH, amorphous C, and amorphous CH; and
a plurality of air gaps, wherein the air gaps are etched into the dielectric layer.

2. The semiconductor structure of claim 1 , wherein the first layer comprises an adhesive layer, and is configured to be in adhesive contact with the one or more conductors.

3. The semiconductor structure of claim 1 , wherein the second layer comprises a protective layer, and is configured to be in adhesive contact with the first layer.

4. The semiconductor structure of claim 1 , wherein the bilayer cap is a self-aligned bilayer cap.

5. The semiconductor structure of claim 1 , wherein the first layer comprises one or more metals including: cobalt, manganese, tantalum, ruthenium, aluminum, nickel, tungsten, platinum, palladium, and rhenium.

6. The semiconductor structure of claim 1 , wherein the first layer comprises an electroless metal capping layer, wherein the electroless metal capping layer comprises one or more of: CoWP, CoWB, NiWP, and a selective CVD Ru cap.

7. The semiconductor structure of claim 1 , wherein the second layer comprises a metal compound, wherein the metal compound includes: C, Si, N, and H.

8. A semiconductor structure comprising:
a dielectric layer present on a semiconductor substrate;
one or more Cu conductors within the dielectric layer, wherein the one or more Cu conductors have a top surface;
a bilayer cap present on the one or more Cu conductors, wherein the bilayer cap comprises a first layer deposited on the top surface of the Cu conductors and a second layer deposited on the first layer, wherein the second layer comprises one or more of: a metal containing alloy including MC x , MN y , MC x N y , MSi x C y , MSi x N y , and MSi x N y C z , wherein M is selected from Co, Mn, Ta, Re, Al, Ni, W, Pt, Pd, Re;
a plurality of air gaps, wherein the air gaps are etched to a selected depth within the dielectric layer; and
a conformal cap layer deposited on, at least, the top surface of the dielectric layer, and a non-conformal cap layer deposited on, at least, the top surface of the deposited conformal cap layer.

9. The semiconductor structure of claim 8 , wherein the bilayer cap comprises a repeated plurality of first layers and second layers to form a multiple layer cap.

10. The semiconductor structure of claim 8 , wherein the plurality of air gaps are etched to a selected depth range from 2 nm to 50 nm below the top surface of the one or more conductors.

Assignees

• IBM

Inventors

• Gates Stephen M
• Huang Elbert E
• Kioussis Dimitri R
• Penny Christopher J
• Priyadarshini Deepika

Classifications

• H10P50/283

  by chemical means · CPC title

• H10P14/46

  using a liquid · CPC title

• H10P14/43

  Chemical deposition, e.g. chemical vapour deposition [CVD] · CPC title

• H10W20/0526

  by thermal treatment thereof · CPC title

• H10W20/0523

  by irradiating with ultraviolet or particle radiation · CPC title