Back to results
US 9,960,117 B2Granted
Air gap semiconductor structure with selective cap bilayer
AssigneeInternational Business Machines Corporation
InventorsStephen M. Gates, Elbert E. Huang, Dimitri R. Kioussis, Christopher J. Penny, Deepika Priyadarshini
Life of this patent
Estimating the term…
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.
Claims18
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 and a lower surface, wherein the top surface has a height equal to the dielectric layer, and wherein the bottom surface has a barrier layer;
- a bilayer cap present on the one or more conductors, wherein the bilayer cap comprises a first layer and a second layer, wherein the second layer is a protective layer containing carbon (C) based structures and is self-aligned to the top surface of the one or more conductors, and wherein the first layer is an adhesive layer, which promotes electromigration, comprising:
- one or more metals, and is between 1 nanometer (nm) to 10 nanometers (nm) thick;
- a plurality of air gaps, wherein the plurality of air gaps are etched into the dielectric layer to a depth between 2 nm to 50 nm, below the top surface of the one or more conductors;
- a modified layer on top of the dielectric layer within the plurality of air gaps, wherein the modified layer forms in response to removal of the carbon (C) based structures by plasma treatment;
- and
- a dielectric cap layer, wherein the dielectric cap layer is a sacrificial protective layer.
5 more elements
A semiconductor structure comprising:
- a dielectric layer present on a semiconductor substrate;
- one or more copper (Cu) conductors within the dielectric layer, wherein the one or more Cu conductors have a top surface and a bottom surface, wherein the top surface has a height equal to the dielectric layer, and wherein the bottom surface has a barrier layer;
- a bilayer cap present on the one or more Cu conductors, wherein the bilayer cap comprises a repeated plurality of a first layer deposited on the top surface of the one or more Cu conductors and a second layer deposited on the first layer, wherein the first layer is an adhesive, which promotes electromigration, comprising:
- one or more metals, and is between 1 nm to 10 nm thick, and wherein the second layer contains carbon (C) based structures and is self-aligned to the top surface of the one or more Cu conductors of the first layer;
- a plurality of air gaps, wherein the plurality of air gaps are etched to a depth between 2 nm to 50 nm, below the top surface of the one or more Cu conductors within the dielectric layer;
- a surface modification of the first layer, wherein the surface modification of first layer modifies density;
- a modified layer on top of the dielectric layer within the plurality of air gaps, wherein the modified layer forms in response to removal of the carbon (C) based structures by plasma treatment;
- a dielectric cap layer, wherein the dielectric cap layer is a sacrificial protective layer;
- and
- a deposited non-conformal cap layer and a deposited conformal cap layer, wherein the deposited non-conformal cap layer and the deposited conformal cap are above the bilayer cap.
7 more elements
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 and a bottom surface, wherein the top surface has a height equal to the dielectric layer, and wherein the bottom surface has a barrier layer;
- a bilayer cap present on the one or more conductors, wherein the bilayer cap comprises a first layer and a second layer, wherein the first layer is an adhesive, between 1 nm to 10 nm thick which promotes electromigration, comprising an electroless metal capping layer, wherein the electroless metal capping layer comprises one or more of:
- CoWP, CoWB, and NiWP and a selective CVD Ru cap and the second layer is a chemical modification of the first layer, wherein the second layer contains carbon (C) based structures;
- a plurality of air gaps, wherein the plurality of air gaps are etched to a depth corresponding to a bottom surface of the one or more conductors within the dielectric layer;
- a modified layer on top of the dielectric layer within the plurality of air gaps, wherein the modified layer forms in response to removal of the carbon (C) based structures by plasma treatment;
- and
- a dielectric cap layer, wherein the dielectric cap layer is a sacrificial protective layer.
5 more elements
Dependencies are inferred from the claim text.