Method for manufacturing copper layer
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsKen-Yu Chang, Hung-Wen Su
Life of this patent
Estimating the term…
Abstract
A method of forming a semiconductor structure includes the steps: providing a substrate; forming a dielectric over the substrate; forming an opening recessed under a top surface of the dielectric; forming a barrier layer on a sidewall of the opening; performing a physical vapor deposition (PVD) to form a copper layer over the barrier layer, a corner of the opening intersecting with the top surface and the top surface with a predetermined resputter ratio so that the ratio of the thickness of the copper layer on the barrier layer and the thickness of the copper layer over the top surface is substantially greater than 1.
Claims20
A method of forming a semiconductor structure, comprising:
- providing a substrate;
- forming a dielectric over the substrate;
- forming a trench recessed under a top surface of the dielectric;
- forming a barrier layer on a lateral sidewall of the trench;
- and
- depositing a first copper layer over the barrier layer and the top surface of the dielectric, wherein the depositing provides a ratio of the thickness of the first copper layer on the barrier layer at a middle portion of the lateral sidewall and the thickness of the first copper layer over the top surface is greater than 1.
A method of forming a semiconductor structure, comprising:
- providing a substrate;
- forming a dielectric over the substrate;
- forming an opening recessed under a top surface of the dielectric;
- forming a barrier layer on a sidewall of the opening;
- performing a physical vapor deposition (PVD) to form a copper layer over the barrier layer;
- and
- reflowing the copper layer by an annealing operation,
- wherein a resputter ratio, which is a ratio of the thickness of the copper layer applied to the substrate without a substrate bias to the thickness of copper layer applied to the substrate with the substrate bias, is greater than 2.5.
A method of forming a semiconductor structure, comprising:
- forming a substrate;
- forming a dielectric over the substrate;
- forming a damascene interconnect structure with a critical dimension (CD) less than about 38 nm and surrounded by the dielectric, wherein the damascene interconnect comprises:
- a barrier layer adjacent to a sidewall of the dielectric and the barrier layer comprising a metallic nitride compound;
- and
- forming a first copper film in a deposition operation with an impurity concentration below about 1 ppm disposed over the barrier layer and the top surface of the dielectric, wherein the deposition operation provides a ratio of a thickness of the first copper film at a middle portion of a lateral sidewall of the dielectric and a thickness of the first copper film over a top surface of the dielectric is greater than 1.
Dependencies are inferred from the claim text.