Selective refractory metal and nitride capping
AssigneeNovellus Systems, Inc.
InventorsJames A. Fair, Robert H. Havemann, Jungwan Sung, Nerissa Taylor, Sang-Hyeob Lee, Mary Anne Plano
Life of this patent
Estimating the term…
Abstract
A method for creating a refractory metal and refractory metal nitride cap effective for reducing copper electromigration and copper diffusion is described. The method includes depositing a refractory metal nucleation layer and nitriding at least the upper portion of the refractory metal layer to form a refractory metal nitride. Methods to reduce and clean the copper lines before refractory metal deposition are also described. Methods to form a thicker refractory metal layer using bulk deposition are also described.
Claims55
A method of forming a capping layer on copper lines of a semiconductor device, the method comprising:
- (a) providing a partially fabricated semiconductor device having a surface comprising exposed surfaces of the copper lines and dielectric around the copper lines,
- (b) creating a nucleation refractory metal layer over at least the exposed surfaces of the copper lines;
- (c) depositing a bulk refractory metal layer over at least the nucleation refractory metal layer created in (b);
- and
- (d) nitriding at least an upper portion of the bulk refractory metal layer deposited in (c) to form a refractory metal nitride layer effective for reducing electromigration of the copper line and for blocking diffusion of copper from the copper conductive lines.
A method of forming a capping layer on copper lines of a semiconductor device, the method comprising:
- (a) providing a partially fabricated semiconductor device having a surface comprising exposed surfaces of the copper lines and dielectric around the copper lines;
- (b) creating a nucleation refractory metal layer over at least the exposed surfaces of the copper lines;
- (c) depositing a bulk refractory metal layer over at least the nucleation refractory metal layer created in (b).
A method of forming a capping layer on copper lines of a semiconductor device, the method comprising:
- (a) providing a partially fabricated semiconductor device having a surface comprising exposed surfaces of the copper lines and dielectric around the copper lines;
- (b) creating a refractory metal layer over at least the exposed surfaces of the copper lines;
- and
- (c) nitriding at least an upper portion of the refractory metal layer deposited in (c) to form a refractory metal nitride layer effective for reducing electromigration of the copper line and for blocking diffusion of copper from the copper conductive lines,
- wherein the exposed surfaces of the copper lines comprise copper oxide and wherein the method further comprises reducing the copper oxide before creating the refractory metal layer.
A method of forming a capping layer on copper lines of a semiconductor device, the method comprising:
- (a) providing a partially fabricated semiconductor device having a surface comprising exposed surfaces of the copper lines and dielectric around the copper lines;
- (b) creating a nucleation refractory metal layer over at least the exposed surfaces of the copper lines;
- and
- (c) nitriding at least an upper portion of the nucleation refractory metal layer deposited in (b) to form a refractory metal nitride layer effective for reducing electromigration of the copper line and for blocking diffusion of copper from the copper conductive lines.
Dependencies are inferred from the claim text.