Apparatus and method for electrolytically depositing copper on a semiconductor workpiece
AssigneeSemitool, Inc.
InventorsLinlin Chen, Thomas Taylor
Life of this patent
Estimating the term…
Abstract
A process for applying a metallization interconnect structure to a semiconductor workpiece having a barrier layer deposited on a surface thereof is set forth. The process includes the forming of an ultra-thin metal seed layer on the barrier layer. The ultra-thin seed layer having a thickness of less than or equal to about 500 Angstroms. The ultra-thin seed layer is then enhanced by depositing additional metal thereon to provide an enhanced seed layer. The enhanced seed layer has a thickness at all points on sidewalls of substantially all recessed features distributed within the workpiece that is equal to or greater than about 10% of the nominal seed layer thickness over an exteriorly disposed surface of the workpiece.
Claims24
A method of forming copper interconnect structures, comprising:
- providing a workpiece having a dielectric layer, a plurality of submicron micro-recesses in the dielectric layer, a first layer that conforms to the submicron micro-recesses, and a copper seed layer that conforms to the first layer, the seed layer having a thickness of approximately 50 Å to 500 Å, and the seed layer being a non-continuous layer with voids over portions of the first layer;
- filling the voids within the non-continuous seed layer with additional copper to form a conformal seed layer that covers substantially all of the first layer by contacting the non-continuous seed layer with an alkaline solution containing copper;
- and
- electroplating copper onto the conformal seed layer in an acidic solution containing copper to fill the micro-recesses with copper.
A method of forming copper interconnect structures, comprising:
- providing a workpiece having a dielectric layer, a plurality of submicron micro-recesses in the dielectric layer, a first layer that conforms to the submicron micro-recesses, and a copper seed layer that conforms to the first layer, the seed layer having a thickness of approximately 50 Å to 500 Å, and the seed layer being a non-continuous layer with voids over portions of the first layer;
- filling the voids within the non-continuous seed layer with additional copper and reducing copper oxide on the non-continuous seed layer to metallic copper to form a conformal seed layer that covers substantially all of the first layer by contacting the non-continuous seed layer with an alkaline solution containing copper;
- and
- electroplating copper onto the conformal seed layer in an acidic solution containing copper to fill the micro-recesses with copper.
A method of forming copper interconnect structures in submicron micro-recesses on a workpiece having a barrier layer conforming to the micro-recesses and a copper seed layer over the barrier layer, the seed layer having a thickness of approximately 50 Å to 500 Å, and the seed layer being a non-continuous layer having voids, the method comprising:
- reducing copper oxide on the non-continuous seed layer to metallic copper and filling the voids within the non-continuous seed layer by contacting the non-continuous seed layer with a first solution containing copper to form a conformal seed layer that covers substantially all of the barrier layer;
- and
- electroplating additional copper over the conformal seed layer to fill the micro-recesses by contacting the workpiece with a second solution containing copper, wherein the second solution is different than the first solution.
A method of forming copper interconnect structures in submicron micro-recesses on a workpiece having a barrier layer conforming to the micro-recesses and a copper seed layer over the barrier layer, the seed layer having a thickness of approximately 50 Å to 500 Å, and the seed layer being a non-continuous layer having voids, the method comprising:
- reducing copper oxide on the non-continuous seed layer to metallic copper and adhering additional copper to exposed areas of the barrier layer to fill the voids within the non-continuous seed layer by contacting the non-continuous seed layer with a first solution containing copper to form a conformal metallic copper seed layer that covers substantially all of the barrier layer;
- and
- electroplating additional copper over the conformal seed layer to fill the micro-recesses by contacting the workpiece with a second solution containing copper, wherein the second solution is different than the first solution.
A method of forming copper interconnect structures in submicron micro-recesses having widths less than 0.5 μm on a workpiece having a barrier layer conforming to the micro-recesses and a copper seed layer over the barrier layer, the seed layer having a thickness of approximately 50 to 500 Å, and the seed layer being a non-continuous layer having voids, the method comprising:
- reducing copper oxide on the non-continuous seed layer to metallic copper and filling the voids within the non-continuous seed layer by contacting the non-continuous seed layer with a first solution containing copper to form a conformal seed layer that covers substantially all of the barrier layer;
- and
- electroplating additional copper over the conformal seed layer to fill the micro-recesses by contacting the workpiece with a second solution containing copper, wherein the second solution is different than the first solution.
A method of forming copper interconnect structures, comprising:
- providing a semiconductor workpiece having a dielectric layer, a plurality of submicron micro-recesses having a width less than 0.5 μm in the dielectric layer, a barrier layer that conforms to the micro-recesses, and a copper seed layer over the barrier layer, the seed layer having a thickness of approximately 50 Å to 500 Å, and the seed layer being a non-continuous layer having voids;
- filling the voids in the non-continuous seed layer by depositing additional copper onto the seed layer in an alkaline solution containing copper;
- removing the workpiece from the alkaline solution and rinsing the workpiece;
- and
- filling the micro-recesses with copper by electroplating copper into the micro-recesses in an acidic solution containing copper.
A method of forming copper damascene interconnect structures, comprising:
- providing a workpiece having a dielectric layer, a plurality of trenches having submicron widths, a barrier layer conforming to the trenches, and a copper seed layer over the barrier layer, the seed layer having a thickness of approximately 50 Å to 500 Å, and the seed layer being a non-continuous layer having voids:
- contacting the non-continuous seed layer with an alkaline solution containing copper to form a conformal seed layer that covers substantially all of the barrier layer;
- removing the workpiece from the alkaline solution;
- rinsing the workpiece;
- electroplating the conformal copper seed layer in an acidic solution to fill the trenches with copper;
- and
- planarizing the workpiece to form inlaid copper lines in the trenches.
Dependencies are inferred from the claim text.