Wetting pretreatment for enhanced damascene metal filling

Patent metadata

Field	Value
Publication number	US-2018138044-A1
Application number	US-201715818329-A
Country	US
Kind code	A1
Filing date	Nov 20, 2017
Priority date	Jun 17, 2009
Publication date	May 17, 2018
Grant date	—

Abstract

Disclosed are pre-wetting apparatus designs and methods. These apparatus designs and methods are used to pre-wet a wafer prior to plating a metal on the surface of the wafer. Disclosed compositions of the pre-wetting fluid prevent corrosion of a seed layer on the wafer and also improve the filling rates of features on the wafer.

First claim

1 . A method of electroplating a layer of metal on a wafer substrate, the method comprising:
(a) providing the wafer substrate having an exposed metal layer on at least a portion of its surface to a pre-wetting process chamber; (b) contacting the wafer substrate with a pre-wetting fluid comprising a water-miscible solvent to form a layer of pre-wetting fluid on the wafer substrate; (c) contacting the pre-wetted wafer substrate with a plating solution comprising metal ions to electroplate a layer of metal on the wafer substrate.

2 . The method of claim 1 , wherein the water-miscible solvent is selected from the group consisting of an alcohol, dimethylcarbonate, diethylcarbonate, dimethyl sulfoxide, and dimethyl formamide.

3 . The method of claim 1 , wherein the plating solution comprises copper ions to electroplate a layer of copper on the wafer substrate.

4 . A method of electroplating a layer of metal on a wafer substrate, the method comprising:
(a) providing the wafer substrate having an exposed metal layer on at least a portion of its surface to a pre-wetting process chamber; (b) reducing pressure in the pre-wetting process chamber to a subatmospheric pressure; (c) contacting the wafer substrate, at a subatmospheric pressure, with a pre-wetting fluid comprising an acid to at least partially remove surface oxide from the exposed metal layer and to form a layer of pre-wetting fluid on the wafer substrate, wherein the pre-wetting fluid has a pH of between about 2 to 6; (d) contacting the pre-wetted wafer substrate with a plating solution comprising metal ions to electroplate a layer of metal on the wafer substrate, wherein the plating solution has a pH of between about 2 to 6, wherein the plating solution and the pre-wetting fluid have different compositions.

5 . The method of claim 4 , wherein the plating solution comprises copper ions to electroplate a layer of copper on the wafer substrate.

6 . A method of electroplating a layer of metal on a wafer substrate, the method comprising:
(a) providing the wafer substrate having an exposed metal layer on at least a portion of its surface to a pre-wetting process chamber; (b) contacting the wafer substrate with a pre-wetting fluid comprising a reducing agent to at least partially reduce surface oxide on the exposed metal layer and to form a layer of pre-wetting fluid on the wafer substrate; (c) contacting the pre-wetted wafer substrate with a plating solution comprising metal ions to electroplate a layer of metal on the wafer substrate.

7 . The method of claim 6 , wherein the plating solution comprises copper ions to electroplate a layer of copper on the wafer substrate.

8 - 9 . (canceled)

Assignees

• Novellus Systems Inc

Inventors

• Mayer Steven T
• Porter David W
• Willey Mark J

Classifications

• H10W20/023

  the interconnections being through-semiconductor vias · CPC title

• H10W20/052

  by treatments not introducing additional elements therein · CPC title

• H10P14/47 Primary

  Electrolytic deposition, i.e. electroplating; Electroless plating · CPC title

• H10P90/12

  Preparing bulk and homogeneous wafers · CPC title

• H10P14/40 Primary

  of conductive or resistive materials · CPC title