Method of forming metal and metal alloy features

Patent metadata

Field	Value
Publication number	US-2016355941-A1
Application number	US-201615174735-A
Country	US
Kind code	A1
Filing date	Jun 6, 2016
Priority date	Aug 18, 2006
Publication date	Dec 8, 2016
Grant date	—

Abstract

Electric potential, current density, agitation, and deposition rate are controlled to deposit metal alloys, such as tin based solder alloys or magnetic alloys, with minimal variations in the weight ratios of alloying metals at different locations within the deposited metal alloy feature. Alternative embodiments include processes that form metal alloy features wherein the variation in weight ratio of alloying metals within the feature is not necessarily minimized, but is controlled to provide a desired variation. In addition to metal alloys, alternative embodiments include processes for improving the deposition of single metal features.

First claim

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1 . A method of forming a metal feature by plating through a patterned dielectric layer in an electroplating bath, the method comprising:
providing a microfeature workpiece that includes a substrate having a continuous metal seed layer disposed on the substrate and a dielectric layer patterned on the metal seed layer to provide a recess defining sidewall surfaces and a bottom surface, wherein the bottom surface of the recess is a metal surface and the sidewall surfaces of the recess are dielectric surfaces; providing an electroplating bath in contact with an electrode; contacting the microfeature workpiece with the electroplating bath; applying an electric potential between the metal seed layer and the electrode to produce a first current density in the electroplating bath; agitating the electroplating bath with an agitator at a first agitation speed in the electroplating bath; electrochemically depositing a first metal layer on the exposed top surface of the metal seed layer in the recess in the electroplating bath; and controlling metal deposition by adjusting at least one of the electric potential and the agitator to at least one of a second current density and a second agitation speed as a second metal layer is deposited in the electroplating bath, wherein the second current density is greater than the first current density or the second agitation speed is less than the first agitation speed and wherein first metal layer and the second metal layer are substantially the same.

2 . The method of claim 1 , wherein the metal in the first and second metal layers is a metal alloy.

3 . The method of claim 2 , wherein the metal alloy is from the group consisting of noble metal alloys, lead-free alloys, Permalloy, nickel alloys, tin-silver tin-copper, tin-silver-copper, and tin-bismuth.

4 . The method of claim 2 , wherein the first and second metal layers have a substantially constant weight ratio of alloying metals.

5 . The method of claim 1 , wherein the metal in the first and second metal layers is a single metal.

6 . The method of claim 1 , wherein the depth of the recess is in the range of about 21 microns to 134 microns.

7 . The method of claim 1 , further comprising controlling metal deposition by adjusting both the electric potential and the agitator as the second metal layer is deposited in the electroplating bath, wherein the adjusted current density is greater than the first current density and the adjusted agitation speed is less than the first agitation speed.

8 . The method of claim 1 , further comprising controlling metal deposition by adjusting at least one of the electric potential and the agitator as a third metal layer is deposited in the electroplating bath, wherein the adjusted current density is greater than the first current density or the adjusted agitation speed is less than the first agitation speed and wherein first, second, and third metal layers are substantially the same.

9 . The method of claim 8 , further comprising controlling metal deposition by adjusting both the electric potential and the agitator as the third metal layer is deposited in the electroplating bath, wherein the adjusted current density is greater than the first current density and the adjusted agitation speed is less than the first agitation speed.

10 . A method of forming a metal feature by plating through a patterned dielectric layer in an electroplating bath, the method comprising:
providing a microfeature workpiece that includes a substrate having a continuous metal seed layer disposed on the substrate and a dielectric layer patterned on the metal seed layer to provide a recess defining sidewall surfaces and a bottom surface, wherein the bottom surface of the recess is a metal surface and the sidewall surfaces of the recess are dielectric surfaces; providing an electroplating bath in contact with an electrode; contacting the microfeature workpiece with the electroplating bath; applying an electric potential between the metal seed layer and the electrode and producing a first current density; electrochemically depositing a first metal layer within the recessed feature on an exposed top surface of the metal seed layer at a first deposition rate in the same electroplating bath; adjusting the electric potential to change the first current density to a second current density, wherein the second current density is increased from the first current density in the electroplating bath; electrochemically depositing a second metal layer within the same recessed feature on the exposed top surface of the first metal layer at a second deposition rate in the same electroplating bath, wherein the second deposition rate is greater than the first deposition rate; adjusting the electric potential to change the second current density to a third current density, wherein the third current density is increased from the second current density in the electroplating bath; and electrochemically depositing a third metal layer within the same recessed feature on the exposed top surface of the second metal layer at a third deposition rate in the same electroplating bath, wherein the third deposition rate is greater than the second deposition rate, wherein the first metal layer is deposited to a first depth, the second metal layer is deposited to a second depth, and the third metal layer is deposited to a third depth, wherein the first, second, and third current densities achieve an increasing deposition rate at the first, second, and third depths, wherein first, second, and third metal layers are substantially the same.

11 . The method of claim 10 , wherein the metal in the first, second, and third metal layers is a metal alloy.

12 . The method of claim 11 , wherein the metal alloy is from the group consisting of noble metal alloys, lead-free alloys, Permalloy, nickel alloys, tin-silver tin-copper, tin-silver-copper, and tin-bismuth.

13 . The method of claim 11 , wherein the first, second, and third metal layers have a substantially constant weight ratio of alloying metals.

14 . The method of claim 10 , wherein the metal in the first, second, and third metal layers is a single metal.

15 . The method of claim 10 , wherein the depth of the recess is in the range of about 21 microns to 134 microns.

16 . The method of claim 10 , further comprising agitating the electroplating bath with an agitator at a first agitation speed.

17 . The method of claim 16 , further comprising adjusting the other of the agitator from the first agitation speed to a second agitation speed as the metal is deposited.

18 . The method of claim 17 , wherein the second agitation speed is less than the first agitation speed.

19 . The method of claim 18 , further comprising adjusting the agitator from the second agitation speed to a third agitation speed as the metal is deposited, wherein the third agitation speed is less than the second agitation speed.

20 . A method of forming a metal feature by plating through a patterned dielectric layer in an electroplating bath, the method comprising:
providing a microfeature workpiece that includes a substrate having a continuous metal seed layer disposed on the substrate and a dielectric layer patterned on the metal seed layer to provide a recess defining sidewall surfaces and a bottom surface, wherein the bottom surface of the recess is a metal surface and the sidewall surfaces of the rec

Assignees

• Applied Materials Inc

Inventors

• Kim Bioh
• Bernt Marvin
• Wilson Greg
• Mchugh Paul R

Classifications

• C25D3/56

  of alloys · CPC title

• C25D5/02 Primary

  Electroplating of selected surface areas · CPC title

• C25D21/10

  Agitating of electrolytes; Moving of racks · CPC title

• C25D5/18

  Electroplating using modulated, pulsed or reversing current · CPC title

• C25D7/123

  Semiconductors first coated with a seed layer or a conductive layer · CPC title