Methods of electrochemical deposition for void-free gap fill

Patent metadata

Field	Value
Publication number	US-2018171502-A1
Application number	US-201615380771-A
Country	US
Kind code	A1
Filing date	Dec 15, 2016
Priority date	Dec 15, 2016
Publication date	Jun 21, 2018
Grant date	—

Abstract

A method of electroplating on a workpiece having at least one sub-30 nm feature includes applying a first electrolyte chemistry to the workpiece, the chemistry including a metal cation solute species having a concentration in the range of about 50 mM to about 250 mM and a suppressor resulting in polarization greater than 0.75 V and reaching 0.75 V of polarization at a rate greater than 0.25 V/s, and applying an electric waveform, wherein the electric waveform includes a period of ramping up of current followed by a period of partial ramping down of current.

First claim

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

1 . A method of electroplating on a workpiece having at least one sub-30 nm feature, the method comprising:
(a) applying a first electrolyte chemistry to the workpiece, the chemistry including a metal cation solute species having a concentration in the range of about 50 mM to about 250 mM and a suppressor resulting in polarization greater than 0.75 V and reaching 0.75 V of polarization at a rate greater than 0.25 V/s; and (b) applying an electric waveform, wherein the electric waveform includes a period of ramping up of current followed by a period of partial ramping down of current.

2 . The method of claim 1 , wherein the metal cation is copper.

3 . The method of claim 1 , wherein either or both of the ramping up of current and the ramping down of current is selected from the group consisting of linear continuous ramping, non-linear continuous ramping, or pulsed ramping.

4 . The method of claim 1 , wherein the ramping up period is in the range of about 50 ms to about 200 ms.

5 . The method of claim 1 , wherein the ramping up period begins either immediately upon entry or after an initial delay.

6 . The method of claim 1 , wherein the ramping up achieves a current level selected from the group consisting of in the range of about 1 amps to about 15 amps and in the range of about 7 amps to about 15 amps.

7 . The method of claim 1 , wherein the partial ramping down period is for a period in the range of about 50 ms to 5000 ms.

8 . The method of claim 1 , wherein the ramping down is from the current level achieved by ramping up to a current level in the range of about 2 amps to about 8 amps.

9 . The method of claim 1 , wherein the electric waveform includes a period of ramping up of current immediately followed by a period of partial ramping down of current.

10 . The method of claim 1 , wherein the electric waveform includes a period of ramping up of current immediately followed by an entry hold period of steady state current, immediately followed by a period of partial ramping down of current.

11 . The method of claim 10 , wherein the entry hold period is for a time period in the range of about 0 to about 200 ms.

12 . The method of claim 1 , further comprising a ramp down hold period of steady state current immediately following the period of partial ramp down of current and at the current level of the completion of the partial ramp down.

13 . The method of claim 12 , wherein the ramp down hold period of steady state current is for a period in the range selected from the group consisting of about 0 secs to about 1.0 sec and about greater than 0 secs to about 1.0 sec.

14 . The method of claim 12 , wherein the ramp down hold period of steady state current is held at a current level in the range of about 2 amps to about 8 amps.

15 . The method of claim 12 , further comprising a first period of steady state current following the hold period of steady state current to fill one or more features on the workpiece.

16 . The method of claim 15 , wherein the first period of steady state current is for a period in the range of about 10 secs to about 240 secs.

17 . The method of claim 15 , wherein the first period of steady state current is held at a current level in the range of about 2 amps to about 8 amps.

18 . The method of claim 15 , further comprising a second period of steady state current following the first period of steady state current to fill one or more features on the workpiece.

19 . The method of claim 18 , wherein the second period of steady state current is for a period in the range of about 0 secs to about 240 secs.

20 . The method of claim 18 , wherein the second period of steady state current is held at a current level in the range of about 4 amps to about 8 amps.

21 . The method of claim 18 , wherein the second period of steady state current has a current level greater than the first period of steady state current.

22 . The method of claim 15 , further comprising a capping step for the workpiece.

23 . The method of claim 22 , wherein the current for the capping step has a current level in the range of 15 amps to about 25 amps.

24 . The method of claim 1 , wherein the workpiece is rotated during entry at a speed in the range of about 35 to about 175 rpms.

Assignees

• Applied Materials Inc

Inventors

• Aksu Serdar
• Lee Jung Gu
• Sakry Bart
• Shaviv Roey

Classifications

• H10P14/47

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

• H10W20/056

  by filling conductive material into holes, grooves or trenches · CPC title

• C25D17/001

  Apparatus specially adapted for electrolytic coating of wafers, e.g. semiconductors or solar cells · CPC title

• C25D5/02

  Electroplating of selected surface areas · CPC title

• C25D5/34

  Pretreatment of metallic surfaces to be electroplated · CPC title