Plating and deplating currents for material co-planarity in semiconductor plating processes

Patent metadata

Field	Value
Publication number	US-2023279576-A1
Application number	US-202217686129-A
Country	US
Kind code	A1
Filing date	Mar 3, 2022
Priority date	Mar 3, 2022
Publication date	Sep 7, 2023
Grant date	—

Abstract

A method of plating substrates may include placing a substrate in a plating chamber comprising a liquid, and applying a current to the liquid in the plating chamber to deposit a metal on exposed portions of the substrate, where the current may include alternating cycles of a forward plating current and a reverse deplating current. To determine the current characteristics, a model of a substrate may be simulated during the plating process to generate data points that relate characteristics of the plating process and a pattern on the substrate to a range nonuniformity of material formed on the substrate during the plating process. Using information from the data points, values for the forward and reverse currents may be derived and provided to the plating chamber to execute the plating process.

First claim

1 . A method of plating substrates, the method comprising:
placing a substrate in a plating chamber comprising a liquid, wherein the substrate comprises a patterned mask that exposes the substrate through a plurality of vias; and applying a current to the liquid in the plating chamber to deposit a metal on exposed portions of the substrate, wherein the current comprises alternating cycles of:
a forward plating current that deposits the metal unevenly in the plurality of vias at varying heights; and
a reverse deplating current that removes some of the metal in the plurality of vias such that the metal in the plurality of vias is evenly distributed.

2 . The method of claim 1 , wherein the patterned mask comprises exposed portions of the substrate adjacent to an open area, wherein a current density during a plating process is more concentrated at the exposed portions of the substrate adjacent to the open area compared to exposed portions of the substrate that are not adjacent to the open area.

3 - 4 . (canceled)

5 . The method of claim 1 , wherein the forward plating current and the reverse deplating current are both applied in the alternating cycles in the plating chamber when the substrate is in the liquid, without using separate chambers or liquids to apply the forward plating current and the reverse deplating current.

6 . The method of claim 1 , wherein the exposed portions of the substrate comprise a plurality of thru-silicon vias (TSVs), where there exists a difference between a maximum height of the TSVs and a minimum height of the TSVs.

7 . The method of claim 1 , further comprising, prior to applying the current to the liquid in the plating chamber:
simulating a model of the substrate during a plating process to generate data points that relate characteristics of the plating process and a pattern on the substrate to a predicted range nonuniformity of the metal on the substrate for the forward plating current and the reverse deplating current.

8 . The method of claim 7 , further comprising, prior to applying the current to the liquid in the plating chamber:
determining a value for the reverse deplating current using the data points that relate the characteristics of the plating process and the pattern on the substrate to the predicted range nonuniformity of the metal on the substrate.

9 . The method of claim 7 , further comprising, prior to applying the current to the liquid in the plating chamber:
determining a duty cycle for the alternating cycles of the forward plating current and the reverse deplating current using the data points that relate the characteristics of the plating process and the pattern on the substrate to the predicted range nonuniformity of the metal on the substrate.

10 . A system comprising:
a plating chamber comprising a liquid configured to receive a substrate comprising a patterned mask that exposes the substrate through a plurality of vias; and a controller configured to cause a current to be applied to the liquid in the plating chamber to deposit a metal on exposed portions of the substrate, wherein the current comprises alternating cycles of:
a forward plating current that deposits the metal unevenly in the plurality of vias at varying heights; and
a reverse deplating current that removes some of the metal in the plurality of vias such that the metal in the plurality of vias is evenly distributed.

11 . The method of claim 1 , further comprising applying the alternating cycles of the forward plating current and the reverse deplating current with a frequency that is based at least in part on a rotation speed of the substrate in the plating chamber.

12 . The method of claim 1 , further comprising applying the alternating cycles of the forward plating current and the reverse deplating current with a frequency that is based at least in part on a motion of a paddle in the plating chamber.

13 . The method of claim 1 , wherein the plating chamber comprises an electrochemical deposition chamber, and the liquid comprises an electrolyte.

14 . The method of claim 1 , wherein the forward plating current is applied at least 10 times as long as the deplating current.

15 . A non-transitory computer-readable medium comprising instructions that, when executed by one or more processors, cause the one or more processors to perform operations comprising:
simulating a model of a substrate in a plating process to generate data points that relate characteristics of the plating process and a pattern on the substrate to a range nonuniformity of material formed on the substrate during the plating process; using information from the data points, determining values for a forward plating current and a reverse deplating current to be applied in a plating chamber; and providing the values for the forward plating current and the reverse deplating current to the plating chamber to execute a plating process.

16 . The non-transitory computer-readable medium of claim 15 , wherein determining the values for the forward plating current and the reverse deplating current comprises:
receiving a target deposition rate for the plating process; receiving a forward plating rate for the plating process; and determining a reverse deplating rate for the plating process.

17 . The non-transitory computer-readable medium of claim 16 , wherein determining the values for the forward plating current and the reverse deplating current comprises:
determining a duty cycle for the forward plating current and the reverse deplating current based on the target deposition rate, the forward plating rate, and the reverse deplating rate.

18 . The non-transitory computer-readable medium of claim 16 , wherein the reverse deplating rate minimizes a range nonuniformity of the material formed on the substrate during the plating process.

19 . The non-transitory computer-readable medium of claim 15 , wherein the data points that relate characteristics of a plating process and a pattern on the substrate to a range nonuniformity of material formed on the substrate during the plating process comprises a linear relationship.

20 . The non-transitory computer-readable medium of claim 15 , wherein the data points that relate characteristics of a plating process and a pattern on the substrate to a range nonuniformity of material formed on the substrate during the plating process comprises a non-linear relationship.

Assignees

• Applied Materials Inc

Inventors

• Mchugh Paul R
• Sharbono Charles
• Xu Jing
• Klocke John L
• Lee Sam K
• Ypma Keith Edward

Classifications

• H10W20/0261

  characterised by the filling method or the material of the conductive fill · CPC title

• H10W20/023

  the interconnections being through-semiconductor vias · CPC title

• H10P14/47

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

• G06F30/20 Primary

  Design optimisation, verification or simulation (optimisation, verification or simulation of circuit designs G06F30/30) · CPC title

• C25F3/02

  Etching · CPC title