Apparatus for electroless metal deposition having filter system and associated oxygen source

Patent metadata

Field	Value
Publication number	US-2017327952-A1
Application number	US-201715663382-A
Country	US
Kind code	A1
Filing date	Jul 28, 2017
Priority date	May 11, 2012
Publication date	Nov 16, 2017
Grant date	—

Abstract

One or more aspects of this invention pertain to fabrication of electronic devices. One aspect of the present invention is a system for electroless deposition of metal on a substrate. According to one or more embodiments of the present invention, the system comprises a main subsystem in combination with one or more subsystems for electroless deposition on a substrate. Another aspect of the present invention is a method of making an electronic device. According to one or more embodiments of the present invention, the method comprises one or more processes. Descriptions according to one or more embodiments of the system and the processes are presented.

First claim

What is claimed is:

1 . A system for electroless deposition of metal on a substrate, the system comprising:
an electroless deposition chamber to hold the substrate for electroless deposition; a reservoir to hold an electroless deposition solution; an input line between the electroless deposition chamber and the reservoir to provide electroless deposition solution from the reservoir to the electroless deposition chamber; a reclaim line between the electroless deposition chamber and the reservoir to recycle electroless deposition solution from the electroless deposition chamber back to the reservoir; a sensor responsive to dissolved oxygen, the sensor being disposed so as to measure the dissolved oxygen concentration of the electroless deposition solution in the input line; an oxygen source coupled to the reservoir; and a controller connected with the oxygen source and connected with the sensor so as to adjust the concentration of dissolved oxygen of the electroless deposition solution in response to signals from the sensor.

2 . The system of claim 1 , wherein the controller maintains a dissolved oxygen concentration in the electroless deposition solution to inhibit plating out of particles of the metal.

3 . The system of claim 1 , wherein the electroless deposition solution comprises cobalt ions and the controller maintains a dissolved oxygen concentration in the electroless deposition solution at a predetermined level.

4 . The system of claim 1 , wherein the electroless deposition solution comprises cobalt ions and the controller maintains a dissolved oxygen concentration in the electroless deposition solution at a level in equilibrium with 0.5% oxygen gas in a gas mixture above the deposition solution at one atmosphere pressure.

5 . The system of claim 1 , wherein the substrate comprises a semiconductor wafer.

6 . The system of claim 1 , wherein the oxygen source is configured to provide oxygen gas.

7 . The system of claim 1 , wherein the oxygen source is configured to provide an oxygen compound or a compound capable of oxidizing the metal.

8 . The system of claim 1 , wherein the oxygen source is configured to provide hydrogen peroxide.

9 . The system of claim 1 , further comprising an agitator for liquids coupled with the reservoir so as to accomplish mixing of the electroless deposition solution in the reservoir.

10 . A system for electroless deposition of metal on a substrate, the system comprising:
an electroless deposition chamber to hold the substrate for electroless deposition; a reservoir to hold an electroless deposition solution; an agitator for liquids coupled with the reservoir so as to accomplish mixing of the electroless deposition solution in the reservoir; an input line between the electroless deposition chamber and the reservoir to provide electroless deposition solution from the reservoir to the electroless deposition chamber; and a reclaim line between the electroless deposition chamber and the reservoir to recycle electroless deposition solution from the electroless deposition chamber back to the reservoir.

11 . The system of claim 10 , wherein the agitator comprises a stirring mechanism.

12 . An electroless deposition system for deposition of metal on a substrate, the electroless deposition system comprising:
an electroless deposition chamber to hold the substrate for electroless deposition; a reservoir to hold an electroless deposition solution; an input line between the electroless deposition chamber and the reservoir to provide electroless deposition solution from the reservoir to the electroless deposition chamber; a reclaim line between the electroless deposition chamber and the reservoir to recycle electroless deposition solution from the electroless deposition chamber back to the reservoir, the reclaim line having a section separated into a first fluid flow channel and a second fluid flow channel; a filter system coupled into the reclaim line so as to filter the electroless deposition solution to remove particles of the metal, the filter system comprises:
a first filter;
a second filter;
one or more valves;
the first filter being coupled into the first fluid flow channel so as to filter electroless deposition fluid flow there through, the second filter being coupled into the second fluid flow channel so as to filter electroless deposition fluid flow there through, the one or more valves being coupled to the reclaim line so that reclaimed electroless deposition solution can flow to the reservoir through the first fluid flow channel and the first filter or through the second fluid flow channel and the second filter.

13 . The system of claim 11 , wherein the one or more valves of the filter system are connected to a source of cleaning liquid and connected to a drain line, the one or more valves are configured to alternately direct the cleaning liquid to the first filter then to the drain line to clean the first filter after a period of operation or to direct the cleaning liquid to the second filter then to the drain line to clean the second filter after a period of operation.

14 . The system of claim 11 , wherein the first filter and the second filter are disposed at the same height.

15 . The system of claim 11 , wherein the reclaim line is configured to trap electroless deposition solution so as to substantially keep the first filter wet and to substantially keep the second filter wet.

16 . The system of claim 11 , further comprising:
a liquid sensor to detect the presence of liquid in the electroless deposition chamber, the liquid sensor disposed proximate the connection of the reclaim line to the electroless deposition chamber; a pump coupled into the reclaim line so as to move liquids from the electroless deposition chamber through the reclaim line, the pump being disposed between the filter system and the liquid sensor; the reclaim line being formed so as to trap liquid at the first filter and/or the second filter; the liquid sensor being connected with the pump so that pump operation stops when the liquid sensor stops detecting liquid in the electroless deposition chamber.

17 . The system of claim 11 , further comprising a connection to an oxygen source coupled to the reclaim line to provide dissolved oxygen to the electroless deposition solution in the reclaim line.

18 . A method of electroless deposition, the method is performed using a system that includes an electroless deposition chamber to hold a substrate for electroless deposition, a reservoir, a reclaim fluid line, a feed fluid line, a filter, and a pump; the filter is coupled into the feed fluid line so as to remove particles from the electroless deposition solution before the electroless deposition solution enters the electroless deposition chamber; the pump is coupled into the reclaim fluid line so as to pump liquids from the electroless deposition chamber to the reservoir; the reservoir is configured to hold an electroless deposition solution; the reservoir is connected with the electroless deposition chamber by the feed fluid line to provide electroless deposition solution to the deposition chamber; the reclaim fluid line is connected between the electroless deposition chamber and the reservoir to return electroless deposition solution back to the reservoir as a reclaim stream; the method comprising one or more of processes:
maintaining an effective concentration of dissolved oxygen in the electroless deposition solution present in the reservoir by adjusting oxygen input to the reservoir in response to

Assignees

• Lam Res Corp

Inventors

• Li Shijian

Classifications

• H10P14/46

  using a liquid · CPC title

• C23C18/1683

  Control of electrolyte composition, e.g. measurement, adjustment (regeneration of bath C23C18/1617) · CPC title

• C23C18/1617 Primary

  Purification and regeneration of coating baths · CPC title

• C23C18/31

  Coating with metals · CPC title

• C23C18/16 Primary

  by reduction or substitution, e.g. electroless plating (C23C18/54 takes precedence) · CPC title