SYSTEMS AND METHODS FOR IN SITU ANNEALING OF ELECTRO- AND ELECTROLESS PLATINGS DURING DEPOSITION

• US 20090081386A1
• Filed: 09/10/2008
• Published: 03/26/2009
• Est. Priority Date: 02/08/2005
• Status: Active Grant

• Current Assignee: Trustees Of Columbia University In The City Of New York (Columbia University)
• Original Assignee: Trustees Of Columbia University In The City Of New York (Columbia University)
• Inventors: VON GUTFELD, ROBERT J., WEST, ALAN C.
• Granted Patent: US 8,496,799 B2
• Time in Patent Office: Days
• US Class Current: 427/597
• CPC Class Codes: C23C 18/161 from plating step, e.g. inkjet
• CPC Class Codes: C23C 18/1612 through irradiation means
• CPC Class Codes: C23C 18/1628 Specific elements or parts of the apparatus
• CPC Class Codes: C23C 18/163 Supporting devices for articles to be coated
• CPC Class Codes: C23C 18/1678 Heating of the substrate
• CPC Class Codes: C23C 18/1692 Heat-treatment
• CPC Class Codes: C25D 17/00 Constructional parts, or assemblies thereof, of cells for electrolytic coating
• CPC Class Codes: C25D 17/06 Suspending or supporting devices for articles to be coated
• CPC Class Codes: C25D 21/02 Heating or cooling
• CPC Class Codes: C25D 5/024 using locally applied electromagnetic radiation, e.g. lasers
• CPC Class Codes: C25D 5/026 using locally applied jets of electrolyte
• CPC Class Codes: C25D 5/50 by heat-treatment

Abstract

Systems and methods for in-situ annealing of metal layers as they are being plated on a substrate by action of a chemical solution are provided. The in-situ annealing, in conjunction with controlled slow growth rates, allows control of the structure of the plated metal layers. The systems and methods are used for maskless plating of the substrates.

Claims

1. A system for metal-plating a substrate by action of a chemical solution, the substrate having a front and a back surface, the system comprising:

a substrate-holding fixture disposed in a container so that portions of the substrate are held in contact with the chemical solution and so that a metal layer grows on select portions of the front surface of the substrate by action of the chemical solution; and

a heating arrangement supplying heat to the metal layer/sub-layers during their growth phase so that the metal layer is annealed in-situ during its growth.

2. The system of claim 1, wherein the substrate-holding fixture moves the substrate in the container.

3. The system of claim 1, wherein the chemical solution in contact with the substrate comprises a jet of dilute chemical solution incident on the front growth surface of the substrate.

4. The system of claim 1, wherein the chemical solution in contact with the substrate comprises a bath of the chemical solution.

5. The system of claim 1, wherein the heating arrangement comprises a laser configured to irradiate a back surface of the substrate opposite its front growth surface.

6. The system of claim 1, further comprising an anode disposed opposite the front growth surface of the substrate, wherein the anode comprises pass-through holes and/or a transparent structure, and wherein the heating arrangement comprises a laser configured to irradiate the front growth surface of the surface through the anode during the growth phase of the metal layer.

7. The system of claim 1, wherein the heating arrangement comprises a mechanism for conducting heat to the substrate via the substrate-holding fixture during the growth phase of the metal layer.

8. The system of claim 6, wherein the substrate-holding fixture comprises conductive connectors in thermal contact with the substrate.

9. The system of claim 1, wherein the chemical solution in contact with the growth surface of the substrate comprises one of an electrolytic solution and an electroless solution of one or more metal ions to be deposited in the metal layer on the growth surface of the substrate.

10. A system for maskless metal-plating substrates by action of a chemical solution, each substrate having a front and a back surface, the system comprising:

a moving substrate-holding fixture holding substrates disposed in a container so that portions of at least one substrate of a set of spaced-apart substrates are in contact with the chemical solution and so that metal layers grow on select portions of a front growth surface of the substrates by action of the chemical solution,

wherein the substrate-holding fixture comprises;

a rail in intimate thermal contact with each one of the set of substrates, and wherein the rail is heated by means of an electrical source which is continuous or pulsed.

11. The system of claim 10, wherein the rail is in sliding and/or rolling electrical contact with contacts from an electric power source.

12. The system of claim 10, further comprising a heating arrangement supplying heat to the metal layer during its growth phase so that the metal layer is annealed in-situ during its growth.

13. A method of controlling the structure of a metal layer plated on a substrate by action of a chemical solution, the substrate having a front and a back surface, the method comprising:

annealing the metal layer in-situ during its growth phase as it is being deposited on the front surface of the substrate from the chemical solution,

wherein the chemical solution comprises one of an electrolytic and electroless solution of one or more metal ions to be deposited in the metal layer on the front surface of the substrate.

14. The method of claim 13, further comprising depositing the metal layer at a slow growth rate using a dilute chemical solution, the slow growth rate being on the order of 1-10 nm/s.

15. The method of claim 13, further comprising:

heating the metal layer during deposition without substantial heating of the chemical solution; and

circulating the chemical solution to maintain its operational temperature.

16. The method of claim 13, wherein annealing the metal layer in-situ during its growth phase as it is being deposited from the chemical solution comprises irradiating the back surface of the substrate opposite its front growth surface with laser radiation.

17. The method of claim 13, wherein annealing the metal layer in-situ during its growth phase as it is being deposited from the chemical solution comprises irradiating the front growth surface of the substrate with laser radiation.

18. The method of claim 13, wherein annealing the metal layer in-situ during its growth phase as it is being deposited from the chemical solution comprises Joule heating of the substrate during the growth phase of the metal layer.

19. The method of claim 13, wherein annealing the metal layer in-situ during its growth phase as it is being deposited from the chemical solution comprises heating the substrate by thermal conduction of heat through a substrate-holding fixture.

20. The method of claim 13, wherein annealing the metal layer in-situ during its growth phase as it is being deposited from the chemical solution comprises heating the metal layer continuously as it is being deposited from the chemical solution.

21. The method of claim 13, wherein annealing the metal layer in-situ during its growth phase as it is being deposited from the chemical solution comprises heating the metal layer intermittently as it is being deposited from the chemical solution.

22. A method for maskless metal-plating of substrates by action of a chemical solution, each substrate having a front and a back surface, the method comprising:

disposing a set of spaced-apart substrates in a container so that at least a portion of each substrate is in contact with the chemical solution and so that a metal layer grows on select portions of the front surface of each substrate by action of the chemical solution; and

annealing the metal layer in-situ during its growth phase as it is being deposited on the front surface of each substrate from the chemical solution.

23. The method of claim 22, wherein annealing the metal layer in-situ comprises:

heating a rail in intimate contact with the back surface of each substrate by one of an electrical heater and a laser; and

thermally conducting heat to each substrate via the rail during the metal layer'"'"'s growth phase.

24. The method of claim 22, wherein annealing the metal layer in-situ comprises:

scanning a laser in a raster pattern across each substrate surface to heat the entire surface sequentially while the metal layer is growing.

25. The method of claim 24, wherein scanning a laser in a raster pattern across each substrate surface to heat the entire surface sequentially while the metal layer is growing comprises laser irradiating the substrate through a transparent anode or an anode having pass-through holes.