METHOD AND DEVICE FOR PLATING A RECESS IN A SUBSTRATE

Abstract

The teaching relates to a method for plating a recess in a substrate, a device for plating a recess in a substrate and a system for plating a recess in a substrate comprising the device. The method for plating a recess in a substrate includes the following:

a) Providing a substrate with a substrate surface comprising at least one recess,
b) applying a replacement gas to the recess to replace an amount of ambient gas in the recess to at least partially clear the recess from the ambient gas,
c) applying a processing fluid to the recess, wherein the replacement gas dissolves in the processing fluid to at least partially clear the recess from the replacement gas, and
d) plating the recess.

Claims

1. A method for plating a recess in a substrate (10), comprising the following steps: providing a substrate (10) with a substrate surface (11) comprising at least one recess, applying a replacement gas (30) to the recess to replace an amount of ambient gas (20) in the recess to at least partially clear the recess from the ambient gas (20), applying a processing fluid (40) to the recess, wherein the replacement gas (30) dissolves in the processing fluid (40) to at least partially clear the recess from the replacement gas (30), and plating the recess in the substrate (10).

2. Method according to claim 1, wherein the replacement gas (30) and the processing fluid (40) essentially remove any gaseous barrier in the recess before plating the recess.

3. Method according to claim 2, wherein the replacement gas (30) has at a processing temperature a higher solubility in the processing fluid (40) than the ambient gas (20).

4. Method according to claim 3, wherein the ambient gas is air and the Henry's law solubility constant H.sup.cp of the replacement gas (30) in the processing fluid (40) at room temperature is larger than 6.4×10.sup.−6 mol m.sup.−3 Pa.sup.−1, preferably equal to or larger than 1.2×10.sup.−5 mol m.sup.−3 Pa.sup.−1 and more preferably equal to or larger than 3.3×10.sup.−4 mol m.sup.−3 Pa.sup.−1

5. Method according to claim 4, wherein the replacement gas (30) comprises CO.sub.2 and the processing fluid (40) is essentially water.

6. Method according to claim 5, wherein the plating is an at least partial filling of the recess with an alloy or a metal and in particular with copper, nickel, indium, or cobalt.

7. Method according to claim 6, wherein the processing fluid (40) is a plating fluid (40a) and the substrate (10) is immersed in the plating fluid (40a).

8. Method according to claim 7, wherein the plating fluid (40a) is an electrolyte of an electrochemical deposition system.

9. Method according to claim 8, wherein the replacement gas (30) comprises SO.sub.2 and the processing fluid (40) comprises H.sub.2SO.sub.4.

10. Method according to claim 1, wherein the processing fluid (40) is a rinsing fluid (40b) and the recess is rinsed by the rinsing fluid (40b).

11. Method according to claim 10, wherein the replacement gas (30) dissolved in the processing fluid (40) forms a chemically reactive modification fluid, which modifies a surface of the recess.

12. Method according to claim 11, wherein the chemically reactive modification fluid is an acid or a base for cleaning or etching the surface of the recess.

13. Method according to claim 12, wherein the replacement gas (30) comprises NH.sub.3, SO.sub.2, NO.sub.2, HCl and/or HF and the processing fluid (40) is essentially water or a solvent.

14. Method according to claim 1, wherein the replacement gas (30) has a lower solubility in the processing fluid (40) than the ambient gas (20) and the replacement gas (30) and/or the processing fluid (40) comprises an initiating agent to initiate a chemical reaction between the replacement gas (30) and the processing fluid (40).

15. Method according to claim 14, wherein the chemical reaction between the replacement gas (30) and the processing fluid (40) consumes the replacement gas (30).

16. Method according to claim 15, wherein the ambient gas (20) is air.

17. Method according to claim 16, wherein the substrate surface (11) comprises a plurality of recesses.

18. Method according to claim 1, wherein a replacement gas unit (51) is directly above a processing fluid unit (52) and a plating unit (59).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Exemplary embodiments of the invention will be described in the following with reference to the accompanying drawings:

[0050] FIG. 1 shows a schematic overview of the steps of the method for plating a recess in a substrate according to the invention.

[0051] FIG. 2 shows schematically and exemplarily an embodiment of a system and a device according to the invention for plating a recess in a substrate.

[0052] FIG. 3 shows schematically and exemplarily an embodiment of a device according to the invention for plating a recess in a substrate.

[0053] FIG. 4 shows schematically and exemplarily an embodiment of a device according to the invention for plating a recess in a substrate.

[0054] FIGS. 5a, 5b, and 5c show schematically and exemplarily an embodiment of a device according to the invention for plating a recess in a substrate.

[0055] FIGS. 6a, 6b, and 6c show schematically and exemplarily an embodiment of a device according to the invention for plating a recess in a substrate.

[0056] FIG. 7 shows schematically and exemplarily an embodiment of a device according to the invention for plating a recess in a substrate.

DETAILED DESCRIPTION OF EMBODIMENTS

[0057] According to the present invention, a method for plating a recess in a substrate 10 is presented. FIG. 1 shows a schematic overview of the steps of the method for plating a recess in a substrate 10. It comprises the following steps: [0058] In a first step S1, providing a substrate 10 with a substrate surface 11 comprising a plurality of recesses. [0059] In a second step S2, applying a replacement gas 30 to the recesses to replace an amount of ambient gas 20 in the recesses to clear the recesses from the ambient gas 20. [0060] In a third step S3, applying a processing fluid 40 to the recesses, wherein the replacement gas 30 dissolves in the processing fluid 40 to clear the recesses from the replacement gas 30. [0061] In a fourth step S4, plating the recesses.

[0062] FIGS. 2 to 7 show schematic and exemplary embodiments of a system 70 and a device 50 according to the invention for plating a recess in a substrate 10. The system 70 for plating a recess comprises a device control 71 and a device 50 for plating a recess in a substrate 10 as described further below. The device control 71 controls a gas replacement in a recess of a substrate 10, an application of a processing fluid 40 to the recess and/or a plating of the recess. The device control 71 may be a processor.

[0063] The device 50 for plating a recess comprises a replacement gas unit 51, a processing fluid unit 52 and a plating unit 59. The replacement gas unit 51 applies the replacement gas 30 to one or more recesses in the substrate 10 to replace the ambient gas 20 in the recesses. The replacement gas 30 may be continuously circulated. The processing fluid unit 52 applies the processing fluid 40 to the recesses, wherein the replacement gas 30 dissolves in the processing fluid 40 to clear the recesses from the replacement gas 30. The plating unit 59 then plates the recesses in the substrate 10.

[0064] The method, system 70 and device 50 for plating a recess in a substrate 10 according to the present invention may essentially replace the ambient gas 20 in the recesses of the substrate 10 by the replacement gas 30. As a result, essentially no gaseous barrier prevents a continuous and essentially complete plating or filling of the recesses. Thereby, the method, system 70 and device 50 for plating a recess in a substrate 10 according to the present invention works at atmospheric pressure and without any application of sub-atmospheric pressure or vacuum with associated needs for expensive and complex equipment parts, which makes the method less complex, time and cost intensive when compared to the conventional methods. In addition, a premium quality method, system 70 and device 50 are provided, which enable the manufacturing of premium quality products with superior electrical and/or mechanical properties, reliability and life span.

[0065] As stated above, the device 50 for plating a recess comprises the replacement gas unit 51, which applies the replacement gas 30 to the recesses in the substrate 10 to replace the ambient gas 20. As shown in FIGS. 2 to 4, the replacement gas unit 51 or inlet portion is arranged spaced apart, at a distance and not in contact with the processing fluid 40. The replacement gas unit 51 comprises or is formed as a replacement gas chamber, which can be filled with the replacement gas 30. The replacement gas unit 51 or the replacement gas chamber comprises here several gas inlets in form of gas nozzles 53 (FIG. 4) spaced apart from the processing fluid 40. They are configured to generate a replacement gas cushion or replacement gas curtain to be passed by the substrate 10 and its recesses.

[0066] As also stated above, the device 50 for plating a recess comprises the processing fluid unit 52, which applies the processing fluid 40 to the recesses, so that the replacement gas 30 dissolves in the processing fluid 40 and clears the recesses from the replacement gas 30. There are at least two options:

[0067] First and as shown in FIG. 2, the processing fluid unit 52 comprises a reservoir of a plating fluid 40a as processing fluid 40 for filling and plating the recesses (and the substrate 10). The substrate 10 is immersed in the plating fluid 40a. The processing fluid unit 52 is then a plating unit 59 and the processing fluid 40 is the plating fluid 40a for plating the recesses.

[0068] Second and as shown in FIGS. 3 and 4, the processing fluid 40 is not the plating fluid 40a, but a rinsing fluid 40b to rinse the recesses. The processing fluid unit 52 is then a rinsing unit 60 and comprises several media inlets and in particular media nozzles for the rinsing fluid 40b to generate a processing or rinsing fluid cushion or a processing or rinsing fluid curtain to be passed by the substrate 10 and its recesses. The media inlets are here arranged close to or in the replacement gas unit 51 or in the inlet portion and close to the gas inlets. Also in this embodiment, the device 50 for plating a recess in a substrate 10 according to the present invention comprises a reservoir of a plating fluid 40a (not shown) for filling and plating the recesses (and the substrate 10). The substrate 10 is immersed in the plating fluid 40a, which is in this case not the processing fluid 40. The media inlets are here spaced apart from the plating fluid 40a.

[0069] In FIG. 4, the gas nozzles 53 for the replacement gas and the media inlets for the rinsing fluid 40b are moveably arranged. The gas nozzles 53 may move together as a nozzle unit or independent of each other. They are moveable perpendicular to a longitudinal direction of the substrate 10 and they can be driven by means of a drive unit in the chamber wall or a drive unit entering the chamber through the same opening also used by the substrate 10.

[0070] As discussed above and shown in FIGS. 2 to 4, it is an option to provide the gas inlets and/or the media inlets with a distance from the plating fluid 40a close to or in the replacement gas unit 51 or in the inlet portion. As another option and as shown in FIGS. 5a to 5c, the gas inlets for the replacement gas 30 can be arranged directly above and in contact with the processing fluid 40 or the plating fluid 40a. The substrate 10 is then subjected to the replacement gas 30 and immersed in the processing fluid 40 or the plating fluid 40a contained in the reservoir to plate the recesses. Not shown, but also possible is an arrangement of media inlets for the rinsing fluid 40b directly above and in contact with the plating fluid 40a.

[0071] While FIGS. 2 to 5 show a vertical plating system, FIG. 6a shows a horizontal plating system, in which the substrate 10 is horizontally inserted into a horizontal plating chamber. The plating chamber is then filled with the replacement gas 30 and, afterwards, the substrate 10 is immersed into the processing fluid 40 also contained in the plating chamber. The replacement gas 30 is here provided via chamber walls and via the substrate holder 12.

[0072] As shown in FIGS. 6b and 6c, the replacement gas 30 may also be provided via an arm-shaped member 57. The arm-shaped member 57 can also apply the rinsing fluid 40b, an initiating agent and/or a chemically active substance to the recess and/or the substrate 10. The substrate 10 is here rotatable relative to the arm-shaped member 57 and the movement between the substrate 10 and the arm-shaped member 57 is a record player like motion. These gases and/or fluids are preferably applied from an outer, larger dimension or circumference to an inner, smaller dimension or circumference of the substrate 10.

[0073] FIG. 7 shows a high speed plating system, in which the replacement gas unit 51 and in particular the gas inlets and/or the media inlets are integrated into a substrate holder 12 holding the substrate 10. The gas inlets and the media inlets (the latter not shown) are arranged at a top portion of the substrate holder 12 and thereby in the inlet portion of the plating device 50.

[0074] It has to be noted that embodiments of the invention are described with reference to different subject matters. In particular, some embodiments are described with reference to method type claims whereas other embodiments are described with reference to the device type claims. However, a person skilled in the art will gather from the above and the following description that, unless otherwise notified, in addition to any combination of features belonging to one type of subject matter also any combination between features relating to different subject matters is considered to be disclosed with this application. However, all features can be combined providing synergetic effects that are more than the simple summation of the features.

[0075] While the invention has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive. The invention is not limited to the disclosed embodiments. Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing a claimed invention, from a study of the drawings, the disclosure, and the dependent claims.

[0076] In the claims, the word “comprising” does not exclude other elements or steps, and the indefinite article “a” or “an” does not exclude a plurality. A single unit may fulfil the functions of several items re-cited in the claims. The mere fact that certain measures are re-cited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. Any reference signs in the claims should not be construed as limiting the scope.