GB2564893A

GB2564893A - Distribution system for chemical and/or electrolytic surface treatment

Info

Publication number: GB2564893A
Application number: GB1712064.3A
Authority: GB
Inventors: Ötzlinger Herbert
Original assignee: Semsysco GmbH
Current assignee: Semsysco GmbH
Priority date: 2017-07-27
Filing date: 2017-07-27
Publication date: 2019-01-30
Anticipated expiration: 2037-07-27
Also published as: JP7161445B2; TW201911408A; CN109306474A; JP6539390B2; GB2564893B; JP2019167628A; TWI800356B; TW202230507A; TWI759514B; GB201712064D0; JP2019049046A

Abstract

A distribution system 10 for chemical and/or electrolytic surface treatment of a substrate 30 in a process fluid, a device for chemical and/or electrolytic surface treatment of a substrate in a process fluid, and a distribution method for chemical and/or electrolytic surface treatment of a substrate in a process fluid is described. The distribution system 10 for chemical and/or electrolytic surface treatment comprises a distribution body 21, at least a process fluid inlet 23, and a channel 24. The distribution body 21 is configured to direct a flow of the process fluid and/or an electrical current to the substrate 30. The channel 24 at least partially surrounds a circumference of the distribution body 21. The distribution body 21 comprises a nozzle array (figure 4, 25) and the channel is configured to distribute the process fluid from the process fluid inlet 23 to the nozzle array (figure 4, 25).

Description

DISTRIBUTION SYSTEM FOR CHEMICAL AND/OR ELECTROLYTIC SURFACE

TREATMENT

FIELD OF THE INVENTION

The invention relates to a distribution system for chemical and/or electrolytic surface treatment of a substrate in a process fluid, a device for chemical and/or electrolytic surface treatment of a substrate in a process fluid, and a distribution method for chemical and/or electrolytic surface treatment of a substrate in a process fluid.

BACKGROUND OF THE INVENTION

In the semiconductor industry, various processes can be used to deposit or remove materials on or from the surface of wafers.

For example, electrochemical deposition (ECD) or electrochemical mechanical deposition (ECMD) processes can be used to deposit conductors, such as copper, on previously patterned wafer surfaces to fabricate device interconnect structures.

Chemical mechanical polishing (CMP) is commonly used for a material removal step. Another technique, electropolishing or electroetching, can also be used to remove excess materials from the surface of the wafers.

Electrochemical (or electrochemical mechanical) deposition of materials on wafer surfaces or electrochemical (or electrochemical mechanical) removal of materials from the wafer surfaces are collectively called electrochemical processing. Electrochemical, chemical and/or electrolytic surface treatment techniques may comprise electropolishing (or electroetching), electrochemical mechanical polishing (or electrochemical mechanical etching), electrochemical deposition and electrochemical mechanical deposition. All techniques utilize a process fluid.

Chemical and/or electrolytic surface treatment techniques involve the following steps. A substrate to be processed is attached to a substrate holder, immersed into an electrolytic process fluid and serves as a cathode. An electrode is immersed into the process fluid and serves as an anode. A direct current is applied to the process fluid and dissociates positively charged metal ions at the anode. The ions then migrate to the cathode, where they plate the substrate attached to the cathode.

A problem in such a process is the formation of a uniform layer. A plating current may not be uniform when passing from an anode to a cathode of the system and/or a fluid distribution in a process chamber may not be uniform. Non-uniform current or fluid distribution may lead to non-uniform layer thickness. A uniform distribution of the current and/or the flow shall be implemented by a distribution body, which should correspond to the substrate to be treated. However, the formation of a uniform layer can still be improved.

SUMMARY OF THE INVENTION

Hence, there may be a need to provide an improved distribution system for chemical and/or electrolytic surface treatment of a substrate in a process fluid, which allows or improves a uniform surface treatment of a substrate.

The problem of the present invention is solved by the subject-matters of the independent claims, wherein further embodiments are incorporated in the dependent claims. It should be noted that the aspects of the invention described in the following apply also to the distribution system for chemical and/or electrolytic surface treatment of a substrate in a process fluid, the device for chemical and/or electrolytic surface treatment of a substrate in a process fluid, and the distribution method for chemical and/or electrolytic surface treatment of a substrate in a process fluid.

According to the present invention, a distribution system for chemical and/or electrolytic surface treatment of a substrate in a process fluid is presented. The distribution system may be a vertical distribution system with a vertical plating chamber, in which the substrate is inserted vertically. The distribution system may also be a horizontal distribution system with a horizontal plating chamber, in which the substrate is inserted horizontally.

The chemical and/or electrolytic surface treatment may be any material deposition, galvanized coating, chemical or electrochemical etching, anodal oxidation, metal separation or the like.

The substrate may comprise a conductor plate, a semi-conductor substrate, a film substrate, an essentially plate-shaped, metal or metallized workpiece or the like. A surface of the surface to be treated may be at least partially masked or unmasked.

The distribution system for chemical and/or electrolytic surface treatment comprises at least a distribution body, at least a process fluid inlet, and at least a channel.

The distribution body is configured to direct a flow of process fluid and/or electrical current to the substrate. The distribution body may correspond to the substrate to be treated in particular in view of its shape and size.

The process fluid inlet is e.g. a duct, where the process fluid enters the distribution system and the distribution body.

The distribution body comprises a nozzle array. The nozzle array may be an area or field of several or a plurality of nozzles. It may comprise outlet openings to direct the flow of process fluid to the substrate and/or backflow openings to receive the backflow of process fluid from the substrate. The nozzle array may be, in other words, an active field of the distribution body.

The channel is configured to distribute the process fluid from the process fluid inlet to the nozzle array. The channel at least partially surrounds a circumference of the distribution body. The channel may surround e.g. between 50 and 90 % of the circumference of the distribution body and preferably about 75 %% of the circumference of the distribution body. Exemplary values are given further below. The channel may also entirely surrounds the circumference of the distribution body. The term “circumference” can be understood as outer limit of the distribution body independent of a shape of the distribution body (round, angular etc.).

The system for chemical and/or electrolytic surface treatment according to the invention may thereby allow or improve a uniform surface treatment of the substrate and in particular a uniform deposition rate and/or a formation of a uniform layer on the substrate. As the channel at least partially surrounds the circumference of the distribution body, it improves a distribution of process fluid from the process fluid inlet to the single nozzles of the nozzle array and thereby from the distribution body to the substrate and at the substrate. A better distribution of process fluid may lead to a more uniform surface treatment of the substrate, a more uniform deposition rate and/or a formation of a more uniform layer on the substrate.

The system for chemical and/or electrolytic surface treatment according to the invention may further facilitate a construction of the distribution system, because it makes a positioning of the process fluid inlet independent of the following distribution of process fluid to the nozzle array and the substrate. In other words, the process fluid inlet may be arranged only based on structural, constructive, dimensional or geometrical considerations without (or at least to a lesser extend) considering the later distribution of process fluid.

The at least one process fluid inlet can therefore be arranged decentral or asymmetrical to the distribution body. There may be at least two, several or a plurality of process fluid inlets, which can be arranged decentral or arranged asymmetrical to the distribution body. The term “asymmetrical” can be understood in that process fluid inlets are not arranged on all sides of the distribution body and not even on two opposite sides of the distribution body. For example, the process fluid inlets are arranged at only one side of the distribution body. This single side may be a lower or bottom side of the distribution body, but also an upper or top side. The process fluid inlets may also be arranged at only two adjacent sides of the distribution body.

In an example, the channel is configured to evenly distribute the process fluid from at least one process fluid inlet to the nozzle array. In an example, the channel is configured to distribute the process fluid to an essentially uniform flow of process fluid in the distribution body. In an example, the channel is configured to distribute the process fluid to an essentially uniform exit velocity of process fluid leaving the nozzle array. The configuration of the channel may thereby allow a uniform surface treatment of the substrate, a uniform deposition rate and/or a formation of a uniform layer on the substrate.

In an example, the distribution body and the channel, in a top view, have an angular shape. In another example, the distribution body has a circular shape and the channel has a ring shape in a top view. The distribution body may have any kind of shape, for example a rectangular, square, oval, triangular or other suitable geometric configuration.

In an example, the channel has a rectangular cross section. The channel may have any kind of shape, for example an angular, square, round, oval, triangular or other suitable geometric configuration. In an example, the channel has a width in the range of 1 to 20 % of a width of the nozzle array, preferably in the range of 3 to 15 %, and more preferably in the range of 5 to 10 %. In an example, a size of the cross section of the channel varies along the circumference of the distribution body. For example, a lower side of the channel adjacent to the process fluid inlet may have a width wl and the lateral sides of the channel may have a width w2 larger wl. Further, a top side of the channel (opposite to the lower side adjacent to the process fluid inlet) may have a width w3, which starts at the corners with w3 = w2 and increases to an apex width w4 in a center of the top side. The dimensions of the channel may further improve a uniform surface treatment of the substrate, a uniform deposition rate and/or a formation of a uniform layer on the substrate.

According to the present invention, also a device for chemical and/or electrolytic surface treatment of a substrate in a process fluid is presented. The device for chemical and/or electrolytic surface treatment comprises a distribution system for chemical and/or electrolytic surface treatment of a substrate in a process fluid as described above and a substrate holder.

The substrate holder is configured to hold the substrate. The substrate holder may be configured to hold one or two substrates (one substrate on each side of the substrate holder).

The device for chemical and/or electrolytic surface treatment may further comprise an anode. The device for chemical and/or electrolytic surface treatment may further comprise a power supply. The device for chemical and/or electrolytic surface treatment may further comprise a process fluid supply.

According to the present invention, also a distribution method for chemical and/or electrolytic surface treatment of a substrate in a process fluid is presented. The method for chemical and/or electrolytic surface treatment comprises the following steps, not necessarily in this order:

a) providing a distribution body configured to direct a flow of the process fluid and/or an electrical current to the substrate,

b) providing at least a process fluid inlet,

c) providing a channel at least partially surrounding a circumference of the distribution body, and

d) distributing the process fluid from at least a process fluid inlet to a nozzle array of the distribution body by means of the channel.

As a result, the invention relates to a method for chemical and/or electrolytic surface treatment, which allows, improves and/or facilitates a uniform surface treatment of the substrate, a uniform deposition rate, a formation of a uniform layer on the substrate and/or the like. The channel at least partially surrounds the circumference of the distribution body and thereby may improve a distribution of process fluid from the process fluid inlet to the single nozzles of the nozzle array, from the distribution body to the substrate and/or at the substrate.

Devices and methods are suitable, in particular, for the processing of structured semi-conductor substrates, conductor plates, and film substrates, but also for processing of the entire surface of planar metal and metallized substrates. Device and methods may also be used according to the invention for the production of large surface photoelectric panels for solar energy generation, or large-scale monitor panels.

It shall be understood that the system, the device, and the method for chemical and/or electrolytic surface treatment of a substrate in a process fluid according to the independent claims have similar and/or identical preferred embodiments, in particular, as defined in the dependent claims. It shall be understood further that a preferred embodiment of the invention can also be any combination of the dependent claims with the respective independent claim.

These and other aspects of the present invention will become apparent from and be elucidated with reference to the embodiments described hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

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

Figure 1 shows schematically and exemplarily an embodiment of a device for chemical and/or electrolytic surface treatment of a substrate in a process fluid according to the invention.

Figure 2 shows schematically and exemplarily an embodiment of a substrate holder holding two substrates.

Figure 3 shows schematically and exemplarily an embodiment of a device for chemical and/or electrolytic surface treatment and a distribution system for chemical and/or electrolytic surface treatment of a substrate in a process fluid according to the invention.

Figure 4 shows schematically and exemplarily an embodiment of a device for chemical and/or electrolytic surface treatment and a distribution system for chemical and/or electrolytic surface treatment of a substrate in a process fluid according to the invention.

Figure 5 shows basic steps of an example of a distribution method for chemical and/or electrolytic surface treatment of a substrate in a process fluid according to the invention.

DETAILED DESCRIPTION OF EMBODIMENTS

Figure 1 shows schematically and exemplarily an embodiment of a device 100 for chemical and/or electrolytic surface treatment of a substrate 30 in a process fluid according to the invention. The device 100 for chemical and/or electrolytic surface treatment comprises a substrate holder 20 and a vertical distribution system 10 for chemical and/or electrolytic surface treatment of the substrate 30 in a process fluid.

The substrate holder 20 is also shown in Figure 2. It is configured to hold one or two substrates 30, one substrate 30 on each side of the substrate holder 20. The substrate holder 20 here holds rectangular substrates 30 with rounded corners and a size of e.g. 370 x 470 mm. Of course, the device 100 for chemical and/or electrolytic surface treatment may also be used with a substrate holder 20, which is configured to hold only one substrate 30 for single or dual side surface treatment in a preferably vertical arrangement.

The substrate 30 may be an essentially plate-shaped workpiece for the production of electric or electronic components, which is mechanically fixed in the substrate holder 20, and the surface of which to be treated is bathed in the process fluid as the treatment medium coming from a distribution body 21. In a special case, the substrate 30 may be a masked or unmasked conductor plate, a semi-conductor substrate, or a film substrate, or even any metal or metallized workpiece having an approximately planar surface.

The distribution system 10 for chemical and/or electrolytic surface treatment of the substrate 30 in the process fluid as shown in Figures 1, 3 and 4 produces targeted flow and current density patterns for a chemical and/or electrolytic surface treatment. It comprises here two distribution bodies 21 submerged in the process fluid (not shown). Opposite of each distribution body 21 is the substrate 30 that is attached to the substrate holder 20. The surface of the substrate 30 is wetted by the process fluid. Two electrodes, here two anodes 22, are present, which each are located on a side of the distribution body 21 opposite of the substrate 30, and which are also bathed in the process fluid. The anode 22 is attached in a rear region of the distribution body 21, in mechanical contact with, or spatially separated from, the distribution body 21 such that the electric current flow is carried out between the anode 22 and the substrate 30 acting as counter electrode within the process fluid. Depending on the surface treatment method used, the anode 22 may consist of a material that is insoluble in the process liquid, such as platinizized titanium, or otherwise a soluble material, such as for example, the metal to be galvanically separated.

The distribution system 10 further comprises several process fluid inlets 23 for the process fluid and two channels 24, which surround a circumference of each distribution body 21. The process fluid inlets 23 are openings, where the process fluid enters the distribution system 10 and the distribution body 21.

The distribution bodies 21 each comprise a nozzle array 25 and each channel 24 is arranged and dimensioned to distribute the process fluid from the respective process fluid inlet 23 to the respective nozzle array 25. The process fluid then flows from the fluid inlet 23 to the channel 24, from the channel 24 to the nozzle array 25 and from the nozzle array 25 to outlet openings of the nozzle array 25. The outlet openings direct a flow of process fluid to the substrate 30, where it carries out the desired chemical and/or electrolytic reaction. The distribution body 21 further comprises backflow openings to receive a backflow of process fluid from the substrate.

The process fluid inlets 23 are decentral and asymmetrical arranged at one side of the distribution body 21, namely at a bottom side of the distribution body 21. The distribution body 21 and the channel 24 have an angular shape when seen in a top view. The size of a cross section of the channel 24 varies along the circumference of the distribution body 21. For a nozzle array of 513x513 mm, a width of the channel 24 may vary between about 25.5 mm at a bottom side adjacent to the process fluid inlets, about 35.5 mm at the lateral sides and increasing at a top side from rounded corners to an apex at a center of the top side with a width of about 45.5 mm. At the apex, a ventilation opening of the distribution body 21 may be arranged.

The channel 24 and in particular its configurations improve a uniform surface treatment of the substrate, a uniform deposition rate and/or a formation of a uniform layer on the substrate. Further, it facilitates the construction of the distribution system 10, because it makes a positioning of the process fluid inlets 23 independent of the following distribution of process fluid to the nozzle array 24 and the substrate 30. In other words, the process fluid inlets 23 may be arranged only based on structural considerations without (or at least to a lesser extend) considering the later distribution of process fluid.

The distribution body 21 may advantageously comprise plastic, in particularly advantageous manner polypropylene, polyvinyl chloride, polyethylene, acrylic glass, i.e. polymethyl methacrylate, polytetrafluoroethylene, or another material that will not be decomposed by the process fluid.

Figure 5 shows a schematic overview of steps of a distribution method for chemical and/or electrolytic surface treatment of a substrate 30 in a process fluid. The method for chemical and/or electrolytic surface treatment comprises the following steps:

In a first step SI, providing a distribution body 21 configured to direct a flow of the process fluid and/or an electrical current to the substrate 30.

In a second step S2, providing at least a process fluid inlet 23.

In a third step S3, providing a channel 24 at least partially surrounding a circumference of the distribution body 21.

In a fourth step S4, distributing the process fluid from at least the process fluid inlet 23 to a nozzle array 25 of the distribution body 21 by means of the channel 24.

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.

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.

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 processor or other 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.

Claims

CLAIMS:

1. A distribution system (10) for chemical and/or electrolytic surface treatment of a substrate (30) in a process fluid, comprising:

a distribution body (21), at least a process fluid inlet (23), and a channel (24), wherein the distribution body (21) is configured to direct a flow of the process fluid and/or an electrical current to the substrate (30), wherein the channel (24) at least partially surrounds a circumference of the distribution body (21), wherein the distribution body (21) comprises a nozzle array (25), and wherein the channel (24) is configured to distribute the process fluid from the process fluid inlet (23) to the nozzle array (25).

2. System (10) according to claim 1, wherein the process fluid inlet (23) is arranged decentral to the distribution body (21).

3. System (10) according to one of the preceding claims, wherein the process fluid inlet (23) is arranged asymmetrical to the distribution body (21).

4. System (10) according to the preceding claim, comprising at least two process fluid inlets (23), which are arranged at only one side of the distribution body (21).

5. System (10) according to one of the preceding claims, wherein the channel (24) is configured to distribute the process fluid to an essentially uniform flow of process fluid in the distribution body (21).

6. System (10) according to one of the preceding claims, wherein the channel (24) is configured to distribute the process fluid to an essentially uniform exit velocity of process fluid leaving the nozzle array (25).

7 System (10) according to one of the preceding claims, wherein the channel (24) entirely surrounds the circumference of the distribution body (21).

8. System (10) according to one of the preceding claims, wherein the channel (24) is configured to evenly distribute the process fluid from at least one process fluid inlet (23) to the nozzle array (25).

9. System (10) according to one of the preceding claims, wherein the distribution body (21) and the channel (24), in a top view, have an angular shape.

10. System (10) according to one of the claims 1 to 8, wherein the distribution body (21) has a circular shape and the channel (24) has a ring shape in a top view.

11. System (10) according to one of the preceding claims, wherein the channel (24) has a rectangular cross section.

12. System (10) according to one of the preceding claims, wherein the channel (24) has a width in the range of 1 to 20 % of a width of the nozzle array (25), preferably in the range of 3 to 15 %, and more preferably in the range of 5 to 10 %.

13. System (10) according to one of the preceding claims, wherein a size of the cross section of the channel (24) varies along the circumference of the distribution body (21).

14. A device (100) for chemical and/or electrolytic surface treatment of a substrate (30) in a process fluid, comprising: a distribution system (10) according to one of the proceeding claims, and a substrate holder (20), wherein the substrate holder (20) is configured to hold the substrate (30).

15. A distribution method for chemical and/or electrolytic surface treatment of a substrate (30) in a process fluid, comprising the following steps:

providing a distribution body (21) configured to direct a flow of the process

5 fluid and/or an electrical current to the substrate (30), providing at least a process fluid inlet (23), providing a channel (24) at least partially surrounding a circumference of the distribution body (21), and distributing the process fluid from the process fluid inlet (23) to a nozzle array

10 (25) of the distribution body (21) by means of the channel (24).