JP2001329400A - Plating device and plating method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plating device and plating method which exhibit the performance, such as a plating film thickness distribution, equal to or higher than that of the conventional system by providing a plating tank which is simple the structure of the plating tank by taking advantage of a single sheet shielding plate system, is short and compact in length and is simple in the work for controlling and regulating the film thickness distribution. SOLUTION: This plating device has the plating tank and is pendently provided with an anode plate 7 in the plating tank 1. An object to be plated 8 is pendently disposed to face the anode plate and a sheet of the shielding plate 11 having an aperture 30 is disposed between the anode plate 7 and cathode holder 9 in the plating liquid in the plating tank. The opening area of this aperture is made adjustable.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a plating apparatus for forming a metal film on an object to be plated, particularly a semiconductor substrate,
In particular, the present invention relates to a plating apparatus and a plating method having a shielding plate between an anode plate and a cathode plate arranged in a plating solution.

[0002]

2. Description of the Related Art Japanese Patent Publication No. 43990/1992 discloses a conventional technique relating to a plating apparatus for controlling a plating film thickness distribution with high accuracy. A structure in which a horizontal current path is provided between the plate and the cathode plate is adopted.

Further, a pair of shielding plates are disposed between an anode plate and a cathode plate in the plating tank to partition the plating tank into an anode chamber, an intermediate chamber, and a cathode chamber. A relatively complicated structure of connecting with a cylindrical body is adopted.

[0004]

The conventional single shielding plate system is relatively simple in structure and therefore easy to adopt, but it has to meet recent customer requirements in plating film thickness distribution accuracy and controllability. Is no longer possible.

[0005] On the other hand, the above-mentioned cylindrical shielding plate system has relatively high performance in terms of film thickness distribution accuracy, but the plating tank structure becomes complicated, and the cylindrical current path becomes long (about 100 mm).
It is necessary to set, and as a result, the depth of the plating tank becomes long, and the plating tank is inferior in terms of downsizing.

Further, the control adjustment method such as the change of the shielding plate becomes complicated, and there is an unsatisfactory point in obtaining a required film thickness distribution accuracy with a compact device recently required.

The present invention provides a plating tank having a simple structure in a plating tank, a short depth, a compact size, and a simple film thickness distribution control adjustment work, taking advantage of the advantage of a single shielding plate method. It is an object of the present invention to provide a plating apparatus and a plating method which exhibit a distribution accuracy equal to or higher than that of a conventional method.

[0008]

The feature of the present invention that solves the above-mentioned problem is that one shielding plate having an opening having an area corresponding to the shape of the substrate between the anode plate and the cathode plate in the plating solution is provided. Have
The purpose is to focus and form a current path that contracts and expands around this opening.

Further, in order to effectively form the current path, the shielding path is disposed close to the cathode plate, whereby the current path after passing through the opening can be regulated.

[0010] The shielding plate is placed sufficiently close to the object to be plated (10
mm or less). Therefore, the dimensional accuracy of the resin plating tank
A fitting structure was adopted to improve the assembly accuracy, shield plate production and mounting accuracy.

The present invention specifically provides the following apparatus and method.

According to the present invention, there is provided a plating apparatus comprising a plating tank, wherein an anode plate is suspended in the plating tank, and an object to be plated is suspended in opposition to the anode plate. Provided is a plating apparatus in which one shielding plate having an opening is disposed between an anode plate and a cathode folder, and the opening area of the opening is adjusted.

The opening of the shielding plate may be formed in a perforated shape, and an opening may be provided around the perforated portion of the perforated plate, and a detachable shielding ring plate may be provided.

According to the present invention, an anode plate is suspended in a plating tank,
In a plating method performed by vertically suspending an object to be plated facing the anode plate, an opening of a shielding plate provided between the anode plate and the cathode folder in the plating solution in the plating tank is covered. Provided is a plating method that focuses and forms a current path with an area corresponding to the area of a plating object.

[0015]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram showing a plating tank section and an entire configuration of a plating apparatus according to an embodiment of the present invention.

The plating tank 1 is formed in a rectangular shape made of resin, has a partition plate 2 inside, and the inside of the tank is divided into two, and a plating solution discharge pipe 4 is provided in one room 3. A plating solution introduction pipe 6 is connected to the other chamber 5.

An anode plate 7 is installed in the vicinity of the partition plate 2 in the plating tank, and a cathode folder (cathode plate) 9 having an object 8 to be plated is installed in the vicinity of the opposite wall surface.

Further, a liquid stirring member, which is a squeegee rod 10 for stirring the plating solution in the lateral direction, near the surface of the object to be plated, and a single porous shielding plate 11 for controlling the plating thickness distribution with high precision are provided on the cathode folder 9. It is arranged between the anode plate 7.

The anode plate 7 and the cathode folder 9 are electrically connected to a constant current power supply 17 for supplying a plating current. The squeegee bar 10 is connected to a squeegee bar driving device 12.

The plating solution 13 in the plating tank is sent from the external plating solution storage tank 14 to the plating tank 1 via the filter 16 by the circulation pump 15 and circulates.

The distance between the surface of the object 8 to be plated and the shielding plate 11 which affects the plating film thickness distribution accuracy is 10 mm or less, 6 mm or more, 8 mm as an example, and the distance between the anode and the cathode is sufficiently short. Shorter depth by adoption within 35mm
It has a compact structure.

FIG. 2 and FIG. 3 are structural diagrams of a shield plate vertically provided in a plating tank according to the present embodiment.

The perforated shielding plate 11 has a perforated portion 30 at the center.
Is seated thinly on a circle, and this portion has a hole 31 in a honeycomb shape within a required diameter range. This hole 3
Reference numeral 1 denotes a resin screw (not shown) that can be closed at an arbitrary position. The plating current distribution is controlled by partially closing the holes of the porous portion, and the plating film thickness distribution accuracy is controlled. Can also be performed.

Further, as shown in FIGS. 4 and 5, a shielding ring plate 18 having an arbitrary circular opening (which becomes a second opening) 32 is added to the porous shielding plate 11 by a screw hole 33. Attach. In this case, by adjusting the opening area, it is possible to finely control the plating film thickness distribution accuracy.

As described above, the opening of the perforated shielding plate 11 is formed into a perforated plate having a threaded hole, and the perimeter of the perforated portion is provided with an arbitrary opening so that the ring-shaped shielding ring can be freely removed and attached. Shielded by plate 18.

When electroplating a plating thin film on a substrate, an anode plate is vertically provided in a plating tank, and an object to be plated is vertically provided facing the anode plate. A current path having a cross-sectional area corresponding to the shape of the substrate is focused and formed at the opening of one shielding plate disposed between the cathode plate and the cathode plate.

The distance between the shielding plate and the cathode plate is reduced as much as possible in order to enhance the effect of forming a current path.

FIG. 6 shows a structure for improving positioning accuracy in a method of installing a shielding plate in a plating apparatus according to the present invention. FIG. 7 shows a conventional plating tank for comparison. In the conventional type plating bath 19, the mounting guide 20 of the cathode folder, the mounting guide 21 for the perforated shielding plate, and the mounting guide 22 of the anode plate on which the object to be plated is mounted, are fixed to the plating bath main body by the adhesive structure 40. In this method, there is a problem in the positioning accuracy. To improve this, an improved type shown in FIG. 6 was adopted. In the positioning accuracy improving type plating tank 23, the plating tank frame 41 itself is constituted by a fitting structure 42, and the above-mentioned various component mounting guides, that is, the cathode folder mounting guide 24, the perforated shielding plate mounting guide 25, and the anode plate mounting guide 26. Also, it is attached to the plating tank main body by the fitting structure 43, and positioning dimensional accuracy can be secured.

The opening of the shielding plate is determined in accordance with the size and shape of the substrate by experiments, experiences, calculations, and the like, and the size and shape of the opening change depending on these differences.

Further, by disposing a perforated plate having a large number of holes formed in the opening of the shielding plate and closing any holes, it is possible to control the concentration and distribution of current to the substrate, and the The plating film thickness distribution accuracy can be controlled.

A single perforated shield plate can be relatively easily removed from the plating tank, and a shield ring plate having an opening of any size attached thereto is also removed and attached from the shield plate. Since it is possible, the work of adjusting the film thickness distribution becomes easy.

Further, the plating solution is stirred between the cathode plate and the shielding plate with a stirring rod to make the plating solution turbulent, whereby a high-precision fine pattern can be plated.

FIG. 8 shows plating film thickness distribution data when plating is performed by the plating apparatus according to the present invention.

For comparison, the distribution data in the case of plating with an apparatus based on the prior art is also shown. It can be seen that if the distance between the object to be plated and the shielding plate is sufficiently shorter than the conventional one and is 10 mm or less, desirably about 8 mm, the plating film thickness distribution accuracy in the surface of the object to be plated can exhibit the same or better performance than the conventional technology. .

[0036]

The plating tank and plating method of the present invention provide the following effects.

1) By applying the present invention to a vertical dip type plating apparatus in which an object to be plated is vertically placed to perform plating, air bubbles remain on the plating surface, and the plating film is peeled off and dropped from the anode plate. Can be controlled, and a high quality plating film surface can be formed.

2) Further, a plating adjustment mechanism (shielding plate, plating solution stirrer) is arranged between the object to be plated and the anode plate vertically installed opposite thereto, and the plating film is adjusted by adjusting it to an appropriate position. A plating method and a plating apparatus in which thickness distribution control is easy.

3) By adopting the one-plate structure for the shielding plate for controlling the plating film thickness distribution, the depth of the plating tank can be shortened, which can contribute to the downsizing of the plating apparatus.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of an embodiment according to the present invention.

FIG. 2 is a structural diagram of a shielding plate in a plating tank.

FIG. 3 is a side view of FIG. 2;

FIG. 4 is a structural view of a shield ring plate.

FIG. 5 is a side view of FIG. 4;

FIG. 6 is a diagram showing a positioning structure of a shielding plate and other components in a plating tank.

FIG. 7 is a structural view of a shielding plate and other positions in a conventional plating bath.

FIG. 8 is a diagram showing a plating film thickness distribution data by a plating method and a plating apparatus of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Plating tank, 2 ... Partition board, 3, 5 ... Room, 4 ... Discharge pipe, 6 ... Introductory pipe, 7 ... Anode plate, 8 ... Plated object, 9 ... Cathode folder, 10 ... Squeegee rod, 11 ... Porous Shielding plate, 1
2 ... Squeegee rod drive device, 13 ... Plating solution, 14 ... Plating solution storage tank, 15 ... Circulation pump, 16 ... Filter, 17 ...
Constant current power supply, 18 ... Shielding ring plate, 19 ... Conventional plating bath, 20, 24 ... Cathode folder installation guide, 2
1, 25: Installation guide for perforated shielding plate, 22, 26: Installation guide for anode plate, 23: Improved plating bath, 30
... perforated plate, 31 ... hole, 32 ... circular opening, 33 ... mounting screw hole, 40 ... adhesive structure, 41 ... frame, 42, 43 ...
Fitting structure.

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Hiromi Shiina 3-10-2 Bentencho, Hitachi City, Ibaraki Prefecture Within Hitachi Kyowa Engineering Co., Ltd. (72) Inventor Takeya Eguchi 3-chome Bentencho, Hitachi City, Ibaraki Prefecture No.2 F-term in Hitachi Kyowa Engineering Co., Ltd. (reference) 4K024 BB12 CB12 CB21 CB26 GA02

Claims (6)

[Claims] 1. A plating apparatus comprising a plating tank, an anode plate suspended from the plating tank, and an object to be plated suspended from the anode plate, wherein the anode plate in a plating solution in the plating tank is provided. A plating apparatus, comprising: disposing a single shielding plate having an opening between the electrode and the cathode folder, and adjusting the opening area of the opening. 2. The plating method according to claim 1, wherein the opening of the shielding plate is formed in a perforated plate shape, and a removable shielding ring plate having an opening around the perforated portion of the perforated plate is provided. apparatus. 3. The plating apparatus according to claim 1, wherein a plating solution agitating member is provided in the plating tank between the shielding plate and the object to be plated and close to the object to be plated. . 4. The frame according to claim 1, wherein the frame constituting the plating tank has a fitting structure, and holding members respectively holding the anode plate, the cathode plate and the shielding plate are fitted to the frame. A plating apparatus characterized by being mounted by mounting. 5. A plating method performed by dropping an anode plate in a plating tank and dropping an object to be plated facing the anode plate, comprising: an anode plate and a cathode folder in a plating solution in the plating tank. A method of forming a current path by forming an opening corresponding to an area of an object to be plated by making an opening of a shielding plate disposed between the shielding plate and the substrate. 6. The plating method according to claim 5, wherein plating is performed with a distance between the object to be plated and the shielding plate being 10 mm or less.