JP2002053953A - Method for manufacturing sputtering target - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method by which the operation of removing an excess bonding agent remaining in the periphery of the bonding layer of a target- backing plate assembly and also a bonding agent remaining the bottom of a division section formed between target members of a multi-division target can be carried out easily in a short time. SOLUTION: After the target member of ITO, Cr, etc., and the backing plate are bonded by the bonding agent, high-pressure water of (200 to 700) kgf/cm2 is sprayed onto the bonding agent remaining on the periphery of the bonding layer or on the bottom of the division section of the multi-division target to remove the bonding agent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for manufacturing a target. More specifically, a method of manufacturing a target obtained by removing a bonding agent remaining at a bonding portion between a target member and a backing plate or a bonding agent remaining at a bottom of a divided portion formed between target members in a multi-split target About.

[0002]

2. Description of the Related Art A variety of thin films are used in devices such as semiconductor elements, recording media, flat panel displays, etc., which support the information society and multimedia in recent years. Means for forming a thin film include a sputtering method,
A vacuum deposition method, a CVD method and the like can be given. In particular, the sputtering method is advantageous in forming a uniform film over a large area, and is therefore often used in the field of flat panel displays.

[0003] A sputtering target used in the sputtering method, except for a special one, is manufactured by joining a target member and a backing plate. As a method for joining the target member and the backing plate, there are various methods such as brazing with a metal joining agent (for example, indium solder), diffusion bonding, explosion, EB welding, etc. Selected and adopted.

[0004] Among them, a brazing method using a metal bonding agent is common, the cost for introducing a manufacturing facility is low, and a relatively large target for a flat panel display is relatively easily used. It has the advantage of being adaptable.

[0005] The joining of the target member and the backing plate by brazing is performed by applying a joining agent heated to a melting point or higher to the joining surface of the target member and the backing plate, and then disposing them at predetermined positions and cooling them to room temperature. It is done by doing. At this time, excess bonding agent that has overflowed during bonding remains around the bonding layer (solder layer) of the target-backing plate assembly that has been cooled to room temperature. It is not preferable because it causes particles. When such a target is installed in a sputtering apparatus,
Discharge is not possible if it comes in contact with the earth shield.
A process for removing these is required.

The step of removing the excess bonding agent has conventionally been performed manually using a metal spatula or the like. However, such a method has a long working time because it is a manual operation, and thus affects the cost of the target.

A method of removing the bonding agent at a temperature at which the bonding agent has a certain degree of fluidity is also conceivable. In this case, however, a necessary portion of the bonding agent may flow out. In addition, there is a problem that the working temperature is close to the melting point of the bonding agent (156 ° C. for indium solder), which involves danger.

On the other hand, in order to increase the size of the liquid crystal panel and improve productivity, the size of the mother glass for producing the liquid crystal panel has increased, and a large target capable of responding to the increase has been demanded. A multi-split target in which a plurality of target members are joined on the same backing plate is used. Although this multi-segmented target can produce a large target with good yield, the bonding agent remaining at the bottom of the split part of the target is taken into the film as an impurity, deteriorating the characteristics of the thin film, or reducing the bonding agent itself. The particles had a size of μm and caused a problem of lowering the product yield.

Conventionally, in order to solve this problem, the bonding agent remaining in the divided portion has been scraped and removed using a metal spatula or the like. However, such a method has a long working time because it is a manual operation, and thus affects the cost of the target.

Therefore, an extra bonding agent remaining around the bonding layer (solder layer) of the target-backing plate assembly and a bonding agent remaining at the bottom of the divided portion in the multi-split target are employed in an actual production line. Like you can
It has been desired to develop a method for manufacturing a target that can be removed in a short time and with a simple method.

[0011]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an excessive bonding agent remaining around a bonding layer (solder layer) of a target-backing plate assembly and a bonding agent remaining at the bottom of a split portion in a multi-split target. It is an object of the present invention to provide a method for easily and quickly removing a bonding agent.

[0012]

In view of the above situation, the present inventors have made intensive studies and as a result, cooled the target member-backing plate assembly and the multi-split target after joining operation to near room temperature. After that, it has been found that the bonding agent can be removed by spraying high-pressure water to the bonding agent remaining around the bonding layer or at the bottom of the divided portion, thereby completing the present invention.

[0013] That is, the present invention provides a method for manufacturing a sputtering target, comprising joining a target member and a backing plate with a bonding agent and then spraying high-pressure water on the bonding agent remaining around the bonding layer to remove the bonding agent. And, after joining the plurality of target members on the same backing plate with a bonding agent, high-pressure water is sprayed on the bonding agent remaining at the bottom of the divided portion formed between the target members and removed. The present invention relates to a method for manufacturing a sputtering target.

Hereinafter, the present invention will be described in detail.

The material of the sputtering target used in the present invention can be used without any particular limitation. In particular, it is suitable for materials such as ITO (indium-tin oxide), AZO (aluminum-zinc oxide), magnesium oxide, chromium, and molybdenum, which are often joined by brazing using a solder material.

The sputtering target used in the present invention may be a sputtering target in which one target member is joined on one backing plate, or a multi-split target in which a plurality of target members are joined on the same backing plate. A sputtering target may be used.

In the multi-split sputtering target, the distance between the individual target members is preferably maintained on a backing plate with a gap having a width of preferably 0.05 to 0.2 mm. Also,
The number of divisions and the shape are not particularly limited. The size of each target member may be substantially equal, and the size of each divided target member may be different. Further, in the case of four divisions, it may be divided into crosses.

First, a target member is manufactured by a commonly used method. There are no particular restrictions on the types of raw materials, molding methods, sintering methods, etc., when manufacturing the target member. What is necessary is just to select and manufacture suitably according to the characteristic of the target member used.

Next, the obtained target member is processed mechanically to produce a target member.

At this time, when manufacturing the individual target members constituting the multi-split target, the edge portion of the target member on the side where the target members face each other, and the edge portion existing on the sputtering surface has a radius of 0.
To have a roundness of 5 to 2 mm, that is, R0.5
It is preferable to process to R2. Note that other edge portions existing on the sputtering surface of the target member are not necessarily required, but may be appropriately rounded.

Subsequently, the obtained target member is joined on a backing plate. The backing plate and the solder material used in the present invention are not particularly limited, but examples of the backing plate include oxygen-free copper and phosphor bronze, and examples of the solder material include indium solder.

The joining can be performed, for example, by the following method. First, a bonding agent such as metal indium is applied to a target member obtained by processing into a predetermined shape and cleaning the surface, and each bonding surface of the backing plate that has also been cleaned. At this time, if the target member or the backing plate is made of a material that does not directly adhere to the bonding agent, a thin film layer of copper, nickel, or the like having excellent wettability with the bonding agent is previously formed on the bonding surface by sputtering. Law,
It may be formed by a plating method or the like, or a bonding agent may be directly applied to the bonding surface using an ultrasonic soldering iron.

Before applying the bonding agent, a masking process may be performed on unnecessary portions of the bonding agent using a polyamide tape or the like as necessary in order to prevent contamination of the portion other than the bonding surface by the bonding agent. preferable.

Next, the target member and the backing plate are heated to a temperature equal to or higher than the melting point of the bonding agent to be used to melt the bonding agent on the surface. I do. At this time, a bonding agent may be further applied as necessary to obtain a sufficient bonding strength.

When a polyamide tape or the like is used for preventing contamination, the tape is peeled off after cooling. In this state, an extra bonding agent remains around the bonding layer.

On the other hand, in the case of a multi-split target, first, the plurality of processed target members and the backing plate are heated to a temperature equal to or higher than the melting point of the bonding agent to be used, and the bonding agent is applied to each bonding surface. To join. At this time, if the target member has been subjected to the R processing, the edge part subjected to the R processing is arranged on the sputtering surface of the divided portion and joined.

The width of the divided portion of each target is 0.05 to
0.2 mm is preferred. If it is less than 0.05 mm, when it is installed in a vacuum device and actually sputtered,
Each target increases due to thermal expansion, and adjacent sintered bodies may collide with each other and be damaged.

The width of the divided portion at the time of joining (at the time of heating) is
The material may be appropriately selected in consideration of the materials and sizes of the target member and the backing plate to be used and the melting point of the bonding agent to be used.

For example, an 800 mm × 280 mm ITO
When bonding three sintered bodies onto one backing plate to form one target, if oxygen-free copper is used for the backing plate and indium solder is used for the bonding agent, it is fired at 158 ° C. By setting the width of the divided portion to 0.53 mm in a state where the body and the backing plate are heated, the width of the joined portion after cooling is 0.2 mm.

The actual control of the width of the divided portion is performed, for example, by inserting a jig having a thickness of 0.53 mm into the divided portion, joining the backing plate and each target to perform positioning, and solidifying the joining agent. After that, the jig inserted into the divided portion can be extracted and cooled to room temperature. In this state, an extra bonding agent remains at the bottom of the divided portion.

The jig to be inserted into the division is not particularly limited as long as it can withstand the temperature at the time of joining.
Examples thereof include stainless steel, iron, brass, carbon, Teflon (registered trademark), and polyimide resin.

In the present invention, high pressure water is sprayed on the remaining bonding agent to remove the excess bonding agent. 200-700 kgf / cm ² as high pressure water
Is preferred. More preferably, 300-600k
gf / cm ² . The shape of the nozzle for injecting high-pressure water can be a direct shape, a fan shape, or the like, but a direct shape is preferable because the solder material can be efficiently removed. By using such high-pressure water, it is possible to remove only the bonding agent in a short time without damaging the target member or the backing plate.

As the high-pressure water to be sprayed, general tap water can be used. However, in consideration of prevention of contamination of the target, water that has passed through a filter having a size of 50 μm or less, more preferably ion-exchanged water, and particularly preferably water is preferred. Is ultrapure water having a resistivity of 10 MΩ · cm or more.

The amount of water is preferably from 10 to 40 L / min from the viewpoint of workability and reduction of wastewater treatment amount, and the water temperature is preferably from 15 to 35 ° C from the viewpoint of work safety.

[0035]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited thereto.

Example 1 Indium oxide powder and tin oxide powder were mixed, molded and sintered according to a conventionally known method to obtain an ITO sintered body. The obtained sintered body was 4
It processed to inch x 7 inch mm x 6 mm. After covering unnecessary portions of the obtained sintered body with aluminum foil and polyamide tape, the sintered body and the flat backing plate are heated to 158 ° C., and an ultrasonic soldering iron is applied to each joint surface. Was used to apply indium solder.

Next, after placing this sintered body at a desired position on the backing plate, it was cooled to room temperature, and the aluminum foil and the polyamide tape were removed to obtain an ITO target.

Next, high-pressure water was sprayed using a high-pressure water injection device to remove the solder material remaining around the bonding layer.
The injection conditions are as follows.

(Injection conditions) Medium: tap water passed through a 50 μm filter (water temperature: 2)
(3 ° C.) Water pressure: 300 kgf / cm ² Water volume: 20 L / min
5 seconds, 140 seconds in total. Further, no scratch was observed on the sintered body and the backing plate after the treatment.

(Example 2) The solder material around the joining layer was removed in the same manner as in Example 1 except that the medium used was ion-exchanged water. The time required for the operation was 2.5 seconds per 10 mm of the processed length. Further, no scratch was observed on the sintered body and the backing plate after the treatment.

Example 3 The medium used was 12.3 MΩ.
The solder material around the bonding layer was removed in the same manner as in Example 1 except that ultrapure water of cm was used. The time required for the operation was 2.5 seconds per 10 mm of the processed length.
Further, no scratch was observed on the sintered body and the backing plate after the treatment. (Comparative Example 1) In the same manner as in Example 1, an ITO sintered body was manufactured and joined to a backing plate. The solder material remaining around the joining layer was manually removed using a metal spatula. The time required for the work was 10
5 seconds per mm, a total of 280 seconds. In addition, many scratches were found on the backing plate.

Example 4 A chromium powder was formed by a CIP method and then sintered by a HIP method to obtain a sintered body of chromium. The obtained sintered body is 4 inches x 7 inches mm x 6 m
m. After covering unnecessary portions of the solder material of the thus obtained sintered body with aluminum foil and polyamide tape, the sintered body and the flat backing plate were heated to 158 ° C., and indium was applied to each joint surface. Solder was applied.

Next, after placing this sintered body at a desired position on the backing plate, it was cooled to room temperature, and the aluminum foil and the polyamide tape were removed to obtain a chromium target.

Next, using a high-pressure water injection device, high-pressure water was sprayed to remove the solder material remaining around the bonding layer.
The injection conditions are as follows.

(Injection conditions) Medium: tap water passed through a 50 μm filter (water temperature: 2)
3 ° C.) Water pressure: 300 kgf / cm ² Water volume: 20 L / min The time required for removing the solder material remaining around the joining layer is as follows:
2.5 seconds per 10 mm of treated length. Also,
No scratch was observed on the sintered body and the backing plate.

Example 5 The solder material around the joining layer was removed in the same manner as in Example 4 except that the medium used was ion-exchanged water. The time required for the operation was 2.5 seconds per 10 mm of the processed length. No damage was found on the sintered body or the backing plate.

Example 6 The medium used was 12.3 MΩ.
The solder material around the joining layer was removed in the same manner as in Example 4 except that ultrapure water of cm was used. The time required for the operation was 2.5 seconds per 10 mm of the processed length.
No damage was found on the sintered body or the backing plate. (Comparative Example 2) A chromium sintered body was produced in the same manner as in Example 4, and joined to a backing plate. The solder material remaining around the joining layer was manually removed using a metal spatula. The time required for the work is 10m
5 seconds per m. In addition, many scratches were found on the backing plate.

(Example 7) Indium oxide powder and tin oxide powder were mixed, molded and sintered according to a conventionally known method to obtain an ITO sintered body. The obtained sintered body was machined to obtain two ITO sintered bodies of 4 inches × 3.5 inches × 6.35 mm. Next, R1 processing was performed on an edge portion to be a sputtering surface.

After the thus obtained sintered body and backing plate were heated to 158 ° C., indium solder was applied to each joint surface.

The bonding surfaces of the thus obtained target member coated with the metal bonding agent and the flat backing plate were bonded together, and then cooled to room temperature.
The width of the divided part after cooling was 0.15 mm.

Next, using a high-pressure water injection device, water was sprayed to remove the solder material remaining in the divided portions. The injection conditions are as follows.

(Injection conditions) Medium: tap water passed through a 50 μm filter (water temperature: 2)
(3 ° C.) Water pressure: 300 kgf / cm ² Water volume: 20 L / min The time required for removing the solder material remaining in the divided portion was 1 second per 10 mm of the divided portion. No damage was found on the sintered body or the backing plate.

(Embodiment 8) Except that the medium used was ion-exchanged water, the solder material at the divided portion was removed in the same manner as in Embodiment 7. The time required for removing the solder material remaining in the divided portion was 1 second per 10 mm of the divided portion. No damage was found on the sintered body or the backing plate.

(Embodiment 9) The medium used was 12.3 MΩ.
The solder material at the divided portion was removed in the same manner as in Example 7 except that ultrapure water of cm was used. The time required for removing the solder material remaining in the divided portion was 1 second per 10 mm of the divided portion. No damage was found on the sintered body or the backing plate. (Comparative Example 3) In the same manner as in Example 7, an ITO sintered body was manufactured and joined to a backing plate. The solder material remaining in the divided portion was manually removed using a metal spatula and a thin piece. The time required for removing the solder material remaining in the divided portion was 25 seconds per 10 mm of the divided portion.
In addition, many scratches were found on the backing plate.

[0055]

According to the manufacturing method of the present invention, it is possible to remove the solder material remaining around the bonding layer and at the bottom of the divided portion in the multi-split target in a very simple manner and in a short time.

Claims (8)

[Claims] 1. A method for manufacturing a sputtering target, comprising: after joining a target member and a backing plate with a bonding agent, removing high-pressure water by spraying the bonding agent remaining around the bonding layer. 2. A method in which a plurality of target members are joined on the same backing plate with a bonding agent, and then high-pressure water is sprayed on a bonding agent remaining at a bottom of a division formed between the target members to remove the target members. Characteristic method for manufacturing a sputtering target. 3. The pressure of high-pressure water is 200 to 700 kgf.
/ Cm ^{2. The} method for producing a sputtering target according to claim 1, wherein: 4. The method according to claim 1, wherein high-pressure water passed through a filter of 50 μm or less is used.
13. The method for producing a sputtering target according to item 9. 5. The method for producing a sputtering target according to claim 1, wherein ion-exchanged water is used. 6. The method for producing a sputtering target according to claim 1, wherein ultrapure water having a resistivity of 10 MΩ · cm or more is used. 7. The target member according to claim 1, wherein the target member consists essentially of indium, tin and oxygen.
7. The method for producing a sputtering target according to any one of items 6 to 6. 8. The method for manufacturing a sputtering target according to claim 1, wherein the target member is substantially made of chromium.