TWI798589B - Surface Roughness Processing Method of Sputtering Target - Google Patents

Abstract

The invention discloses a roughness processing method of a sputtering surface of a target material, which is used to form surfaces with different roughnesses on the predetermined area of the target material. First, take a target to confirm the sputtering processing area, and shield the non-processing area, then sandblast the processing area, cover the processing area partially to define the secondary processing area, and The processing area is coated, and finally the target is cleaned by wiping. Through the above method, different rough surfaces with a roughness (Ra) of 10~25 microns (μm) and a uniformity of less than 5% are processed on the surface of the preset position of the target, and the overall cleanliness of the target must be dust-free According to the class1000 requirement in the chamber standard (US standard 209e), the target can provide an excellent adhesion surface in the subsequent sputtering process.

Description

Surface Roughness Processing Method of Sputtering Target

The invention relates to a technical field related to surface treatment of a target, in particular to a method for processing the roughness of a sputtering surface of a target.

Sputtering is a physical vapor deposition (PVD) method used to form metal thin films, which can be applied in the manufacturing process of liquid crystal display panels, plasma display panels or semiconductor microcircuits. The so-called sputtering is to use a magnetic field or an electric field to make the ions in the plasma bombard the sputtering material (target), so that the atoms on the surface (front) of the sputtering material sputter out and fly to the target (the object to be sputtered). The atoms of the sputtered material flying towards the target then attach to the target surface to form a metal layer on the target surface.

It has been proved by experiments that the roughness of the target surface helps to improve the sputtering material atoms and the effect of attaching to the target surface; please refer to Figure 5, for example, the surface roughness of the target is between (Ra)2~5 In micrometers (μm) (area A), during the sputtering process, the particle count of the sputtering material measured on the surface of the target is about 30% to 40%. If the surface roughness of the target increases, the atomic number of the sputtering material measured on the surface of the target has the characteristics of an upward curve. Among them, when the surface roughness of the target material is between (Ra) 10~12 (μm) microns (ie, area B), it has better curve characteristics (more than half of the sputtering material atoms are measured). When the surface roughness of the target is between (Ra) 12~25 (μm) microns, relatively better curve characteristics can be obtained (more than half of the atoms of the sputtering material are measured).

The above-mentioned average roughness of the center line (Ra, arithmetic mean deviation) is defined as: cut a section of rough curve measured as L from the processing surface, and take the center line of the rough depth within the length L as the x-axis, and take the vertical line of the center line If the line is the y axis, the rough curve can be represented by y=f(x). Invert the lower curve based on the center line. Then calculate the area covered by all the curves above the center line after reflexion, and then divide it by the measured length L. The value obtained is in microns (μm), which is the average roughness value of the center line within the measured length of the machined surface (standard known in the prior art).

Therefore, providing a moderately rough surface on the target can improve the effect of sputtering. For this reason, many teachings have been proposed in the industry to form a surface with a predetermined roughness on the target. However, due to the requirement of precision processing, it is obviously impossible to provide a surface with a single roughness in the sputtering area to meet the current processing requirements. Therefore, how to further provide a surface with different roughness in a single area has been expected by the industry.

In view of the above-mentioned problems and deficiencies in the prior art, the main purpose of the present invention is to provide a method for processing the surface roughness of the sputtering surface of the target, by using an innovative process to process surfaces with different roughness in the predetermined area of the surface of the target.

According to the above-mentioned purpose of the present invention, the present invention proposes a method for processing the surface roughness of the sputtering surface of the target, which is used to form surfaces with different roughnesses on the predetermined area of the target. First, take a target to confirm the sputtering processing area, and shield the non-processing area, then sandblast the processing area, cover the processing area partially to define the secondary processing area, and The processing area is coated, and finally the target is cleaned by wiping. Through the above method, different rough surfaces with a roughness (Ra) of 10~25 microns (μm) and a uniformity of less than 5% are processed on the surface of the preset position of the target, and the overall cleanliness of the target must be dust-free Room specification (US regulation 209e) The class1000 grade requirement allows the target to provide an excellent adhesion surface in the subsequent sputtering process.

10: target

12: Processing area

122: Secondary processing area

14: Non-processing area

20: Tape

100~600: steps

A, B: area

[Fig. 1] is a schematic diagram of the roughness processing method of the sputtering surface of the target material according to the present invention.

[Fig. 2] is a schematic diagram (1) of an embodiment of the present invention.

[Fig. 3] is the schematic diagram (2) of the embodiment of the present invention.

[Fig. 4] is the schematic diagram (3) of the embodiment of the present invention.

[Figure 5] is a schematic diagram of the curves of the number of particles obtained by different roughness in the prior art.

Hereinafter, please refer to the relevant drawings to further describe the embodiment of the method for processing the surface roughness of the sputtering surface of the present invention. In order to facilitate the understanding of the implementation of the present invention, the same components are described below with the same symbols.

Please refer to Figures 1 to 4, the sputtering surface roughness processing method of the present invention comprises the following steps:

Step 100: Take a target 10 and confirm the processed area 12 to be sputtered and the non-processed area 14 not to be sputtered.

Step 200: Cover the target 10 with the adhesive tape 20 and define the processing area. The target material 10 is covered by the adhesive tape 20 and only the processing area is exposed, so as to prevent the impact of external force on the non-processing area 14 . During implementation, the tape 20 is selected from polyester (PET) tape, polyethylene (PE) tape, polyvinyl chloride (PVC) tape, masking paper tape (Crepe Paper), glass cloth tape (Glass Cloth), silicone tape (Silicone ), and one or a combination of acrylic tape (Acrylic).

Step 300: Sandblasting the processing area 12 with a sand material. The sand material is accelerated by sandblasting equipment (not shown in the figure, such as a sandblasting gun), and sandblasting is performed on the processing area 12 exposed to the target 10, so that the surface of the processing area 12 has an average roughness (Ra) of 10-12 microns (μm ) and a rough surface with a uniformity below 5%. As for the non-processing area 14, it is not affected due to the protection of the adhesive tape 2 . During implementation, the sand material is selected from one or a combination of white alumina sand or titanium dioxide sand with a particle size of #14~20. As for the preferred method of sandblasting, it is recommended to blast the target 10 at an angle of 10~60 degrees with a pressure of 5~10kg/cm ² at a distance of about 20-40 cm from the target 10.

Step 400: Wrap part of the processing area with adhesive tape 20 to define a secondary processing area. The scope of the secondary processing area in the processing area is confirmed, and the adhesive tape 20 is used to cover part of the processing area 12 again to define the secondary processing area 122 . With the covering of tape 20, the impact of external force on areas other than the secondary processing area 122 is blocked

Step 500: Spray the secondary processing area 122 with a molybdenum coating material. Coating operation is performed on the surface of the secondary processing area 122 through thermal spraying equipment (not shown in the figure) hot-melt molybdenum (Mo) coating material, so that the secondary processing area 122 forms an average roughness (Ra) of 12 to 25 microns ( μm), and a rough surface with a uniformity below 5%.

The basic principle of common thermal spraying equipment, such as arc spraying equipment, is to contact two metal wires with positive and negative charges respectively to generate an electric arc, and instantly generate high heat to melt the coating material (metal wire), and then blow it to the target through high-pressure air The material then forms accumulations, and finally forms a coating after cooling and solidification. The result of this operation can be greater than the surface roughness formed by sandblasting.

During the implementation, the molybdenum (Mo) coating material is selected from the molybdenum wire with a purity of 99.95 and a wire diameter of 1.6mm. As for the better method of coating operation, it is recommended to place the thermal spraying equipment at a distance of about 50-80 cm from the target. At an angle of 80-90 degrees, with an air pressure of 4-8 such as kg/cm ² , the molybdenum (Mo) coating material is passed through a current of about 10kw and then sprayed on the target material.

According to the statistics of the implementation process, different roughness results can be obtained at different working times. For example, if the surface roughness is greater than 20μm, the working time is about 30~35sec. The surface roughness is 18~20μm, and the working time is about 25~30sec. The surface roughness is 14~18μm, and the working time is 15~25sec. The surface roughness is 12~14μm, and the working time is 10~15sec.

Step 600: remove the adhesive tape 20 and clean the target 10 until the cleanliness meets the requirements for entering a class1000 standard environment. Remove the masking tape 20 from the target 10, and use a wiper (not shown) to wipe and clean the target 10 until the cleanliness of the target 10 meets the clean room specification class 1000 entry requirements. During implementation, the wiper is selected from the wiper cloth (or dust-free paper) used in the corresponding clean room class 1000 to class 1, and is used alternately in order from large to small for cleaning.

Therefore, the above is a preferred embodiment provided by the present invention, the introduction of the roughness processing method of the sputtering surface of the target, and then the operating characteristics of the present invention are introduced as follows:

A rough surface with an average roughness (Ra) of 10-12 microns (μm) and a uniformity of less than 5% is formed on the processing area 12 of the target 10 by the sandblasting process. A uniform surface is formed on the processing area 12 .

Then define a secondary processing area in the preset area of the processing area 12, and form a rough surface with an average roughness (Ra) of 12~25 microns (μm) and a uniformity of less than 5% on the secondary processing area by spraying .

According to the above-mentioned processing procedures of different processes and regions, two kinds of surfaces with different roughnesses are formed in the predetermined regions of the target 10 to cope with the subsequent sputtering process.

The above-mentioned cleaning process eliminates the wet cleaning method, and uses the wiping method with different grades of wipers to wipe the target 10 multiple times, so that the cleanliness of the target 10 meets the environmental requirements of class 1000 for entering the clean room specification. In this way, it is possible to avoid the loss of rust caused by the wet cleaning process on the target material 10 .

The above description is only a preferred embodiment of the present invention, and is intended to clarify the characteristics of the present invention, and is not intended to limit the scope of the embodiments of the present invention. Those of ordinary skill in the art will make equivalent changes according to the present invention. , and changes well known to those skilled in the art should still fall within the scope of the present invention.

100~600: steps

Claims (7)

A method for processing the roughness of a sputtering surface of a target, which comprises (a) taking a target, and confirming a processing area to be sputtered on the target and a non-processing area not to be sputtered; (b) using A tape covers the target material and defines (exposes) the processing area; (c) sandblasting the processing area with a sandblasting material to form an average roughness (Ra) of 10-12 microns (μm) on the surface of the processing area ), and a rough surface with a uniformity of less than 5%; (d) using the adhesive tape to partially cover the processing area to define a secondary processing area; (e) spraying the second processing area with a molybdenum coating material , so that the surface of the two processing areas forms a rough surface with an average roughness (Ra) of 12 to 25 microns (μm) and a uniformity of less than 5%; Wipe and clean the target material so that the cleanliness of the target material meets the environmental requirements of class 1000. The method for processing the roughness of the sputtering surface of the target as described in claim 1, wherein the tape is selected from polyester (PET) tape, polyethylene (PE) tape, polyvinyl chloride (PVC) tape, masking paper tape (Crepe Paper), glass cloth tape (Glass Cloth), silicone tape (Silicone), and acrylic tape (Acrylic), one or a combination thereof. The method for processing the surface roughness of the sputtering surface of the target material as described in claim 1, wherein the sand material is selected from one or a combination of white alumina sand or titanium dioxide sand with a particle size of #14-20. The method for processing the roughness of the sputtering surface of the target as described in claim 1, wherein the sandblasting in step (c) is performed at a distance of 20 to 40 centimeters from the processing area, at an angle of 10 to 60 degrees, and at an angle of 5 to 60 degrees. The processing area is sand blasted with a pressure of 10kg/cm ² . The method for processing the roughness of the sputtering surface of the target as described in Claim 1, wherein the wiper is selected from the wiper or dust-free paper used in the clean room class 1000 to class 1. The method for processing the roughness of the sputtering surface of the target as described in Claim 1, wherein the molybdenum coating material is selected from molybdenum wires with a purity of 99.95 and a wire diameter of 1.6 mm. The method for processing the roughness of the sputtering surface of the target as described in item 6 of the scope of the patent application, wherein the spraying treatment in step (e) is about 50-80 cm away from the secondary processing area, at an angle of 80-90 degrees , with an air pressure of 4~8kg/cm2.

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