KR100479315B1 - Sputtering target and method for producing the target - Google Patents

Abstract

Provided are a sputtering target and a method for producing the same, which can prevent the occurrence of an initial arc, significantly improve the initial stability, and can be produced with a low cost.

By surface treatment with a laser output with a pulse width of 100 µsec or less, burrs, grinding powders, and also dust and dust generated during processing such as grinding are removed by sublimation, so that initial arcs generated at the beginning of use of the target are removed. It can remarkably reduce and initial stability can be improved.

Description

Sputtering target and its manufacturing method {SPUTTERING TARGET AND METHOD FOR PRODUCING THE TARGET}

This invention relates to a sputtering target and its manufacturing method.

Generally, the sputtering method is known as one of the methods of forming a thin film. The sputtering method is a method of obtaining a thin film by sputtering a sputtering target, and since it can form into a film efficiently, it is industrially used.

In particular, the indium tin oxide (composite oxide of In ₂ O ₃ -SnO ₂ , hereinafter referred to as "ITO") film has high visible light transmittance and high conductivity, and thus is a transparent conductive film for preventing liquid crystal display devices or glass condensation. It is widely used in heat generating films, infrared reflecting films, and the like.

For this reason, in order to form a film more efficiently and with a low cost, improvement of sputter | spatter conditions, a sputter apparatus, etc. is performed day by day, and how to operate an apparatus efficiently becomes important.

In this type of ITO sputtering, the short time between setting the new sputtering target and the initial arc (abnormal discharge) is eliminated and the product can be manufactured, and how long can be used after setting it once (integrated sputtering Time: target life) becomes a problem.

Conventionally, the initial arc of the sputtering target is reduced as the target surface is polished and smoothed, and the surface polishing target having the smoothed surface becomes the mainstream.

If sputtering is performed continuously, a black deposit called nodule is formed on the target surface, which causes an abnormal discharge or a source of particle generation. Therefore, in order to prevent a thin film defect, regular nodule removal is required and there exists a problem of being connected with the fall of productivity.

Therefore, research on the ITO sputtering target which prevented generation | occurrence | production of a nodule is also performed.

However, even if an ITO sputtering target with a predetermined surface roughness is used to prevent the nodule, there is a problem that the initial arc cannot be prevented. Therefore, after setting a new sputtering target, it must be idle for a comparatively long time, and it has become a obstacle of productivity improvement.

In addition, in order to manufacture an ITO sputtering target having a predetermined surface roughness as described above, after the sintering, after adjusting the thickness by grinding, three to four polishing steps are required using a gradually fine grinding wheel, There was a problem that the manufacturing time and cost are increased.

This problem also applies to sputtering targets of ceramics or metals other than ITO.

Then, in view of such a situation, an object of this invention is to provide the sputtering target which can prevent generation | occurrence | production of initial arc, remarkably improve initial stability, and can manufacture with low cost, and its manufacturing method.

The inventors of the present invention believe that the cause of the initial arc is mainly caused by burrs, grinding powders, etc. generated in the polishing process, and these can be effectively removed by surface treatment by a laser output at a predetermined pulse width rather than by polishing. It has been found and the present invention has been completed. That is, by surface treatment with a laser, a thermal shock by plasma is applied to a target surface at the start of a sputter | spatter, and the sputter | spatter crack and the granules on the surface near the target edge which slide down by the impact are sputtered. The present invention has been completed on the basis of the fact that sublimation or the like can be carried out until the start, and the slippage does not occur due to the thermal shock at the start of the sputter.

The 1st aspect of this invention is the sputtering target characterized by surface-treating by the laser output by the pulse width of 100 microseconds or less.

In this first aspect, the surface is treated by a laser output with a predetermined pulse width, so that burrs, grinding powders, and even dust and dust generated during processing such as grinding are removed by sublimation or the like. It is possible to significantly reduce the initial arc generated in the process, and to improve the initial stability. In addition, since a laser output with a predetermined pulse width is used, energy by the laser is not diffused in the depth direction, and a deteriorated portion (in the case of an oxide, a reduced (lower oxide) portion) is not generated.

In the second aspect of the present invention, in the first aspect, the laser is output by a pulse of peak energy of 3 MW / cm ² or more.

In this second aspect, by surface treatment with a laser output with a pulse of a predetermined peak energy, burrs, grinding powders, and even dust and dust generated during processing such as grinding are removed by sublimation or the like.

According to a third aspect of the present invention, there is provided a sputtering target, wherein the wavelength of the laser is 1.1 µm or less in the first or second aspect.

In this third aspect, by surface treatment with a laser having a wavelength of 1.1 μm or less, burrs, grinding powders, and even dust and dust generated during processing such as grinding are removed by sublimation or the like.

A fourth aspect of the present invention is the sputtering target according to any one of the first to third aspects, wherein the laser is a YAG laser or an excimer laser.

In this fourth aspect, the surface treatment is effectively performed by the YAG laser or the excimer laser to improve the initial stability.

The 5th aspect of this invention is a sputtering target characterized by the target which consists of ceramics in any one of 1st-4th aspect.

In the fifth aspect, burrs and grinding powders generated during processing such as grinding of ceramics are removed.

A sixth aspect of the present invention is the sputtering target according to the fifth aspect, which is a target made of an oxide containing at least one of indium oxide and tin oxide.

In this sixth aspect, the initial stability of the ITO sputtering target is significantly improved.

According to a seventh aspect of the present invention, there is provided a sputtering target, which is characterized in that linear processing marks are reduced.

In the seventh aspect, since the process of reducing the linear processing marks is carried out, the burrs and grinding powders generated during processing such as grinding and the like, and dust and dust are removed by sublimation, so that the initial stages of the initial use of the target The arc can be significantly reduced, and the initial stability can be improved.

In the eighth aspect of the present invention, in the seventh aspect, 100 linear machining marks on the target surface observed by the scanning electron microscope (SEM) at 50X magnification are in a range of 24Oμm orthogonal to the processing marks. It is in the sputtering target characterized by the following.

In this eighth aspect, the processing marks are processed to be reduced, so that the processing marks in the straight line on the target surface observed by the scanning electron microscope (SEM) at 50X magnification are within the range of 24Oμm in the direction orthogonal to the processing marks. It becomes

A ninth aspect of the present invention is the sputtering target according to the seventh or eighth aspect, wherein the surface treatment is performed by a laser output with a pulse width of 100 mu sec or less.

In this ninth aspect, since a laser output with a predetermined pulse width is used, energy by the laser is not diffused in the depth direction, and a deteriorated portion (in the case of an oxide, a reduced (lower oxide) portion) is not generated.

The 10th aspect of this invention is a sputtering target in any one of 7th-9th aspect which surface-treated by the laser output by the pulse of the peak energy of 3 MW / cm <^2> or more.

In this 10th aspect, surface treatment can be performed effectively with the laser output by the pulse of predetermined peak energy.

The eleventh aspect of the present invention is the sputtering target, wherein any one of the seventh to tenth aspects is subjected to surface treatment by a laser having a wavelength of 1.1 μm or less.

In this eleventh aspect, effective surface treatment can be performed with a laser having a predetermined wavelength such that the wavelength is 1.1 μm or less.

A twelfth aspect of the present invention is a sputtering target according to any one of seventh to eleven, which is a target made of ceramics.

In the twelfth aspect, burrs and grinding powders generated during processing such as grinding of ceramics are removed.

A thirteenth aspect of the present invention is a sputtering target according to a twelfth aspect, which is a target made of an oxide containing at least one of indium oxide and tin oxide.

In this thirteenth aspect, the initial stability of the ITO sputtering target is significantly improved.

According to a fourteenth aspect of the present invention, there is provided a method for producing a sputtering target, comprising the step of performing a surface treatment by a laser output with a pulse width of 100 mu sec or less.

In the fourteenth aspect, the surface treatment is performed by a laser output with a predetermined pulse width, so that burrs, grinding powders, and even dust and dust generated during processing such as grinding are removed by sublimation. The initial arc generated in the film can be significantly reduced, and the initial stability can be improved. In addition, since a laser output with a predetermined pulse width is used, energy by the laser is not diffused in the depth direction, and a deteriorated portion (in the case of an oxide, a reduced (lower oxide) portion) is not generated.

According to a fifteenth aspect of the present invention, there is provided the sputtering target according to a fourteenth aspect, wherein the laser outputs a pulse of peak energy of 3 MW / cm ² or more.

In this fifteenth aspect, surface treatment is performed by a laser output with a pulse of a predetermined peak energy, thereby removing burrs, grinding powders, and even dust and dust generated during processing such as grinding by sublimation.

A sixteenth aspect of the present invention is the manufacturing method of the sputtering target according to the fourteenth aspect or the fifteenth aspect, wherein the wavelength of the laser is 1.1 µm or less.

In the sixteenth aspect, by surface treatment with a laser having a wavelength of 1.1 μm or less, burrs, grinding powders, and even dust and dust generated during processing such as grinding are removed by sublimation or the like.

According to a seventeenth aspect of the present invention, there is provided a method for producing a sputtering target, wherein the laser is a YAG laser or an excimer laser in any one of the modes 14 to 16.

In this 17th aspect, surface treatment is performed effectively with a YAG laser or an excimer laser, and initial stage stability improves.

An eighteenth aspect of the present invention is a method for producing a sputtering target, wherein in any one of the fourteenth to seventeenth aspects, the surface treatment is performed after the target is processed to adjust its thickness.

In this 18th aspect, since the burr and grinding powder which generate | occur | produce in the process of grinding etc. are removed by sublimation etc., the initial arc which a target produces at the beginning of use can be reduced remarkably, and initial stability can be improved.

19th aspect of this invention is a manufacturing method of the sputtering target in any one of 14th to 18th aspect WHEREIN: The said surface treatment is performed in the last stage of a manufacturing process.

In the nineteenth aspect, the initial arc can be effectively reduced by performing the surface treatment by the laser in the final stage as much as possible.

The aspect of 20th of this invention is a manufacturing method of the sputtering target in any one of 14th-19th aspect, The said surface treatment is performed after joining a target to a backing plate.

In such a form of 20O, since it is surface treatment by a laser, it can carry out even after joining to a backing plate, and can reduce an initial arc more effectively.

21st aspect of this invention is a manufacturing method of the sputtering target characterized by the target which consists of ceramics in any one of 14th to 20th forms.

In this twenty-first aspect, burrs and grinding powders generated during the grinding of ceramics are removed.

A twenty-second aspect of the present invention is a method for producing a sputtering target, characterized in that, in the twenty-first aspect, it is a target made of an oxide containing at least one of indium oxide and tin oxide.

In this twenty-second aspect, an ITO sputtering target with significantly improved initial stability can be provided.

A twenty-third aspect of the present invention is a method for producing a sputtering target, comprising a step of reducing surface marks by applying a surface treatment with a laser.

In the twenty-third aspect, the surface treatment with a laser removes burrs, grinding powders, and even dust and dust generated during processing such as grinding by sublimation. It can reduce and initial stage stability can be improved.

A twenty-fourth aspect of the present invention is the twenty-third aspect of the present invention, wherein the linear processing marks on the target surface observed by the scanning electron microscope (SEM) at 50,000 magnification are in a range of 24Oμm in a direction perpendicular to the processing marks. The manufacturing method of the sputtering target characterized by the following.

In the twenty-fourth aspect, the processing marks are processed to be reduced, so that the processing marks on the target surface observed by the scanning electron microscope (SEM) at 50X magnification are within the range of 24Oμm in the direction of orthogonal to the processing marks. It becomes

A twenty-fifth aspect of the present invention is the manufacturing method of the sputtering target according to the twenty-third or twenty-fourth aspect, wherein the surface treatment is performed by a laser output with a pulse width of 100 mu sec or less.

In the twenty-fifth aspect, since the laser outputs with a predetermined pulse width is used, energy by the laser is not diffused in the depth direction, and a deteriorated portion (in the case of an oxide, a reduced (lower oxide) portion) is not generated.

A twenty-sixth aspect of the present invention is the method for producing a sputtering target according to any one of aspects ²³ to 25, wherein the surface treatment is performed by a laser output with a pulse of peak energy of 3 MW / cm ² or more. Is in.

In the twenty-sixth aspect, effective surface treatment can be performed with a laser output with a pulse of a predetermined peak energy.

According to a twenty-seventh aspect of the present invention, there is provided a method for producing a sputtering target, wherein the surface treatment is performed by a laser having a wavelength of 1.1 μm or less in any one of the twenty-third aspect.

In the twenty-seventh aspect, effective surface treatment can be performed with a laser having a predetermined wavelength such that the wavelength is 1.1 μm or less.

28th aspect of this invention is a manufacturing method of the sputtering target in any one of 23-27, after processing a target and adjusting thickness, and performing the said surface treatment.

In this 28th aspect, since the burr and grinding powder which generate | occur | produce in the process of grinding etc. are removed by sublimation etc., the initial arc which arises at the beginning of use of a target can be remarkably reduced, and initial stage stability can be improved.

A twenty-ninth aspect of the present invention is the method for producing a sputtering target, according to any one of aspects 23 to 28, wherein the surface treatment is performed at a final stage.

In the twenty-ninth aspect, the initial arc can be effectively reduced by performing the surface treatment by the laser in the final stage as much as possible.

The third aspect of the present invention is the method for producing a sputtering target, according to any one of aspects 23 to 29, wherein the surface treatment is performed at a final stage after the target is bonded to the backing plate.

In such a form of 30O, since it is a surface treatment by a laser, it can carry out even after joining to a backing plate, and an initial arc can be reduced more effectively.

A thirty-first aspect of the present invention is a method for producing a sputtering target, wherein the target is made of ceramics in any one of the 23rd to the 30th aspect.

In this 31st aspect, the burr and grinding powder which arise at the time of grinding of ceramics are removed.

A thirty-second aspect of the present invention is the thirty-first aspect of the present invention provides a method for producing a sputtering target, wherein the target is made of an oxide containing at least one of indium oxide and tin oxide.

In this thirty-second aspect, an ITO sputtering target with significantly improved initial stability can be provided.

In the present invention, since the surface finish of the sputtering target is performed by a laser output with a predetermined pulse width, burrs or grinding powders generated during processing such as dirt, dust or hand oil, and grinding (or polishing), Furthermore, since sublimation or the like is easily eliminated at the point where the sputtering is easily released due to thermal shock, the initial arc hardly occurs at the beginning of use of the sputtering target, and transition to thin film production can be performed with little preliminary operation. In addition, the initial stability can be significantly improved. In addition, since a laser output with a predetermined pulse width is used, energy by the laser is not diffused in the depth direction, and a deteriorated portion (in the case of an oxide, a reduced (lower oxide) portion) is not generated. In addition, in this specification, the phrase "grinding" may represent "grinding (or polishing)."

In this case, a laser having a pulse width of 100 mu sec or less does not generate thermal stress to the target as much as possible, and burrs, grinding powders, etc., generated during processing such as dirt, dust, hand oil, and grinding (or polishing), It is possible to effectively remove a part which is easily separated by thermal shock when using sputtering, and the kind of the medium, the oscillation method, and the like are not particularly limited.

In the present invention, the use of a laser output with a pulse width of 100 mu sec or less, preferably 0.2 mu sec or less, particularly preferably 0.1 mu sec or less, results in no thermal diffusion and dust on the surface near the end of the target. Only sublimation and the like occur, and the particles constituting the surface layer are not melted and integrated.

In particular, in the laser having a pulse width of 0.1 mu sec or less, the grinding marks can be reduced, and the type of the medium, the oscillation method, and the like are not particularly limited.

Irradiation of the laser does not generate thermal stress to the target as much as possible, and burrs, grinding powder, and even thermal shock during sputtering, which are generated during processing such as dust, dust, hand oil, and the like (grinding). It is set as the condition which can remove the location which is easy to separate by effectively. In order to generate sublimation and the like efficiently, large energy is required, and it is preferable to use a laser of peak energy of 1 MW / cm ² or more, preferably 3 MW / cm ² or more. In addition, the irradiation method is not particularly limited, either a large diameter laser may be scanned, or a small diameter laser beam may be scanned.

In this invention, it is preferable to use the laser whose wavelength is 5 micrometers or less, Preferably it is 1.1 micrometers or less. This is to prevent energy from the laser from diffusing in the depth direction and to prevent a deteriorated portion (in the case of an oxide, a reduced (lower oxide) portion). As a laser which can be used by this invention, a YAG: Nd laser (wavelength 1.O6micrometer), an ArF excimer laser (wavelength 192nm), etc. are mentioned.

The sputtering target to which the present invention can be applied is not particularly limited, and a sputtering target of a high melting point metal can be applied to a ceramic target made of an oxide or the like.

In particular, in a ceramic target obtained by sintering an oxide powder material, a brittle part which is easily detached by burr or thermal shock is likely to be produced during grinding or surface polishing for thickness adjustment, and thus the present invention can be effectively applied. Among these, in the ITO sputtering target which consists of an oxide containing indium oxide and tin oxide, since high initial stability is calculated | required for efficient sputtering, this invention can be applied especially effectively.

An example of the manufacturing method of the sputtering target which concerns on this invention is demonstrated using a ceramic target as an example.

First, the powder used as a raw material is mixed at a desired compounding ratio, and is molded and fired using various conventionally known wet methods or dry methods.

As a dry method, the cold press method, the hot press method, etc. are mentioned. In the cold press method, a mixed powder is filled into a molding die, a molded article is produced, and fired and sintered in an air atmosphere or an oxygen atmosphere. In the hot press method, the mixed powder is directly sintered in a molding die.

As the wet method, for example, it is preferable to use a filtration molding method (see Japanese Patent Laid-Open No. 11-286OO2). The filtration molding method is a filtration molding mold made of a non-aqueous material for obtaining a molded body by depressurizing and draining water from a ceramic raw material slurry, and is a molding lower mold having one or more drain holes, and is placed on the molding lower mold. It consists of a water-permeable filter and a molding mold which is fitted from the upper surface side through a sealing material for sealing the filter, and the molding lower mold, the molding mold, the sealing material, and the filter can each be disassembled. It is assembled so that the filter molding mold which drains the water in the slurry under reduced pressure is used only at the filter surface side, the slurry which consists of mixed powder, ion-exchange water, and an organic additive is prepared, and this slurry is inject | poured into a filter molding mold, The ceramic molded body obtained by manufacturing the molded object by depressurizingly draining water in a slurry only at this filter surface side. After drying degreasing, it is baked.

In each method, baking temperature, for example, in the case of an ITO target, 130000-160000 degreeC is preferable, More preferably, it is 1450-16600 degreeC. Thereafter, machining is carried out for molding and processing at a predetermined dimension to be a target.

Generally, after molding, the surface is ground for thickness adjustment, and further, polishing is performed at various stages to smooth the surface. The surface treatment by the laser of this invention may be performed after grinding of thickness adjustment, or may be performed after grinding | polishing. Either way, after performing the surface treatment with a laser, the subsequent polishing or the like is not performed at all.

When surface treatment with such a laser is carried out, for example, even if the surface is not smooth, burrs and grinding powders generated during grinding, and moreover, parts easily removed by thermal shock when using sputtering are removed by sublimation or the like. I think. That is, when applying this invention, the process of grinding | polishing a surface can be skipped, Furthermore, it is preferable to perform the surface treatment by a laser, omitting the grinding | polishing process after a grinding process.

Therefore, the surface roughness Ra of the sputtering target of this invention may be larger than 0.5 micrometers conventionally said, and may be about 0.8 micrometer <Ra <3 micrometers. This is because even if surface roughness Ra is larger than 0.5 micrometer, since the surface treatment by a laser is performed, initial arc is drastically reduced and initial stability improves. In addition, since the surface roughness Ra tends to be increased by surface treatment with a laser, the surface roughness may be increased as a result.

Of course, even if surface roughness Ra is 0.5 micrometer or less, it cannot be overemphasized that initial arc reduces significantly when this invention is applied.

In the related art, after the polishing step is completed, the target is bonded to the backing plate to form a sputtering target. The surface treatment by the laser of the present invention can also be performed after bonding to the backing plate. Moreover, in consideration of the initial stability of the produced sputtering target, it is preferable to carry out after joining to a backing plate. This is to prevent dust, dust, etc. from adhering to the surface after the surface treatment by the laser.

Therefore, it is preferable to package immediately after surface treatment with the laser of the present invention. In the case of packaging with a resin film, since the particles may be transferred to the target surface in contact with the resin film, it is preferable to use a resin film containing no detachable particles. It is preferable to pack so as not to contact.

Generally, when a target such as a ceramic having a cleavage property is ground and polished with a grindstone or the like as described above, specifically, the target is ground and polished by sliding the rotating grindstone. In the present specification, a straight grinding mark (grinding marks) parallel to the polishing direction is left (in this specification, the grinding marks and polishing marks are collectively referred to as "machining marks"), but when the surface treatment is performed by the laser of the present invention, This is reduced.

In addition, in the metal target, the processing of the thickness direction is performed with a phrase board or a shelf, or the adjustment of thickness is performed by rolling etc. In this case, a process wound remains, and it becomes "a process mark" in this specification. Such processing marks are also reduced by surface treatment with a laser and, in some cases, substantially removed.

Specifically, when the surface treatment is performed by the laser of the present invention, 10 or less linear cutting marks on the target surface observed by the scanning electron microscope (SEM) at 50X magnification are within a range of 24Oμm orthogonal to the cutting marks. It becomes

Here, the reduction means that the shredded processing marks have a rounded shape or are removed, so that they cannot be reliably seen and, in some cases, disappear substantially. Further, the reduction in processing marks is determined by the relationship between the material of the target, the wavelength and the output of the laser, and it is not necessary to eliminate the processing marks when the surface treatment is performed by the laser of the present invention.

Although different depending on the laser irradiation conditions, for example, in the case of using a YAG: Nd laser (wavelength 1.O6 μm), processing marks are often reduced to be virtually invisible. ArF excimer laser (wavelength 192 nm) As for the processing mark, although there is some reduction, it does not reach to the extent that it becomes invisible.

Either way, according to the present invention, by surface treatment with a laser, at the start of the sputter, the thermal shock by the plasma is applied to the target surface, and the granules and the shell-shaped cracks on the surface near the target tip that slide down due to the impact. The effect of sublimation and the like until the start of the sputtering, and the thermal shock at the start of the sputtering, can be prevented from slipping off, and the initial arc generated at the beginning of use of the target can be significantly reduced, and the initial stability can be improved. Can be.

In particular, by using a laser with a peak energy of 3 MW / cm ² or more at a pulse width of 100 mu sec or less, partial deterioration (partial reduction (low oxide) in the case of an oxide) by diffusion in the depth direction of energy by laser irradiation is achieved. It can prevent, only sublimation, such as dust, on the surface near the end of a target arises, and it does not integrate by melt | dissolving the particle | grains which comprise a surface layer, and can improve target life.

In addition, Japanese Unexamined Patent Publication No. 6O-215761 discloses a surface of the sintered body by irradiating energy rays such as a near infrared laser beam, integrating particles of the surface layer by melting to form a molten layer on the surface portion, and A method of forming a sputtering target for reducing or eliminating collapse collapse is disclosed. This method is to melt the fine powder of the surface portion by energy ray irradiation to form a dense solid layer and to prevent the collapse and fall of the powder. The object and effect are completely different from the surface treatment of the present invention. . The molten layer as described in the publication cannot be formed by a laser output with a very short pulse width, and the laser actually used in the publication is a carbon dioxide gas laser having a wavelength of about 10 µm, which is different from that used in the present invention. . In addition, when the powder is melted with a laser beam to form a molten layer in this manner, conversion to low-level oxides occurs by reduction (see first row to second row on page 3 of the same publication). A significant drop is expected.

Embodiment of the invention

EMBODIMENT OF THE INVENTION Hereinafter, although this invention is demonstrated based on an Example, it is not limited to this.

(Example 1)

In ₂ O ₃ powder and SnO ₂ powder having a purity> 99.99% were prepared. The powder _{SnO 2 1Owt%, In 2 O} 3 the total amount at a rate of about 1.5Kg 9Owt% prepared to obtain a molded product by filtration molding. Thereafter, the fired body was fired and sintered at 16OOC for 8 hours in an oxygen atmosphere. This sintered compact was processed and the target of 99.5% of relative density with respect to theoretical density was obtained.

The target was ground with a grinding wheel of 17O in a flat grinding machine to adjust the thickness, and then surface treatment was performed using a YAG: Nd laser (wavelength 1064 nm).

The irradiation condition of YAG laser is spot size It was 2 mm, pulse width 1 Onsec, peak energy 32OMW / cm <^2> , pulse frequency 1OHz, and the output per pulse was 100mJ / pulse. The average effective irradiation energy was 6.4 J / cm ² .

It was 2.O6 micrometers when the surface roughness Ra after surface treatment was measured according to JIS BO6O1. Specifically, using a stylus type surface roughness meter (P10 manufactured by Tencor), using a needle with a tip radius of 0.5 μm, a needle pressure of 15 mg, measuring at a feed rate of 20 μm / sec, a measuring width of 1.5 mm, and a cutoff filter of 8OO μm. did.

In addition, the surface state observed with the scanning electron microscope (SEM) of 50 magnification is shown in FIG. Straight grinding marks could not be observed. In addition, the observation viewing area of the 500-times scanning electron microscope (SEM) is about 230 micrometers x about 170 micrometers, and the same also in the following example and a comparative example.

(Example 2)

A target was produced in the same manner as in Example 1 except that an ArF excimer laser (wavelength of 192 nm) was used instead of the YAG laser.

The irradiation conditions of the excimer laser were spot size of 3.3 mm x 1.5 mm, pulse width of 3 Onsec, peak energy of 11 MW / cm ² , pulse frequency of 1 Hz, and output per pulse of 16 mJ / pulse. The average effective irradiation energy was 0.32 J / cm ² .

It was 1.77 micrometers when the surface roughness Ra after surface treatment was measured according to JIS BO6O1.

In addition, the surface state observed with the scanning electron microscope (SEM) of 50 magnification is shown in FIG. 10 linear grinding marks were observed in the range of about 24 micrometers orthogonal to the process mark on a target. However, it was not observed reliably like the grinding | polishing trace of the comparative example mentioned later, and was in the state which was slightly rounded and reduced.

(Example 3)

The target of Example 1 was ground with a grinding wheel of 17O in a flat grinding machine to adjust the thickness, and then polished three times with 4OO, 6OO, and 10O. Thereafter, surface treatment was performed using a YAG: Nd laser (wavelength 1064 nm).

The irradiation condition of YAG laser is spot size It was 2 mm, pulse width 1 Onsec, peak energy 32OMW / cm <^2> , pulse frequency 1OHz, and the output per pulse was 100mJ / pulse. The average effective irradiation energy was 3.2 J / cm ² .

It was 0.59 micrometer when the surface roughness Ra after surface treatment was measured according to JIS BO6O1.

In addition, the surface state observed with the scanning electron microscope (SEM) of 50 magnification is shown in FIG. A straight grinding mark could not be observed within the range of about 175 μm × about 24 μm on the target.

(Example 4)

After adjusting the thickness of the target of Example 1 by grinding | polishing with the grinding wheel of 17O in a planar grinding mill, it surface-treated using the YAG: Nd laser (wavelength 1064nm).

The irradiation condition of YAG laser is spot size It was 0.82 mm, pulse width 10 nsec, peak energy 6.6 MW / cm <^2> , pulse frequency 50OHz, and the output per pulse was 3.6 mJ / pulse. The average effective irradiation energy was 2.05 J / cm ² .

It was 1.70 micrometers when the surface roughness Ra after surface treatment was measured according to JIS BO6O1.

In addition, the surface state observed with the scanning electron microscope (SEM) of 50 magnification is shown in FIG. Six linear grinding marks were observed in the range of about 24Om orthogonal to the processing marks on the target.

(Comparative Example 1)

After performing surface grinding in Example 1, it was set as the target of the comparative example 1 not to perform surface treatment by a laser.

It was 1.68 micrometers when surface roughness (Ra) was measured according to JIS BO6O1.

Moreover, the surface state observed with the scanning electron microscope (SEM) of 50 magnification is shown in FIG. Eleven grinding marks were observed in the range of approximately 24Om in the direction orthogonal to the processing marks on the target. However, it was observed more reliably than the abrasive marks of Example 2 mentioned above.

(Comparative Example 2)

After performing surface polishing with 10000 times in Example 3, it was set as the target of the comparative example 2 not to perform the surface treatment by a laser.

The surface roughness Ra was measured in accordance with JIS BO6O1 and found to be 19 µm.

Moreover, the surface state observed with the scanning electron microscope (SEM) of 50 magnification is shown in FIG. About 14O linear grinding marks were observed in the range of about 24Oμm orthogonal to the processing marks on the target.

(Comparative Example 3)

The target was manufactured like Example 1 except having used the YAG laser of the following irradiation conditions.

The irradiation condition of YAG laser is spot size It was 2 mm, pulse width 0.3 msec, peak energy 22 kW / cm <^2> , pulse frequency 20 Hz, and the output per pulse was 10mJ / pulse. The average effective irradiation energy was 19 J / cm ² .

It was 1.70 micrometers when the surface roughness Ra after surface treatment was measured according to JIS BO6O1.

In addition, the surface state observed with the scanning electron microscope (SEM) of 50 magnification is shown in FIG. Twelve linear polishing marks were observed in the range of approximately 24Om orthogonal to the processing marks on the target. However, it was not reliably observed like the grinding marks of the other comparative example, and had a slightly rounded shape and was in a reduced state. In addition, in some places, partial reducing parts (lower oxides: black-looking parts) were observed.

(Test example)

Using the target of Examples 1-4 and Comparative Examples 1-3, it sputter | spattered continuously with the DC magnetron sputter on the following conditions, and measured the initial arc count and 50 count lifetime. The results are shown in Table 1 below. In addition, the laser irradiation conditions of each Example and the comparative example 3 are shown in Table 2.

Here, the number of initial arcs is the number of arcings (abnormal discharges) that occur from the start of each target use up to the input power amount 1OWh / cm ² . Incidentally, the arcing was detected by an arc detector (MAM Genesis) manufactured by Landmark Technology.

The 50 count life refers to the input power amount (Wh / cm ² ) when the cumulative arcing time reaches 50 times, except for the initial arc number from the start of each target use to the input power amount 1OWh / cm ² .

Sputtering conditions

Target Dimensions: Diameter 6 inches, Thickness 6 mm

Sputter Method: DC Magnetron Sputter

Exhaust System: Rotary Pump + Clio Pump

Reach Vacuum: 3.O × 1O ^-7 [Torr]

Ar pressure: 3.O × 1O ^-3 [Torr]

Oxygen partial pressure: 3.O × 10 ^-5 [Torr]

Sputter Power: 3OOW (Power Density 1.6W / cm ² )

From the above results, it was confirmed that the initial arc recovery was greatly reduced and the initial stability was greatly improved by the surface treatment with a laser, regardless of the surface roughness. In addition, it was found that the extent to which the processing traces are reduced by the surface treatment by the laser is different depending on the type of laser, and even if the processing marks remain substantially, the initial arc recovery is not directly affected. Moreover, when surface treatment with a laser was performed, the generation of nodules was also reduced, and it was also confirmed that the target life was improved.

Also, if the laser of relatively weak energy is irradiated for a relatively long time as in Comparative Example 3, the energy is diffused in the depth direction of the target, so that a reduced portion (lower oxide: black-looking portion) is observed. The result was a marked drop.

As described above, according to the present invention, by the surface treatment with a laser, the thermal particles by the plasma are applied to the target surface at the start of the sputter, and the powder or granules on the surface near the target tip slipping by the impact, and It is possible to sublimate shell-shaped cracks until the sputtering starts, to prevent the shell from slipping due to thermal shock at the start of the sputtering, and to significantly reduce the initial arc occurring at the beginning of use of the target. Stability can be improved. Moreover, when surface treatment by a laser is performed, several grinding | polishing processes can be skipped and it can manufacture as a low cost as a result.

FIG. 1 is a photograph showing the surface state observed by a scanning electron microscope (SEM) at 50,000 magnification of Example 1 of the present invention.

Fig. 2 is a diagram showing the surface state observed by the 50% magnification scanning electron microscope (SEM) of Example 2 of the present invention.

Fig. 3 is a diagram showing the surface state observed by a scanning electron microscope (SEM) of 50 magnification of Example 3 of the present invention.

Fig. 4 is a diagram showing the surface state observed by a scanning electron microscope (SEM) at 50 magnification of Example 4 of the present invention.

Fig. 5 is a diagram showing the surface state observed by a scanning electron microscope (SEM) at 50% magnification of Comparative Example 1 of the present invention.

Fig. 6 is a diagram showing the surface state observed by a scanning electron microscope (SEM) at 50 magnification of Comparative Example 2 of the present invention.

FIG. 7 is a diagram showing the surface state observed by a scanning electron microscope (SEM) at 50 magnification of Comparative Example 3 of the present invention.

Claims (32)

It is a target made of ceramic, and has a pulse width of 100 μsec or less and a laser beam output with a pulse of peak energy of 3 MW / cm ² or more. A sputtering target, characterized in that, in a range of 230 μm in a direction orthogonal to the processing marks, the linear processing marks observed by the scanning electron microscope (SEM) at magnification are 10 or less. delete The sputtering target according to claim 1, wherein the surface treatment is performed by a laser having a wavelength of 1.1 mu m or less. delete delete The sputtering target according to claim 1 or 3, which is a target made of an oxide containing at least one of indium oxide and tin oxide. delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete