JP6436006B2 - Sputtering target and manufacturing method thereof - Google Patents

Description

  The present invention relates to a sputtering target used when forming a Cu—In—Ga—Se compound film (hereinafter sometimes abbreviated as CIGS film) for forming a light absorption layer of a CIGS thin film solar cell, and It relates to the manufacturing method.

  In recent years, thin film solar cells based on chalcopyrite compound semiconductors have come into practical use, and thin film solar cells based on this compound semiconductor form a Mo electrode layer serving as a positive electrode on a soda-lime glass substrate. A light absorption layer made of a CIGS film is formed on the Mo electrode layer, a buffer layer made of ZnS, CdS, or the like is formed on the light absorption layer, and a transparent electrode layer serving as a negative electrode is formed on the buffer layer. It has a basic structure formed.

  As a method for forming the light absorption layer, a method of forming a film by vapor deposition is known. Although a light absorption layer obtained by this method can obtain high energy conversion efficiency, film formation by vapor deposition has a vapor deposition rate. Since it is slow, the uniformity of the film thickness distribution tends to decrease when the film is formed on a large-area substrate. Therefore, a method for forming a light absorption layer by a sputtering method has been proposed.

  As the light absorption layer method by sputtering, first, an In film is formed by sputtering using an In target. A Cu-Ga binary alloy film is formed on the In film by sputtering using a Cu-Ga binary alloy target, and the resulting In film and Cu-Ga binary alloy film are formed. A method (so-called selenization method) for forming a CIGS film by heat-treating a laminated precursor film in a Se atmosphere has been proposed.

  Furthermore, against the background of the above technology, the Cu-Ga alloy film and the In film laminated precursor film are formed from the metal back electrode layer side with a high Ga content Cu-Ga alloy layer, a low Ga content Cu-Ga alloy. A layer and an In layer are formed by a sputtering method in this order, and this is heat-treated in a selenium and / or sulfur atmosphere, so that the inside of the thin-film light absorption layer from the interface layer (buffer layer) side to the metal back electrode layer side A technique for realizing a thin film type solar cell with a large open circuit voltage by gradually changing the Ga concentration gradient (stepwise) and preventing peeling of the thin film light absorption layer from other layers has been proposed. . In this case, the Ga content in the CuGa target has been proposed as 1 to 40 atomic% (see, for example, Patent Document 1).

On the other hand, in order to obtain a chalcopyrite structure semiconductor having a low resistance p-type conductivity type used for photovoltaic devices such as solar cells, a p-type conductivity type chalcopyrite structure semiconductor is applied to Vb such as P, Sb, Bi, etc. A method of doping a genus element by ion doping (ion implantation) has been proposed (see, for example, Non-Patent Document 1).
In addition, when high concentration doping of N, P, Sb, and Bi elements into a chalcopyrite structure semiconductor is performed using a molecular beam or an ion beam, there are problems such as crystal defects and the like, which is difficult. Has been. Furthermore, a technique using sodium phosphate for doping a Vb group element into a chalcopyrite structure semiconductor has been proposed (see, for example, Patent Document 2).

JP-A-9-213978 US Patent Publication No. 2005/0056863

Shigemi Kohiki, Mikihiko Nishitani, Takayuki Negami, Takahiro Wada, `` Valence manipulation and homojunction diode fabrication of chalcopyrite structure Cu In Se thin films '', Thin Solid Films, 15 April 1993, Vol. 115, Issue 1, Pages 149-155

The following problems remain in the conventional technology.
That is, in the method described in Non-Patent Document 1, since the ion doping process is used, the manufacturing cost is high, and as described in Patent Document 2, crystal defects are generated in the semiconductor film. There is. In addition, when doping P and As, it is not preferable in view of process safety because highly toxic PH ₃ and AsH ₃ are used.

  The present invention has been made in view of the above-mentioned problems, and among the Vb group elements, in particular, a Cu-Ga film doped with a high concentration of N and P can be produced safely, uniformly and at low cost. It is an object of the present invention to provide a sputtering target capable of forming a film and a manufacturing method thereof.

The present invention employs the following configuration in order to solve the above problems.
That is, the sputtering target according to the present invention contains Ga: 0.1 to 50% by mass, one or more elements selected from N and P in an amount of 0.01 to 2% by mass, the balance being Cu and inevitable impurities. And is contained in a state of a compound of any one of N and P and at least Ga or Cu, and an average particle size of the compound is 10 μm or less.
Moreover, the sputtering target according to the present invention includes Ga: 0.1 to 50% by mass, one or more elements selected from N and P, 0.01 to 2% by mass, oxygen: 0.01 to 6% by mass. And the remainder has a component composition consisting of Cu and inevitable impurities, is contained in the state of a compound of any element of N and P and at least Ga or Cu, and the average particle size of the compound is 10 μm or less It is characterized by being.

  In this sputtering target, any element of N and P is contained in a compound state of at least Ga or Cu, and the average particle diameter of the compound is 10 μm or less. Therefore, a precursor of a chalcopyrite structure semiconductor is formed by a sputtering method. During the formation of the (CuGa film), N and P elements can be doped at a high concentration. In addition, since doping is performed by a sputtering process, the doping is cheaper, safer and more uniform than conventional ion doping. Further, since N and P can be doped into the precursor, crystal defects or the like do not occur and the chalcopyrite structure semiconductor film is not damaged.

In addition, since the average particle diameter of the compound by any element of said N and P and at least Ga or Cu is set to 10 micrometers or less, generation | occurrence | production of abnormal discharge at the time of sputtering can be suppressed.
The reason why the Ga content is 0.1 to 50% by mass is that if it exceeds 50% by mass, a low melting point phase is precipitated, and if it is less than 0.1% by mass, CIGS This is because, when used as a solar cell precursor, since the amount of Ga is small, it is necessary to add Ga before or after sputtering film formation in order to obtain a film having desired characteristics, which increases the number of manufacturing steps. .
The reason why the content of one or more elements selected from N and P is set to 2% by mass or less is that abnormal discharge frequently occurs when the content exceeds 2% by mass. The reason for setting it to 0.01 mass% or more is that the effect of adding one or more elements selected from N and P into the film does not appear.

The sputtering target according to the present invention is characterized in that, in the sputtering target, the compound is at least one of GaN, GaP, Cu ₃ N, and Cu ₃ P.
In the sputtering target according to the present invention, in the above sputtering target, the compound is at least one of Ga (NO ₃ ) ₃ , GaPO ₄ , Cu ₃ (PO ₄ ) ₂ , and Cu (NO ₃ ) _2. It is characterized by that.
That is, this sputtering target contains N and P due to the addition of these compounds, suppresses the generation of crystal defects and the like in the CuGa film formed by sputtering, and provides a chalcopyrite structure semiconductor film. In addition, a high-purity raw material can be used, and the content of inevitable impurities can be reduced as much as possible.

  Moreover, the manufacturing method of the sputtering target which concerns on this invention is a method of manufacturing said sputtering target of this invention, Comprising: The compound powder by any element of N and P, and at least Cu, Cu-Ga alloy powder, A mixed powder of a compound powder of any one of N and P and at least Ga and a Cu-Ga alloy powder or Cu powder, or a mixed powder of any of N and P and at least Ga or Cu It has the process of sintering the compact which consists of mixed powder of a compound powder, Cu-Ga alloy powder, and Cu powder in a vacuum, an inert gas, or a reducing atmosphere (below) Then, it is called atmospheric pressure sintering method).

  Moreover, the method for producing a sputtering target according to the present invention is another method for producing the sputtering target according to the present invention, and is a compound powder and a Cu-Ga alloy composed of any element of N and P and at least Cu. Mixed powder of powder, mixed powder of compound powder of any element of N and P and at least Ga and Cu-Ga alloy powder or Cu powder, or any element of N and P and at least Ga or Cu Characterized in that it has a step of hot pressing the mixed powder of the compound powder, Cu-Ga alloy powder and Cu powder in vacuum or in an inert gas atmosphere (hereinafter referred to as hot pressing method). ).

  Moreover, the manufacturing method of the sputtering target which concerns on this invention is another method of manufacturing said sputtering target of this invention, Comprising: The compound powder by any element of N and P, and at least Cu, and Cu-Ga Mixed powder with alloy powder, mixed powder of compound powder of any element of N and P and at least Ga and Cu-Ga alloy powder or Cu powder, or any element of N and P and at least Ga or It is characterized by having a step of sintering a mixed powder of a compound powder of Cu, Cu-Ga alloy powder and Cu powder using a hot isostatic pressing method (hereinafter referred to as HIP method). Called).

  As described above, in these sputtering target manufacturing methods, the above mixed powder is manufactured by adding a compound of a Vb group element and Ga by a melting method by using a powder sintering method. As compared with the above, it is possible to uniformly disperse and distribute the compound of any element of N and P and at least Ga or Cu.

The present invention has the following effects.
That is, according to the sputtering target according to the present invention, any element of N and P is contained in a compound state of at least Ga or Cu, and the average particle size of the compound is 10 μm or less. When forming a precursor (CuGa film) of a chalcopyrite structure semiconductor, it is possible to dope N and P at a high concentration, inexpensively, safely and uniformly.
Therefore, according to the sputtering method using the sputtering target of the present invention, by forming the light absorption layer of the CIGS thin film type solar cell, N and P are added at a high concentration, and a solar cell with high power generation efficiency is obtained. It can be manufactured.

  Hereinafter, embodiments of a sputtering target and a manufacturing method thereof according to the present invention will be described separately for the first embodiment and the second embodiment in the manner of containing N and P elements.

As described above, the sputtering target of this embodiment contains 0.01 to 2% by mass of one or more elements selected from Ga: 0.1 to 50% by mass and N and P, and selectively. Oxygen: 0.01 to 6% by mass, with the balance being a component composition consisting of Cu and inevitable impurities, any element of N and P is contained in the state of a compound of at least Ga or Cu, The average particle size of the compound is basically 10 μm or less, and the compound is composed of GaN, GaP, Cu ₃ N, Cu ₃ P, Ga (NO ₃ ) ₃ , GaPO ₄ , Cu ₃ (PO ₄ ) _2. And at least one of Cu (NO ₃ ) ₂ . Here, the case where the inclusion of N and P elements is added as GaN or GaP as the compound is a first embodiment, and Cu ₃ N, Cu ₃ P, Ga (NO ₃ ) ₃ , GaPO ₄ , The case where Cu ₃ (PO ₄ ) ₂ and Cu (NO ₃ ) ₂ are added is the second embodiment.

[First Embodiment]
The sputtering target of the first embodiment contains Ga: 0.1 to 50% by mass, one or more elements selected from N and P: 0.01 to 2% by mass, with the balance being Cu and inevitable impurities. The N and P elements are contained in the state of a compound with Ga. Examples of the compound include GaN and GaP.

  The analysis of the target composition in the sputtering target is first manufactured, then the sputtering target is divided to produce a sample with the cross section exposed, and the obtained sample cross section is processed by cross section polisher (CP) processing. . Furthermore, the processed surface is subjected to quantitative analysis (surface analysis) with Cu, Ga, N, and P by EPMA (electron beam microanalyzer), thereby measuring the content and performing composition analysis.

  The maximum particle diameter of the compound (GaN, GaP) is determined by observing the target cross section with EPMA, and five 200-times COMPO images are taken. Then, the largest particle size of the above-mentioned compound among these five images is measured to obtain the maximum particle size. About average particle diameter, the average value was computed from the particle diameter of the said compound which exists in five photograph image | photographed similarly.

  The method for producing the sputtering target of the first embodiment is prepared by preparing Ga compound powder and Cu—Ga alloy powder or a mixed powder of Ga compound powder, Cu—Ga alloy powder and Cu powder in advance, and the following 3 It can be produced by two sintering methods.

(1) The mixed powder is filled in a mold and press-molded in a cold state to produce a molded body. Alternatively, the mixed powder is filled into a molding mold and tapped to form a molded body having a certain bulk density. The molded body is sintered in a vacuum, in an inert gas, or in a reducing atmosphere. In particular, when sintering in a hydrogen atmosphere, the hydrogen content in the atmosphere is set to 1% or more, preferably 90% or more.
(2) The mixed powder is hot-pressed in a pressure range of 10 to 60 MPa in a vacuum or an inert gas atmosphere.
(3) The mixed powder is sintered by the HIP method at a pressure of 15 to 150 MPa.

In order to prepare this mixed powder, for example, the following method is used.
First, the prepared GaN compound powder or GaP compound powder has a purity of 3N or more, suppresses an increase in oxygen content, and considers the mixability of Cu-Ga alloy powder and Cu powder, and has a primary particle size of 0. The thing of 3 micrometers or less is preferable. In particular, when GaN and GaP are used as compounds, they do not contain oxygen, and high-purity raw materials can be used, and the content of oxygen and inevitable impurities in the target can be reduced. Therefore, it is preferable.
In order to reduce the oxygen content in the target, it is necessary to remove the adsorbed moisture and hydrate in the GaN and GaP compound powder before mixing. For example, drying at 120 ° C. for 10 hours in a vacuum environment in a vacuum dryer is effective.

Crushing of the GaN and GaP compound powder is performed using a pulverizer (for example, a ball mill, a jet mill, a Henschel mixer, an attritor, etc.). The average secondary particle size obtained is preferably 10 μm or less. The pulverization step is preferably performed in a dry environment with a humidity of RH 40% or less.
Furthermore, at least one of the dried crushed powder and the Cu-Ga alloy powder and Cu powder of the target composition are mixed in a dry environment having a relative humidity of RH 40% or less using a dry mixing device, and a raw material for sintering Prepare powder. The mixing is more preferably performed in a reducing atmosphere.

The average particle size of the Cu—Ga alloy powder and Cu powder is preferably less than 250 μm. This is because if it is 250 μm or more, sintering failure occurs.
Further, when it is necessary to remove adsorbed moisture from the mixed powder after mixing, for example, drying at 80 ° C. for 3 hours or more in a vacuum environment in a vacuum dryer is effective.

Next, the raw material powder mixed by the above method is sealed in a plastic resin bag in a dry environment of RH 30% or less and stored.
In order to prevent oxidation during sintering of the Cu—Ga alloy or Cu, atmospheric pressure sintering, hot pressing, or HIP is performed in a reducing atmosphere, a vacuum, or an inert gas atmosphere.

In atmospheric pressure sintering, when GaN and GaP compounds are added, the presence of hydrogen in the atmosphere is advantageous for improving the sinterability. The hydrogen content in the atmosphere is preferably 1% or more, more preferably 90% or more.
In the hot press, since the pressure of the hot press greatly affects the density of the target sintered body, the preferable pressure is 10 to 60 MPa. Further, the pressurization may be performed before the start of temperature rise or after reaching a certain hot press temperature.
In the HIP method, a preferable pressure is 15 to 150 MPa.
The sintering time of the sintered body varies depending on the composition, but 1 to 10 hours is preferable. If the time is shorter than 1 hour, sintering is insufficient, cracks and chips are generated during sputtering, and there is a high possibility that abnormal discharge will occur during sputtering. On the other hand, even if it is longer than 10 hours, there is almost no effect of improving the density.

Next, the sintered body is processed into a specified shape of the sputtering target using normal electric discharge machining, cutting, or grinding.
Next, the processed sputtering target is bonded to a backing plate made of Cu or SUS (stainless steel) or other metal (for example, Mo) using In as solder, and is used for sputtering.
In addition, when storing the processed sputtering target, it is preferable to apply a vacuum pack or a packing obtained by replacing the entire target with a vacuum in order to prevent oxidation and moisture absorption.

The sputtering target thus manufactured is subjected to direct current (DC) magnetron sputtering using Ar gas as a sputtering gas. In this case, direct current (DC) sputtering may be performed using a pulsed DC power source to which a pulse voltage is applied or a DC power source without a pulse. The input power during sputtering is, for example, 3 W / cm ² and the gas pressure is 0.67 Pa.

  The sputtering target of the first embodiment thus produced contains N and P elements in a compound state with Ga, and the average particle size of the compound is 10 μm or less. At the time of forming the precursor (CuGa film) of the chalcopyrite structure semiconductor, the elements of N and P can be doped at a high concentration. In addition, since doping is performed by a sputtering process, the doping is cheaper, safer and more uniform than conventional ion doping. Further, since the precursor can be doped with N and P elements, crystal defects and the like are not generated, and the chalcopyrite structure semiconductor film is not damaged.

In addition, since the average particle diameter of the compound of the element of N and P and Ga is set to 10 micrometers or less, generation | occurrence | production of abnormal discharge at the time of sputtering can be suppressed.
In addition, by employing at least one of GaN and GaP as the compound, the compound does not contain oxygen and a high-purity raw material can be used, so that the content of inevitable impurities can be reduced.
Furthermore, in the manufacturing method of the sputtering target of this embodiment, the above mixed powder is compared with a target manufactured by adding a compound of a Vb group element and Ga by a melting method by using a powder sintering method. The compound of N and P elements and Ga can be uniformly dispersed and distributed.

(Example)
Next, the evaluation result is demonstrated by the Example produced based on the above-mentioned manufacturing method regarding the sputtering target which concerns on 1st Embodiment, and its manufacturing method.

First, Cu-Ga alloy powder having the component composition and particle size shown in Table 1 and Table 3, Cu powder (purity 4N), and GaN powder or GaP powder having a purity of 3N and a primary average particle diameter of 10 μm, It mix | blended so that it might become the quantity shown by Table 1 and Table 3, and it was set as the raw material powder of Examples 1-30. These raw material powders were dried at 120 ° C. for 10 hours in a vacuum environment of 10 ⁻¹ Pa in a vacuum dryer, then placed in a 10 L polyethylene pot and further dried at 120 ° C. for 10 hours. 5 mm zirconia balls were put and mixed by a ball mill at the times shown in Tables 1 and 3. Mixing was performed in an argon atmosphere.

The obtained mixed powder was sintered under the conditions specified in Tables 2 and 4. In the case of normal pressure sintering, first, the mixed powder is filled in a metal mold and pressed at room temperature at a pressure of 500 to 2000 kgf / cm ² to produce a compact, and hydrogen (H ₂ ) as a reducing atmosphere gas. Calcination was performed using a reducing gas such as carbon monoxide (CO) or ammonia cracking gas, or a mixed gas of these reducing gas and inert gas. In the case of hot pressing, the raw material powder was filled in a graphite mold and vacuum hot pressing was performed. In the case of HIP, similarly to the normal pressure sintering, the mixed powder is first filled in a metal mold and pressure-molded at a normal temperature of 1500 kgf / cm ² . The obtained molded body is placed in a 0.5 mm-thick stainless steel container and then sealed through vacuum deaeration and used for HIP treatment.
In addition, the dry-cut process was given to the sintered compact after sintering, and the sputtering target (sputtering target of Examples 1-30) of diameter 125 (mm) x thickness 5 (mm) was produced.

<Evaluation>
For the sputtering targets of Examples 1 to 30, the GaN particles or GaP particles in the sintered body were observed with an electron beam probe microanalyzer (EPMA) (JXA-8500F) manufactured by JEOL Ltd., and the measurement method described above. The maximum particle size and the average particle size of the particles were determined.
Moreover, each content of Ga, Cu, and P in the produced target was quantitatively analyzed using an ICP method (high frequency inductively coupled plasma method). Further, N was quantitatively analyzed using an inert gas melting thermal conductivity method.

Furthermore, about the sputtering target of Examples 1-30, 1000 nm was formed into a film on Si wafer by direct current (DC) sputtering of input electric power: 3.3W / cm < ² > for 10 minutes using the magnetron sputtering device. The Ar flow rate during sputtering was 30 sccm, and the pressure was 0.67 Pa.
EPMA qualitative analysis is performed on each of the deposited films, and if a peak related to N or P is detected, it is determined that there is an element of N or P (added) in the film, and the peak Was not detected, it was determined that there was no N or P element (not added) in the film.

Further, continuous sputtering (power: 3.3 W / cm ² , power source: DC) was performed for 10 minutes under the above conditions, and the number of occurrences of abnormal discharge was automatically recorded by an arcing counter attached to the sputtering power source. Further, in arcing generated during sputtering, arcing that can be continuously sputtered is distinguished as soft arc, and arcing in which sputtering target is largely damaged and cannot be sputtered is distinguished as hard arc. For soft arcs, the number of occurrences was recorded because it can be measured with an arcing counter. Moreover, about hard arc, since sputtering had to be interrupted, the presence or absence of generation | occurrence | production of the interruption and the crack of the target surface after sputtering, and a chip were evaluated visually. These results are also shown in Tables 2 and 4. When the number of abnormal discharges exceeded 300, direct current (DC) sputtering could not be performed stably, and an evaluable film could not be obtained.

(Comparative example)
First, the Cu—Ga alloy powder having the component composition and particle size shown in Table 1 and Table 3, the Cu powder (purity 4N), and the GaN powder or GaP powder of purity 3N are shown in Table 1 and Table 3. The raw material powders of Comparative Examples 1 to 6 were blended so that the amount was adjusted. The obtained mixed powder was sintered under the conditions shown in Tables 2 and 4, and sputtering targets of Comparative Examples 1 to 6 were produced. The sputtering targets of these comparative examples were also evaluated in the same manner as in the examples. The results are also shown in Tables 2 and 4.

  As can be seen from these results, all the examples had a small number of abnormal discharges, and there were no target cracks or chips during sputtering. Further, it was confirmed that N or P was detected and added in the sputtered film. On the other hand, in Comparative Example 1, the content of N exceeded 2% by mass, the number of abnormal discharges increased, and stable sputter film formation was not possible, and target chipping occurred during sputtering. In Comparative Examples 2 and 3, the average particle diameter of GaN exceeded 10 μm, the number of abnormal discharges increased, and stable sputter film formation was not possible, and cracking or chipping of the target during sputtering occurred.

  Furthermore, in Comparative Example 4, the P content exceeded 2 mass%, the number of abnormal discharges increased, and stable sputter film formation could not be performed, and target chipping during sputtering occurred. In Comparative Examples 5 and 6, the average particle size of GaP exceeded 10 μm, the number of abnormal discharges increased, and stable sputtering film formation could not be performed, and target cracks or chipping occurred during sputtering.

[Second Embodiment]
1st Embodiment mentioned above contains Ga: 0.1-50 mass%, 1 or more types of elements selected from N and P: 0.01-2 mass%, remainder is Cu and an unavoidable impurity. In the case of a sputtering target, the elements of N and P are contained in the state of a compound with Ga, that is, GaN and GaP. In contrast, the second embodiment contains Ga: 0.1 to 50% by mass, one or more elements selected from N and P: 0.01 to 2% by mass, and selectively contains oxygen. : A sputtering target containing 0.01 to 6% by mass with the balance being composed of Cu and inevitable impurities, wherein the N and P elements are in a compound state of at least Cu or Ga, that is, Cu _{3 N,} a case where _{Cu 3 P, Ga (NO 3} ) 3, GaPO 4, Cu 3 (PO 4) 2, Cu (NO 3) is added in _2.

Therefore, in the production of the sputtering target according to the second embodiment, Cu ₃ N, Cu ₃ P, Ga (NO) is used instead of the addition of the GaN compound or the GaP compound in the sputtering target production method of the first embodiment. ₃ ) ₃ , GaPO ₄ , Cu ₃ (PO ₄ ) ₂ , or Cu (NO ₃ ) ₂ may be added, and the manufacturing procedure of the second embodiment is the same as that of the first embodiment described above. The manufacturing procedure is the same.

In addition, target composition analysis on the sputtering target of the second embodiment, and compounds [Cu ₃ N, Cu ₃ P, Ga (NO ₃ ) ₃ , GaPO ₄ , Cu ₃ (PO ₄ ) ₂ , Cu (NO ₃ ) _2]. The measurement of the maximum particle size and the average particle size is the same as in the case of the first embodiment. Regarding oxygen, the obtained sputtering target was measured using a TC600 manufactured by LECO Co., Ltd. in accordance with the infrared absorption method described in JIS Z 2613 “General Rules for Determination of Oxygen of Metallic Materials”.

In the sputtering target of the second embodiment manufactured in this way, the elements of N and P are Cu ₃ N, Cu ₃ P, Ga (NO ₃ ) 3, GaPO ₄ , Cu ₃ (PO ₄ ) ₂ , It is contained in the state of any compound of Cu (NO ₃ ) ₂ , and the average particle size of the compound is 10 μm or less, and the maximum particle size is 15 μm or less, thereby suppressing the occurrence of abnormal discharge during sputtering. In addition, it is possible to dope N and P elements at a high concentration when forming a precursor (CuGa film) of a chalcopyrite structure semiconductor by sputtering. In addition, since doping is performed by a sputtering process, the doping is cheaper, safer and more uniform than conventional ion doping. Further, since the precursor can be doped with N and P elements, crystal defects and the like are not generated, and the chalcopyrite structure semiconductor film is not damaged.

  Furthermore, in the manufacturing method of the sputtering target of 2nd Embodiment, compared with the sputtering target manufactured by adding the compound of Vb group element and Ga by a melting method by carrying out powder sintering of the above-mentioned mixed powder, A compound of N and P elements and at least Cu or Ga can be uniformly distributed.

(Example)
Next, the evaluation result is demonstrated by the Example produced based on the above-mentioned manufacturing method regarding the sputtering target which concerns on 2nd Embodiment, and its manufacturing method.

First, Cu-Ga alloy powder having the component composition and particle size shown in Table 5, Cu powder (purity 4N), Cu ₃ N compound powder of purity 3N, Cu ₃ P compound powder, Ga (NO ₃ ) ₃ Compound powder, GaPO ₄ compound powder, Cu ₃ (PO ₄ ) ₂ compound powder, Cu (NO ₃ ) ₂ compound powder were blended so as to have the amounts shown in Table 5, and raw material powders of Examples 31 to 37 It was. These raw material powders were dried at 120 ° C. for 10 hours in a vacuum environment of 10 ⁻¹ Pa in a vacuum dryer, then placed in a 10 L polyethylene pot and further dried at 120 ° C. for 10 hours. 5 mm zirconia balls were put and mixed with a ball mill for the time shown in Table 5. Mixing was performed in an argon atmosphere.

The obtained mixed powder was sintered under the conditions specified in Table 6. In the case of the hot press method, the raw material powder was filled in a graphite mold and vacuum hot press was performed. In the case of the HIP method, the mixed powder is filled in a metal mold and pressure-molded at a normal temperature of 1500 kgf / cm ² . The obtained molded body was placed in a stainless steel container having a thickness of 0.5 mm, and then sealed through vacuum deaeration and subjected to HIP treatment. Note that the sintered body was subjected to dry cutting to produce a sputtering target having a diameter of 125 (mm) × thickness of 5 (mm) (a sputtering target of Examples 31 to 37).

<Evaluation>
For the sputtering targets of Examples 31 to 37, Cu ₃ P particles, Ga (NO ₃ ) ₃ particles, GaPO ₄ particles, Cu ₃ (PO ₄ ) ₂ particles, and Cu (NO ₃ ) ₂ particles in the sintered body were used. The maximum particle size and the average particle size of the particles were determined by the above-described measurement method, using an electron beam probe microanalyzer (EPMA) (JXA-8500F) manufactured by JEOL Ltd.
Moreover, each content of Ga, Cu, and P in the produced target was quantitatively analyzed using an ICP method (high frequency inductively coupled plasma method). Further, N was quantitatively analyzed using an inert gas melting thermal conductivity method. Oxygen was measured using a TC600 manufactured by LECO in accordance with the infrared absorption method described in JIS Z 2613 “General Rules for Determination of Oxygen of Metallic Materials”.

Further, with respect to the sputtering targets of Examples 31 to 37, a 1000 nm film was formed on a Si wafer by direct current (DC) sputtering with an input power of 3.3 W / cm ² and 10 min using a magnetron sputtering apparatus. Here, the Ar flow rate during sputtering was 30 sccm, and the pressure was 0.67 Pa. EPMA qualitative analysis is performed on each of the deposited films, and if a peak related to N or P is detected, it is determined that there is an element of N or P (added) in the film, and the peak Was not detected, it was determined that there was no N or P element (not added) in the film.

Further, continuous sputtering (power: 3.3 W / cm ² , power source: DC) was performed for 10 minutes under the above conditions, and the number of occurrences of abnormal discharge was automatically recorded by an arcing counter attached to the sputtering power source. Further, in arcing generated during sputtering, arcing that can be continuously sputtered is distinguished as soft arc, and arcing in which sputtering target is largely damaged and cannot be sputtered is distinguished as hard arc. For soft arcs, the number of occurrences was recorded because it can be measured with an arcing counter. Moreover, about hard arc, since sputtering had to be interrupted, the presence or absence of generation | occurrence | production of the interruption and the crack of the target surface after sputtering, and a chip were evaluated visually. These results are also shown in Table 6. When the number of abnormal discharges exceeded 300, direct current (DC) sputtering could not be performed stably, and an evaluable film could not be obtained.

(Comparative example)
First, a Cu—Ga alloy powder having the component composition and particle size shown in Table 5, a Cu powder (purity 4N), and a Cu ₃ P compound powder or a Cu (NO ₃ ) ₂ compound powder having a purity of 3N The raw material powders of Comparative Examples 7 and 8 were blended so that the amount shown in FIG. The obtained mixed powder was sintered under the conditions shown in Table 6 to prepare sputtering targets of Comparative Examples 7 and 8. The sputtering targets of these comparative examples were also evaluated in the same manner as in the examples. The results are also shown in Table 6.

As can be seen from the results shown in Table 6, in each of Examples 31 to 37, the number of abnormal discharges was small, and there were no target cracks or chips during sputtering. Further, it was confirmed that N or P was detected and added in the sputtered film.
On the other hand, in the case of Comparative Example 7, the maximum particle size of the Cu ₃ P compound exceeds 15 μm, and the average particle size also exceeds 10 μm, so that the number of abnormal discharges increases and stable sputter film formation is achieved. In both cases, target cracks occurred during sputtering. In the case of Comparative Example 8, the maximum particle size of the Cu (NO ₃ ) ₂ compound exceeds 15 μm, and the average particle size also exceeds 10 μm, so that the number of abnormal discharges increases and stable sputter film formation is achieved. It was not possible and a target crack occurred during sputtering.

In order to use the present invention as a sputtering target, relative density: 90% or more, surface roughness Ra: 1.5 μm or less, specific resistance: 10 ⁻² Ω · cm or less, bending strength: 10
It is preferably 0 MPa or more. Each example in the first and second embodiments satisfies these conditions.
The technical scope of the present invention is not limited to the above-described embodiments and examples, and various modifications can be made without departing from the spirit of the present invention.

Claims (7)

Ga: 0.1 to 50% by mass, containing at least one element selected from N and P in an amount of 0.01 to 2% by mass, with the balance being composed of Cu and inevitable impurities,
One of the elements of N and P is contained in the state of a compound of at least Ga or Cu, and the average particle size of the compound is 10 μm or less.   Ga: 0.1 to 50% by mass, one or more elements selected from N and P are contained in an amount of 0.01 to 2% by mass, oxygen: 0.01 to 6% by mass, the balance being Cu and inevitable impurities A sputtering target characterized in that it is contained in the state of a compound of any one of N and P and at least Ga or Cu, and the compound has an average particle size of 10 μm or less. The sputtering target according to claim 1,
The sputtering target, wherein the compound is at least one of GaN, GaP, Cu ₃ N, and Cu ₃ P. In the sputtering target according to claim 2,
The sputtering target, wherein the compound is at least one of Ga (NO ₃ ) ₃ , GaPO ₄ , Cu ₃ (PO ₄ ) ₂ , and Cu (NO ₃ ) ₂ . A method for producing the sputtering target according to any one of claims 1 to 4,
Mixed powder of compound powder and Cu-Ga alloy powder by any element of N and P and at least Cu, compound powder and Cu-Ga alloy powder or Cu powder by any element of N and P and at least Ga Or a compact made of a compound powder of any element of N and P and at least Ga or Cu, and a mixed powder of Cu-Ga alloy powder and Cu powder, in a vacuum or in an inert gas Or the manufacturing method of the sputtering target characterized by having the process sintered in a reducing atmosphere. A method for producing the sputtering target according to any one of claims 1 to 4,
Mixed powder of compound powder and Cu-Ga alloy powder by any element of N and P and at least Cu, compound powder and Cu-Ga alloy powder or Cu powder by any element of N and P and at least Ga Or a mixed powder of a compound powder of at least one of N and P and at least Ga or Cu, a Cu-Ga alloy powder, and a Cu powder in a vacuum or an inert gas atmosphere. The manufacturing method of the sputtering target characterized by having the process to do. A method for producing the sputtering target according to any one of claims 1 to 4,
Mixed powder of compound powder and Cu-Ga alloy powder by any element of N and P and at least Cu, compound powder and Cu-Ga alloy powder or Cu powder by any element of N and P and at least Ga Or a powder powder of a compound powder of at least one of N and P and at least Ga or Cu, a Cu-Ga alloy powder, and a Cu powder is sintered using a hot isostatic pressing method. The manufacturing method of the sputtering target characterized by having the process to tie.