TWI541371B - Sputtering method and manufacturing method of functional element - Google Patents

Description

Sputtering method and method of manufacturing functional element

The present invention relates to a sputtering method for forming a film on a substrate, and a method for producing a functional element using the sputtering method.

As a film forming technique on a substrate, the following sputtering (hereinafter also referred to simply as sputtering) method is generally used: a target made of a desired material is placed opposite to the substrate, and the target is sputtered. The particles are deposited on the substrate.

In the sputtering apparatus, particles scattered from the target adhere to other articles than the substrate. In order to facilitate the cleaning and maintenance of the attached film, an anti-adhesion member is generally provided in the sputtering apparatus (Patent Documents 1 and 2).

One of the functional elements fabricated using such a sputtering method has a tunneling magnetoresistance effect element (TMR element). The TMR element is used for a MRAM (Magnetoresistive Random Access Memory) as a non-volatile memory, a read head of a magnetic circuit medium, and the like.

The TMR element has the following characteristics: an external magnetic field is applied in a state where a fixed current flows between the ferromagnetic layers applied to the both sides of the tunnel barrier layer, and the magnetization direction of the ferromagnetic layer is the same in parallel. At the time (called "parallel state"), the resistance of the TMR element becomes the smallest (resistance value R _P ), and when the direction of magnetization of the ferromagnetic layer is reversed in parallel (referred to as "anti-parallel state"), the resistance of the TMR element changes. Maximum (resistance value R _A ). This resistance value can be used to memorize or read information.

The TMR element requires a large difference between the resistance value R _P of the "parallel state" and the resistance value R _A of the "anti-parallel state". The magnetoresistance ratio (MR ratio) is used as an indicator of the characteristics of the element. The MR ratio is defined as "(R _{A -} R _P ) ÷ R _P "".

In recent years, it has been reported that a good MR ratio can be obtained at room temperature in a TMR element using CoFeB in a ferromagnetic layer and using MgO in a barrier layer (Patent Document 3).

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] JP-A-2003-226967

[Patent Document 2] WO2011/77653

[Patent Document 3] JP-A-2006-80116

When the deposition of the sputter particles adhering to such an anti-adhesion member is a certain amount or more, the particles are peeled off from the anti-adhesion member to become particles. When the fine particles are dropped onto the substrate, the malfunction of the element formed on the substrate is caused, and the yield is deteriorated.

Further, the fine particles in the present invention are made of a metal or a material containing a metal, and refer to fine particles having a diameter of approximately 0.01 μm or more and 1 μm or less.

The problem of peeling off the film from the anti-adhesion member is, for example, a method of forming a predetermined thermal spray film on the anti-adhesion member in order to improve the adhesion between the anti-adhesion member and the deposited film. Since the thermal spray film is formed on the anti-adhesion member, the surface of the anti-adhesion member becomes thick, and the film stress of the deposited film is alleviated, so that the peeling of the deposit on the anti-adhesion member can be suppressed.

On the other hand, as a result of intensive studies, the inventors have found that in the case of performing a sputtering film formation process on a substrate by using an anti-adhesion member forming such a thermal spray film, the film formed on the substrate contains a large amount. An atom other than the target material. The incorporation of impurities into the film on the substrate causes deterioration of film properties and diffusion of impurities into other films. In addition, it is a main cause of problems such as electromigration during the operation of the apparatus manufactured using the film. In particular, the crystallinity of the ferromagnetic layer connected to the tunnel barrier layer and the tunnel barrier layer in the TMR element has a large influence on the film characteristics, so it is preferable to minimize the impurities in such a film.

The present invention has been made in view of the above problems, and an object of the invention is to provide a sputtering method and a method for producing a functional element, which are capable of reducing the accumulation of impurities in a sputtering process using an anti-adhesion member formed on a surface of a thermal spray film. In the film on the substrate, the element characteristics of the functional element including the film can be improved.

In order to solve the above problems, an aspect of the present invention resides in a sputtering method in which a target is used in a processing chamber to form a film on a substrate. The anti-adhesion member including the substrate, the thermal spray film formed on the substrate, and the diffusion preventive film formed on the thermal spray film is placed in the processing chamber, and is subjected to a sputtering process. Film formation was performed on the aforementioned substrate.

Further, an aspect of the present invention resides in a method of manufacturing a functional device having a process of forming a film on a substrate by a sputtering process using a target in a processing chamber, characterized in that a substrate is formed and formed. The thermal spray film on the substrate and the anti-adhesion member of the diffusion preventive film formed on the thermal spray film are placed on the substrate by the sputtering treatment while being placed in the processing chamber.

According to the present invention, impurities can be reduced in the film deposited on the substrate by sputtering, and the characteristics of the functional element including the film can be improved.

1‧‧‧Sputtering device

2‧‧‧Vacuum container

3‧‧‧Anti-adhesion member (barium)

4‧‧‧ Target

6‧‧‧Backplane (target holder)

7‧‧‧Substrate holder

8‧‧‧Exhaust gas

10‧‧‧Substrate

100‧‧‧Anti-adhesion member

101‧‧‧Substrate

102‧‧‧ Thermal spray film

106‧‧‧Oxide layer

11‧‧‧ mask

12‧‧‧Power supply

13‧‧‧Target occlusion

14‧‧‧Target shielding member drive mechanism

15‧‧‧ gas introduction mechanism

16a, 16b‧‧‧ gas inlet

17‧‧‧ Fixed Department

19‧‧‧ magnet

20‧‧‧Insulating components

40‧‧‧Anti-adhesion member

401‧‧‧Substrate

402‧‧‧thermal spray film

403‧‧‧Proliferation film

41‧‧‧ pressure gauge

47‧‧‧Main valve

48‧‧‧ Turbo Molecular Pumping

49‧‧‧Dry pump

500‧‧‧TMR components

501‧‧‧Substrate

502‧‧‧Ta layer

503‧‧‧PtMn layer

504‧‧‧CoFe layer

505‧‧‧Ru layer

506‧‧‧CoFeB layer

507‧‧MgO (manganese oxide) layer

508‧‧‧CoFeB

508‧‧‧CoFeB layer

509‧‧‧Ta layer

700‧‧‧Vertical magnetization type TMR element (P-TMR element)

701‧‧‧Substrate

702‧‧‧RuCoFe layer

703‧‧‧Ta layer

704‧‧‧CoFeB layer

705‧‧‧MgO layer

706‧‧‧CoFe layer

707‧‧‧CoFeB layer

708‧‧‧Ta layer

709‧‧‧Magnetized fixed layer

710‧‧‧Ru layer

711‧‧‧Magnetized fixed layer

712‧‧‧Ta layer

800‧‧‧Substrate

801a‧‧‧汲

801b‧‧‧ source

803‧‧‧Selecting a crystal

804‧‧‧lower insulation

805‧‧‧Insert

806‧‧‧Perovskite layer (oxide layer)

807‧‧‧chalcogenide layer

808‧‧‧ upper electrode layer

809‧‧‧hard mask

811‧‧‧1st hole

Fig. 1 is a view for explaining the sputtering apparatus according to the present invention.

Fig. 2 is a view for explaining the periphery of a target in a sputtering apparatus according to the present invention.

Fig. 3 is an explanatory view of an anti-adhesion member used in a sputtering apparatus according to the present invention.

Fig. 4 is an explanatory view of an anti-adhesion member used in a conventional sputtering apparatus.

Fig. 5 is a view for explaining an example of a functional element to which the present invention is applicable.

Fig. 6 is a diagram for explaining an example of a functional element to which the present invention is applicable.

Fig. 7 is a view for explaining an example of a functional element to which the present invention is applicable.

(First embodiment)

The overall configuration of the sputtering apparatus according to the present embodiment will be described with reference to Fig. 1 . Fig. 1 is a view schematically showing a sputtering apparatus 1 according to this embodiment. The sputtering apparatus 1 is provided with a vacuum container 2 as a substrate processing chamber. The vacuum vessel 2 is connected to a vacuuming device having a turbo molecular pump 48 and a dry pump 49 that exhausts the vacuum vessel 2 through the exhaust port 8. Further, the sputtering apparatus 1 is provided with a gas introduction mechanism 15 that can introduce a gas for discharge into the vacuum vessel 2.

The exhaust port 8 is, for example, a duct having a rectangular cross section, and is connected between the vacuum vessel 2 and the turbo molecular pump 48. A main valve 47 is provided between the exhaust port 8 and the turbo molecular pump 48.

Inside the vacuum vessel 2, the target 4 exposed by the sputtering surface is held by the target holder 6. Further, a substrate holder 7 for mounting the substrate 10 is provided at a predetermined position at which the sputtering particles discharged from the target 4 reach. A mask 11 for preventing the film from adhering to the end portion, the side wall, the back surface, and the like of the substrate 10 may be provided around the substrate mounting surface of the substrate holder 7.

Further, a pressure gauge 41 for measuring the pressure of the vacuum vessel 2 is provided in the vacuum vessel 2. On the inner surface of the vacuum vessel 2, there is a grounding A cylindrical anti-adhesion member 40. The adhesion preventing member 40 prevents the sputtering particles from directly adhering to the inner surface of the vacuum vessel 2. In addition, although the number of targets in FIG. 1 is 2, it is the number of the above. Further, in Fig. 1, although the gas introduction port is provided beside the two targets, it is not limited to this position but may be provided at other positions.

In the case of a sputtering apparatus having two or more targets, when one target is discharged, the sputtering particles adhere to the adjacent target. When the sputtered particles of different materials adhere to the target, materials other than the target are mixed into the film, and an increase in the number of particles due to the generation of nodules becomes a problem.

Therefore, in order to prevent the sputtered particles from being wound around the adjacent target, an anti-adhesion member is generally provided around the target.

The adhesion preventing member 3 (hereinafter also referred to as chimney 3) provided around the target has a structure in which the sputtering particles flying out from the target are coated. In the present embodiment, the bake material 3 has a cylindrical shape and is designed such that the inner surface faces the direction of the target, so that the particles flying onto the bake material 3 are strongly adhered without peeling off.

The target 4 is disposed obliquely forward of the substrate 10 and is inclined with respect to the substrate 10 . A power source 12 to which power for sputtering discharge is applied is connected to the target holder 6. The sputtering apparatus 1 shown in FIG. 1 is provided with a DC power supply, but is not limited thereto. For example, when the target 4 is an insulator, an RF power source is used. In the case of using an RF power source, an integrator needs to be provided between the power source 12 and the target holder 6. A voltage is applied to the target 4 by the power source 12 to form a plasma for sputtering. Arranged on the back of the target holder 6 The magnet 19 forms a magnetic line of force for trapping the plasma in the vicinity of the target 4.

Since the target holder 6 is made of a metal such as Cu, it is an electrode when DC or RF power is applied. The target 4 is known to be composed of a material component to be formed on a substrate. Due to the purity of the membrane, high purity is preferred.

In the vicinity of the target holder 6, a cylindrical anti-adhesion member 3 is provided so as to cover the target holder 6, and the sputter particles are prevented from directly adhering to the inner surface of the vacuum container 2.

Further, a target shielding member 13 may be provided between the target holder 6 and the substrate holder 7. The target shutter 13 is controlled by the target shutter driving mechanism 14 and is configured to be switchable between a state in which the target 4 and the substrate 10 are opposed to each other or a closed state in which the target 4 and the substrate 10 are shielded from each other.

The gas introduction mechanism 15 is configured to introduce a gas for discharge into the vacuum container 2 through a gas introduction port 16a, 16b provided in a wall surface of the vacuum container 2, a cylinder for storing a gas, and a gas for controlling the gas. A mass flow controller for flow, a valve for interrupting or starting the flow of gas, a pressure reducing valve, and a filter. Further, the gas introduction mechanism 15 has a configuration in which a predetermined gas flow rate can be stably flowed by the control device.

Further, a mixed gas in which a reaction gas is mixed with a discharge gas may be introduced from the gas introduction mechanism 15. Other introduction mechanisms for introducing the reaction gas may also be provided.

Next, the configuration of the baffle 3 used in the present embodiment and the sputtering device therearound will be described with reference to Fig. 2 .

The target 4 is attached to the backing plate (target holder) 6 by the fixing portion 17. Furthermore, there is a bunker 3 that surrounds the periphery of the target 4. The fixing portion 17 is fixed to the back plate 6 by a fastener such as a screw so that the target 4 is pressed against the back plate 6. The back sheet 6 may have a conductive sheet or the like from the viewpoint of thermal conductivity. Since the target 4 is exposed to the plasma generated by the discharge, the temperature thereof rises and expands. Therefore, it is preferable that the fixing portion 17 fixes the target 4 so as to allow the target 4 to expand. The bake material 3 is disposed around the target 4 so as to cover the fixing portion 17 . Thereby, the rise of the temperature of the fixing portion 17 can be suppressed. The backing plate 6 is fixed to the chamber wall via the insulating member 20. The backing plate 6 can also form a vacuum vessel 2 with the chamber walls. The baffle 3 extends cylindrically in the normal direction of the target 4, and reduces the deposition of sputtered particles scattered from the target 4 on the substrate.

A magnet 19 that provides a magnetic field around the target 4 is provided on the back surface of the target 4, and is configured as a magnetron sputtering device. The magnet 19 is disposed such that the magnet 19 and the target 4 sandwich the back plate 6. The target 4 may be composed of a target material, for example, but may have a structure in which a target material is joined by solder or the like on a plate member (for example, a plate member made of oxygen-free copper) that is in contact with the back sheet 6.

FIG. 4 illustrates a state in which a conventional one of the anti-adhesion members 100 is enlarged. 101 is a substrate of the adhesion preventing member, and a blast treatment is applied to the surface of the substrate 101. 102 is a thermal spray film thermally sprayed onto a substrate.

A ceramics 3 of aluminum or aluminum oxide was used as the thermal spray film 102 in the processing apparatus of Fig. 1, and various films were formed by sputtering. The film formed was a film shown in Table 1, and the film was deposited on a 12-inch Si substrate. Make A target made of a material for forming a film is used as a target for forming various films. Film formation was carried out using an inert gas as a sputtering gas.

As an example, the film formation conditions of CoFeB are exemplified. The substrate temperature was set to room temperature, the target power was 1000 W, the sputtering gas pressure was 0.1 Pa, and the Ar gas flow rate was set to 200 sccm to form a film.

Next, the contents of Na and Al in the various films produced by the above-described formation method were quantitatively analyzed by inductively coupled plasma mass spectrometry (ICP-MS).

The ICP-MS measurement was carried out in an elemental analysis device using inductively coupled plasma (ICP) as an ion source. The sample solution to be measured is introduced into the ion source, and ions in the plasma generated by the ion source are detected by a mass spectrometry unit (MS) to analyze an element contained in the sample solution. This test can simultaneously determine almost all of the periodic table Elements.

In this experiment, initially, a 12 mm outer circumference of a 12-inch Si substrate was sandwiched by a Teflon (registered trademark) jig and masked, and the film on the surface side was acid-etched. After the main component was separated and removed from the obtained liquid, it was taken to an evaporating dish, heated, evaporated and solidified, and the obtained acid residue was used as a sample solution for measurement.

The obtained sample solution was measured by ICP-MS. In addition, the elemental mass (ng) of each element is converted into a molar number by dividing the measured element mass (ng), and then converted into an atomic number by the Afocalt constant, and the substrate area (615 cm ² ) after etching is further divided by The film thickness was divided and converted into atomic numbers per unit volume (×10 ¹⁰ atms‧cm ³ ). The detection limit of Na is 8.5 × 10 ⁸ atoms/cm ² per unit area, and the detection limit of Al is 7.3 × 10 ⁸ atoms/cm ² per unit area.

Table 1 shows the amount of impurities in each film obtained by the measurement results of the above ICP-MS method. In the case of using the bake material 3 subjected to the blast treatment and the thermal spray treatment, Na and Al were detected in the film depending on the type of the film. That is, although the film is often caused to adhere to the thermal spray film 102 by sputtering, it is known that impurities are mixed into the film formed on the substrate.

Hereinafter, an explanation will be given of the adhesion preventing member 40 according to the present invention in order to solve the above problems.

Fig. 3 is a view showing an enlarged view of the anti-adhesion member 40 used in the present embodiment. 401 is a substrate for the anti-adhesion member, and 402 is a thermal spray film thermally sprayed on the substrate. The substrate 401 is subjected to blast treatment on the surface and roughened. By roughening the surface of the substrate 401 to make the thermal spray film 402 The adhesion is improved.

In order to reduce film peeling deposited on the film of the adhesion preventing member 40, the surface of the thermal spray film 402 also has a predetermined surface roughness.

In the present embodiment, a diffusion preventive film 403 is formed on the thermal spray film 402. The diffusion preventive film 403 has a function of preventing diffusion of impurities such as Na and Al contained in the surface of the substrate 401 subjected to the blast treatment or the thermal spray film 402 into the substrate processing space. In the present embodiment, Al is used as the material of the thermal spray film 402, and titanium nitride (TiN) is used as the diffusion preventive film 403.

A comparative experiment was conducted for the case of using the chimney 3 to which the present invention is applied and the case of using a conventional bake. First, as a conventional chimney, a chimney to which a thermal spray treatment is applied on a substrate subjected to blast treatment, or a SiN-coated bake material other than the thermal spray treatment is used in the treatment apparatus of FIG. The SiN film is formed on the substrate by sputtering. Next, a thermal spray treatment is applied to the substrate to which the blast treatment is applied, and a TiN-coated chimney as a diffusion preventive film is applied to the thermal spray film, which is used in the processing apparatus of FIG. 1 by sputtering on the substrate. Film-forming SiN film.

The film formation conditions of the SiN film were such that the substrate temperature was room temperature, and a ruthenium target was used. The target power was 1000 W, the sputtering gas pressure was 0.1 Pa, the Ar gas flow rate was 20 sccm, and the nitrogen gas flow rate was 20 sccm. As the substrate, a 12-inch Si substrate having a fine particle size of 0.12 μm or more and 50 or less was used.

The content of Na and Al contained in the SiN film having a film thickness of 38 nm produced by the film formation method described above was quantitatively analyzed by ICP-MS.

In the case of using a conventional bake which is subjected to blast treatment and thermal spray treatment without forming a diffusion preventive film, Na contained in the SiN film is found to be 1.3 × 10 ¹⁰ atoms/cm ² , and Al is detected as 2.5 × 10 ⁹ atoms/cm ² . Further, in the application of the blast treatment and the thermal spray treatment plus the application of a 3 μm SiN film to the surface of the chimney, the Na contained in the SiN film detected 8.9 × 10 ¹⁰ atoms / cm ² , and Al detected 2.2 × 10 ¹¹ atoms/cm ² . The surface of the other anti-adhesion member 40 provided in the processing apparatus other than the chimney was treated by air blowing and the thermal spray film was not formed.

On the other hand, in the case where a blower treatment and a thermal spray treatment were applied, and a 3 μm-thick TiN film was applied to the surface of the chimney, the Na contained in the SiN film was 8.9 × 10 ⁹ atoms/cm ² , Al. It is 7.3 × 10 ⁸ atoms/cm ² . The content of Na and Al is reduced as compared with the case of using the above-described conventional bake.

Here, the Al997Powder system Al used in Al thermal spraying has a purity of 99.813% by weight, and contains a trace amount of Si, Fe, etc. in a trace amount, but no Na is detected. However, on the surface of the anti-adhesion member to which the Al thermal spray treatment was applied, Na was detected by inductively coupled plasma mass spectrometry (ICP-MS), and 3.8 × 10 ¹³ atoms/cm ^{2 was} detected. At this time, the detection limit of Na measured by ICP-MS was 3.7 × 10 ¹⁰ atoms/cm ² .

Further, the analysis of the surface of the adhesion preventing member to which the thermal spraying treatment was applied was performed as follows. First, a test piece (5 cm square) of Al was prepared, and a thermal spray film was formed thereon in the same manner as the thermal spray treatment applied to the surface of the adhesion preventing member. Then, the center portion (opening size: 30 mm) of the obtained thermal spray film was sandwiched by a Teflon (registered trademark) jig and masked, and the liquid surface was acid-contacted. Take the full capacity of the liquid obtained from the borrowed liquid to the evaporating dish, plus After heat, evaporation and solidification, the obtained acid residue was used as a test solution, and the mass of the impurities in the thermal spray film was measured by ICP-MS.

The surface of the thermal sprayed film, that is, Na and Al mixed into the SiN film in the form of impurities, is considered to be in the thermal spraying process and the subsequent cleaning process, and the Na contained in the working environment adheres and diffuses to the thermal spray film. The Al contained in the thermal spray film is deposited on the surface of the thermal spray film.

Further, as the abrasive generally used in the blast treatment of the anti-adhesion member, glass beads and alumina abrasives are exemplified. These abrasives contain a large amount of the above-mentioned impurities of Na and Al. Since these abrasives are roughened by slamming the surface of the anti-adhesion member with high energy, it is thought that some of the impurities contained in the abrasive cannot be borrowed. The cleaning process is completely removed.

Such Na and Al which are applied to the surface of the anti-adhesion member subjected to the blast treatment are thought to be such that when a thermal spray film is formed on the anti-adhesion member, impurities adhere to the thermal spray film, and are mixed into the film by diffusion. In the film on the substrate.

The reason why impurities are mixed into the film formed by sputtering is as follows. For example, when the vapor pressure of Na and Al in the film forming treatment space is 0.1 Pa, the evaporation temperature of Na is 600 K, and the evaporation temperature of Al is 1300 K. Therefore, under the film forming conditions used in this experiment, Na and Al hardly evaporate. That is, only the anti-adhesion member to which the blast treatment and the thermal spray treatment are applied is placed in a vacuum, and evaporation of Na and Al from the surface of the anti-adhesion member (the surface of the thermal spray film) hardly occurs.

However, in the case where the anti-adhesion member is exposed to the plasma, the inner wall of the anti-adhesion member is negatively charged. Since the inner wall of the anti-adhesion member is negatively charged, the ions of Na and Al contained in the thermal spray film are diffused to the thermal spray film. In the near future, the surface of the anti-adhesion member was isolated. However, the collision of Ar ions occurs on the surface of the anti-adhesion member of the ions on which the impurities are precipitated, and impurities deposited on the surface are ejected. It is conceivable that impurities such as Na and Al scattered in the processing chamber are taken into the deposited film on the substrate.

In the case of coating the SiN film, if the surface of the SiN is negatively charged, Na and Al diffuse into the SiN film and precipitate on the surface, so that it is considered to be an impurity taken into the SiN film of the deposited film.

When the TiN film is used to exert the anti-diffusion effect of Na and Al contained in the thermal spray film, the TiN film is a high melting point material which generally exhibits a NaCl-type crystal structure. Since the two substances are in close contact with each other and are thermally stable, it is thought to have an effect of suppressing diffusion of impurities contained in the thermal spray film of the lower layer of the TiN film to the surface of the adhesion preventing member. In the case where the TiN film is coated on the anti-adhesion member, under the influence of the plasma, on the surface of the thermal spray film, impurities in the thermal spray film may diffuse, but the diffusion into the TiN film is less than that of the other films. For this reason, the precipitation of impurities is small on the surface of the anti-adhesion member, and as a result, it is thought that the scattering into the processing chamber is reduced, and the mixing into the deposited film is reduced.

According to the above results, it is conceivable that the diffusion preventing film is formed on the surface of the adhesion preventing member 40 to which the blasting treatment and the thermal spraying treatment are applied, and the formation of the sputtering by the other film can also suppress the incorporation of impurities into the film. .

In the case of the chimney disposed near the target, it is directly exposed to the plasma, and the negative electric current of the belt is also large. In addition, the number of collisions of Ar ions is also higher than that of other anti-adhesion members. For this reason, I can think of it as a loan. Do not apply a diffusion-preventing film to the surface of the chimney to obtain a large effect. That is, it is conceivable that a large effect can be obtained by forming a diffusion preventive film in the anti-adhesion member facing the target and directly exposing it to the portion of the plasma.

Next, a method of manufacturing the anti-adhesion member for forming the above-described diffusion preventive film 403 will be described. First, a base material 401 of an adhesion preventing member such as Al is prepared. Next, a blast treatment is applied to the surface of the substrate to form a thermal spray film 402 thereon. As the material of the thermal spray film 402, various materials can be applied, and Al, Al ₂ O ₃ , Y ₂ O ₃ , Ti, or the like can be used. After the thermal spray film 402 is formed, a diffusion preventive film 403 is formed on the thermal spray film 402. The diffusion prevention film is formed by various film formation methods such as a sputtering method, a CVD method, and a vapor deposition method. In the case where yttrium oxide was used as the diffusion preventive film in addition to the above-described titanium nitride, the effect of reducing impurities in the film formed was confirmed. Therefore, in order to exhibit this effect, the diffusion preventive film 403 may contain at least one of titanium nitride and ruthenium oxide. The surface of the base material 401 does not have to be subjected to the blast treatment, or the thermal spray treatment may be performed without performing the blast treatment to form the thermal spray coating 402. On the contrary, in the case where the adhesion of the substrate 401 and the diffusion preventive film 403 is obtained by the blast treatment applied to the surface of the substrate 401, the thermal spray film 402 may not be formed directly on the surface of the substrate 401. A diffusion preventive film 403 is formed.

By depositing the anti-adhesion member manufactured in this manner in the inside of the sputtering apparatus 1, sputtering of the metal target, the magnetic target, or the like is performed, and the film formed on the substrate can be reduced. Impurities can reduce deterioration of component characteristics.

(Example 1)

An example of forming a magnetoresistive film by using the anti-adhesion member according to the present invention in the film forming apparatus of Fig. 1 will be described below.

Fig. 5 is a view showing an example of a laminated structure of a TMR element according to the present embodiment. This TMR element 500 is provided with a multilayer film of, for example, eight layers laminated on the substrate 501. In the 8-layer multilayer film, from the first layer of the lowermost layer to the eighth layer of the uppermost layer, Ta layer 502, PtMn layer 503, CoFe layer 504, Ru layer 505, CoFeB layer 506, MgO layer 507, CoFeB The layer 508 and the Ta layer 509 are sequentially laminated with a magnetic film or the like.

These films are formed by providing the anti-adhesion member 40 and the baffle 3 according to the present invention in a state in which the film forming apparatus shown in Fig. 1 is provided.

The Ta layer 502 as the first layer is a foundation layer, and the PtMn layer 503 as the second layer is an antiferromagnetic layer. The laminated body of the CoFe layer 504 as the third layer, the Ru layer 505 as the fourth layer, and the CoFeB layer 506 as the fifth layer is a magnetization fixed layer. The substantially magnetized pinned layer is the fifth layer of CoFeB layer 506. The layered structure of the PtMn-containing layer 503 to the CoFeB layer 506 is also referred to as a reference layer. The MgO (magnesia) layer 507 as the sixth layer is an insulating layer and is a tunnel barrier layer. The CoFeB layer 508 as the seventh layer is a ferromagnetic layer and is a magnetization free layer (free layer). The sixth layer of the MgO layer 507 is an intermediate layer between the ferromagnetic layers (CoFeB) of one of the upper and lower layers. The Ta layer 509 as the eighth layer is a hard mask layer. The CoFeB layer 506 of the fifth layer which is the magnetization fixed layer described above and the MgO layer 507 which is the sixth layer of the tunnel barrier layer and the CoFeB layer 508 which is the seventh layer of the magnetization free layer are formed into a basic structure. TMR component part. The CoFeB layer 506 which is the fifth layer of the magnetization fixed layer and the CoFeB 508 which is the seventh layer which is the magnetization free layer are known as a ferromagnetic body in an amorphous state. The MgO layer 507 which is the tunnel barrier layer is formed in such a manner as to have a single crystal structure in the entire thickness direction.

In addition, in FIG. 5, the numerical value in the parentheses in each layer shows the thickness of each layer, and the unit is "nm (nano)." These thicknesses are an example and are not limited to these.

In the present embodiment, an example of film formation conditions of the TMR element portion which is a main portion of the TMR element will be described.

The magnetization fixed layer (the fifth layer of the CoFeB layer 506) was formed by a magnetron DC sputtering using a target having a CoFeB composition ratio of 60/20/20 at%. Next, the tunnel barrier layer (the MgO layer 507 of the sixth layer) is formed by RF sputtering using a target of MgO. Further, next, the magnetization free layer (the seventh layer of the CoFeB layer 508) is formed into a film under the same film formation conditions as the magnetization fixed layer (the fifth layer of the CoFeB layer 506).

According to the present invention, it is possible to reduce impurities contained in the TMR element 500, and it is possible to suppress deterioration of element characteristics due to impurities, malfunction, and the like.

(Example 2)

FIG. 6 is a schematic view showing a laminated structure of a perpendicular magnetization type TMR element (hereinafter also referred to as a P-TMR element) 700. The P-TMR element first forms a RuCoFe layer 702 and a Ta layer 703 as a base layer on the substrate 701. On top of it, filming CoFeB as a magnetization free layer (free layer) Layer 704 forms an MgO layer 705 as a barrier layer. The barrier layer is preferably MgO in order to obtain a high MR ratio. Further, it may be an oxide containing at least one or more of magnesium (Mg), aluminum (Al), titanium (Ti), zinc (Zn), hafnium (Hf), or germanium (Ge). The CoFe layer 706 is formed thereon as the first magnetization fixed layer, the CoFeB layer 707 is used as the second magnetization fixed layer, and the Ta layer 708 is used as the alignment separation layer and the third magnetization fixed layer 709. The third magnetization fixed layer is formed by a laminated structure of Co and Pd. In the present embodiment, Co is mixed with four layers of Co/Pd, and Co is formed.

Next, the formed Ru layer 710 is used as a non-magnetic intermediate layer, a fourth magnetization fixed layer 711, and a Ta layer 712 as a cover layer. The fourth magnetization fixed layer 711 is formed of a laminated structure of Co/Pd, and Co and Pd are alternately laminated to each other with 14 layers. The laminated structure of the CoFe-containing layer 706 to the Ta layer 712 is also referred to as a reference layer.

These films are formed in a state in which the adhesion preventing member 40 and the capillary 3 according to the present invention are provided in the film forming apparatus shown in Fig. 1. Thereby, the impurities contained in the P-TMR element 700 can be reduced.

(Example 3)

Fig. 7 is a view exemplarily showing a configuration of a main portion of a phase change element as a functional element and a phase change memory using a phase change element. The RAM using the phase change memory is configured by, for example, arranging a phase change memory cell at the intersection of a complex word line and a complex bit line. A selection transistor 803 having a drain 801a and a source 801b is formed on the surface of the substrate 800. Here, the selection of the transistor 803 acts to form the sulfur of the phase change memory element. The control means for heating the genus layer 807 (phase change recording material layer) to a desired temperature. Although a MOSFET is used here, it can also be a bipolar transistor.

Next, the lower insulating layer 804 is formed on the substrate 800 on which the selective transistor 803, the drain 801a, and the source 801b are formed. Next, the first hole 811 is provided through the lower insulating layer 804, and a material having high conductivity such as tungsten is embedded in the first hole 811 as the plug 805. The plug 805 penetrates the lower insulating layer 804 and is electrically connected to the selective transistor 803 and the chalcogenide layer 807.

Examples of the chalcogenide forming the chalcogenide layer 807 include, for example, any one of S, Se, and Te, or a material containing one or more of Sb and Ge as a main component, and may be suitably used. Medium Ge, Sb, and Te are used as the main component materials. In particular, Ge ₂ Sb ₂ Te ₅ can be suitably used.

Next, on the plug 805 and the lower insulating layer 804, a perovskite layer 806 (hereinafter also referred to as "oxide layer 806"), a chalcogenide layer 807, and a material having a perovskite structure are formed. The upper electrode layer 808, a hard mask 809 made of a tantalum oxide film or the like is formed in this order.

Here, the oxide layer 806 can be formed, for example, by an oxide target or a combination of an oxide target and a metal target by sputtering. As a method of forming the oxide layer 806 other than the above, there are, for example, a physical vapor deposition method, a chemical vapor deposition method, an atomic layer deposition method, a method of depositing a metal compound by oxidation treatment, and a metal compound in an oxygen-absorbing atmosphere. The method of forming a reactive sputtering method, and the like. Vacuum treatment device, vacuum, to be described later In the method of manufacturing a phase change memory device of a processing device, the oxide layer 806 can be formed by using any of these methods.

The thickness of the oxide layer 806 is, for example, 10 nm, and can be sufficiently produced by the above-described method of forming the oxide layer 806. The difficulty of the manufacturing technique is particularly reduced in comparison with the technique of uniformly forming a thin film of 3 nm or less required for an extremely thin insulating layer of the prior art.

The chalcogenide layer 807 is formed on the perovskite layer 806 (oxide layer 806) and functions to be phased into a crystalline state or an amorphous state by heating or cooling the perovskite layer 806 (the oxide layer 106). Change the layer of recording material.

In the above embodiments, the TMR element and the phase change element are described as examples of the functional elements, but the present invention is not limited to these functional elements, and may be applied to a variable resistance memory (RRAM (registered trademark)). A method of manufacturing a variable resistance element and a ferroelectric element used in a ferroelectric random access memory (FeRAM).

1‧‧‧Sputtering device

2‧‧‧Vacuum container

3‧‧‧Anti-adhesion member (barium)

4‧‧‧ Target

6‧‧‧Backplane (target holder)

7‧‧‧Substrate holder

8‧‧‧Exhaust gas

10‧‧‧Substrate

11‧‧‧ mask

12‧‧‧Power supply

13‧‧‧Target occlusion

14‧‧‧Target shielding member drive mechanism

15‧‧‧ gas introduction mechanism

16a, 16b‧‧‧ gas inlet

19‧‧‧ magnet

40‧‧‧Anti-adhesion member

41‧‧‧ pressure gauge

47‧‧‧Main valve

48‧‧‧ Turbo Molecular Pumping

49‧‧‧Dry pump

Claims (12)

A sputtering method in which a target material is used in a processing chamber to form a film on a substrate disposed on a substrate holder, characterized in that the target member is splashed while the adhesion preventing member is disposed in the processing chamber. The anti-adhesion member includes a substrate, a thermal spray film formed on the substrate, and a diffusion preventive film formed on the thermal spray film, and a space between the target and the substrate holder The side is surrounded by a film; and a film formed of a film different from the diffusion preventing film is formed on the substrate by the sputtering. The sputtering method according to the first aspect of the invention, wherein the anti-diffusion film is formed on a portion of the anti-adhesion member facing the target. A sputtering method according to the first aspect of the invention, wherein a surface of the substrate on which the thermal sprayed film is formed is subjected to a blast treatment. The sputtering method of claim 1, wherein the diffusion preventive film comprises at least one of titanium nitride and cerium oxide. The sputtering method according to claim 1, wherein the target metal-based target is sputtered on the metal target to form a metal film on the substrate. A method of manufacturing a functional element having a substrate disposed on a substrate holder by a sputtering process using a target in a processing chamber The film forming process is characterized in that the target member is sputtered in a state in which the anti-adhesion member is disposed in the processing chamber, and the anti-adhesion member includes a substrate and thermal spraying formed on the substrate. a film and a diffusion preventive film formed on the thermal spray film are simultaneously provided to surround a side of a space between the target and the substrate holder; and the sputtering is performed on the substrate Film formation of a film different from the above-described diffusion preventive film is performed. The method of manufacturing a functional device according to the sixth aspect of the invention, wherein the anti-adhesion member is provided around the target, and the anti-diffusion film is formed in a portion of the anti-adhesion member facing the target. The method for producing a functional device according to claim 6, wherein the surface of the substrate on which the thermal sprayed film is formed is subjected to an air blowing treatment. The method of manufacturing a functional element according to claim 6, wherein the diffusion preventive film comprises at least one of titanium nitride and cerium oxide. A method of manufacturing a functional element according to claim 6 wherein said functional element is a tunneling magnetoresistance effect element. The method for producing a functional device according to claim 6, wherein the target metal target is sputtered on the metal target to form a metal film on the substrate. The method for producing a functional device according to claim 10, wherein the target Co-based CoFeB target is sputtered on the CoFeB target to form a magnetic film on the substrate.