JP2011014679A - Method of manufacturing magnetic element, and storage medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing a TMR (Tunnel Magnetic-Resistance effect) element high in performance, the method suppressing mixing of particles generated in etching a magnetic film or a diamagnetic film.SOLUTION: The magnetic film or the diamagnetic film is etched in a plasma atmosphere in which at least one gasification compound selected from a group of gasification compounds consisting of hydrocarbons, alcohols, ethers, aldehydes, carboxylic acids, esters and geons is formed under condition that the particle flow rate is at least 0.5×10molecular number/min/mand preferably at least 2×10molecular number/min/m.

Description

The present invention relates to a method of manufacturing a magnetic element having a dry etching process. More particularly, the present invention relates to a method for manufacturing a magnetic element and a storage medium, which include a step of performing dry etching at a high etching rate and a high selection ratio when finely processing a magnetic thin film.

MRAM (magnetic random access memory), which is an integrated magnetic memory, has attracted attention as a memory that has an integration density comparable to that of a DRAM and has a high speed equivalent to that of an SRAM and can be rewritten without limitation. Further, development of a thin film magnetic head, a magnetic sensor, and the like constituting a magnetoresistive element such as GMR (giant magnetoresistance) and TMR (tunneling magnetoresistance) is rapidly progressing.

Until now, ion milling has been often used for etching magnetic materials. However, since ion milling is a physical sputter etching, there is a problem in that it is difficult to take selectivity with respect to various materials as a mask, and the processed shape has a tapered skirt of the material to be etched. Therefore, it is not suitable for manufacturing a large-capacity MRAM that requires a particularly fine processing technique, and it is difficult to process the uniformity with a large-area substrate of 300 mm, and the yield does not increase.

Instead of such ion milling, the technology cultivated in the semiconductor industry has begun to be introduced.

Among them, an RIE (Reactive Ion Etching) technique that can ensure uniformity with a large substrate of 300 mm and is excellent in fine workability is expected.

However, even with the RIE technology widely used in the semiconductor industry, magnetic materials such as FeNi, CoFe, and CoPt are generally poor in reactivity, and it is difficult to process them without etching residue and sidewall deposits.

As a solution to the above problems, Japanese Patent Application Laid-Open Nos. 8-253881 and 2005-42143 disclose a method of manufacturing a magnetic element using a step of dry etching a magnetic film.

JP-A-8-253881 JP 2005-42143 A JP 2005-268349 A

The present invention relates to a dry etching process capable of suppressing the amount of particles generated when a ferromagnetic layer is etched to a minimum, and preventing impurities from being mixed into the ferromagnetic layer, and the dry etching process. It is an object of the present invention to provide a magnetic element using the above, particularly a tunnel magnetoresistive element.

In order to achieve the above object, the present invention provides at least one gasification compound selected from the group of gasification compounds consisting of hydrocarbons, alcohols, ethers, aldehydes, carboxylic acids, esters and diones. .5 × 10 ¹⁷ molecules / min · m ² or more, preferably 2 × 10 ¹⁷ molecules / min · m ² or more in a plasma atmosphere formed under the condition of a molecular flow rate (soft magnetic layer) Or a ferromagnetic layer) and / or a diamagnetic layer (an anti-soft magnetic layer or an anti-ferromagnetic layer), and a magnetic element, particularly a magnetization fixed layer having a ferromagnetic film, This is a method for manufacturing a tunnel magnetoresistive element using a tunnel barrier layer disposed adjacent to the fixed layer and a magnetization free layer having a ferromagnetic film disposed adjacent to the tunnel barrier layer.

In the present invention, at least one gasified compound selected from the group of gasified compounds consisting of hydrocarbons, alcohols, ethers, aldehydes, carboxylic acids, esters, and diones is 0.5 × 10 ^17. A magnetic layer (soft magnetic layer or ferromagnetic material) in a plasma atmosphere formed under the condition of a molecular flow rate of molecular number / min · m ² or more, preferably 2 × 10 ¹⁷ molecules / min · m ² or more. Layer) and / or a diamagnetic layer (an antisoft magnetic layer or an antiferromagnetic layer) is a storage medium storing a control program for executing an etching process.

As the gasification compound used in the production method of the present invention, hydrocarbon compounds such as paraffinic hydrocarbons or olefinic hydrocarbons can be used. Examples of the paraffinic hydrocarbons used in the present invention include lower paraffinic hydrocarbons such as methane, ethane, propane, butane and pentane. Examples of the olefinic hydrocarbons used in the present invention include lower olefinic hydrocarbons such as ethylene, propylene, butylene, and amylene.

The gasification compounds used in the production method of the present invention are alcohols such as methanol CH ₃ OH), ethanol (C ₂ H ₅ OH), n (normal) -propanol (n-C ₃ H ₇ OH), iso-propanol. _{(iso-C 3 H 7 OH} ), n ( n) - butanol _{(n-C 4 H 9 OH} ), iso - butanol _{(iso-C 4 H 9 OH} ), t ( tertiary) - butanol (tC ₄ H Lower alcohols such as ₉ OH) can be used.

Examples of the gasification compound used in the production method of the present invention include at least one selected from the group consisting of dimethyl ether, diethyl ether, methyl ethyl ether, methyl propyl ether, and ethylene oxide as the ethers.

The gasification compound used in the production method of the present invention can include at least one selected from the group consisting of formaldehyde and acetaldehyde as the aldehydes.

The gasification compound used in the production method of the present invention can include at least one selected from the group consisting of formic acid, acetic acid and propionic acid as the carboxylic acids.
Examples of the gasification compound used in the production method of the present invention include at least one selected from a compound group consisting of a compound group consisting of ethyl chloroformate and ethyl acetate as esters.

Examples of the gasification compound used in the production method of the present invention include at least one selected from the group consisting of tetramethylheptadione, acetylacetone and hexafluoroacetylacetone as the diones.

In the production method of the present invention, a magnetic material layer (soft layer) composed of at least one metal selected from the metal group consisting of elements of Groups 8, 9, and 10 of the periodic table subjected to the etching step. Magnetic layer or ferromagnetic layer) or antiferromagnetic layer is FeN film, NiFe film, CoFe film, CoFeB film, PtMn film, IrMn film, CoCr film, CoCrPt film, NiFeCo film, NiFeMo film, CoFeB A film, FeMn film, CoPt film, NiFeCr film, CoCr film, CoPd film, CoFeB film, NiFeTb film, or the like can be used. In the present invention, the magnetic substance contained in these magnetic layer (soft magnetic layer or ferromagnetic layer) or antiferromagnetic layer is 10 atomic% or more, preferably 50 atomic% or more. However, it is not limited to this value.

In particular, in the present invention, the pair of ferromagnetic layers sandwiching the tunnel barrier layer of the tunnel magnetoresistive effect element is preferably at least one kind from an alloy group consisting of a CoFeB alloy, a CoFe alloy, a CoFeNi alloy, a CoFeNiB alloy, and a NiFe alloy. Can be selected.
In the production method of the present invention, the ferromagnetic layer or antiferromagnetic layer subjected to the etching step may be a single layer film or a laminated film. When a single layer film is formed, the film thickness is 2 to 300 nm, preferably 15 to 30 nm. When the laminated film is formed, the laminated film thickness is 2 to 300 nm, preferably 15 to 30 nm.

In the present invention, an aluminum oxide layer can be used instead of the crystalline magnesium oxide used in the tunnel barrier layer. The element at this time can be applied as a GMR element.

The magnetic layer (soft magnetic layer or ferromagnetic layer) used in the present invention is formed by magnetron DC (direct current) sputtering using a magnetic target (soft magnetic target or ferromagnetic target). In addition, it is preferable to be a crystal body that is in an amorphous state during sputtering film formation and phase-changed to a column crystal body after the annealing step. In particular, in the present invention, it is preferable to be in an amorphous state after the tunnel barrier layer forming step and before the annealing step.

The columnar crystal of the magnetic layer (soft magnetic layer or ferromagnetic layer) used in the present invention is a single crystal in which (001) crystal planes are preferentially oriented in the film thickness direction for each column. Preferably there is. The average diameter of the columnar single crystal used in the present invention is 10 nm or less, preferably in the range of 2 nm to 5 nm, and the film thickness is 10 nm or less, preferably 0.5 nm to 5 nm. It is a range.

In the magnetic element of the present invention, in particular, the tunnel magnetoresistive effect element, a crystalline magnesium oxide layer, a crystalline magnesium oxide boron layer, a crystalline zinc magnesium oxide layer, or the like can be used as a tunnel barrier layer. The crystal at this time preferably has a polycrystalline structure formed by an aggregate of columnar crystals. These tunnel barrier layers are formed by a magnetron RF (radio frequency) non-reactive sputtering method using an oxide target such as magnesium oxide, zinc magnesium oxide, or magnesium oxide boron, or a reactive sputtering method using metal magnesium and oxygen gas. Can be formed.

The dry etching step used in the production method of the present invention comprises at least one gasification compound selected from the group of gasification compounds consisting of hydrocarbons, alcohols, ethers, aldehydes, carboxylic acids, esters and diones. A plasma atmosphere is formed under the condition of a molecular flow rate of 0.5 × 10 ¹⁷ molecules / minute · m ² or more, preferably 2 × 10 ¹⁷ molecules / minute · m ² or more. The magnetic layer is manufactured by etching the body layer with a predetermined pattern. However, “m ² ” in the above formula is the plasma exposure area of the inner wall of the processing chamber (for example, plasma etching chamber) and the shield disposed in the processing chamber, and “m ⁻² ” is “per unit area”. It appears.

The 2 × 10 ¹⁷ molecules / min · m ² can be obtained based on the following formula A.
Formula A:

N (number of molecules) = PV / (kβ) T

In the formula, P is the pressure in the processing chamber (Pa: Pascal), V is the gas flow rate (m ³ / min) of the introduced gasification compound, kβ is the Boltzmann constant, and T is the absolute temperature (K) of the etching gas.

The pressure P (Pa: Pascal) in the equation is in the vicinity of the exhaust pipe 21B in the container 2 connected to the vacuum exhaust system 21A (position within a radius of 50 cm around the exhaust pipe 21B) in the apparatus of FIG. 1A described later. It is measured by the arranged pressure gauge 20. The gas flow velocity V (m ³ / min) is obtained from the flow rate (sccm) set by the flow rate regulator 34 in the apparatus shown in FIG.

The maximum molecular flow rate of the gasification compound used in the method of the present invention is set to 5 × 10 ¹⁸ molecules / minute · m ² , but preferably 1 × 10 ¹⁸ molecules / minute · m ² . It may be set as the maximum value.

The annealing step used in the present invention is performed at a temperature of 200 ° C. to 350 ° C. (preferably 230 ° C. to 300 ° C.) and a heating time of 1 hour to 6 hours (preferably 2 hours to 5 hours). Depending on the temperature and heating time of the annealing step, the crystallinity of the produced crystal can be changed. In the present invention, the crystallinity can be 90% or more per total volume, and in particular, the crystallinity can be 100%.

In the production apparatus of the present invention, at least one gasification compound selected from the group of gasification compounds consisting of hydrocarbons, alcohols, ethers, aldehydes, carboxylic acids, esters, and diones is used as the condition for the molecular flow rate. A storage medium storing a control program for executing an etching process for etching a magnetic layer (soft magnetic layer or ferromagnetic layer) under a plasma atmosphere formed below can be used.

Examples of the storage medium used in the present invention include hard disk media, magneto-optical disk media, flexible disk media, and non-volatile memories such as flash memory and MRAM, and include programs-storable media.

The dry etching process used in the present invention is performed after a non-organic material mask made of a non-organic material is formed on the uppermost layer of the magnetic element. Non-organic material masks that can be used in the present invention include, for example, metal atoms of Periodic Table Group 3, Group 4, Group 6 or Group 6 such as Ta, Ru, Ti, Al, or Si, or A non-organic material mask material composed of a single layer film or a laminated film formed of a substance obtained by mixing these metal atoms and non-metal atoms can be given. In particular, in the present invention, a laminated metal film of Ta (upper layer) and Ru (lower layer), a laminated metal film of Ta (upper layer) and Ti (lower layer), and the like are preferable.

When the non-organic material mask used in the present invention is the single layer film, the film thickness is 2 to 300 nm, preferably 15 to 30 nm. When the laminated film is used, the laminated film thickness is 2 to 300 nm, preferably 15 to 30 nm.

In the production method of the present invention, the etching temperature at the time of etching the magnetic layer (soft magnetic layer or ferromagnetic layer) and / or antiferromagnetic layer is maintained within a range of 250 ° C. or lower. It is desirable. If it exceeds 250 ° C., unnecessary thermal damage is imparted to the magnetic film. The more preferable temperature range of this invention is 20-100 degreeC.

Moreover, in the manufacturing method of this invention, the vacuum degree at the time of an etching has the desirable range of 0.05-10Pa. If it is this pressure range, it can process with sufficient anisotropy by formation of a high-density plasma.
In the production method of the present invention, an oxidizing gas or nitriding gas (addition gas) such as oxygen, ozone, nitrogen, H ₂ O, N ₂ O, NO ₂ and CO _{2 is} added to 50 atoms with respect to the gasified compound. % Can be added within a range not exceeding%.

In the present invention, it is desirable to add an inert gas in a range not exceeding 90 atomic% with respect to the gasified compound. Ar, Ne, Xe, or Kr can be used as the inert gas. At this time, a mixed gas of the additive gas and the inert gas may be used. Also in this case, it is preferable to be within the range of the addition amount.

In the manufacturing method of the invention, when the additive gas or the inert gas is added to the gasified compound in the above-described range, the etching rate can be further increased, and at the same time, the selectivity to the mask is greatly increased. It can be made. Further, when the additive gas is used in excess of 50 atomic%, the etching rate is reduced and the selectivity with respect to the non-organic material mask is also lowered.

The present invention relates to a magnetic element including a magnetic layer (soft magnetic layer or ferromagnetic layer) and / or an antimagnetic layer (antisoft magnetic layer or antiferromagnetic layer), particularly a tunnel. When the magnetoresistive effect element is dry-etched, the adhering state can be stably maintained without dropping off the adhering matter to the dry etching processing chamber inner wall and the shield disposed in the processing chamber. It was possible to suppress particles from being mixed in.

Furthermore, the present invention has greatly improved the yield of manufacturing highly integrated MRAM.

1 is a schematic cross-sectional view of an etching apparatus that can be used in the method of the present invention. The schematic structure top view of the etching apparatus which can be used for the method of this invention. Schematic cross-section before starting the process. FIG. 2B is a schematic cross-sectional view of the Ta mask manufacturing process following FIG. 2A. FIG. 2B is a schematic cross-sectional view of an etching process following FIG. 2B. The cross-sectional schematic which shows another Example of this invention. It is a longitudinal cross-sectional view which shows the basic structure of the TMR element part manufactured by this invention. It is a figure explaining one change of the resistance value in the TMR element part manufactured by the present invention. It is a figure explaining the other change of the resistance value in the TMR element part manufactured by the present invention.

Example 1
FIG. 1 shows an ICP (Inductive
It is a schematic diagram of an etching apparatus equipped with a coupled plasma) plasma source.

In this embodiment, a process of etching the tunnel magnetoresistive element shown in FIG. 2 (hereinafter referred to as “TMR element”) using methyl alcohol as an etching gas and the apparatus shown in FIG. 1 will be described.

2C and 3 show two examples of TMR elements manufactured by the manufacturing method of the present invention.

FIG. 2A shows an element structure before the etching process used in the present invention. In the figure, 9 is a 300 mm wafer (quartz or the like can be used), 201 is a Ta film, 202 is an Al film, 203 is a Ta film, and 204 is a 1 nm to 20 nm soft magnetic CoFe film (preferably a film thickness of 5 nm). 205 is an insulating film formed by a crystalline magnesium oxide layer (cry.MgO) having a film thickness of 0.1 nm to 10 nm, preferably 0.5 nm to 2 nm. , 206 is a soft magnetic film formed of a CoFe film (preferably 5 nm thick) having a film thickness of 1 nm to 20 nm to be a free layer, 207 is a soft magnetic film formed of a NiFe film, 208 is a mask formed of Ta, 209 Is a patterned photoresist film.

FIG. 4 shows the basic structure of a TMR element manufactured by the manufacturing method of the present invention.

The basic structure of the TMR element 401 is that the insulating layer 402 (corresponding to the crystalline magnesium oxide of FIG. 2; corresponding to the insulating film 205 of cry.MgO) is laminated on both sides of the ferromagnetic layer 403 (the NiFe film 207 and the CoFe film 206 of FIG. 2) (corresponding to the CoFe / PtMn film 204 in FIG. 2).

In each of the ferromagnetic layers 403 and 404, arrows 403a and 404a indicate the directions of magnetization.

5A and 5B are diagrams for explaining a resistance state in the TMR element 401 when the voltage V is applied to the TMR element 401 by the power source 405. FIG.

The TMR element 401 has a characteristic that the resistance value is changed according to the respective magnetization states of the ferromagnetic layers 403 and 404 in accordance with the applied voltage V. When the magnetization directions of the ferromagnetic layers 403 and 404 are the same as shown in FIG. 5A, the resistance value of the TMR element 401 is minimized, and as shown in FIG. 5B, the magnetization values of the ferromagnetic layers 403 and 404 are reduced. When the directions are opposite, the resistance value of the TMR element 401 is maximized. The minimum resistance value of the TMR element 401 is represented by Rmin, and the maximum resistance value of the TMR element 401 is represented by Rmax. Here, in general, a CIP (Current-in-Plane) type structure in which a sense current flows parallel to the element film surface, and a CPP (Current Perpendicular to Plane) in which a sense current flows in a direction perpendicular to the element film surface. 4 and 5 are examples of a CPP type magnetoresistive effect element.

FIG. 2B illustrates a state after the Ta film 208 is etched using the patterned photoresist film (PR) 209 illustrated in FIG. 1 and CF ₄ gas as an etching gas.

The Ta film 208 is etched using the apparatus shown in FIG.

1A and 1B, 1 is a plasma source, 2 is a vacuum vessel, 3 is a gas introduction system, 4 is a substrate holder, 5 is a high frequency power source for biasing, 9 is a wafer, 11 is a dielectric wall vessel, 12 is an antenna, 13 Is a high-frequency power source for plasma, 14 is an electromagnet, 15 is a transmission line, 16 is an etching gas molecular flow rate control device, 17 is a storage medium, 18 is a shield, 19 is an etching gas introduction pipe, 20 is a pressure gauge, and 21A is an exhaust system. , 21B is an exhaust pipe in the container, 22 is a side wall magnet, 31 is an etching gas cylinder, 32 is piping, 33 is a valve, 34 is a flow controller, and 41 is a temperature control mechanism.

The vacuum vessel 2 shown in FIG. 1 is evacuated by an exhaust system 21, a gate valve (not shown) is opened, and a wafer 9 provided with the magnetic laminated film shown in FIG. 2A is carried into the vacuum vessel 2. Was held by the substrate holder 4, and the wafer 9 was maintained at a predetermined temperature by the temperature control mechanism 41. Next, the gas introduction system 3 is operated, and an etching gas (with a predetermined flow rate) is supplied from a cylinder storing CF ₄ gas (not shown in FIG. 1) through a pipe (not shown), a valve 33 and a flow rate regulator 34. CF ₄ ) is introduced into the vacuum vessel 2.

The introduced etching gas diffuses into the dielectric wall container 11 through the vacuum container 2. Here, the plasma source 1 is operated. The plasma source 1 includes a dielectric wall container 11 that is hermetically connected so that the internal space communicates with the vacuum container 2, an induction magnetic field generated in the dielectric wall container 11, an antenna 12, and the antenna 12 A high frequency power source for plasma 13 for generating RF high frequency power (source power) to be supplied to the antenna 12 connected by the transmission line 15 via a matching unit (not shown) and a predetermined magnetic field are generated in the dielectric wall container 11. It is comprised from the electromagnet 14 grade | etc.,.

When a high frequency generated by the plasma high frequency power supply 13 is supplied to the antenna 12 through the transmission line 15, a current flows through the antenna 12, and as a result, plasma is formed inside the dielectric wall container 11. In addition, on the outside of the side wall of the vacuum vessel 2, a large number of side wall magnets 22 are arranged side by side in the circumferential direction so that the adjacent magnetic poles of the surfaces facing the side wall of the vacuum vessel 2 are different from each other. A cusp magnetic field is continuously formed along the inner surface of the side wall of the vacuum vessel 2 in the circumferential direction, and plasma diffusion to the inner surface of the side wall of the vacuum vessel 2 is prevented.

At the same time, the bias high-frequency power source 5 is operated to apply a self-bias voltage, which is a negative direct current voltage, to the wafer 9 that is the object to be etched, and the ion incident energy from the plasma to the surface of the wafer 9. Is controlling. The plasma formed as described above diffuses from the dielectric wall container 11 into the vacuum container 2 and reaches the vicinity of the surface of the wafer 9. At this time, a Ta mask 208 is formed on the Ta film 208 on the wafer 9 as shown in FIG. 2B.

In this apparatus, the flow rate of the etching gas introduced through the introduction pipe 19 is controlled by the flow rate controller 16 so that the etching gas has a predetermined molecular flow rate. The flow controller 16 controls the valve 33 based on the control program stored in the storage medium 17. The storage medium 17 is placed under the condition of a predetermined molecular flow rate with an etching gas of 0.5 × 10 ¹⁷ molecules / min · m ² or more, and in a plasma atmosphere in the vacuum vessel 2, A control program for executing the process of etching the magnetic layer is stored.

Further, the plasma exposure area is determined by the area of the plasma exposure portion formed by the shield 18 and the inner wall door of the processing container 2 of the shield non-covering portion. When the use of the shield 18 is omitted, it can be obtained from the plasma irradiated surface of the inner wall of the vacuum vessel 2.

The etching conditions of the Ta film 208 by the photoresist film 209 using CF ₄ were as follows.

<Etching conditions>
Etching gas (CF ₄ ) flow rate:
50 sccm
Source power:
500W
Bias power:
70W
Pressure in the vacuum vessel 2:
0.8 Pa
The temperature of the substrate holder 4:
40 ° C

Next, after removing the photoresist 209 (PR), an etching process was performed using the metal rule gas as an etching gas and Ta formed by the above process as a mask material, and the TMR element shown in FIG. 2C was manufactured. . 2A to 2C, reference numeral 207 denotes a NiFe film, 206 denotes a CoFe film, and 205 denotes an Al ₂ O ₃ film (preferably, a crystalline magnesium oxide film, a crystalline magnesium oxide boron film, or a crystalline zinc magnesium oxide film may be used. 204 is a CoFe / PtMn film, 203 is a metal Ta film, 202 is a metal Al film, and 201 is a metal Ta film.

In the above process, the apparatus shown in FIG. 1 was used except that CF ₄ gas was used instead of methanol gas. The conditions at this time were as follows. The etching rate (nm / min) at this time was measured by a conventional method. The results are shown in Table 1 below.

<Etching conditions>
Molecular flow rate of methanol (CH ₃ OH):
2.0 × 10 ¹⁷ number of molecules / min · m ² (methanol gas flow rate: set to 100 sccm)
Source power:
1000W
Bias power:
800W
Pressure in the vacuum vessel 2:
0.4 Pa
The temperature of the substrate holder 4:
40 ° C

At this time, the gas introduction system 3 is operated, and the molecular flow rate of methanol gas is 2.0 from the container 31 storing liquid methanol shown in FIG. The flow rate of methanol gas (100 sccm) was adjusted so as to be × 10 ¹⁷ molecules / min · m ² , introduced into the vacuum vessel 2 and etched. After the etching in this step, the structure of FIG. 2C was confirmed.

After completing all the above processes, the same process was repeated again 200 times to create 200 types of TMR element pulls.

Of the 200 kinds of samples, the number of particles contained in the 100th sample and the 200th sample was measured. As a result, the number of particles per 300 mm wafer was 100th and 200th, respectively. It was less than the number.

The molecular flow rate of methanol used in the above experimental examples was 0.1 × 10 ¹⁷ molecules / min · m ² (outside the present invention), 0.5 × 10 ¹⁷ molecules / min · m ² (in the present invention) and 3 The number of particles was measured in the same manner as in the above experiment except that the number was changed to 0.0 × 10 ¹⁷ molecules / minute · m ² (within the present invention).

The results are shown in Table 1 below.
In the determination of the number of particles (per 300 mm wafer) in Table 1, 100 or less “good” per unit area (per 300 mm wafer), and 101 or more “bad”.

In particular, in the above experimental example, when the etching gas was introduced at a molecular flow rate of 2 × 10 ¹⁷ molecules / min · m ² or more, the number of particles per unit area (300 mm wafer) was 20 or less. As a result, a remarkable improvement was obtained.

Further, in the above experimental example, it was found that the etching residue film adhering to the inner wall of the processing container 2 and the surface of the shield 8 is a stable film and not an unstable film such as dropping or peeling.

Examples 2-20
The element shown in FIG. 2C was prepared in the same manner as in Example 1 except that the etching gas shown in Table 2 below was used instead of the etching gas composed of methanol gas used in Example 1 above. The number of particles was measured.

As described above, the dry etching method used in the production method of the present invention has an unexpectedly remarkable effect. In particular, in Examples 2 to 20 above, when the etching gas was introduced at a molecular flow rate of 2 × 10 ¹⁷ molecules / min · m ² or more, the number of particles per unit area (per 300 mm wafer) was 20 or less. As a result, a significant improvement was obtained.

Further, in Examples 2 to 20, it was found that the etching residue film attached to the inner wall of the processing container 2 and the surface of the shield 8 is a stable film and not an unstable film such as dropping or peeling.

Although the preferred embodiments of the present invention and comparative test examples have been described, the present invention is not limited to the above-described embodiments, and various technical scopes can be obtained from the description of the scope of claims. The form can be changed.

For example, the etching apparatus is not limited to the ICP type plasma apparatus having the antenna 12 shown in FIG. 1, but a helicon type plasma apparatus called a so-called high density plasma source, a two-frequency excitation parallel plate type plasma apparatus, a microwave type plasma apparatus, etc. Can be used.

Further, even when a magnetic material is etched using a non-organic material as a mask material and the magnetic material is a TMR element, the configuration of the TMR element is not limited to the configuration shown in FIG. Absent. The present invention is not limited to the TMR element, but can be applied to a GMR element.

Further, as shown in FIG. 3, the present invention can use a process using the insulating film 205 shown in FIG. 2A as an etching stopper.

DESCRIPTION OF SYMBOLS 1 Plasma source 2 Vacuum container 3 Gas introduction system 4 Substrate holder 5 Bias high frequency power supply 9 Wafer 11 Dielectric wall container 12 Antenna 13 Plasma high frequency power supply 14 Electromagnet 15 Transmission path 16 Etch gas molecular flow rate control device 17 Storage medium 18 Shield 19 Etching gas introduction pipe 20 Pressure gauge 21A Exhaust system 21B Exhaust pipe 22 in vessel 22 Side wall magnet 31 Cylinder 32 Pipe 33 Valve 34 Flow rate regulator 41 Temperature control mechanism

Claims (8)

0.5 × 10 ¹⁷ molecules / min · m of at least one gasification compound selected from the group of gasification compounds consisting of hydrocarbons, alcohols, ethers, aldehydes, carboxylic acids, esters and diones ^A method for producing a magnetic element, comprising: an etching step of etching a magnetic layer or a diamagnetic layer in a plasma atmosphere formed under a condition of ^two or more molecular flow rates. ^{2. The} method of manufacturing a magnetic element according to claim 1, wherein the molecular flow rate is 2.0 × 10 ¹⁷ molecules / min · m ² or more. 0.5 × 10 ¹⁷ molecules / min · m of at least one gasification compound selected from the group of gasification compounds consisting of hydrocarbons, alcohols, ethers, aldehydes, carboxylic acids, esters and diones ^A method of manufacturing a magnetic element, comprising: an etching step of etching a magnetic layer and a diamagnetic layer in a plasma atmosphere formed under conditions of a molecular flow rate of ² or more. The method of manufacturing a magnetic element according to claim 3, wherein the molecular flow velocity is 2.0 × 10 ¹⁷ molecules / min · m ² or more. 0.5 × 10 ¹⁷ molecules / min · m of at least one gasification compound selected from the group of gasification compounds consisting of hydrocarbons, alcohols, ethers, aldehydes, carboxylic acids, esters and diones A storage medium storing a control program for executing an etching process for etching a magnetic layer or a diamagnetic layer in a plasma atmosphere formed under conditions of ^two or more molecular flow rates. The storage medium according to claim 5, wherein the molecular flow rate is 2.0 × 10 ¹⁷ molecules / min · m ² or more. 0.5 × 10 ¹⁷ molecules / min · m of at least one gasification compound selected from the group of gasification compounds consisting of hydrocarbons, alcohols, ethers, aldehydes, carboxylic acids, esters and diones A storage medium storing a control program for executing an etching process for etching a magnetic layer and a diamagnetic layer in a plasma atmosphere formed under conditions of ^two or more flow velocity molecules. The storage medium according to claim 7, wherein the molecular flow rate is 2.0 × 10 ¹⁷ molecules / min · m ² or more.