JP2008004770A - Method for manufacturing magnetoresistive element - Google Patents

Abstract

A method of manufacturing a magnetoresistive element capable of efficiently forming a nanocontact portion having a width of about 1 to 50 nm is provided.
A first resist layer is formed on a ferromagnetic layer, and the first resist layer is exposed and developed with a first exposure pattern in which at least a part of a boundary between an exposed portion and a non-exposed portion is V-shaped. Then, the V-shaped notch 20 corresponding to the V-shape is formed in the ferromagnetic layer 16 by etching the ferromagnetic layer 16, and the second resist layer 34 is formed on the ferromagnetic layer 16 and exposed. The second resist layer 34 is exposed and developed with a second exposure pattern having a linear shape arranged so that at least a part of the boundary 36 between the exposed portion and the non-exposed portion is opposed to the apex of the V-shaped notch 20. By etching the magnetic layer 16, a linear portion corresponding to the linear shape is formed in the ferromagnetic layer 16.
[Selection] Figure 14

Description

  The present invention relates to a method for manufacturing a magnetoresistive element having a nanocontact portion.

  Conventionally, the surface recording density of magnetic recording media has been gradually increased, and further increases in surface recording density are expected in the future.

  On the other hand, the higher the areal recording density, the smaller the recording bit and the smaller the intensity of the reproduced signal. Therefore, a magnetoresistive element having a high MR ratio is required as a reproducing element for a magnetic head.

  As such a magnetoresistive element with a high MR ratio, a TMR (Tunneling Magneto Resistance) element is known. The TMR element has a configuration in which an insulating spacer layer is provided between a first ferromagnetic layer and a second ferromagnetic layer. In the TMR element, when the magnetization direction of the second ferromagnetic layer is parallel to the magnetization direction of the first ferromagnetic layer, the resistance value of the sense current in the thickness direction becomes minimum, and the magnetization of the second ferromagnetic layer When the direction is antiparallel to the magnetization direction of the first ferromagnetic layer, the resistance value of the sense current in the thickness direction is maximized, and a high MR ratio is obtained.

  In recent years, research on a BMR (Bullistic Magneto Resistance) element in which two ferromagnetic portions are joined by a ferromagnetic nanocontact portion whose width in the direction perpendicular to the energizing direction is about 1 to 50 nm has been reported (for example, non-conducting). (See Patent Documents 1 and 2). The BMR element is expected to have a higher MR ratio than the TMR element. In addition, considering the controllability of the width in the direction perpendicular to the energization direction (difficulty of keeping the width within a predetermined range), it is considered that the nanocontact portion preferably has a length in the energization direction of about 1 to 50 nm. .

  As a method for manufacturing such a BMR element, a resist layer is formed on a ferromagnetic layer, a part of the resist layer is removed by exposure and development, and the ferromagnetic layer is etched, whereby the outer periphery of the ferromagnetic layer is obtained. Two V-shaped notches are formed so that the V-shaped vertices face each other with an interval of 1 to 50 nm, and the width between the two V-shaped notched vertices is 1 to 50 nm. A method for forming a contact portion is known (see, for example, Patent Document 1).

S.Z.Hua et.al., Phys. Review B67,060401 (R) (2003) G. Tatara et.al., Phys. Review Letters, Vol. 83, 2030 (1999) JP-A-2005-109241

  However, it is actually not easy to process the resist layer to a width of about 1 to 50 nm by exposure and development, and the two V-shaped notches are opposed to each other with a V-shaped apex having an interval of 1 to 50 nm. It was difficult to form.

  In addition, the inventor tried a method of forming two V-shaped notches in two steps in the process of conceiving the present invention. Specifically, first, a first resist layer is formed on the ferromagnetic layer, and the first resist layer is exposed with a first exposure pattern in which at least a part of the boundary between the exposed portion and the non-exposed portion is V-shaped. By developing and etching the ferromagnetic layer, a first V-shaped notch corresponding to a V-shape is formed in the ferromagnetic layer, and a second resist layer is formed on the ferromagnetic layer, thereby exposing the exposed portion. The second resist is a second exposure pattern in which at least a part of the boundary of the non-exposed portion is a V-shaped second apex in which the apex of the first V-shaped notch is opposed to the apex with an interval of about 1 to 50 nm. The layer is exposed and developed, and the ferromagnetic layer is etched to form a second V-shaped notch in the ferromagnetic layer, and the top of the first V-shaped notch and the second V-shaped An attempt was made to form a nanocontact between the top of the notch.

  In this way, the first resist layer for forming the first V-shaped notch and the second resist layer for forming the second V-shaped notch are both about 1 to 50 nm. This is because a nanocontact portion having a width of about 1 to 50 nm can be formed between the first V-shaped notch portion and the second V-shaped notch portion without being processed into a very small size.

  However, although the first V-shaped notch and the second V-shaped notch can be formed in almost desired shapes, the current exposure apparatus generally has a thickness of 10 nm or more (at 3σ). In the exposure for forming the second V-shaped notch, the V-shape corresponding to the second V-shaped notch becomes the first V-shaped notch. In some cases, the exposure is shifted.

  Therefore, for example, when the two V-shaped notches are formed so as to be shifted in the direction of the gap, the width of the nanocontact portion may be shifted from the target value.

  Even if the two V-shaped notches are not displaced in the direction of the gap between these apexes, as shown in FIG. 22, the apex of the first V-shaped notch 102 and the second V-notch It is difficult to form them in a symmetrical arrangement in which the apex of the notch 104 faces each other. Accordingly, as shown in FIG. 23, the first V-shaped notch portion 102 and the second V-shaped notch portion 104 are displaced in a direction perpendicular to the direction in which the vertices face each other. The width of the contact portion may deviate from the target value.

  As described above, the method of forming two V-shaped notches in two steps has a problem that the yield is low even if a nanocontact portion having a width of about 1 to 50 nm can be formed.

  The present invention has been made in view of the above problems, and an object thereof is to provide a method of manufacturing a magnetoresistive element capable of efficiently forming a nanocontact portion having a width of about 1 to 50 nm.

  In the present invention, a first resist layer is formed on a ferromagnetic layer, and the first resist layer is exposed and developed with a first exposure pattern in which at least a part of the boundary between the exposed portion and the non-exposed portion is V-shaped. By etching the ferromagnetic layer, a V-shaped notch corresponding to the V-shape is formed in the ferromagnetic layer, a second resist layer is formed on the ferromagnetic layer, and a boundary between the exposed portion and the non-exposed portion The second resist layer is exposed and developed with a second exposure pattern having a linear shape arranged so that at least a part thereof faces the apex of the V-shaped notch, and the ferromagnetic layer is etched to develop the straight line. The above object is achieved by forming a linear portion corresponding to the shape in the ferromagnetic layer.

  In the present invention, the first resist layer is formed on the ferromagnetic layer, and the first resist layer is exposed and developed with a first exposure pattern in which at least a part of the boundary between the exposed portion and the non-exposed portion is linear. Then, by etching the ferromagnetic layer, a linear portion corresponding to a linear shape is formed in the ferromagnetic layer, a second resist layer is formed on the ferromagnetic layer, and at least a part of the boundary between the exposed portion and the non-exposed portion The second resist layer is exposed and developed with a second exposure pattern having a V-shape arranged so that the apexes face each other toward the linear portion of the ferromagnetic layer, and the V-shape is etched by etching. The above object is achieved by forming a V-shaped notch corresponding to the shape in the ferromagnetic layer.

  Thus, by forming the straight portion and the V-shaped notch in separate steps, a first resist layer for forming one of the straight portion and the V-shaped notch and a second resist layer for forming the other. Each of the resist layers can be formed into a linear portion and a V-shaped notch portion without being processed into a minute size of about 1 to 50 nm, and a nanocontact portion having a width of about 1 to 50 nm can be formed therebetween.

  In addition, since the nanocontact portion is formed between the straight portion and the V-shaped notch portion whose apex faces the straight portion, even if the second exposure pattern is shifted and exposed, the straight portion and the V-shaped cut portion are formed. The deviation in the direction perpendicular to the gap with the notch does not mean the deviation of the width of the nanocontact portion. Accordingly, as compared with the case where the nanocontact portion is formed between the two V-shaped notches, the variation in the width of the nanocontact portion due to the exposure deviation of the second exposure pattern is suppressed, and the yield is improved.

  That is, the above object is achieved by the following invention.

(1) A first resist layer is formed on the ferromagnetic layer, and the first resist layer is exposed and developed with a first exposure pattern in which at least part of the boundary between the exposed portion and the non-exposed portion is V-shaped. Etching the ferromagnetic layer to form a V-shaped notch corresponding to the V-shape in the ferromagnetic layer; and forming a second resist layer on the ferromagnetic layer. The second resist layer is exposed and developed with a second exposure pattern having a linear shape formed so that at least a part of the boundary between the exposed portion and the non-exposed portion is arranged to face the apex of the V-shaped notch. And a step of forming a linear portion corresponding to the linear shape in the ferromagnetic layer by etching the ferromagnetic layer, and a method of manufacturing a magnetoresistive element.

(2) forming a first resist layer on the ferromagnetic layer, exposing and developing the first resist layer with a first exposure pattern in which at least a part of a boundary between the exposed portion and the non-exposed portion is linear; Forming a linear portion corresponding to the linear shape in the ferromagnetic layer by etching the ferromagnetic layer; forming a second resist layer on the ferromagnetic layer; exposing portions and non-exposed portions; The second resist layer is exposed and developed with a second exposure pattern having a V shape in which at least a part of the boundary is arranged so that apexes face each other toward the linear portion of the ferromagnetic layer, and the ferromagnetic layer is developed. And a V-shaped notch forming step of forming a V-shaped notch corresponding to the V-shape in the ferromagnetic layer by etching the layer.

(3) The magnetoresistive element according to (1) or (2), wherein the ferromagnetic layer is processed so that a distance between a vertex of the V-shaped notch and the linear portion is 1 to 50 nm. Manufacturing method.

(4) In any one of (1) to (3), in the V-shaped notch forming step, the V-shaped notch has a contour corresponding to the shape of the boundary between the exposed portion and the non-exposed portion, and The magnetoresistive device is characterized in that exposure is performed using a mask in which a portion corresponding to a vertex of the shape is substantially rectangular and a gap in a direction perpendicular to the direction in which the vertex protrudes is larger than a portion near the vertex of the V-shape. Device manufacturing method.

  According to the present invention, a nanocontact portion having a size of about 1 to 50 nm can be efficiently formed.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

  The first embodiment of the present invention relates to a method of manufacturing the magnetoresistive element 10 as shown in FIG.

  In order to understand the first embodiment, first, the structure of the magnetoresistive element 10 will be briefly described.

  The magnetoresistive element 10 includes a substrate 12, a buffer layer 14, and a ferromagnetic layer 16.

  As a material of the substrate 12, glass, Si, Si oxide, Al oxide, AlTiC, or the like can be used.

  The buffer layer 14 has a resistance 10 times or more that of the ferromagnetic layer 16. The buffer layer 14 is preferably insulating. As a specific material of the buffer layer 14, for example, an oxide such as Si, Al, Zr, Hf, Mg, Ti, or the like can be used. The buffer layer 14 preferably has an effect of increasing the crystallinity of the ferromagnetic material constituting the ferromagnetic layer 16 in addition to the insulating property.

As the material of the ferromagnetic layer _{16, Co, Fe, Ni,} CoFe, NiFe, CoFeNi, CrO 2, Fe 3 O 4, CoFeB, CoNi, CoMnAl, NiMnSb, as _{Co 2} Cr 0.6 _{Fe 0.4} Al A material consisting essentially of Co, Cr, Fe and Al, a material consisting essentially of Co, Cr and Al such as Co ₂ Cr _0.6 Al, a material consisting essentially of Co, Mn and Co ₂ MnAl A material consisting of Al, a material consisting essentially of Co, Fe and Al, such as Co ₂ FeAl, a material consisting essentially of Co, Mn and Ge, such as Co ₂ MnGe, and a material substantially consisting of Co ₂ MnSi. A material made of Co, Mn, and Si can be used.

  As shown in FIG. 2, the ferromagnetic layer 16 has a straight portion 18 on the outer periphery and a V-shaped notch portion 20 arranged so that the apex faces the straight portion 18 when viewed from the thickness direction. ing.

  The ferromagnetic layer 16 includes a first ferromagnetic portion 22, a nanocontact portion 24, and a second ferromagnetic portion 26, and the nanocontact portion 24 is between the straight portion 18 and the V-shaped notch portion 20. It is formed in the part. FIG. 1 is a cross section of the nanocontact portion 24 cut in the thickness direction along the direction in which the linear portion 18 and the V-shaped notch portion 20 face each other.

  The first ferromagnetic portion 22 has a shape that becomes narrower toward the nanocontact portion 24, and functions as a free layer whose magnetization direction changes according to the reproducing magnetic field of the magnetic recording medium. The direction of the easy axis of magnetization of the first ferromagnetic portion 22 is preferably regulated to be perpendicular to the direction of the reproducing magnetic field and perpendicular to the rotation axis of the reproducing magnetic field. By providing a permanent magnet layer or an in-stack bias layer adjacent to the first ferromagnetic part 22, the direction of the easy axis of magnetization of the first ferromagnetic part 22 can be regulated.

  The width of the nanocontact portion 24 (in the direction in which the straight portion 18 and the apex of the V-shaped notch 20 face each other) is preferably 1 to 100 nm, and more preferably 1 to 20 nm or less. The length of the nanocontact portion 24 (in the direction of the gap between the first ferromagnetic portion 22 and the second ferromagnetic portion 26) is also preferably 1 to 100 nm. The thickness of the ferromagnetic layer 16 including the nanocontact portion 24 is preferably 0.1 to 50 nm.

  The second ferromagnetic portion 26 has a shape that becomes narrower toward the nanocontact portion 24 like the first ferromagnetic portion 22, and the magnetization direction is fixed in a direction parallel to the direction of the reproducing magnetic field of the magnetic recording medium. , Function as a pinned layer. It is possible to fix the magnetization direction of the second ferromagnetic portion 26 by providing a permanent magnet layer or an in-stack bias layer adjacent to the second ferromagnetic portion 26 or by providing magnetic anisotropy in shape. it can.

  Next, a method for manufacturing the magnetoresistive element 10 will be described along the flowchart of FIG.

  First, as shown in FIG. 4, the buffer layer 14 is formed on the substrate 12 by sputtering or the like (S102). As shown in FIG. 5, the substrate 12 is provided with reference points 12A and 12B for exposure. FIG. 5 schematically shows the reference points 12A and 12B, and the size and arrangement of the reference points 12A and 12B are not limited to those shown in FIG.

  Next, as shown in FIG. 6, the ferromagnetic layer 16 is formed on the buffer layer 14 by sputtering or the like (S104).

  Next, the V-shaped notch 20 is formed in the ferromagnetic layer 16 (S106).

  Specifically, first, as shown in FIG. 7, the first resist layer 28 is formed on the ferromagnetic layer 16 by spin coating or the like (S106A). The first resist layer 28 may be a positive type or a negative type.

  Next, as shown in FIG. 8, by irradiating an electron beam or the like with reference points 12A and 12B of the substrate 12 as a reference, at least a part of the boundary 30 between the exposed part and the non-exposed part (V-shaped notch). The first resist layer 28 is exposed with a first exposure pattern having a V-shape 30A (corresponding to the portion 20) (S106B). When the first resist layer 28 is a positive type, the side opposite to the side from which the vertex of the V-shaped 30A protrudes at the boundary 30 is exposed. When the first resist layer 28 is negative, the side where the apex of the V-shaped 30A at the boundary 30 protrudes is exposed.

  Next, as shown in FIG. 9, the portion of the first resist layer 28 opposite to the side where the apex of the V-shaped 30A protrudes from the boundary 30 is removed by development (S106C).

  Next, as shown in FIGS. 10 and 11, the portion of the ferromagnetic layer 16 exposed from the first resist layer 28 is removed by ion beam etching or the like (S106D). As a result, a V-shaped notch 20 corresponding to the V-shaped 30 </ b> A is formed in the ferromagnetic layer 16. The buffer layer 14 may be removed together with the ferromagnetic layer 16.

  Next, as shown in FIG. 12, the first resist layer 28 remaining on the ferromagnetic layer 16 is removed by reactive ion beam etching or the like using oxygen as a reactive gas (S106E). The first resist layer 28 remaining on the ferromagnetic layer 16 may be removed with a solvent or the like.

  Next, the linear part 18 is formed in the ferromagnetic layer 16 (S108).

  Specifically, first, as shown in FIG. 13, the second resist layer 34 is formed on the ferromagnetic layer 16 and the buffer layer 14 (or the substrate 12) exposed from the ferromagnetic layer 16 by spin coating or the like. (S108A). The second resist layer 34 may be a positive type or a negative type.

  Next, as shown in FIG. 14, an electron beam or the like is irradiated with reference points 12A and 12B of the substrate 12 as a reference, and at least a part of the boundary 36 between the exposed portion and the non-exposed portion is V-shaped in the ferromagnetic layer 16. The second resist layer 34 is exposed with a second exposure pattern having a linear shape 36A facing the apex of the notch 20 (S108B). At this time, an error between the design position and posture of the V-shaped notch 20 relative to the reference points 12A and 12B of the substrate 12 and the actual position and posture of the V-shaped notch 20 is corrected, and the second exposure pattern of the second exposure pattern is corrected. Determine the exposure position. When the second resist layer 34 is a positive type, the side opposite to the V-shaped notch 20 at the boundary 36 is exposed. When the second resist layer 34 is negative, the V-shaped notch 20 side at the boundary 36 is exposed.

  Next, as shown in FIG. 15, the portion of the second resist layer 34 opposite to the V-shaped notch 20 is removed by development (S108C).

  Next, as shown in FIGS. 16 and 17, the portion of the ferromagnetic layer 16 exposed from the second resist layer 34 is removed by ion beam etching or the like (S108D). The buffer layer 14 may be removed together with the ferromagnetic layer 16. As a result, a linear portion 18 corresponding to the linear shape 36 </ b> A is formed in the ferromagnetic layer 16.

  Next, the second resist layer 34 remaining on the ferromagnetic layer 16 is removed by reactive ion beam etching using oxygen as a reactive gas (S108E). The second resist layer 34 remaining on the ferromagnetic layer 16 may be removed with a solvent or the like. Thereby, the magnetoresistive element 10 shown in FIGS. 1 and 2 is completed.

  Thus, since the straight portion 18 and the V-shaped notch portion 20 are formed in separate steps, the first resist layer 28 for forming the straight portion 18 and the first resist layer 28 for forming the V-shaped notch portion 20 are formed. The two resist layers 34 are not processed into a minute size of about 1 to 50 nm, and the linear portion 18 and the V-shaped notch portion 20 are formed, and the nanocontact portion 24 having a width of about 1 to 50 nm therebetween. Can be formed.

  Further, since the nanocontact portion 24 is formed between the straight portion 18 and the V-shaped notch portion 20 whose apex faces the straight portion 18, even if the second exposure pattern is shifted and exposed, the straight portion The deviation in the direction perpendicular to the gap between the V-shaped notch portion 18 and the V-shaped notch portion 20 does not become a deviation in the width of the nanocontact portion 24. Therefore, as compared with the case where the nanocontact portion is formed between the two V-shaped notches, the variation in the width of the nanocontact portion 24 due to the exposure deviation of the second exposure pattern is suppressed, and the yield is high.

  Next, a second embodiment of the present invention will be described.

  The second embodiment is different from the first embodiment in the first resist layer exposure step (S106B) of the V-shaped notch formation step (S106) and the exposed portion and the non-exposure as shown in FIG. Direction having a contour corresponding to the shape of the boundary 30 with the portion, the portion corresponding to the apex of the V-shaped 30A is substantially rectangular, and the direction perpendicular to the direction in which the apex protrudes from the portion near the apex of the V-shaped 30A The exposure is performed using a mask 50 having a large gap.

  Thus, exposure can be performed efficiently by using the mask 50.

  When an acute angle shape such as the vicinity of the vertex of the V shape is to be exposed with a mask, the acute angle portion may not be exposed due to the optical proximity effect, and the target V shape 30A as shown in FIG. As shown in FIG. 20, the first resist layer 28 is exposed with a round exposure pattern in which the portion corresponding to the vertex of the V-shaped 30A is rounded. May end up. As a result, the width of the nanocontact portion becomes larger than the design value, and the length (in the direction of the gap between the first ferromagnetic portion and the second ferromagnetic portion) may become excessively long.

  On the other hand, the mask 50 has a substantially rectangular portion corresponding to the vertex of the V-shaped 30A, and a gap in a direction perpendicular to the direction in which the vertex protrudes is larger than a portion near the vertex of the V-shaped. The resist layer 28 is exposed in a shape close to the target V-shape 30A as shown in FIG. Therefore, the width of the nanocontact portion and the length (in the direction of the gap between the first ferromagnetic portion and the second ferromagnetic portion) can be made closer to the design value.

  In the first and second embodiments, the straight portion 18 is formed after the V-shaped cutout portion 20 is formed. However, after the straight portion 18 is formed, the V-shaped cutout portion 20 is formed. May be.

  In the first and second embodiments, the step of providing a permanent magnet layer or an in-stack bias layer adjacent to the first ferromagnetic portion 22 and the second ferromagnetic portion 26 is omitted. Similar to the formation and processing of the ferromagnetic layer 16 described above, these layers can be formed in a desired shape by using a film forming method such as sputtering and a processing method such as lithography.

  The present invention can be used for manufacturing a magnetoresistive element having a nanocontact portion.

Sectional drawing which shows typically the structure of the magnetoresistive element which concerns on 1st Embodiment of this invention. Plan view A flowchart showing an outline of a method of manufacturing the magnetoresistive element Sectional drawing which shows typically the state in which the buffer layer was formed on the board | substrate in the manufacturing process of the same magnetoresistive element Plan view of the board Sectional drawing which shows typically the state in which the ferromagnetic layer was formed on the buffer layer Sectional drawing which shows typically the state in which the 1st resist layer was formed on the ferromagnetic layer The top view which shows typically the 1st exposure pattern of the 1st resist layer Sectional drawing which shows the state by which the same 1st resist layer was developed Sectional drawing which shows typically the state by which the said ferromagnetic layer was etched and the V-shaped notch part was formed Plan view Sectional drawing which shows the state from which the 1st remaining resist layer was removed typically Sectional drawing which shows typically the state in which the 2nd resist layer was formed on the said ferromagnetic layer The top view which shows typically the 2nd exposure pattern of the 2nd resist layer Sectional drawing which shows the state by which the 2nd resist layer was developed typically Sectional drawing which shows typically the state by which the said ferromagnetic layer was etched and the linear part was formed Plan view The top view which shows typically the structure of the mask for exposure which concerns on 2nd Embodiment of this invention The top view which shows typically the structure of the mask for exposure which concerns on a comparative example The top view which shows typically the exposure pattern by the mask for exposure which concerns on the comparative example The top view which shows typically the exposure pattern by the mask for exposure which concerns on the said 2nd Embodiment A plan view schematically showing an ideal arrangement of two V-shaped notches A plan view schematically showing an example of improper arrangement of two V-shaped notches

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Magnetoresistive element 12 ... Board | substrate 14 ... Buffer layer 16 ... Ferromagnetic layer 18 ... Linear part 20 ... V-shaped notch part 22 ... 1st ferromagnetic part 24 ... Nanocontact part 26 ... 2nd ferromagnetic part 28 ... 1st 1 resist layer 30, 36 ... boundary 30A ... V-shaped 34 ... second resist layer 36A ... linear shape 50, 200 ... mask S102 ... buffer layer forming step S104 ... ferromagnetic layer forming step S106 ... V-shaped notch forming step S106A: First resist layer forming step S106B: First resist layer exposing step S106C: First resist layer developing step S106D: Ferromagnetic layer etching step S106E: First resist layer removing step S108: Linear portion forming step S108A: Second resist Layer formation step S108B ... second resist layer exposure step S108C ... second resist layer development step S108D Ferromagnetic layer etching step S108E ... second resist layer removing step

Claims (4)

  A first resist layer is formed on the ferromagnetic layer, and the first resist layer is exposed and developed with a first exposure pattern in which at least a part of the boundary between the exposed portion and the non-exposed portion is V-shaped, and developed. Etching a layer to form a V-shaped notch corresponding to the V-shape in the ferromagnetic layer, and forming a second resist layer on the ferromagnetic layer and exposing The second resist layer is exposed and developed with a second exposure pattern having a linear shape arranged so that at least a part of the boundary between the portion and the non-exposed portion faces the apex of the V-shaped notch, and the strong A method of manufacturing a magnetoresistive element, comprising: forming a linear portion corresponding to the linear shape in the ferromagnetic layer by etching the magnetic layer.   A first resist layer is formed on the ferromagnetic layer, and the first resist layer is exposed and developed with a first exposure pattern in which at least a part of a boundary between the exposed portion and the non-exposed portion is linear, and the ferromagnetic layer is developed. Forming a straight line portion corresponding to the straight line shape in the ferromagnetic layer by etching, and forming a second resist layer on the ferromagnetic layer to form a boundary between the exposed portion and the unexposed portion. Etching the ferromagnetic layer by exposing and developing the second resist layer with a second exposure pattern that is V-shaped and arranged such that at least a portion of the ferromagnetic layer faces the linear portion of the ferromagnetic layer. And a V-shaped notch forming step of forming a V-shaped notch corresponding to the V-shape in the ferromagnetic layer. In claim 1 or 2,
The method of manufacturing a magnetoresistive element, wherein the ferromagnetic layer is processed so that a distance between a vertex of the V-shaped notch and the linear portion is 1 to 50 nm. In any one of Claims 1 thru | or 3,
In the V-shaped notch forming step, the V-shaped portion has a contour corresponding to the shape of the boundary between the exposed portion and the non-exposed portion, and the portion corresponding to the vertex of the V-shaped is substantially rectangular. A method of manufacturing a magnetoresistive element, wherein exposure is performed using a mask having a gap in a direction perpendicular to a direction in which the vertex protrudes larger than a portion in the vicinity of the vertex.

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