JP2005232553A - Etching method in stacked film structural body, and wafer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an etching method in a stacked film structural body capable of efficiently etching a removal part in which a layer suited for dry etching is interposed into a space between layers suited for wet etching, and to provide a wafer used for the etching method. <P>SOLUTION: An etching removal part 85 in a wafer comprises: a second layer 77 suited for dry etching; a first layer 75 and a third layer 79 formed on the upper and lower parts and suited for wet etching. With an etchant passage 89 reaching to the first layer left, a cover resist 87 is arranged at a resist space 81, an etchant is acted on the first layer through the etchant passage, and the first layer, second layer and third layer are removed at a time. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an etching method in a laminated film structure and a wafer used in the etching method.

  Conventionally, in the manufacture of a magnetic head that performs recording and reproduction on a magnetic recording medium, etching has been performed to process the laminated film into a predetermined pattern.

  The procedure will be described with reference to FIGS. In the laminated film structure 1 shown in FIG. 14, a remaining portion 5 to be left after etching and an etching removal portion 7 provided around the remaining portion 5 are arranged on the upper surface of the substrate 3.

  The remaining portion 5 and the etching removal portion 7 are formed as a laminated structure including the first layer 11, the second layer 13, and the third layer 15 via the seed film 9 by a so-called frame plating method. The first layer 11 and the third layer 15 are made of NiFe that is preferably removed by wet etching, and the second layer 13 is made of Pt that is difficult to remove by wet etching.

  In the laminated film structure 1 as described above, when only the etching removal portion 7 is to be etched while leaving the remaining portion 5, first, as shown in FIG. 15, the gap between the remaining portion 5 and the etching removal portion 7 is first shown. The photoresist 17 is formed in the full space.

  Next, as shown in FIG. 16, the etching removal portion 7 not surrounded by the photoresist 17 is wet-etched, that is, the third layer 15 is removed.

  Subsequently, as shown in FIG. 17, the second layer 13 is removed by performing dry etching such as ion milling etching.

  Further, as shown in FIG. 18, the first layer 11 and the seed film 9 are removed by performing wet etching again.

  Finally, as shown in FIG. 19, by removing the photoresist 17 with a stripping solution or the like, the process of etching only the etching removal portion 7 while leaving the remaining portion 5 is completed.

  However, in such a conventional etching method, since the second layer 13 which is difficult to perform wet etching is interposed between the first layer 11 and the third layer 15, the wet etching and the dry etching are repeated for each layer. There was annoyance.

Further, for example, a technique disclosed in Japanese Patent Application Laid-Open No. H10-228561 is a technique for covering a portion desired to remain after etching with a photoresist. However, this disclosed technique is based on the premise that the portion to be removed by etching consists of a single layer that can be removed by wet etching.
JP-A-9-190918

  An object of the present invention is to provide an etching method in a laminated film structure capable of efficiently performing etching on a removed portion in which a layer suitable for dry etching is interposed between layers suitable for wet etching, and It is to provide a wafer used in the etching method.

  In order to solve the above-described problems, the present invention provides an etching method for a laminated film structure, wherein the laminated film structure is formed with a remaining portion left after etching and a resist space around the remaining portion. The etching removal portion includes an intermediate layer suitable for removal by dry etching, and an upper layer and a lower layer formed at least one layer above and below the intermediate layer and suitable for removal by wet etching, respectively. A cover resist forming step of disposing a cover resist in the resist space so as to define an etchant passage reaching at least the lower layer in the resist space, and causing the etchant to act on the lower layer through the etchant passage, Etching process to remove upper layer, intermediate layer and lower layer at once Including.

  Therefore, since the enchant is poured so as to directly reach the lower layer of the etching removal portion, the lower layer and the intermediate layer and the upper layer stacked thereon can be etched at a time. That is, the three-layer structure including the intermediate layer that is not suitable for wet etching can be collectively removed by one wet etching. Therefore, the number of steps in the etching process can be greatly reduced, and unnecessary portions can be easily removed by etching in a short time.

  Note that the layer suitable for removal by dry etching in the present invention is not practical because it requires a very long processing time if wet etching is performed, as well as a layer made of a material that cannot be wet etched. It also includes layers made of materials that mostly use dry etching. Further, the layer suitable for removal by wet etching refers to a layer made of a material that can be wet etched in a realistic processing time.

  The etchant passage may be defined by side surfaces of the upper layer, the intermediate layer, and the lower layer, and an outer surface of the cover resist. According to this, the etchant passage can be formed very easily simultaneously with the formation of the cover resist by a method such as photolithography when the cover resist is formed.

  The etching removal portion, the resist space, the cover resist, and the etchant passage may all be formed in an annular shape surrounding the remaining portion.

  The cover resist and the etchant passage preferably have a width of 1 μm or more within the width of the resist space. According to this, it is possible to prevent the enchant from penetrating and corroding the remaining portion during etching, and also to prevent etching from taking a long time due to insufficient penetration of the etchant.

  The remaining portion has the same upper layer, intermediate layer, and lower layer as the etching removal portion, and a pattern resist forming step of disposing a pattern resist for defining the remaining portion and the etching removal portion; and the pattern A plating step of forming the upper layer, the intermediate layer, and the lower layer by plating via a resist may be included. According to this, the remaining part and the etching removal part are constituted by a frame plating method.

  In the pattern resist forming step, a hole pattern resist for providing an etchant soaking hole is also disposed in the etching removal portion, and in the etching step, the etchant is soaked from the etchant soaking hole in addition to the etchant passage. It may be. According to this, by removing the enchant efficiently, the etching removal portion can be removed more reliably in a shorter time.

  The intermediate layer may be composed of a noble metal, a noble metal alloy, an amorphous alloy, or aluminum oxide. The upper layer and the lower layer may each be made of a magnetic material, and the intermediate layer may be made of a nonmagnetic material. According to this, the present invention can be applied to the manufacturing process of the thin film magnetic head.

  Another aspect of the present invention for solving the same problem is a wafer including a laminated film structure, wherein the laminated film structure includes a remaining portion left after etching, and a resist space around the remaining portion. An etching removal portion formed, and the etching removal portion includes an intermediate layer suitable for removal by dry etching, and an upper layer and a lower layer formed at least one layer above and below the intermediate layer and suitable for removal by wet etching, respectively. The remaining portion is covered with a cover resist provided in the resist space, and an etchant passage defined by the cover resist and reaching at least the lower layer of the etching removal portion is formed in the resist space. Has been.

  According to this, the enchant can be directly applied to the lower layer by pouring the enchant into the etchant passage to the wafer. That is, the three-layer structure including the intermediate layer that is not suitable for wet etching can be collectively removed by one wet etching. Therefore, the number of steps in the etching process can be greatly reduced, and unnecessary portions can be easily removed by etching in a short time.

  In addition to the etchant passage, the etch remover may include an etchant soaking hole. According to this, by removing the enchant efficiently, the etching removal portion can be removed more reliably in a shorter time.

  The cover resist and the etchant passage may have a width of 1 μm or more within the width of the resist space. According to this, it is possible to prevent the enchant from penetrating and corroding the remaining portion during etching, and also to prevent etching from taking a long time due to insufficient penetration of the etchant.

  The intermediate layer may be made of a noble metal, a noble metal alloy, an amorphous alloy, or aluminum oxide. In particular, each of the upper layer, the lower layer, and the intermediate layer may be a lower magnetic pole film, an upper shield film, and a nonmagnetic film interposed therebetween, which form a thin film magnetic head. According to this, the present invention can be applied to the manufacturing process of the thin film magnetic head.

  Other features of the present invention and the operational effects thereof will be described in more detail by embodiments with reference to the accompanying drawings.

  Hereinafter, an etching method in a laminated film structure according to the present invention will be described with reference to the accompanying drawings as an embodiment when applied to the manufacture of a magnetic thin film head. In the drawings, the same reference numerals indicate the same or corresponding parts.

  The etching method according to the first embodiment will be described with reference to FIGS.

  In the manufacture of the magnetic thin film head, as shown in FIG. 1, a wafer 37 in which a large number (n rows and m columns) of thin film magnetic head elements Q11 to Qnm are arranged in a lattice pattern on one surface 35 facing the bottom surface 33 of the substrate 31. Manufacturing. The thin film magnetic head elements Q11 to Qnm are usually formed on the wafer 37 so that the formation region thereof is a quadrangular shape.

The wafer 37 is made of, for example, a ceramic structure such as AlTiC (Al ₂ O ₃ · Tic), and the thin film magnetic head elements Q11 to Qnm are formed on the wafer 37 via an insulating film such as Al ₂ O ₃ . It is formed on one side.

  After the thin film magnetic head removes the arc portion (ear) generated outside the formation region of the thin film magnetic head elements Q11 to Qnm in the wafer 37 by cutting to obtain a rectangular wafer portion consisting only of the thin film magnetic head elements. From the rectangular wafer portion, a single row head piece assembly is taken out by cutting. Furthermore, the single-row head piece assembly is cut to obtain individual thin film magnetic heads.

  FIG. 2 shows the end of the thin film magnetic head on the medium facing surface side. The thin film magnetic head 41 has a lower shield film 43 made of a magnetic material, an insulating film 47 including a reading element 45, and an upper shield film 49 made of a magnetic material on a substrate 31. Further, a write element 53 is provided above the upper shield film 49 via a nonmagnetic film 51.

  The write element 53 has a lower magnetic pole film 55 provided on the upper surface of the nonmagnetic film 51, and an upper magnetic pole film 59 coupled to the lower magnetic pole film 55 via the coupling portion 57. A coil 61 is disposed between the lower magnetic pole film 55 and the upper magnetic pole film 59 so as to go around the coupling portion 57. A gap film 63 is disposed on the medium facing surface side between the lower magnetic pole film 55 and the upper magnetic pole film 59.

  Next, a process in which the etching method according to the present embodiment is applied to the above-described upper shield film 49, nonmagnetic film 51, and lower magnetic pole film 55 will be described. As shown in FIG. 3, a seed film 71, which is a base film for performing plating, is formed on the upper surface of the substrate 31 extremely thinly by a film forming method such as sputtering. Next, a pattern resist 73 for pattern formation of a target element portion is formed on the upper surface of the seed film 71 by a method such as photolithography.

  Next, a laminated film is formed on the upper surface of the seed film 71 by frame plating using the pattern resist 73. As shown in FIG. 3, a first layer 75 is formed on the upper surface of the seed film 71 by plating. The first layer 75 is a film that becomes the upper shield film 49 in the thin film magnetic head 41, and is made of a magnetic material. In the present embodiment, the first layer 75 is made of NiFe. The film thickness of the first layer 75 is set to 1.9 μm.

  Subsequently, a second layer 77 is formed on the upper surface of the first layer 75 by plating. The second layer 77 is a film that becomes the nonmagnetic film 51 in the thin film magnetic head 41, and is made of a nonmagnetic insulating material. In the present embodiment, the second layer 77 is made of Pt. The film thickness of the second layer 77 is set to 0.2 μm.

  Further, a third layer 79 is formed on the upper surface of the second layer 77 by plating. The third layer 79 is a film that becomes the lower magnetic pole film 55 in the thin film magnetic head 41, and is made of a magnetic material. In the present embodiment, the third layer 79 is made of FeCoNi. The film thickness of the third layer 79 is set to 2.8 μm.

  Thereafter, as shown in FIG. 4, the pattern resist 73 is removed using a stripping solution or the like. Further, the portion 71a of the seed film 71 exposed by removing the pattern resist 73 is removed by dry etching such as ion milling etching to obtain the state of FIG. A region where the pattern resist 73 and the exposed portion 71 a of the seed film 71 are removed constitutes a resist space 81.

  By such a process, a remaining portion 83 to be left after etching and an etching removal portion 85 formed around the remaining portion 83 via a resist space 81 are formed on the substrate 31.

  The remaining portion 83 and the etching removal portion 85 have a three-layer structure including a first layer 75, a second layer 77, and a third layer 79, except for the extremely thin seed film 71. That is, the second layer 77 is an intermediate layer suitable for removal by dry etching, and the third layer 79 and the first layer 75 are respectively formed above and below the intermediate layer and are suitable for removal by wet etching. It is.

  Etching is performed on the laminated film structure having the remaining portion 83 and the etching removal portion 85 as described above by the following process. As shown in FIG. 6, a cover resist 87 is arranged in the resist space 81 so as to cover and protect the remaining portion 83.

  As shown in FIGS. 6 and 7, in the present embodiment, the remaining portion 83 is a portion formed in a planar rectangular parallelepiped shape, and the resist space 81 and the etching removal portion 85 are around the remaining portion 83. It is provided in an annular shape. The resist space 81 is formed so as to cover the upper surface and the four side surfaces of the remaining portion 83. The resist space 81 is formed by a method such as photolithography. Note that FIG. 7 (the same applies to FIGS. 10 to 13 described later) is cut along a horizontal cross-section in consideration of the clarity of the drawing so that each part appears in the cross-section.

  Further, the cover resist 87 is not filled so as to completely fill the space between the remaining portion 83 and the etching removal portion 85 in the resist space 81. That is, the cover resist 87 is smaller in width than the pattern resist 73 at the time of frame plating, and covers the remaining portion 83 so that the outer peripheral surface is separated from the inner peripheral surface of the etching removal portion 85. With this covering mode, an annular region that is not filled with the cover resist 87 remains in the resist space 81. This annular region functions as an enchantment passage 89. The enchant passage 89 continuously extends in the height direction so as to reach the first layer 75 (further, the seed film 71 in the present embodiment) from the region above the etching removal portion 85.

  In the present embodiment, the width of the cover resist 87 (indicated by symbol X in FIG. 6) and the width of the etchant passage (indicated by symbol Y in FIG. 6) are the width of the resist space 81 (total of X + Y), respectively. In this range, 1 μm or more is secured. This is because if the width of the cover resist 87 is less than 1 μm, the enchant may soak into the remaining portion 83 during etching and cause corrosion. On the other hand, if the width of the etchant passage is less than 1 μm, the etchant does not soak into the etching removal portion 85 and the etching removal portion 85 may not be removed in a short time.

  In the present embodiment, the width of the resist space 81 is set to 10 μm. Therefore, although the upper limit of the width of the cover resist 87 and the width of the etchant passage is not specified, both are set to 9 μm or less. That is, if one width is selected in the range of 1 μm to 9 μm, the other width is inevitably determined in the range of 1 μm to 9 μm.

  Subsequently, at least an enchantment effective for the first layer 75 is supplied to the enchant passage 89, and the first layer 75, the second layer 77, and the third layer 79 are removed together as shown in FIG. .

  Here, since the second layer 77 is originally composed of Pt, wet etching cannot be performed with an enchantment effective for the first layer 75. Therefore, conventionally, it has been necessary to sequentially perform wet etching, dry etching, and wet etching in order from the upper layer, the third layer, the second layer, and the first layer.

  However, in this embodiment, since the enchantment is poured so as to directly reach the first layer 75 which is the lowermost layer of the three layers of the etching removal portion 85, the first layer 75 and the second layer stacked above the first layer 75 77 and the third layer 79 can be etched at once. That is, the three-layer structure including the intermediate layer that cannot be wet-etched can be collectively removed by one wet etching. Therefore, the number of steps in the etching process can be greatly reduced, and unnecessary portions can be easily removed by etching in a short time.

  Further, the enchant passage 89 that contributes to the realization of such an etching mode is not formed through a complicated or dedicated process, but is simply formed in the operation of forming the cover resist 87. There are no harmful effects.

  Further, the enchantment passage 89 is defined by the side surfaces of the first layer 75, the second layer 77, and the third layer 79 and the outer surface of the cover resist 87, and extends continuously in the height direction. It acts not only on the first layer 75 but also on the third layer 79 and the like almost simultaneously. Therefore, the removal of the etching removal portion 85 from the substrate 31 can be promoted more reliably.

  Finally, as shown in FIG. 9, the process of etching only the etching removal portion 85 leaving the remaining portion 83 is completed by removing the cover resist 87 with a stripping solution or the like.

  Next, an etching method according to the second embodiment of the present invention will be described with reference to FIGS. In the present embodiment, an enchant penetration hole is formed in the etching removal portion in the first embodiment. The constituent materials and dimensions of each part are the same as those in the first embodiment unless otherwise specified.

  FIG. 10 is a plan view showing a state in which the first layer 75, the second layer 77, and the third layer 79 are formed on the substrate 31 by frame plating as described in FIG. Therefore, the remaining portion 83 and the etching removal portion 185 formed therearound have a three-layer structure including the first layer 75, the second layer 77, and the third layer 79, respectively.

  In this embodiment, in the pattern resist forming step before frame plating, in addition to the formation of the pattern resist 73, a hole pattern resist 173 for providing an etchant soaking hole in the etching removal portion 185 is also formed.

  When the remaining portion 83 and the etching removal portion 185 are formed by plating through the pattern resist 73 and the hole pattern resist 173, the pattern resist 73 and the hole pattern resist 173 are removed using a stripping solution or the like. Further, the portion of the seed film exposed by removing the pattern resist 73 is removed by dry etching such as ion milling etching.

  FIG. 11 shows a state where dry etching of the exposed portion of the seed film is completed, that is, corresponds to the plane in the state of FIG. The etch remover 185 is provided with etchant soaking holes 191 formed by removing the hole pattern resist 173. In the present embodiment, the etchant soaking hole 191 and the hole pattern resist 173 are configured in a rectangular parallelepiped shape having a planar rectangle.

  Subsequently, as shown in FIG. 12, a cover resist 87 is disposed in the resist space 81 so as to cover and protect the remaining portion 83. The form of the cover resist 87 is the same as that of the first embodiment. Therefore, an annular enchant passage 89 is formed around the cover resist 87 in the resist space 81. Further, the cover resist 87 is provided only in the resist space 81, and no resist is disposed in the etchant soaking hole 191.

  When the arrangement of the cover resist 87 is completed, an enchantment effective for at least the first layer 75 is supplied to the enchant passage 89 and the etchant soaking hole 191. As a result, similarly to the first embodiment, the first layer 75, the second layer 77, and the third layer 79 constituting the etching removal unit 185 are removed together. At this time, as indicated by an arrow in FIG. 12, the enchant penetrates not only from the enchant passage 89 but also from the etchant soaking hole 191, so that it acts on the etching removal portion 185 efficiently, and is shorter. The etching removal portion 185 can be removed with time and reliability.

  Finally, as shown in FIG. 13, the process of etching only the etching removal portion 185 leaving the remaining portion 83 is completed by removing the cover resist 87 with a stripping solution or the like.

  As described above, according to the present embodiment, in addition to the advantages of the first embodiment, the etching removal portion can be reliably removed in a shorter time by efficiently infiltrating the enchantment.

  Next, based on the results of experiments conducted by the present applicant, the relationship between the width of the cover resist and the enchant passage, the presence or absence of etchant soaking holes, and the time until etching is completed will be described. The three layers constituting the etching removal portion include a first layer 75 made of NiFe having a thickness of 1.9 μm, a second layer 77 made of Pt having a thickness of 0.2 μm, and a thickness of 2.8 μm made of FeCoNi. A third layer 79 is used. The width of the resist space 81 is set to 10 μm. Further, for the etchant soaking hole 191, the short side and the long side of the rectangular plane are 34 μm and 90 μm, respectively, and the hole area seen in the plane is 7% of the area of the etching removal portion.

  When the time T (seconds) until the etching removal portion can be completely removed was examined under the above conditions, the results shown in the following table were obtained. The etching state was observed every minute. Also, the dimensions X and Y in the table indicate the widths of the cover resist and the enchantment passage as in FIG.

表の結果から分かるように、エッチャント染み込み用穴が無い態様のように、エッチャントの染み込みが良好ではない場合には、エンチャント通路の幅Ｙは、少なくとも１μｍ以上確保されていないと、除去部のエッチングができない恐れがある。一方、エッチャント染み込み用穴が有る態様のように、エッチャントの染み込みが良好である場合には、カバーレジストの幅Ｘは、少なくとも１μｍ以上確保されていないと、製品を構成する残存部までもがエッチングされる恐れがある。

As can be seen from the results of the table, when the etchant penetration is not good as in the case where there is no etchant penetration hole, if the width Y of the enchant passage is not secured at least 1 μm or more, etching of the removed portion is performed. There is a risk of not being able to. On the other hand, if the etchant penetration is good, as in the case with the etchant penetration hole, if the width X of the cover resist is not secured at least 1 μm or more, even the remaining part constituting the product is etched. There is a fear.

  Therefore, it is recognized that it is practically appropriate that the width of the cover resist 87 and the width of the etchant passage are each 1 μm or more within the range of the width of the resist space.

  Although the contents of the present invention have been specifically described with reference to the preferred embodiments, various modifications can be made by those skilled in the art based on the basic technical idea and teachings of the present invention. It is self-explanatory.

  For example, the configuration of the three-layer structure of the etching removal portion is not limited to the constituent material and film thickness as in the above embodiment. Therefore, both the first layer and the third layer may be made of the same material, and may be made of NiFe as an example.

  The constituent material of the second layer is not limited to Pt, and other platinum-based metals such as Ru, Rh, and Pd, and other noble metals such as Au may be used. Alternatively, an alloy or an amorphous alloy containing such a noble metal may be used, and aluminum oxide employed as an insulating film in a thin film magnetic head can also be used.

  The etching removal portion is not limited to a three-layer structure, and is formed with an intermediate layer suitable for removal by dry etching and at least one layer above and below the intermediate layer, and suitable for removal by wet etching. If it is a laminated film structure including an upper layer and a lower layer, it may be composed of four or more layers.

  Further, the remaining portion, the resist space, the cover resist, the enchant passage, the hole pattern resist, and the etchant soaking hole are not limited to a rectangular plane outline, and can be implemented with various modifications. Further, the resist space, the cover resist, and the enchant passage are not limited to an annular shape surrounding the entire periphery of the remaining portion.

  The above embodiment has been described as applied to the three layers of the upper shield film, the nonmagnetic film, and the lower magnetic pole film in the manufacture of the thin film magnetic head, but the present invention is not limited thereto. However, the present invention can be widely applied to etching in a laminated film structure other than the thin film magnetic head as well as application to other parts of the thin film magnetic head.

It is a perspective view which shows the wafer used for manufacture of a thin film magnetic head. FIG. 4 is a cross-sectional view showing an end portion on the medium facing surface side in a thin film magnetic head. It is a figure which shows 1 process of the process which concerns on embodiment of this invention. FIG. 4 is a diagram showing a step after the step shown in FIG. 3. It is a figure which shows the process after the process shown in FIG. FIG. 6 is a diagram showing a step after the step shown in FIG. 5. It is a figure which shows the state of FIG. 6 planarly. It is a figure which shows the process after the process shown in FIG. It is a figure which shows the process after the process shown in FIG. It is a figure which shows 1 process of the process which concerns on another embodiment of this invention, and shows the state corresponding to the process shown in FIG. 3 planarly. FIG. 11 is a diagram illustrating a step after the step illustrated in FIG. 10 and a plan view illustrating a state corresponding to the step illustrated in FIG. 5. FIG. 13 is a diagram illustrating a step subsequent to the step illustrated in FIG. 11 and a plan view illustrating a state corresponding to the step illustrated in FIG. 6. It is a figure which shows the process after the process shown in FIG. 12, and shows the state corresponding to the process shown in FIG. It is a figure which shows 1 process of the conventional etching process. It is a figure which shows the process after the process shown in FIG. FIG. 16 is a diagram showing a step after the step shown in FIG. 15. FIG. 17 is a diagram showing a step after the step shown in FIG. 16. It is a figure which shows the process after the process shown in FIG. It is a figure which shows the process after the process shown in FIG.

Explanation of symbols

31 Substrate 75 First layer (lower layer)
77 Second layer (intermediate layer)
79 3rd layer (upper layer)
81 Resist space 83 Remaining portion 85, 185 Etching removal portion 87 Cover resist 89 Enchantment passage 173 Hole pattern resist 191 Etchant penetration hole

Claims (13)

An etching method in a laminated film structure,
The laminated film structure includes a remaining portion that remains after etching, and an etching removal portion that is formed around the remaining portion via a resist space,
The etching removal unit includes an intermediate layer suitable for removal by dry etching, and an upper layer and a lower layer formed at least one layer above and below the intermediate layer and suitable for removal by wet etching, respectively.
A cover resist forming step of disposing a cover resist in the resist space so as to define an etchant passage reaching at least the lower layer in the resist space;
An etching step of causing an etchant to act on the lower layer through the etchant passage and removing the upper layer, the intermediate layer, and the lower layer at a time.
Etching method. An etching method in the laminated film structure according to claim 1,
The etching method, wherein the etchant passage is defined by side surfaces of the upper layer, intermediate layer, and lower layer and an outer surface of the cover resist. An etching method in the laminated film structure according to claim 1 or 2,
The etching method, wherein the etching removal portion, the resist space, the cover resist, and the etchant passage are all formed in an annular shape surrounding the remaining portion. An etching method in the laminated film structure according to any one of claims 1 to 3,
The width of the cover resist and the etchant passage is 1 μm or more in the range of the width of the resist space, respectively. An etching method in the laminated film structure according to any one of claims 1 to 4,
The remaining portion has the same upper layer, intermediate layer and lower layer as the etching removal portion,
A pattern resist forming step of arranging a pattern resist for defining the remaining portion and the etching removal portion;
A plating step of forming the upper layer, the intermediate layer and the lower layer by plating through the pattern resist,
Etching method. An etching method in the laminated film structure according to claim 5,
In the pattern resist forming step, a hole pattern resist for providing an etchant soaking hole in the etching removal portion is also arranged,
In the etching step, the etchant is infiltrated from the etchant infiltration hole in addition to the etchant passage.
Etching method. An etching method in the laminated film structure according to any one of claims 1 to 6,
The said intermediate | middle layer is an etching method comprised from a noble metal, a noble metal alloy, an amorphous alloy, or aluminum oxide. An etching method in the laminated film structure according to any one of claims 1 to 7,
The upper layer and the lower layer are each composed of a magnetic material,
The intermediate layer is made of a nonmagnetic material,
Etching method. A wafer including a laminated film structure,
The laminated film structure includes a remaining portion that remains after etching, and an etching removal portion that is formed around the remaining portion via a resist space,
The etching removal unit includes an intermediate layer suitable for removal by dry etching, and an upper layer and a lower layer formed at least one layer above and below the intermediate layer and suitable for removal by wet etching, respectively.
The remaining portion is covered with a cover resist provided in the resist space;
In the resist space, an etchant passage defined by the cover resist and reaching at least the lower layer of the etching removal portion is formed.
A wafer including a laminated film structure. A wafer comprising the laminated film structure according to claim 9,
A wafer having an etchant soak-in hole in the etching removal portion separately from the etchant passage. A wafer comprising the laminated film structure according to claim 9 or 10,
The width of the cover resist and the etchant passage is secured to 1 μm or more within the width of the resist space. A wafer comprising the laminated film structure according to any one of claims 9 to 11,
The intermediate layer is a wafer made of a noble metal, a noble metal alloy, an amorphous alloy, or aluminum oxide. A wafer comprising the laminated film structure according to any one of claims 9 to 12,
The upper layer, the lower layer, and the intermediate layer are a lower magnetic pole film, an upper shield film, and a nonmagnetic film interposed therebetween, respectively, constituting a thin film magnetic head.

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