JP3979990B2 - Method for forming thin film pattern and method for forming magnetoresistive element - Google Patents

Description

The present invention relates to methods for forming and magnetoresistive element thin film pattern had use a mask pattern having a suitable bridge structure to form a fine thin film pattern on a substrate.

  Conventionally, various thin film patterns are frequently used in electronic and magnetic devices such as thin film magnetic heads and semiconductor devices formed by using a thin film formation process. For example, a magnetoresistive (MR) element in which a magnetic thin film or the like is laminated is used in a thin film magnetic head, and a wiring pattern made of a conductive thin film is used in a semiconductor device.

  As a method of forming these thin film patterns, there is a lift-off method using a resist pattern as a mask. In this method, first, a resist pattern having a desired pattern shape is formed on a substrate by photolithography or the like. Next, after forming an undercut in the resist pattern, a thin film is formed so as to cover the whole, and the resist pattern is lifted off to form a thin film pattern. This lift-off method is disclosed in Patent Document 1, for example.

  However, in the thin film pattern forming method using the lift-off method as described above, the width and height of the undercut portion cannot be sufficiently secured as the thin film pattern is miniaturized. It has been difficult to obtain high accuracy. For this reason, a method has been devised in which a bridge-type mask pattern having a shape in which both end portions in the longitudinal direction are supported by a support portion and the central portion is suspended in the air is formed, and a thin film pattern having a minute width is formed ( For example, see Patent Documents 2 to 4.)

12 to 18 show an example of an MR element forming method to which a conventional thin film pattern forming method using a bridge type mask pattern is applied. First, as shown in FIG. 12, a substrate 101 is prepared in which a predetermined lower shield layer, lower gap layer, and the like are formed on a base made of, for example, AlTiC (Al ₂ O ₃ .TiC). Next, the MR film 114Z, the lower resist layer 102Z, and the upper resist layer 103Z are sequentially formed on the substrate 101 over the entire surface. Further, as shown in FIG. 13, the lower and upper resist layers 102Z and 103Z are selectively exposed through a photomask 106 to form latent images. Thereafter, development is performed by dissolving and removing the exposed portion using an alkaline aqueous solution or the like, and as shown in FIG. 14, a two-layer resist pattern 105Z comprising a lower resist pattern 102 and an upper resist pattern 103 having a predetermined width W is formed. Form. Further, by dissolving and removing only the lower resist pattern 102 of the two-layer resist pattern 105Z, and washing and drying, as shown in FIG. 15, a gap portion 107 is formed between the upper resist pattern 103 and the MR film 114Z. Form. Thereby, a bridge structure is formed, and the bridge-type mask pattern 105 is completed. Next, as shown in FIG. 16, the MR film 114Z is etched using the bridge type mask pattern 105 (upper resist pattern 103) as a mask, thereby forming an MR film pattern 114 having a predetermined shape. Further, as shown in FIG. 17, the magnetic film 115Z and the conductive film 116Z are sequentially formed over the whole, and finally, the upper resist pattern 103 covered with the magnetic film 115Z and the conductive film 116Z is removed. As shown in FIG. 18, the magnetic control films 115A and 115B and the conductive lead layers 116A and 116B are formed, and the MR element 110 is completed. According to such a method, the height and width of the gap 107 that functions as an undercut portion by the lift-off method can be adjusted with high accuracy, and a finer width without occurrence of burrs or the like. Thus, it is possible to form a thin film pattern.
Japanese Patent Publication No. 7-6058 JP 2003-17785 A JP 2002-214799 A JP 2001-28110 A

  However, even when the bridge-type mask pattern described above is used, the following problems have arisen as the thin film pattern is narrowed along with the miniaturization of the electronic / magnetic device. That is, the bridge portion 103B of the upper resist pattern 103 that should originally extend on a straight line hangs down with bending (curvature) as shown in FIG. 19, for example, and comes into contact with the upper surface of the MR film pattern 114. It is a problem. FIG. 19 is an example of a cross-sectional configuration viewed from a direction orthogonal to FIG. When the bending of the bridge portion 103B as shown in FIG. 19 occurs, the bridge portion 103B may be broken during the development and may be lost. This is thought to be because the bridge portion 103B has an extremely narrow width, resulting in a decrease in rigidity and the inability to withstand its own weight. Even if no breakage or loss occurs, it is difficult to form a thin film pattern with high accuracy due to the deformation of the bridge portion 103B. Therefore, improvement is desired.

The present invention has been made in view of such problems, the first object, the method of forming the thin film pattern using a suitable mask pattern for forming a thin film pattern with higher precision with very small dimensions It is to provide. Furthermore, the second object of the present invention is to provide a method for forming a magnetoresistive effect element using the method for forming a thin film pattern by the mask pattern as described above.

The thin film pattern forming method according to the present invention includes a step of sequentially laminating a lower resist layer and an upper resist layer on a thin film to be processed, and selectively developing the lower resist layer and the upper resist layer after exposure. Forming a two-layer resist pattern including the first and second regions and a third region connecting the first and second regions, and covering at least part of the upper resist layer in the third region; A step of forming a reinforcing layer, a step of forming a mask pattern having a bridge structure by removing the lower resist layer in the third region, and a step of patterning a thin film using the mask pattern It is a thing.

In the method of forming a thin film pattern according to the present invention, since each of the above steps is included, the rigidity of the portion forming the bridge structure in the mask pattern is improved, the bending of the portion forming the bridge structure does not occur, and the thin film is high. Etched with precision.

In the method for forming a thin film pattern according to the present invention, the reinforcing layer may be formed using tantalum (Ta). In that case, it is desirable to form the reinforcing layer so as to have a thickness of 5 nm to 50 nm.

In the method for forming a thin film pattern according to the present invention, in the third region, the width along the direction orthogonal to the direction connecting the first region and the second region is smaller in the lower resist layer than in the upper resist layer. It is desirable to form a two-layer resist pattern so that In this case, for example, the lower resist layer is formed using a material different from that of the upper resist layer, and the developer is formed by using a developer having a higher dissolution rate in the lower resist layer than in the upper resist layer.

  A method for forming a magnetoresistive effect element according to the present invention includes a step of forming a magnetoresistive effect film, a step of sequentially laminating a lower resist layer and an upper resist layer on the magnetoresistive effect film, and the lower resist layer and the upper resist. Forming a two-layer resist pattern including first and second regions and a third region connecting between the first and second regions by selectively exposing and developing the layer; Forming a reinforcing layer so as to cover at least a part of the upper resist layer in the region, forming a mask pattern having a bridge structure by removing the lower resist layer in the third region, and the mask pattern Forming a magnetoresistive film pattern by selectively removing the magnetoresistive film using

  In the method of forming a magnetoresistive effect element according to the present invention, since each of the above steps is included, the rigidity of the portion forming the bridge structure in the mask pattern is improved, the deflection of the portion forming the bridge structure is not generated, and the magnetic The resistance effect film is etched with high accuracy.

  In the method of forming a magnetoresistive effect element according to the present invention, a step of forming a thin film including at least a ferromagnetic film so as to cover the mask pattern and the region from which the magnetoresistive effect film has been removed, and a mask covered with the thin film A step of forming a pair of thin film patterns including a magnetic domain control layer on both sides of the magnetoresistive film pattern by lifting off the pattern may be included. In that case, the step of forming a thin film may include the step of forming a conductive film on the ferromagnetic film, and the pair of thin film patterns may each include a conductive lead layer.

  According to the method for forming a thin film pattern according to the present invention, a step of sequentially laminating a lower resist layer and an upper resist layer on a thin film to be processed, and selectively developing and then developing the lower resist layer and the upper resist layer Forming a two-layer resist pattern including the first and second regions and the third region connecting the first and second regions, and covering at least a part of the upper resist layer in the third region; A step of forming a reinforcing layer, a step of forming a mask pattern having a bridge structure by removing the lower resist layer in the third region, and a step of patterning a thin film using the mask pattern As a result, a mask pattern having a high rigidity in the bridge structure and not easily deformed by its own weight is obtained. Magnetoresistive film pattern having a fine size formed with high precision by there can be obtained.

  According to the method of forming a magnetoresistive effect element according to the present invention, a step of forming a magnetoresistive effect film, a step of sequentially laminating a lower resist layer and an upper resist layer on the magnetoresistive effect film, Forming a two-layer resist pattern including first and second regions and a third region connecting between the first and second regions by selectively exposing and developing the upper resist layer; and Forming a reinforcing layer so as to cover at least a part of the upper resist layer in the third region, forming a mask pattern having a bridge structure by removing the lower resist layer in the third region, and the mask Forming a magnetoresistive film pattern by selectively removing the magnetoresistive film using the pattern. A mask pattern having a structure having high rigidity and being difficult to be deformed by its own weight or the like can be obtained. By using this, a magnetoresistive effect element including a magnetoresistive effect film pattern having a minute dimension formed with high accuracy can be obtained. Obtainable.

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

  First, a configuration of a thin film magnetic head including an MR element formed by a magnetoresistive effect (MR) element forming method according to an embodiment of the present invention will be described with reference to FIGS.

  FIG. 1 is an exploded perspective view showing the structure of a thin film magnetic head 10 formed on one side of a slider in a magnetic head device. 2 is a cross-sectional view showing the structure in the direction of the arrow along the line II-II shown in FIG. 1, and FIG. 3 is a cross-sectional view seen from the direction of the arrow III shown in FIG.

  As shown in FIGS. 1 and 2, the thin film magnetic head 10 is configured by integrally stacking a reproducing head portion 10 </ b> A and a recording head portion 10 </ b> B in order from the side closer to the substrate 100 of the slider. The reproducing head unit 10A is for reproducing magnetic information recorded on a magnetic recording medium (not shown), and one recording head unit 10B is for recording magnetic information on a recording track of the magnetic recording medium. belongs to.

  As shown in FIGS. 1 and 2, the reproducing head unit 10 </ b> A is, for example, on the base 100 on the side exposed to an air bearing surface (ABS) 100 </ b> F that faces the recording surface of the magnetic recording medium. The lower shield layer 11, the lower gap layer 12, the MR element 10C, the upper gap layer 20, and the upper shield layer 21 are stacked in this order.

The MR element 10C is formed on a magnetoresistive effect film (hereinafter referred to as MR film) pattern 14, a pair of magnetic domain control layers 15A and 15B extending on both sides thereof, and the magnetic domain control layers 15A and 15B. A pair of conductive lead layers 16A and 16B is included. As shown in FIG. 3, the MR film pattern 14 includes, for example, an underlayer 31, a fixed working layer (pinning layer) 32, a fixed layer (pinned layer) 33, a nonmagnetic layer 34, on the lower gap layer 12. It has a spin valve structure in which a magnetically sensitive layer (magnetic free layer) 35 and a protective layer 36 are sequentially laminated. The MR film pattern 14 functions as a sensor portion that reads information recorded on the magnetic recording medium. The pair of magnetic domain control layers 15A and 15B and the pair of conductive lead layers 16A and 16B are arranged so as to face each other with the MR film pattern 14 interposed therebetween in a direction (X direction) corresponding to the recording track width direction of the magnetic recording medium. Has been. The magnetic domain control layers 15A and 15B are made of a hard magnetic material including, for example, cobalt platinum alloy (CoPt) and the like, and are bulkized by aligning the magnetic domains of the magnetic sensing layer 35 included in the MR film pattern 14 into a single magnetic domain. It functions to suppress the generation of Hausen noise. The conductive lead layers 16A and 16B function as a current path for causing a sense current to flow through the MR film pattern 14, and are respectively connected to the electrodes EA and EB as shown in FIG.

  In the reproducing head portion 10A having such a configuration, the magnetization direction of the magnetically sensitive layer 35 of the MR film pattern 14 changes according to the signal magnetic field from the magnetic recording medium. This causes a relative change in the magnetization direction of the fixed layer 33 included in the MR film pattern 14. At this time, when a sense current is passed through the MR film pattern 14, a change in the magnetization direction appears as a change in the magnetoresistance. By utilizing this, a signal magnetic field is detected and magnetic information is reproduced.

  As shown in FIGS. 1 and 2, the recording head portion 10B includes an upper shield layer 21, a recording gap layer 41, a pole chip 42, a coil 43, a photoresist layer 44, a coupling portion 45, and an upper portion that also function as a lower magnetic pole. A magnetic pole 46 is provided. The recording head unit 10 </ b> B having such a configuration generates a magnetic flux inside a magnetic path including the upper shield layer 21 and the upper magnetic pole 46 due to the current flowing through the coil 43, and thereby near the recording gap layer 41. Information is recorded by magnetizing the magnetic recording medium by the generated signal magnetic field.

  Subsequently, a method of forming the MR element 10C according to the present embodiment will be described with reference to FIGS. Since the bridge-type mask pattern forming method and the thin film pattern forming method of the present invention are embodied by the MR element forming method described below, they will be described together.

  The MR element 10 </ b> C forming method of the present embodiment includes a pre-process for forming an MR film pattern 14 on a substrate, and a pair of magnetic domain control layers 15 </ b> A, so as to be adjacent to both end edges of the MR film pattern 14. And a subsequent step of forming a pair of thin film patterns composed of 15B and a pair of conductive lead layers 16A and 16B. The pre-process includes a step of forming an MR film to be the MR film pattern 14 on the substrate, a step of sequentially forming a lower resist layer and an upper resist layer on the MR film, and a step of forming the lower and upper resist layers. Forming a two-layer resist pattern including a first region and a second region and a third region connecting the first and second regions by performing development after selective exposure; Forming a reinforcing layer so as to cover at least a part of the upper resist layer in the third region, forming a mask pattern having a bridge structure by removing the lower resist layer in the third region, and the mask Forming the MR film pattern 14 by selectively removing the MR film using the pattern. On the other hand, in the subsequent process, the MR film pattern is formed by lifting off the mask pattern covered with the thin film and the process of forming a thin film including at least the ferromagnetic film so as to cover the mask pattern and the region where the MR film is removed. 14 to form a pair of thin film patterns including magnetic domain control layers 15A and 15B on both sides. The step of forming the thin film includes a step of forming a conductive film on the ferromagnetic film, and each of the pair of thin film patterns has a conductive lead layer. Details will be described below.

First, as shown in FIG. 4, an MR film 14 </ b> Z is formed on a substrate 1 in which a lower shield layer 11 and a lower gap layer 12 are sequentially formed on a base material such as AlTiC (Al ₂ O ₃ .TiC). It is formed over the entire surface. Specifically, by using a sputtering or the like, the base layer 31, the fixed working layer 32, by laminating the fixed layer 33, a nonmagnetic layer 34, the magnetic sensitive layer 35 and the protective layer 3 6 sequentially, for example, 50nm thickness The MR film 14Z is formed. Subsequently, the lower resist layer 2 and the upper resist layer 3 are sequentially stacked so as to cover the MR film 14Z by using, for example, a spin coating method. Here, for example, the lower resist layer 2 is formed using a resist material mainly composed of polymethylglutarimide (PMGI) so as to have a thickness of about 20 nm to 50 nm. After that, the upper resist layer 3 is formed to have a thickness of, for example, 100 nm to 350 nm using a positive resist material which is a material different from that of the lower resist layer 2.

  Next, the lower resist layer 2 and the upper resist layer 3 are subjected to a photolithography process to form a two-layer resist pattern 5Z. Specifically, first, the lower and upper resist layers 2 and 3 are selectively exposed through a photomask 6 as shown in FIG. 5A as shown in FIG. Form. In the photomask 6, the opening 6 </ b> K <b> 1 and the opening 6 </ b> K <b> 2 are formed with an interval of 6 W in order to form a third region 5 </ b> C described later. The width 6W is, for example, 0.05 μm to 0.40 μm (more preferably 0.18 to 0.24 μm). The openings 6K1 and 6K2 are rectangular and each have a width 6D and a length 6L. The width 6D is, for example, 1.0 μm to 20.0 μm, and the length 6L is, for example, 0.5 μm to 5.0 μm. However, when a reduction exposure machine such as a stepper is used, the above values are multiplied by (1 / reduction ratio). 5A is a plan view illustrating a planar configuration parallel to the film formation surface, and FIG. 5B is an enlarged cross-sectional view in the direction of arrows VB-VB in FIG. 5A. After selectively forming latent images on the lower and upper resist layers 2 and 3, for example, heat treatment is performed in an atmosphere of 120 ° C. for 90 seconds, and further, an exposed portion is dissolved and removed using a predetermined developer. Develop, wash with water and dry. By doing so, as shown in FIGS. 6A, 6B, and 6C, the first region 5A and the second region 5B are separated from each other between the first and second regions 5A and 5B. A two-layer resist pattern 5Z having a third region 5C to be connected is formed. The third region 5C corresponds to a portion to be a bridge structure 9 (to be described later) to be formed later.

  In this case, using a predetermined developer capable of dissolving the latent image portion 4 of the upper resist layer 3 and the lower resist layer 2, the development time is so moderate that the lower resist layer 2 in the third region 5C is not lost. By performing the development process, the undercut portion 13 as shown in FIG. 6B can be formed. In the direction orthogonal to the direction connecting the first region 5A and the second region 5B, the width W1 of the upper resist layer 3 of the third region 5C is, for example, about 50 nm to 200 nm (more preferably 50 nm to 100 nm). It is. On the other hand, the width W2 of the lower resist layer 2 is configured to be slightly narrower than the width W1, and the difference is an undercut portion 13. Note that FIG. 6A is a plan view illustrating a planar configuration parallel to the film formation surface. 6B is an enlarged cross-sectional view in the direction of arrow VIB-VIB in FIG. 6A, and FIG. 6C is an enlarged cross-sectional view in the direction of arrow VIC-VIC in FIG. FIG.

Next, as shown in FIG. 7, the reinforcing layer 8 is formed so as to cover at least the upper resist layer 3C in the third region 5C. Specifically, the reinforcing layer 8 is formed by sputtering or the like using tantalum (Ta) so as to have a thickness of 5 nm to 50 nm. In this case, since the undercut portion 13 is formed, the reinforcing layer 8 is not formed on the side wall of the lower resist layer 2C in the third region 5C. Examples of a material applicable for forming the reinforcing layer 8 include an insulating material such as aluminum oxide (Al ₂ O ₃ ) in addition to a metal such as tantalum. Further, the reinforcing layer 8 may cover only the upper surface of the upper resist layer 3C in the third region 5C.

  After forming the reinforcing layer 8, the lower resist layer 2C in the third region 5C is removed to form the gap 7 as shown in FIG. Here, for example, the lower resist layer 2C is dissolved and removed by the developer used in the step of forming the two-layer resist pattern 5Z. As a result, a bridge structure 9 including the gap 7 and the upper resist layer (bridge portion) 3C that is located above the gap 7 and is suspended in the air is formed, and the mask pattern 5 is completed. Further, as shown in FIG. 9, the mask pattern 5 is used as a mask, and the MR film 14Z is selectively used, for example, by dry etching such as ion milling or reactive ion etching (RIE). The MR film pattern 14 is formed by etching. At this time, since the reinforcing layer 8 covering the bridge portion 3C is etched, the thickness is reduced. In anticipation of this decrease, it is desirable that the reinforcing layer 8 covering the bridge portion 3C is formed thicker in advance than the other portions. Thus, all the operations in the previous process are completed.

  After that, as shown in FIG. 10, a ferromagnetic film 15Z and a conductive film 16Z are sequentially laminated so as to cover the lower gap layer 12 and the bridge type mask pattern 5 exposed by etching. Here, the ferromagnetic film 15Z and the conductive film 16Z are one specific example corresponding to the “thin film” in the present invention. Subsequently, the mask pattern 5 covered with the ferromagnetic film 15Z and the conductive film 16Z is removed by a lift-off operation. As described above, all the operations in the subsequent process are completed, and as shown in FIG. 11, the MR film pattern 14 and a pair of magnetic domain control layers disposed so as to face each other so as to be adjacent to both edge portions of the MR film pattern 14 An MR element 10C comprising 15A, 15B and a pair of conductive lead layers 16A, 16B is completed.

  Thus, according to the present embodiment, the step of forming the MR film 14Z, the step of sequentially laminating the lower resist layer 2 and the upper resist layer 3 on the MR film 14Z, the lower resist layer 2 and the upper portion A two-layer resist including first and second regions 5A and 5B and a third region 5C connecting the first and second regions 5A and 5B by selectively exposing and developing the resist layer 3 The bridge structure 9 is formed by forming the pattern 5Z, forming the reinforcing layer 8 so as to cover the upper resist layer 3C in the third region 5C, and removing the lower resist layer 2C in the third region 5C. And a step of forming the mask pattern 5 having the mask, the rigidity of the bridge portion 3C forming the bridge structure 9 is improved, and deformation such as bending is unlikely to occur. It is possible to obtain the turn 5. Furthermore, since the MR film 14Z is selectively removed using this mask pattern 5, the MR film pattern 14 is formed, so that the bridge portion 3C does not bend during etching and has a minute dimension. The MR film pattern 14 can be formed with high accuracy. In particular, in the present embodiment, a step of forming a thin film including the ferromagnetic film 15Z and the conductive film 16Z so as to cover the region from which the MR film 14Z has been removed, and the mask pattern 5 covered with the thin film are lifted off. Thus, the MR film pattern 14 includes a step of forming a pair of thin film patterns in which the pair of magnetic domain control layers 15A and 15B and the pair of conductive lead layers 16A and 16B are laminated on both sides of the MR film pattern 14. The pair of magnetic domain control layers 15A and 15B and the pair of conductive lead layers 16A and 16B can be arranged with high accuracy so as to be adjacently bonded to the substrate 14. As a result, the MR element 10C formed on the substrate 1 with high accuracy can be obtained.

  Next, specific examples in the above embodiment will be described.

  In this example, the mask pattern 5 was formed in the following manner based on the above formation method. Hereinafter, this will be described in detail with reference to FIGS.

First, as shown in FIG. 4, the substrate 1 in which the lower shield layer 11, the lower gap layer 12, and the MR film 14 </ b> Z are sequentially formed on a base such as AlTiC (Al ₂ O ₃ .TiC) is covered. The lower resist layer 2 was formed using a predetermined photoresist material by spin coating so as to have a thickness of about 50 nm. After that, the upper resist layer 3 was formed by spin coating so as to cover the lower resist layer 2 so as to have a thickness of 350 nm. For the upper resist layer 3, a photoresist material different from that of the lower resist layer 2 was used.

Next, as shown in FIGS. 5A and 5B, the lower and upper resist layers 2 and 3 were selectively exposed through a photomask 6 to form latent images. Here, exposure was performed by a KrF excimer stepper using a photomask 6 having a width 6W of 0.2 μm. As the exposure conditions, the numerical aperture NA is 0.6, the aperture (ratio of the numerical aperture NA of the illumination system and the NA of the lens) σ is 0.75, the exposure amount setting is 30 to 60 mJ / cm ² , and the best focus is obtained. I did it. After the exposure, heat treatment is performed for 90 seconds in an atmosphere of 120 ° C., and further, the exposed portion is formed by a paddle method (stirring for 30 seconds) using a tetramethylammonium hydroxide (TMAH) solution having a concentration of 1.79%. Development processing was carried out, followed by washing with water and drying. Thereafter, an ashing process using oxygen gas is performed for the purpose of removing scum remaining without being dissolved in the TMAH solution and making the third region 5C have a predetermined width corresponding to the track width. I did it. By doing so, as shown in FIGS. 6A, 6B, and 6C, a two-layer resist pattern 5Z having first to third regions 5A to 5C was obtained. The width W1 of the upper resist layer 3 in the third region was 80 nm.

  Next, as shown in FIG. 7, the reinforcing layer 8 was formed so as to cover the upper resist layer 3 in the third region 5C. Here, the reinforcing layer 8 was formed by sputtering so as to have a thickness of 5 nm to 50 nm using tantalum. Finally, as shown in FIG. 8, a TMAH solution having a concentration of 1.79% was used as a developing solution, and the lower resist layer 2 in the third region 5C was dissolved and removed to form the gap 7. By this operation, the bridge structure 9 including the bridge portion 3C and the gap portion 7 was formed, and the mask pattern 5 was completed.

  As described above, according to the present embodiment, it is found that the mask pattern 5 including the bridge structure 9 having sufficient rigidity can be formed without causing deformation that becomes an obstacle to the formation of the thin film pattern. It was.

  Although the present invention has been described with reference to the embodiments and examples, the present invention is not limited to the embodiments and examples, and various modifications can be made. For example, in the present embodiment and example, a positive photoresist material is used for forming the upper resist layer, but a negative photoresist material may be used. In the present embodiment, a bottom spin valve type MR element has been described as an example of the magnetoresistive effect element. However, the present invention is not limited to this. A top spin valve MR element or a tunnel junction MR (TMR: Tunneling Magnetoresistive) element may be used. In this embodiment, the case where a KrF excimer stepper is used as an exposure apparatus has been described. However, the present invention is not limited to this, and an ArF excimer stepper, i-line stepper, EUV exposure machine, EB exposure machine, or the like is used. Is also possible. In this case, it is desirable to use a photoresist material suitable for each of the above exposure apparatuses.

The bridge-type mask pattern of the present invention can be suitably used not only for the formation of magnetoresistive elements in thin film magnetic heads but also for the formation of various thin film patterns included in other electronic and magnetic devices such as semiconductor devices. .

It is a disassembled perspective view which shows the structure of the thin film magnetic head containing the magnetoresistive effect element formed by the formation method of the magnetoresistive effect element which concerns on one embodiment of this invention. It is sectional drawing which shows the structure of the arrow direction along the II-II line | wire of the thin film magnetic head shown in FIG. FIG. 3 is a cross-sectional view showing the structure of the thin film magnetic head shown in FIG. It is sectional drawing showing 1 process in the method of forming the magnetoresistive effect element shown in FIG. FIG. 5 is a cross-sectional view and a plan view illustrating one process following FIG. 4. FIG. 6 is a cross-sectional view illustrating a process following FIG. 5. FIG. 7 is a cross-sectional view illustrating a process following FIG. 6. FIG. 8 is a cross-sectional view illustrating a process following FIG. 7. FIG. 9 is a cross-sectional view and a plan view illustrating one process following FIG. 8. FIG. 10 is a cross-sectional view illustrating a process following FIG. 9. It is sectional drawing showing the 1 process following FIG. It is sectional drawing showing 1 process in the formation method of the magnetoresistive effect element as a comparative example. FIG. 13 is a cross-sectional view illustrating a process following FIG. 12. FIG. 14 is a cross-sectional view illustrating a process following FIG. 13. FIG. 15 is a cross-sectional view illustrating a process following FIG. 14. FIG. 16 is a cross-sectional view illustrating a process following FIG. 15. FIG. 17 is a cross-sectional view illustrating a process following FIG. 16. FIG. 18 is a cross-sectional view illustrating a process following FIG. 17. It is sectional drawing showing 1 process in the formation process of the thin film pattern using the mask pattern as a comparative example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Substrate, 2 ... Lower resist layer, 3 ... Upper resist layer, 3C ... Bridge part, 14 ... MR film pattern, 14Z ... MR film, 5 ... Mask pattern, 5A ... 1st area | region, 5B ... 2nd area | region 5C ... third region, 5Z ... two-layer resist pattern, 6 ... photomask, 7 ... gap, 8 ... reinforcing layer, 9 ... bridge structure, 10A ... reproducing head, 10B ... recording head, 10C ... magnetic Resistive effect (MR) element, 11 ... lower shield layer, 12 ... lower gap layer, 13 ... undercut portion, 14 ... MR film pattern, 15A, 15B ... magnetic domain control layer, 16A, 16B ... conductive lead layer, 15Z ... strong Magnetic film, 16Z ... conductive film, 20 ... upper gap layer, 21 ... upper shield layer, 100 ... substrate, 100F ... air bearing surface.

Claims (8)

A step of sequentially laminating a lower resist layer and an upper resist layer on a thin film to be processed;
A two-layer resist including a first region and a second region and a third region connecting the first and second regions by selectively exposing the lower resist layer and the upper resist layer and then developing them Forming a pattern;
Forming a reinforcing layer so as to cover at least part of the upper resist layer in the third region;
Removing a lower resist layer in the third region to form a mask pattern having a bridge structure;
And a step of patterning the thin film using the mask pattern. The method for forming a thin film pattern according to claim 1, wherein the reinforcing layer is formed using tantalum (Ta). The method for forming a thin film pattern according to claim 2, wherein the reinforcing layer is formed to have a thickness of 5 nm to 50 nm. In the third region, the width of the lower resist layer is smaller in width along the direction orthogonal to the direction connecting the first region and the second region than in the upper resist layer. The method for forming a thin film pattern according to claim 1, wherein the thin film pattern is formed. Forming the lower resist layer using a material different from the upper resist layer;
5. The method for forming a thin film pattern according to claim 4, wherein the two-layer resist pattern is formed by using a developer having a higher dissolution rate in the lower resist layer than in the upper resist layer. Forming a magnetoresistive film;
A step of sequentially laminating a lower resist layer and an upper resist layer on the magnetoresistive film;
A two-layer resist including a first region and a second region and a third region connecting the first and second regions by selectively exposing the lower resist layer and the upper resist layer and then developing them Forming a pattern;
Forming a reinforcing layer so as to cover at least part of the upper resist layer in the third region;
Removing a lower resist layer in the third region to form a mask pattern having a bridge structure;
Forming a magnetoresistive film pattern by selectively removing the magnetoresistive film using the mask pattern. A method of forming a magnetoresistive element, comprising: further,
Forming a thin film including at least a ferromagnetic film so as to cover the mask pattern and the region from which the magnetoresistive film has been removed;
The method of claim 6 , further comprising: forming a pair of thin film patterns including a magnetic domain control layer on both sides of the magnetoresistive film pattern by lifting off the mask pattern covered with the thin film. Method for forming magnetoresistive effect element. The magnetic film according to claim 7 , wherein forming the thin film includes forming a conductive film on the ferromagnetic film, and the pair of thin film patterns each include a conductive lead layer. Method for forming a resistance effect element.

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