Hall element, manufacturing method thereof, and semiconductor device

Abstract

To prevent the intrusion of moisture from the interface between an ohmic contact layer and a protective layer.SOLUTION: A Hall element 10 includes a substrate 11, a magnetosensitive layer 12 disposed on a top surface 11a of the substrate 11, a protective layer 13 covering the magnetosensitive layer 12 and having an opening 13a exposing a predetermined region of the magnetosensitive layer 12, an ohmic contact layer 14 electrically connected to the magnetosensitive layer 12 exposed from the opening 13a and having a portion thereof in contact with the protective layer 13 around the opening 13a, and a first metal layer 15 disposed on the ohmic contact layer 14 and having a portion thereof in contact with the protective layer 13 around the ohmic contact layer 14.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present disclosure relates to a Hall element, a manufacturing method thereof, and a semiconductor device. [Background technology]

[0002] Hall elements convert magnetic signals into electric signals for detection, and are used in a wide range of fields, such as current sensors and motor rotation angle detection sensors. As a conventional Hall element configuration, for example, Patent Document 1 discloses a Hall element in which the magnetosensitive layer is made of an n-type semiconductor in which the impurity Si (silicon) is added to GaAs (gallium arsenide). In this Hall element, the magnetosensitive layer is arranged on a substrate so as to form a cross shape in a plan view, electrodes are arranged and electrically connected on the surface of each end of the cross-shaped magnetosensitive layer, and the surface of the magnetosensitive layer where the electrodes are not arranged is covered with a protective layer such as SiN (silicon nitride). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2017-50394 A

[0004] [overview] When a Hall element is placed in a hot and humid environment, moisture can penetrate through the interface between the ohmic contact layer electrically connected to the end of the magnetosensitive layer of the Hall element and the protective layer covering the surface of the magnetosensitive layer, reaching the magnetosensitive layer and causing deterioration of the magnetosensitive layer.

[0005] The present disclosure has been proposed in view of the above-mentioned circumstances, and aims to provide a Hall element that prevents moisture from entering from the interface between an ohmic contact layer and a protective layer, a manufacturing method thereof, and a semiconductor device.

[0006] The Hall element of the present disclosure comprises a substrate, a magnetosensitive layer disposed on the top surface of the substrate, a protective layer covering the magnetosensitive layer and having an opening exposing a predetermined region of the magnetosensitive layer, an ohmic contact layer electrically connected to the magnetosensitive layer exposed from the opening and having a portion thereof in contact with the protective layer around the opening, and a metal layer disposed on the ohmic contact layer and having a portion thereof in contact with the protective layer around the ohmic contact layer. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a plan view of a Hall element. [Diagram 2] FIG. 2 is a cross-sectional view of the Hall element. [Diagram 3] FIG. 3 is a cross-sectional view of a main part of the Hall element. [Figure 4] FIG. 4 is an enlarged cross-sectional view of the Hall element. [Diagram 5] FIG. 5 is a process flow diagram of a method for manufacturing a Hall element. [Figure 6] FIG. 6 is a process flow diagram of the manufacturing method of the Hall element. [Figure 7] FIG. 7 is a process flow diagram of the manufacturing method of the Hall element. [Figure 8] FIG. 8 is a process flow diagram of a manufacturing method of a Hall element. [Figure 9] FIG. 9 is a process flow diagram of the manufacturing method of the Hall element. [Figure 10] FIG. 10 is a process flow diagram of the manufacturing method of the Hall element. [Figure 11] FIG. 11 is a process flow diagram of the manufacturing method of the Hall element. [Figure 12] FIG. 12 is a process flow diagram of the manufacturing method of the Hall element. [Figure 13] FIG. 13 is a process flow diagram of a method for manufacturing a Hall element. [Figure 14] FIG. 14 is a process flow diagram of a method for manufacturing a Hall element.

[0008] [Detailed Description] Hereinafter, embodiments of a Hall element, a manufacturing method thereof, and a semiconductor device will be described in detail with reference to the drawings. Fig. 1 is a plan view of a Hall element 10 according to the present embodiment. Fig. 2 is a cross-sectional view of the Hall element 10 taken along line II-II in Fig. 1.

[0009] In the Hall element 10, the magnetosensitive layer 12 is disposed on the top surface 11a of the substrate 11 having a substantially rectangular shape in plan view so as to form a cross shape in plan view extending in two diagonal directions of the substantially rectangular shape. A protective layer 13 is formed so as to cover the top surface 11a of the substrate 11 on which the magnetosensitive layer 12 is disposed, and an opening 13a is formed in the protective layer 13 so as to expose a predetermined region including an end of the cross-shaped magnetosensitive layer 12 and a part of the top surface 11a of the substrate 11 adjacent to the end.

[0010] The Hall element 10 is also provided with electrodes 17 arranged so as to cover the opening 13a of the protective layer 13 and electrically connected to the ends of the magnetosensitive layer 12. Between the bottom surface of the electrode 17 and the region exposed from the opening 13a of the protective layer 13, i.e., a predetermined region including the end of the magnetosensitive layer 12 and a part of the top surface 11a of the substrate 11 adjacent to the end, an ohmic contact layer 14 forming a eutectic with the magnetosensitive layer 12, a first metal layer 15 preventing ball-up of the ohmic contact layer 14, and a second metal layer 16 forming a base for plating are laminated in this order and interposed, electrically connecting the magnetosensitive layer 12 and the electrode 17.

[0011] 1, the electrodes 17 are composed of four electrodes, a first electrode 171 to a fourth electrode 174. Of these, for example, the first electrode 171 and the fourth electrode 174, which face each other in one diagonal direction, constitute an input terminal, and for example, the second electrode 172 and the fourth electrode 173, which face each other in the other diagonal direction, constitute an output terminal. In the magnetosensitive layer 12, a Lorentz force is applied to carriers moving along a path between a pair of input terminals, such as the first electrode 171 and the third electrode 173, in a direction perpendicular to the moving direction by the magnetic field penetrating the magnetosensitive layer 12, and an electromotive force according to the strength of the magnetic field is detected in output terminals, such as the second electrode 172 and the fourth electrode 174, which face each other in a direction substantially perpendicular to the moving direction.

[0012] In the Hall element 10, the substrate 11 is made of GaAs (gallium arsenide), a III-V group compound semiconductor. The magnetosensitive layer 12 is made of an n-type compound semiconductor of GaAs doped with at least one of Si (silicon) and Te (tellurium) as an impurity. The magnetosensitive layer 12 is doped with a low concentration of impurities to increase carrier mobility and ensure sensitivity in detecting magnetism.

[0013] The protective layer 13 is made of SiN (silicon nitride). The protective layer 13 covers the top surface 11a of the substrate 11 and the magnetosensitive layer 12 except for the region where the opening 13a is formed, and protects the top surface 11a of the substrate and the magnetosensitive layer 12. The four electrodes 17, from the first electrode 171 to the fourth electrode 174, are electrically connected to the four ends of the magnetosensitive layer 12, respectively, and provide the Hall element 10 with connection paths to the outside.

[0014] The ohmic contact layer 14 is made of an AuGeNi (gold germanium nickel) alloy, and forms a eutectic with the magnetosensitive layer 12, ensuring stable ohmic contact with the magnetosensitive layer 12. The first metal layer 15 is made of Ti (titanium), and prevents the alloy components constituting the first metal layer 15 from balling up into granular form, thereby preventing deterioration of electrical conductivity, etc. The second metal layer 16 is made of Au (gold), and forms a base layer for gold plating. The electrode 17 is made of gold plating formed using the second metal layer 16 as a base layer for plating, so as to cover the opening 13a of the protective layer 13.

[0015] 3 is a cross-sectional view of a main part of the Hall element 10, which corresponds to region III in the cross-sectional view of FIG. 2. The surface of the magnetosensitive layer 12 is covered by the protective layer 13, except for an opening 13a formed in the protective layer 13. The opening 13a of the protective layer 13 is formed in a region including the end of the magnetosensitive layer 12, and is covered by an electrode 17. Between the surface of the end of the magnetosensitive layer 12 and the bottom surface of the electrode 17, a laminate in which an ohmic contact layer 14, a first metal layer 15, and a second metal layer 16 are laminated in this order is interposed. This laminate extends from within the opening 13a in contact with the protective layer 13 formed on the top surface of the magnetosensitive layer 12, and is in contact with an island portion 20 in which the first metal layer 15 and the second metal layer 16 are laminated, which is formed on the surface of the protective layer 13 directly below the side surface of the electrode 17.

[0016] 4 is an enlarged cross-sectional view of the vicinity of the island portion 20 in the Hall element 10. On the surface of the protective layer 13, directly below the side surface of the electrode 17, the island portion 20 is formed by laminating a first metal layer 15 and a second metal layer 16. A part of the island portion 20, including its base, is located inside the side surface of the electrode 17, and the remaining part of the island portion 20 protrudes from the side surface of the electrode 17. An end face 20b of the island portion 20 protruding from the side surface of the electrode 17 has an eaves-like shape that protrudes forward as its height from the surface of the protective layer 13 increases.

[0017] The island portion 20 is formed inside the electrode 17 in contact with a main body in which the first metal layer 15 and the second metal layer 16 are laminated on the ohmic contact layer 14. More specifically, the base of the island portion 20 inside the side surface of the electrode 17 is formed to face and face with an end of the laminate of the ohmic contact layer 14, the first metal layer 15, and the second metal layer 16 formed on the surface of the protective layer 13. The end face 14a of the ohmic contact layer 14 facing the base of the island portion 20 has an eaves-like shape that protrudes forward as its height from the surface of the protective layer 13 increases. The gap formed by the eaves-like end face 14a of the ohmic contact layer 14, the end face 20a of the base of the island portion 20, and the surface of the protective layer 13 is filled with gold plating that constitutes the electrode 17, forming a metal filling portion 21.

[0018] In the Hall element 10, an island portion 20 is formed at the boundary between the surface of the protective layer 13 formed on the surface of the magnetosensitive layer 12 and the side surface of the electrode 17. The island portion 20 seals the interface between the ohmic contact layer 14 and the protective layer 13, and prevents moisture from entering through the interface between the ohmic contact layer 14 and the protective layer 13. Titanium constituting the first metal layer 15 of the island portion 20 has a property of having high adhesion to silicon nitride constituting the protective layer 13, so that the gap between the island portion 20 and the protective layer 13 can be reliably sealed.

[0019] Furthermore, a metal filling portion 21 made of gold plating is formed in the gap between the island portion 20 and the ohmic contact layer 14. The metal filling portion 21 is in contact with the interface between the ohmic contact layer 14 and the protective layer 13, and seals the interface between the ohmic contact layer 14 and the protective layer 13. Therefore, even if the island portion 20 is unable to prevent moisture from entering, the metal filling portion 21 can reliably prevent moisture from entering from the interface between the ohmic contact layer 14 and the protective layer 13.

[0020] In the Hall element 10, the substrate 11 and the magnetosensitive layer 12 are made of GaAs, which is a III-V group material, but the present invention is not limited to this. For example, other types of compound semiconductors such as InSb (indium antimonide) and InAs (indium arsenide) may be used.

[0021] Next, a method for manufacturing the Hall element 10 will be described with reference to the process flow diagrams of Figures 5 to 14. Figures 5 to 14, like Figure 3, show a main part of the Hall element 10 corresponding to region III shown in Figure 2.

[0022] As shown in Fig. 5, a magnetosensitive layer 12 made of an n-type compound semiconductor of GaAs doped with at least one of Si (silicon) and Te (tellurium) as an impurity is formed on a top surface 11a of a substrate 11 made of GaAs (gallium arsenide). As described above, the magnetosensitive layer 12 is formed to have a cross shape in a plan view extending in two diagonal directions of the top surface 11a of the substrate 11, which is substantially rectangular in a plan view. Next, a protective layer 13 made of SiN is formed to cover the top surface 11a of the substrate 11 on which the magnetosensitive layer 12 is arranged. An opening 13a is formed in the protective layer 13 so that a predetermined region including the end of the cross-shaped magnetosensitive layer 12 and a part of the top surface 11a of the substrate 11 adjacent to the end is exposed.

[0023] An ohmic contact layer 14 made of an AuGeNi (gold germanium nickel) alloy is formed on the top surface 11a of the substrate 11 on which the protective layer 13 is formed, so as to cover the protective layer 13. Furthermore, on the surface of the ohmic contact layer 14, a first mask 31 made of resin is formed in a predetermined pattern so as to cover predetermined regions such as the opening 13a formed in the protective layer 13 and its surroundings.

[0024] 6, the ohmic contact layer 14 having the first mask 31 formed on the surface thereof in FIG. 5 is etched by a first etching solution 32. Predetermined regions of the ohmic contact layer 14, such as the opening 13a formed in the protective layer 13 and its periphery, are covered by the first mask 31. Therefore, the ohmic contact layer 14 in the exposed region not covered by the first mask 31 is etched by the first etching solution 32 and removed.

[0025] The ohmic contact layer 14 covered by the first mask 31 at the end of the protective layer 13 is also etched away from the end of the first mask 31 to a predetermined depth by the first etching liquid 32 that has penetrated between the surface of the protective layer 13 and the first mask 31. Here, the protective layer 13 made of SiN has a higher affinity for the first etching liquid 32 than the first mask 31 made of resin, and the etching of the ohmic contact layer 14 progresses faster as it moves away from the first mask 31 and closer to the protective layer 13. For this reason, the end surface 14a of the ohmic contact layer 14 interposed between the protective layer 13 and the first mask 31 is formed into a ridge-like shape that protrudes forward as its height increases from the protective layer 13 toward the first mask 31.

[0026] 7, the first mask 31 is removed after etching the ohmic contact layer 14 in FIG. 6. The end of the protective layer 13 formed on the surface of the magnetosensitive layer 12 and the opening 13a of the protective layer 13 are covered with the ohmic contact layer 14. The end face 14a of the ohmic contact layer 14 covering the end of the protective layer 13 is formed in an eaves-like shape that protrudes forward as its height from the protective layer 13 increases.

[0027] 8, by heating in a heating furnace, a eutectic is formed between the magnetosensitive layer 12 and the ohmic contact layer 14 made of an AuGeNi alloy that contacts the magnetosensitive layer 12 at the opening 13a of the protective layer 13. Reference numeral 33 in the figure indicates a high-temperature atmosphere in the heating furnace.

[0028] As shown in Fig. 9, after forming a eutectic between the magnetosensitive layer 12 and the ohmic contact layer 14 in Fig. 8, a first metal layer 15 made of Ti for preventing ball-up of the ohmic contact layer 14 and a second metal layer 16 made of Au as a base layer for gold plating are laminated. Since the end of the protective layer 13 formed on the surface of the magnetosensitive layer 12 and the opening 13a of the protective layer 13 are covered by the ohmic contact layer 14, the first metal layer 15 and the second metal layer 16 are formed on the surface of the ohmic contact layer 14, and a laminate in which the ohmic contact layer 14, the first metal layer 15 and the second metal layer 16 are laminated in order is formed. In the area of ​​the protective layer 13 not covered by the ohmic contact layer 14 except for the end, the first metal layer 15 and the second metal layer 16 are directly laminated on the surface of the protective layer 13. Directly below the ridge-shaped end face 14a of the ohmic contact layer 14 formed at the end of the protective layer 13 and on the surface of the protective layer 13, a gap 19 with a triangular cross section is formed that contacts the end faces of the first metal layer 15 and the second metal layer 16 formed directly on the surface of the protective layer 13.

[0029] As shown in Figure 10, on the surface of the first metal layer 15 and the second metal layer 16 formed on the surface of the protective layer 13 in Figure 9, a second mask 34 made of resin is formed at a predetermined height so as to have a predetermined distance from the laminate consisting of the ohmic contact layer 14, the first metal layer 15 and the second metal layer 16 formed at the end of the protective layer 13.

[0030] As shown in Fig. 11, an electrode 17 is continuously formed by gold plating from the surface of the laminate of the ohmic contact layer 14, the first metal layer 15, and the second metal layer 16 covering the end of the protective layer 13 and the opening 13a of the protective layer 13 in Fig. 10 to the surface of the first metal layer 15 and the second metal layer 16 formed on the surface of the magnetosensitive layer 12 where the second mask 34 is not formed, so as to cover the second metal layer 16 forming the plating base layer. When the electrode 17 is continuously formed by gold plating, the gap 19 formed directly under the eaves-shaped end surface 14a of the ohmic contact layer 14 formed on the surface of the protective layer 13 is also filled by gold plating to form a metal filling portion 21. The electrode 17 shown in Fig. 11 forms the third electrode 173 and the second electrode 172 shown in Fig. 1.

[0031] In Fig. 12, after the electrode 17 is formed by gold plating in Fig. 11, the second mask 34 is removed. By removing the second mask 34, the laminate of the first metal layer 15 and the second metal layer 16 and the side surface of the electrode 17 that were covered by the second mask 34 are exposed.

[0032] 13, after removing the second mask 34 in FIG. 12, a third mask 35 made of resin is formed so as to cover a predetermined area of ​​the electrode 17 and the laminate of the first metal layer 15 and the second metal layer 16 adjacent to the side surface of the electrode 17. The central area of ​​the laminate of the first metal layer 15 and the second metal layer 16 covering the protective layer 13 is exposed without being covered by the second mask 34.

[0033] As shown in Figure 14, after forming a third mask 35 on the electrode 17 and the adjacent area in Figure 13, the central area of ​​the stack of the first metal layer 15 and the second metal layer 16 exposed from the third mask 35 is removed by etching with a second etching solution 36.

[0034] In addition, the laminate of the first metal layer 15 and the second metal layer 16 covered by the third mask 35 at the end of the protective layer 13 is also removed by etching from the end of the third mask 35 to a predetermined depth by the second etching liquid 36 that has penetrated between the protective layer 13 and the third mask 35. Here, the protective layer 13 made of SiN has a higher affinity for the second etching liquid 36 than the third mask 35 made of resin, and the etching of the laminate of the first metal layer 15 and the second metal layer 16 progresses faster as it moves away from the third mask 35 and closer to the protective layer 13. For this reason, the end face of the laminate of the first metal layer 15 and the second metal layer 16 interposed between the protective layer 13 and the third mask 35 is formed into a eaves-like shape that protrudes forward as the height increases from the protective layer 13 toward the third mask 35.

[0035] 3 and 4, when the third mask 35 is removed in Fig. 14, an island portion 20 in which the first metal layer 15 and the second metal layer 16 are laminated is formed in the Hall element 10 directly below the side surface of the electrode 17 on the surface of the protective layer 13 formed on the surface of the magnetosensitive layer 12. A part of the island portion 20, including its base, is located inside the side surface of the electrode 17, and the remaining part of the island portion 20 protrudes from the side surface of the electrode 17. The end face 20b of the island portion 20 protruding from the side surface of the electrode 17 has an eaves-like shape that protrudes forward as its height from the surface of the protective layer 13 increases.

[0036] The island portion 20 is formed inside the electrode 17 in contact with a main body in which the first metal layer 15 and the second metal layer 16 are laminated on the ohmic contact layer 14. More specifically, the base of the island portion 20 inside the side surface of the electrode 17 is formed to face and face with an end of the laminate of the ohmic contact layer 14, the first metal layer 15, and the second metal layer 16 formed on the surface of the protective layer 13. The end face 14a of the ohmic contact layer 14 facing the base of the island portion 20 has an eaves-like shape that protrudes forward as its height from the surface of the protective layer 13 increases. The gap formed by the eaves-like end face 14a of the ohmic contact layer 14, the end face 20a of the base of the island portion 20, and the surface of the protective layer 13 is filled with gold plating that constitutes the electrode 17, forming a metal filling portion 21.

[0037] The Hall element 10 can be manufactured by the series of steps described above. In this Hall element manufacturing method, according to the normal manufacturing process, an island portion 20 is formed by laminating the first metal layer 15 and the second metal layer 16 directly under the side of the electrode 17 on the surface of the protective layer 13 formed on the surface of the magneto-sensitive layer 12, and further a metal filling portion 21 is formed by gold plating in the gap between the ohmic contact layer 14 and the island portion 20. The island portion 20 and metal filling portion 21 thus formed can reliably prevent moisture from entering from the interface between the protective layer 13 and the ohmic contact layer 14.

[0038] In the present embodiment, the Hall element 10 has been taken as an example for explanation, but the present invention is not limited to this. Any semiconductor device that needs to prevent moisture from entering through the interface between the ohmic contact layer and the protective layer, not limited to the Hall element 10, can prevent moisture from entering by forming the island portion 20 and the metal filling portion 21 to seal the interface in the same manner as the Hall element 10. In semiconductor devices, deterioration of the active layer due to moisture intrusion can be prevented by generally protecting the active layer from moisture instead of the magnetosensitive layer 12 in the Hall element 10.

[0039] (Appendix 1) The Hall element 10 includes a substrate 11, a magnetosensitive layer 12 disposed on a top surface 11a of the substrate 11, a protective layer 13 covering the magnetosensitive layer 12 and having an opening 13a exposing a predetermined region of the magnetosensitive layer 12, an ohmic contact layer 14 electrically connected to the magnetosensitive layer 12 exposed from the opening 13a and a portion of which is in contact with the protective layer 13 around the opening 13a, and a first metal layer 15 disposed on the ohmic contact layer 14 and a portion of which is in contact with the protective layer 13 around the periphery of the ohmic contact layer 14. Since the first metal layer 15 is in contact with the protective layer 13 around the periphery of the ohmic contact layer 14, it is possible to prevent water from entering from the interface between the ohmic contact layer 14 and the protective layer 13.

[0040] (Appendix 2) In the Hall element 10 described in Appendix 1, the first metal layer 15 has a main body portion disposed on the ohmic contact layer 14 and an island portion 20 in contact with the protective layer 13 around the ohmic contact layer 14. The island portion 20 seals the interface between the ohmic contact layer 14 and the protective layer 13 to prevent the intrusion of moisture.

[0041] (Appendix 3) The Hall element 10 described in Appendix 2 further includes an electrode 17 made of a plating layer disposed on the first metal layer 15, and forms a metal filling portion 21 in which metal from the plating layer is filled in a gap 19 between the ohmic contact layer 14 and an end face 20a of the island portion 20 facing the ohmic contact layer 14. The metal filling portion 21 further seals the interface between the ohmic contact layer 14 and the protective layer 13, thereby preventing the intrusion of moisture.

[0042] (Appendix 4) In the Hall element 10 described in Appendix 3, the electrode 17 made of a plating layer is continuously disposed from the main body portion of the first metal layer 15 to the island portion 20. The electrode made of a continuously formed plating layer allows the metal of the plating layer to fill the gap between the ohmic contact layer 14 and the island portion 20.

[0043] (Appendix 5) In the Hall element 10 according to any one of Supplementary Notes 1 to 4, the magnetosensitive layer 12 includes a III-V compound semiconductor. For example, by using a semiconductor such as GaAs, the sensitivity of the Hall element 10 can be ensured.

[0044] (Appendix 6) In the Hall element 10 according to any one of Supplementary Notes 1 to 5, the ohmic contact layer 14 is made of an alloy that forms a eutectic with the magnetosensitive layer 12. By forming a eutectic, a stable ohmic contact can be ensured.

[0045] (Appendix 7) In the Hall element 10 described in any one of Supplementary Notes 1 to 6, the first metal layer 15 is for preventing ball-up of the ohmic contact layer 14, and is laminated with the second metal layer 16 forming a base for the electrode 17 that will be a plating layer. By preventing ball-up of the alloy that constitutes the ohmic contact layer 14, stable electrical conduction can be maintained, and by providing a base for the plating layer, stable growth of the plating layer can be ensured.

[0046] (Appendix 8) The manufacturing method of the Hall element 10 includes the steps of forming the magnetosensitive layer 12 on the top surface 11a of the substrate 11, forming a protective layer 13 covering the top surface 11a on which the magnetosensitive layer 12 is formed so that a predetermined region of the magnetosensitive layer 12 is exposed from the opening 13a, forming an ohmic contact layer 14 electrically connected to the magnetosensitive layer 12 exposed from the opening 13a and a part of which is in contact with the protective layer 13 around the opening, and forming a first metal layer 15 formed on the ohmic contact layer 14 and a part of which is in contact with the protective layer 13 around the ohmic contact layer 14. Since the first metal layer 15 is in contact with the protective layer 13 around the ohmic contact layer 14, it is possible to prevent water from entering from the interface between the ohmic contact layer 14 and the protective layer 13.

[0047] (Appendix 9) In the manufacturing method of the Hall element 10 described in Appendix 8, the step of forming the first metal layer 15 forms a main body portion disposed on the ohmic contact layer 14 and an island portion 20 in contact with the protective layer 13 around the ohmic contact layer 14. The island portion 20 seals the interface between the ohmic contact layer 14 and the protective layer 13, thereby preventing the intrusion of moisture.

[0048] (Appendix 10) The method for manufacturing the Hall element 10 described in Appendix 9 further includes a step of forming an electrode 17 of a plating layer on the first metal layer 15, and the step of forming the electrode 17 of the plating layer includes filling a gap 19 between the ohmic contact layer 14 and an end face 20a of the island portion 20 facing the ohmic contact layer 14 with metal of the plating layer to form a metal filling portion 21. The metal filling portion 21 further seals the interface between the ohmic contact layer 14 and the protective layer 13, thereby preventing the intrusion of moisture.

[0049] (Appendix 11) In the manufacturing method of the Hall element 10 described in Appendix 10, the electrode 17 of the plating layer is continuously disposed from the main body portion of the first metal layer 15 to the island portion 20. The electrode made of the continuously formed plating layer allows the metal of the plating layer to fill the gap between the ohmic contact layer 14 and the island portion 20.

[0050] (Appendix 12) The semiconductor device includes a substrate 11, an active layer disposed on a top surface 11a of the substrate 11, a protective layer 13 covering the active layer and having an opening 13a exposing a predetermined region of the active layer, an ohmic contact layer 14 electrically connected to the active layer exposed from the opening 13a and a portion of which is disposed on the protective layer 13 around the opening 13a, and a first metal layer 15 disposed on the ohmic contact layer 14 and a portion of which is in contact with the protective layer 13 around the periphery of the ohmic contact layer 14. Since the first metal layer 15 is in contact with the protective layer 13 around the periphery of the ohmic contact layer 14, it is possible to prevent water from entering from the interface between the ohmic contact layer 14 and the protective layer 13. [Explanation of symbols]

[0051] 10 Hall element 11 Substrate 12 Magnetically sensitive layer 13 Protective layer 13a aperture 14 Ohmic contact layer 15 1st metal layer 16 Second metal layer 17 electrodes 20 Island 21 Metal filling part

Claims

1. A substrate; a magnetosensitive layer disposed on a top surface of the substrate; a protective layer covering the magnetosensitive layer and having an opening exposing a predetermined area of ​​the magnetosensitive layer; an ohmic contact layer electrically connected to the magneto-sensitive layer exposed through the opening and a portion of the ohmic contact layer in contact with the protective layer around the opening; a metal layer disposed on the ohmic contact layer and a portion of the metal layer contacting the protective layer around the ohmic contact layer; A Hall element comprising:

2. The metal layer is a body portion disposed on the ohmic contact layer; an island portion in contact with the protective layer around the ohmic contact layer; 2. The Hall element according to claim 1, comprising:

3. 3. The Hall element according to claim 2, further comprising a plating layer disposed on the metal layer, wherein metal of the plating layer is embedded in a gap between the ohmic contact layer and an end face of the island portion facing the ohmic contact layer.

4. The Hall element according to claim 3 , wherein the plating layer is disposed continuously from the main body portion to the island portion of the metal layer.

5. 4. The Hall element according to claim 3, wherein the magnetosensitive layer includes a III-V compound semiconductor.

6. 6. The Hall element according to claim 5, wherein the ohmic contact layer is made of an alloy that forms a eutectic with the magneto-sensitive layer.

7. The metal layer is a first metal layer for preventing ball-up of the ohmic contact layer; a second metal layer forming a base for the plating layer; 7. The Hall element according to claim 6, wherein:

8. forming a magnetosensitive layer on a top surface of a substrate; forming a protective layer covering the top surface on which the magnetosensitive layer is formed so as to expose a predetermined region of the magnetosensitive layer through an opening; forming an ohmic contact layer electrically connected to the magneto-sensitive layer exposed from the opening and a portion of the ohmic contact layer in contact with the protective layer around the opening; forming a metal layer on the ohmic contact layer, a portion of which is in contact with the protective layer around the ohmic contact layer; A manufacturing method of a Hall element having the above structure.

9. The step of forming the metal layer includes: a body portion disposed on the ohmic contact layer; an island portion in contact with the protective layer around the ohmic contact layer; The method for manufacturing a Hall element according to claim 8, further comprising the steps of:

10. 10. The method for manufacturing a Hall element according to claim 9, further comprising the step of forming a plating layer on the metal layer, the step of forming the plating layer including filling a gap between a side surface of the island portion facing the ohmic contact layer and the ohmic contact layer with metal of the plating layer.

11. The method for manufacturing a Hall element according to claim 10 , wherein the plating layer is disposed continuously from the main body portion to the island portion of the metal layer.

12. A substrate; an active layer disposed on a top surface of the substrate; a protective layer covering the active layer and having an opening exposing a predetermined region of the active layer; an ohmic contact layer electrically connected to the active layer exposed through the opening and a portion of the ohmic contact layer disposed on the protective layer around the opening; a metal layer disposed on the ohmic contact layer, a portion of which is in contact with the protective layer around the ohmic contact layer; A semiconductor device comprising:

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