Electromagnetic transducer element and manufacturing method of the same

Abstract

To reduce a contact resistance between a magnetosensitive layer and a metal electrode layer.SOLUTION: A hole element 10 includes: a substrate 11 including a chemical semiconductor; a magnetosensitive layer 12 formed on a top surface of the substrate 11; an etching stop layer 13 having an etching rate lower than that of the magnetosensitive layer formed on the magnetosensitive layer 12; a contact layer 14 having a contact resistance lower than of the magnetosensitive layer 12 formed on the etching stop layer 13 so that a part of the etching stop layer 13 is exposed; a protection layer 16 formed so as to remove and cover the etching stop layer 13 whose top surface on which the magnetosensitive layer 12, the etching stop layer 13, and the contact layer 14 are formed is exposed; and a metal electrode layer 15 formed on the protection layer 16, and contacting with the contact layer 14 via an opening formed on the protection layer 16. The magnetosensitive layer 12, the etching stop layer 13, and the contact layer 14 include the chemical semiconductor, and a second region 13b of the exposed etching stop layer 13 is made to be an insulation body by oxidation.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to a magnetoelectric transducer and a manufacturing method thereof. [Background technology]

[0002] Hall elements are known as an example of magnetoelectric conversion elements. 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. The configuration of a conventional Hall element is disclosed, for example, in Patent Document 1. Patent Document 1 discloses a Hall element in which a magnetosensitive layer made of an n-type semiconductor in which GaAs (gallium arsenide) is doped with the impurity Si (silicon) is formed on a substrate in a cross shape in a plan view. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2017-50394 A Summary of the Invention [Problem to be solved by the invention]

[0004] In a magneto-sensitive layer made of n-type GaAs doped with Si, it is necessary to increase the carrier mobility in order to increase the magnetic detection sensitivity, which requires a low concentration of Si. This tends to increase the contact resistance at the metal-semiconductor junction between the magneto-sensitive layer and the metal electrode layer. This high contact resistance reduces the sensitivity of the Hall element. In order to reduce the contact resistance, a so-called contact layer with a high concentration of impurities added is sometimes inserted at the interface of the semiconductor in contact with the metal, but as an n-type impurity, Si has a high diffusion coefficient and diffuses into the magneto-sensitive layer, reducing the sensitivity, making it difficult to use Si.

[0005] The present invention has been proposed in view of the above-mentioned circumstances, and aims to reduce the contact resistance at the metal-semiconductor junction between the magnetosensitive layer and the metal electrode layer in a magnetoelectric conversion element having a magnetosensitive layer made of an n-type semiconductor in which GaAs is doped with Si as an impurity. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems, the present disclosure includes a substrate including a compound semiconductor, a magnetosensitive layer formed on a top surface of the substrate, an etching stop layer formed on the magnetosensitive layer and having a lower etching rate than the magnetosensitive layer, a contact layer formed on the etching stop layer so that a portion of the etching stop layer is exposed, the contact layer having a lower contact resistance with metal than the magnetosensitive layer, a protective layer formed to cover the top surface on which the magnetosensitive layer, the etching stop layer, and the contact layer are formed, except for the exposed etching stop layer, and a metal electrode layer formed on the protective layer and in contact with the contact layer through an opening formed in the protective layer, wherein the magnetosensitive layer, the etching stop layer, and the contact layer include a compound semiconductor, and the exposed portion of the etching stop layer is oxidized to an insulator. Effect of the Invention

[0007] According to the present disclosure, the contact resistance between the magnetosensitive layer and the metal electrode layer can be reduced. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a plan view of a Hall element according to the present embodiment. [Diagram 2] FIG. 2 is a cross-sectional view of the Hall element of the present embodiment. [Figure 3A] FIG. 3A is a cross-sectional view showing a series of steps in the method for manufacturing the Hall element of the present embodiment. [Figure 3B] FIG. 3B is a cross-sectional view showing a series of steps in the method for manufacturing the Hall element of the present embodiment. [Figure 3C] FIG. 3C is a cross-sectional view showing a series of steps in the method for manufacturing the Hall element of the present embodiment. [Figure 3D]FIG. 3D is a cross-sectional view showing a series of steps in the method for manufacturing the Hall element of the present embodiment. [Figure 3E] FIG. 3E is a cross-sectional view showing a series of steps in the method for manufacturing the Hall element of the present embodiment. [Figure 3F] FIG. 3F is a cross-sectional view showing a series of steps in the method for manufacturing the Hall element of the present embodiment. [Figure 3G] FIG. 3G is a cross-sectional view showing a series of steps in the method for manufacturing the Hall element of the present embodiment. [Figure 3H] FIG. 3H is a cross-sectional view showing a series of steps in the method for manufacturing the Hall element of the present embodiment. [Figure 3I] FIG. 3I is a cross-sectional view showing a series of steps in the method for manufacturing the Hall element of the present embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, an embodiment of a magnetoelectric conversion element and a manufacturing method thereof will be described in detail with reference to the drawings. In this embodiment, a Hall element will be described as an example of a magnetoelectric conversion element. FIG 1 is a plan view showing a Hall element 10. FIG 2 is a cross-sectional view of the Hall element 10 taken along line II-II in FIG 1.

[0010] In the Hall element 10, the magnetosensitive layer 12 and the etching stop layer 13 are laminated in order on the top surface of the substrate 11 having a substantially rectangular shape in a plan view, so as to form a substantially cross-shaped pattern extending in the two diagonal directions of the substantially rectangular shape. A contact layer 14 is laminated on each of the first regions 13a at the ends of the etching stop layer 13. The top surface of the substrate 11 on which the magnetosensitive layer 12, the etching stop layer 13, and the contact layer 14 are laminated is covered with a protective layer 16, which is an insulator, except for a central second region 13b sandwiched between the first regions 13a of the etching stop layer 13. Metal electrode layers 15 electrically isolated from each other are formed on the protective layer 16. The protective layer 16 has an opening on the contact layer 14, and the metal electrode layers 15 are in contact with the contact layers 14 through the openings, and are electrically connected to the magnetosensitive layer 12 through the contact layers 14. The metal electrode layer 15 further extends to a region adjacent to the contact layer 14 on the protective layer 16.

[0011] The metal electrode layer 15 is composed of four layers, namely, the first metal electrode layer 151 to the fourth metal electrode layer 154. Of these, for example, the first metal electrode layer 151 and the third metal electrode layer 153, which face each other in one diagonal direction, constitute an input terminal, and for example, the second metal electrode layer 152 and the fourth metal electrode layer 154, which face each other in the other diagonal direction, constitute an output terminal. In the magnetosensitive layer 12, a Lorentz force is exerted on carriers moving along a path between a pair of input terminals, such as the first metal electrode layer 151 and the third metal electrode layer 153, 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 metal electrode layer 152 and the fourth metal electrode layer 154, which face each other in a direction substantially perpendicular to the moving direction.

[0012] In the etching stop layer 13, the central second region 13b is exposed without being covered by the contact layer 14, the protective layer 16, or the metal electrode layer 15, and is made into an insulator by oxidation. The etching stop layer 13 in the second region 13b may be covered by another protective layer (not shown).

[0013] In the Hall element 10 of the present embodiment, the substrate 11 is composed of a compound semiconductor made of III-V group GaAs (gallium arsenide). The magnetosensitive layer 12 is composed of an n-type compound semiconductor made of GaAs doped with at least one of Si (silicon) and Te (tellurium) as impurities. The magnetosensitive layer 12 is doped with impurities at a low concentration so that the mobility does not decrease in order to ensure the sensitivity for detecting magnetism, and the carrier concentration is low.

[0014] The etching stop layer 13 is composed of an n-type compound semiconductor of Al x Ga (1-x) As (aluminum gallium arsenide, 0 <x <1) added with Te as an impurity. In the etching stop layer 13, the second region 13b that is exposed without being covered by the contact layer 14, the metal electrode layer 15, or the protective layer 16 is oxidized to form insulators Ga2O3 (gallium oxide) and Al2O3 (aluminum oxide). The etching stop layer 13 is in contact with the magnetosensitive layer 12, but Te, an impurity contained in the etching stop layer 13, has a property of being difficult to diffuse. Therefore, deterioration of the magnetosensitive layer 12 such that impurities diffuse into the magnetosensitive layer 12 and the mobility of carriers decreases does not occur, and the sensitivity of the Hall element 10 is ensured.

[0015] The contact layer 14 is composed of an n-type compound semiconductor made of GaAs doped with Te as an impurity. The contact layer 14 is interposed between the n-type semiconductor etching stop layer 13 and the metal electrode layer 15, and a higher concentration of Te is added compared to the etching stop layer 13 to have a high carrier concentration so that the contact resistance with the metal electrode layer 15 decreases. The contact layer 14 is in contact with the magnetosensitive layer 12 through the etching stop layer 13, but the high-concentration Te contained in the contact layer 14 has a property of being difficult to diffuse. Therefore, as described above, deterioration of the magnetosensitive layer 12 such as a decrease in mobility due to diffusion of Te into the magnetosensitive layer 12 does not occur, and the sensitivity of the Hall element 10 is ensured.

[0016] The metal electrode layer 15 may have a laminated structure, for example, AuGe (gold germanium), Ni (nickel), and Au (gold) may be laminated in this order. The protective layer 16 may be made of SiO2 (silicon dioxide), SiN (silicon nitride), SiON (silicon oxynitride), or the like. In the Hall element 10 of this embodiment, the compound semiconductor contained in the substrate 11, the magnetosensitive layer 12, the etching stop layer 13, and the contact layer 14 is GaAs of the III-V group, but this is not limiting, and other types of compound semiconductors such as InSb (indium antimonide) and InAs (indium arsenide) may also be used.

[0017] In the Hall element 10 of this embodiment, Te is used as the impurity added to the contact layer 14 at a high concentration. Also, Te is used as the impurity of the etching stop layer interposed between the contact layer 14 and the magnetosensitive layer 12. Therefore, in this embodiment, the high concentration of Te added to the contact layer 14 provides a high concentration of carriers, thereby reducing the contact resistance with the metal electrode layer 15. By reducing such contact resistance, the sensitivity or efficiency of the Hall element 10 can be improved. Also, since Te has a property of being difficult to diffuse, even if the etching stop layer 13 to which Te is added is adjacent to the magnetosensitive layer 12 and the contact layer 14 to which Te is added at a high concentration is in contact with the etching stop layer 13 interposed therebetween, the sensitivity is not reduced due to deterioration of the magnetosensitive layer 12 caused by diffusion of Te.

[0018] 3A to 3H are cross-sectional views showing a series of steps for manufacturing the Hall element 10. The manufacturing method of the Hall element 10 will be described with reference to these drawings.

[0019] As shown in Fig. 3A, a substrate 11 made of GaAs is prepared. As shown in Fig. 3B, an n-type compound semiconductor made of GaAs doped with at least one of Si and Te as an impurity is deposited on the top surface of the substrate 11 to form a magnetosensitive layer 12 of a predetermined thickness. In order to ensure sensitivity in detecting magnetism, the magnetosensitive layer 12 is doped with a low concentration of impurities so as to increase mobility.

[0020] As shown in FIG. 3C, the Al is added to the magneto-sensitive layer 12 so as to reduce the etching rate. x Ga (1-x) An n-type compound semiconductor in which Te is added as an impurity to As is deposited to form an etching stop layer 13 with a predetermined thickness. The etching stop layer 13 is set to an appropriate thickness thinner than the magnetosensitive layer 12 so that a predetermined region of the etching stop layer 13 is easily oxidized to Ga2O3 and Al2O3 by exposure to the atmosphere, water vapor, etc. in a process described later. The thickness of the etching stop layer 13 may be in the range of 30 nm to 200 nm.

[0021] 3D, an n-type compound semiconductor made of GaAs doped with Te as an impurity is deposited on the etching stop layer 13 to form a contact layer 14. The contact layer 14 is doped with a higher concentration of Te than the etching stop layer 13 to increase the carrier concentration so that the contact resistance with the metal electrode layer 15 is reduced.

[0022] 3E, parts of the magnetosensitive layer 12, etching stop layer 13 and contact layer 14 stacked on the top surface of the substrate 11 are removed so that the magnetosensitive layer 12, etching stop layer 13 and contact layer 14 form a substantially cross-shaped pattern extending in two diagonal directions on the top surface of the substrate 11 having a substantially rectangular shape in a plan view. These may be removed by etching or lift-off.

[0023] 3F, a protective layer 16 is formed of SiO2, SiN, SiON, or the like so as to cover the top surface of the substrate 11, the magnetosensitive layer 12, the etching stop layer 13, and the contact layer 14 which are laminated on the top surface of the substrate 11. The protective layer 16 is open above the central second region 13b of the contact layer 14 which has a substantially cross shape in a plan view, except for the end first regions 13a.

[0024] 3G, the exposed contact layer 14 that is not covered by the protective layer 16 is removed by etching. The etching stop layer 13 below the contact layer 14 has an etching rate lower than that of the contact layer 14 and the magnetosensitive layer 12. Therefore, by etching the exposed contact layer 14, only the contact layer 14 can be removed, and the etching stop layer 13 can be left behind. When the exposed contact layer 14 is removed by etching, the second region 13b of the etching stop layer 13 that is not covered by the protective layer 16 becomes exposed.

[0025] As shown in FIG. 3H, in the second region 13b of the etching stop layer 13 exposed from the metal electrode layer 15, Al x Ga (1-x) As is oxidized to insulators Ga2O3 and Al2O3. Al x Ga (1-x) The oxidation of As may be achieved by exposing the second region 13b to the atmosphere or water vapor. Since the etching stop layer 13 has an appropriate thickness as described above, the second region 13b is easily oxidized by exposure.

[0026] As shown in Fig. 3I, an opening is formed in the protective layer 16 covering the contact layer 14 by etching. Then, for example, AuGe, Ni and Au are laminated in this order on the protective layer 16 to form the metal electrode layer 15. The metal electrode layer 15 is in contact with the contact layer 14 through the opening in the protective layer 16. By forming the metal electrode layer 15 in this manner, the Hall element 10 as shown in Fig. 2 is obtained.

[0027] 1, the metal electrode layer 15 contacts the first regions 13a at each end of the etching stop layer 13 having a substantially cross shape in a plan view through the openings in the protective layer 16, and further extends to a region adjacent to the first regions 13a on the protective layer 16 on the top surface of the substrate 11. Such a pattern of the metal electrode layer 15 may be formed by etching or lift-off after the metal electrode layer 15 is deposited.

[0028] After the second region 13b of the etching stop layer 13 shown in Fig. 3H is oxidized, another protective layer may be formed to cover the second region 13b. The other protective layer may be formed of, for example, SiO2, SiN, SiON, etc., similar to the protective layer 16.

[0029] In the manufacturing method of the Hall element 10 of this embodiment, the compound semiconductor contained in the substrate 11, the magnetosensitive layer 12, the etching stop layer 13, and the contact layer 14 is GaAs, which is a III-V group, but other types of compound semiconductors such as InSb and InAs may be used. Also, although the predetermined region of the contact layer 14 exposed from the metal electrode layer 15 is removed by etching after the metal electrode layer 15 is formed, the corresponding region of the contact layer 14 may be removed before the metal electrode layer 15 is formed.

[0030] In the manufacturing method of this embodiment, an etching stop layer 13 having an etching rate lower than that of the magnetosensitive layer 12 and the contact layer 14 is formed on the magnetosensitive layer 12. Therefore, the contact layer 14 exposed from the metal electrode layer 15 is removed by etching, but the etching is stopped when it reaches the etching stop layer 13, and does not reach the magnetosensitive layer 12 below the etching stop layer 13.

[0031] In the manufacturing method of this embodiment, when the contact layer 14 exposed from the protective layer 16 is removed, the second region 13b of the etching stop layer 13 is exposed from the protective layer 16. Since the etching stop layer 13 is set to an appropriate thickness so that it is easily oxidized, the second region 13b is oxidized by exposure to an atmosphere containing oxygen and converted into an oxide insulator. The oxidation of the second region 13b may be performed by leaving it in the air for a predetermined time, or may be performed in a short time by exposing it to water vapor or the like. Since the second region 13b is converted into an insulator, the current flowing through the magnetosensitive layer 12 is prevented from passing through the second region 13b, and the sensitivity of the Hall element 10 is ensured.

[0032] In the Hall element 10 manufactured by the manufacturing method of this embodiment, Te is used as the impurity added to the contact layer 14 at a high concentration. Also, Te is used as the impurity of the etching stop layer interposed between the contact layer 14 and the magnetosensitive layer 12. Therefore, in this embodiment, the high concentration of Te added to the contact layer 14 provides a high concentration of carriers, thereby reducing the contact resistance with the metal electrode layer 15. By reducing such contact resistance, the sensitivity or efficiency of the Hall element 10 can be improved. Also, since Te has a property of being difficult to diffuse, even if the etching stop layer 13 to which Te is added is adjacent to the magnetosensitive layer 12 and the contact layer 14 to which Te is added at a high concentration is in contact with the etching stop layer 13 interposed therebetween, the magnetosensitive layer 12 will not deteriorate due to the diffusion of Te, and the sensitivity will not decrease.

[0033] (Appendix 1) The Hall element 10 includes a substrate 11 containing a compound semiconductor, a magnetosensitive layer 12 formed on a top surface of the substrate 11, an etching stop layer 13 formed on the magnetosensitive layer 12 and having a lower etching rate than the magnetosensitive layer 12, a contact layer 14 formed on the etching stop layer 13 and having a lower contact resistance than the magnetosensitive layer 12 such that a part of the etching stop layer 13 is exposed, a protective layer 16 formed to cover the top surface on which the magnetosensitive layer 12, the etching stop layer 13, and the contact layer 14 are formed, except for the exposed etching stop layer 13, and a metal electrode layer 15 formed on the protective layer 16 and in contact with the contact layer 14 through an opening formed in the protective layer 16, wherein the magnetosensitive layer 12, the etching stop layer 13, and the contact layer 14 contain compound semiconductors, and the exposed second region 13b of the etching stop layer 13 is made into an insulator by oxidation. The contact layer 14 reduces the contact resistance with the metal electrode layer 15, and the second region 13b of the etching stop layer 13 is converted into an insulator by oxidation, thereby preventing the current flowing through the magnetosensitive layer 12 from passing through the second region 13b, thereby ensuring the sensitivity of the Hall element 10.

[0034] (Appendix 2) The compound semiconductor described in Appendix 1 may include a III-V group semiconductor. The compound semiconductor may be appropriately selected from III-V group semiconductors.

[0035] (Appendix 3) The III-V semiconductor described in Supplementary Note 2 may include at least one of GaAs, InSb, and InAs. The III-V semiconductor may be appropriately selected from GaAs, InSb, and InAs.

[0036] (Appendix 4) At least one of Si and Te may be added to the magnetosensitive layer 12 described in any one of Supplementary Notes 1 to 3. By adding at least one of Si and Te, an n-type semiconductor can be formed. Furthermore, since Te has a property of being difficult to diffuse, it does not diffuse into the magnetosensitive layer 12 and thereby does not reduce the sensitivity of the Hall element 10.

[0037] (Appendix 5) The etching stop layer 13 described in any one of Supplementary Notes 1 to 4 may be doped with Al and Te. The addition of Al can reduce the etching rate, and the addition of Te can form an n-type semiconductor. Furthermore, Te is difficult to diffuse, so it does not diffuse into the magnetosensitive layer 12 and thereby does not reduce the sensitivity of the Hall element 10.

[0038] (Appendix 6) The contact layers described in Supplementary Notes 1 to 5 may be doped with Te. Doping of Te allows an n-type semiconductor to be formed. Furthermore, since Te is difficult to diffuse, it does not diffuse into the magnetosensitive layer 12 and thus does not reduce the sensitivity of the Hall element 10.

[0039] (Appendix 7) A manufacturing method of the Hall element 10 includes the steps of forming a magnetosensitive layer 12 on the top surface of a substrate 11 made of a compound semiconductor, forming an etching stop layer 13 on the magnetosensitive layer 12, the etching rate of which is lower than that of the magnetosensitive layer 12, forming a contact layer 14 on the etching stop layer 13, the contact layer 14 having a lower contact resistance with metal than that of the magnetosensitive layer 12, forming a protective layer 16 on the contact layer 14 so that a part of the contact layer is exposed, etching the contact layer 14 exposed from the protective layer 16 so that the second region 13b of the etching stop layer 13 is exposed, oxidizing the exposed second region 13b of the etching stop layer 13 to make it an insulator, and forming a metal electrode layer 15 on the protective layer 16, and the magnetosensitive layer 12, the etching stop layer 13 and the contact layer 14 are all made of compound semiconductors. The etching stop layer 13, which has a low etching rate, protects the magnetosensitive layer 12 and also enables removal of a portion of the contact layer 14. By oxidizing the second region 13b of the etching stop layer 13 and converting it into an insulator, the current flowing through the magnetosensitive layer 12 is prevented from passing through the second region 13b, thereby ensuring the sensitivity of the Hall element 10.

[0040] (Appendix 8) The compound semiconductor described in Supplementary Note 7 may include a III-V group semiconductor. The compound semiconductor may be appropriately selected from III-V group semiconductors.

[0041] (Appendix 9) The III-V semiconductor described in Supplementary Note 8 may include at least one of GaAs, InSb, and InAs. The III-V semiconductor may be appropriately selected from GaAs, InSb, and InAs.

[0042] (Appendix 10) At least one of Si and Te may be added to the magnetosensitive layer 12 described in any one of Supplementary Notes 7 to 9. By adding at least one of Si and Te, an n-type semiconductor can be formed. Furthermore, since Te has a property of being difficult to diffuse, it does not diffuse into the magnetosensitive layer 12 and thereby does not reduce the sensitivity of the Hall element 10.

[0043] (Appendix 11) The etching stop layer described in any one of Supplementary Notes 7 to 10 may be doped with Al and Te. The addition of Al can reduce the etching rate, and the addition of Te can form an n-type semiconductor. Furthermore, Te is difficult to diffuse, so it does not diffuse into the magnetosensitive layer 12 and thereby does not reduce the sensitivity of the Hall element 10.

[0044] (Appendix 12) The contact layer 14 described in any one of Supplementary Notes 7 to 11 may be doped with Te. Doping of Te allows an n-type semiconductor to be formed. Furthermore, since Te has a property of being difficult to diffuse, it does not diffuse into the magnetosensitive layer 12 and thereby does not reduce the sensitivity of the Hall element 10.

[0045] (Appendix 13) The method may further include a step of removing parts of the magnetosensitive layer 12, the etching stop layer 13, and the contact layer 14 so that the magnetosensitive layer 12, the etching stop layer 13, and the contact layer 14 described in any one of Supplementary Notes 7 to 12 form a predetermined pattern on the top surface. By forming the magnetosensitive layer 12, the etching stop layer 13, and the contact layer 14 into an appropriate pattern, the Hall element 10 can be formed.

[0046] (Appendix 14) The method may further include a step of forming an opening in the protective layer 16 on the contact layer 14 described in any one of Supplementary Notes 7 to 13, and the metal electrode layer 15 may be in contact with the contact layer 14 through the opening. The metal electrode layer 15 may be electrically connected to the etching stop layer 13 and the magneto-sensitive layer 12 via the contact layer 14.

[0047] (Appendix 15) A protective layer 16 may be formed on the top surface of the substrate 11 described in any one of Supplementary Notes 7 to 13 so as to cover at least the exposed etching stop layer 13. The formation of the protective layer 16 protects the magnetosensitive layer 12 via the etching stop layer 13, thereby ensuring stable operation of the Hall element 10. [Explanation of symbols]

[0048] 10 Hall element 11 Substrate 12 Magnetically sensitive layer 13 Etching stop layer 14 Contact layer 15 Metal electrode layer

Claims

1. A substrate including a compound semiconductor; a magnetosensitive layer formed on a top surface of the substrate; an etching stop layer formed on the magnetosensitive layer and having an etching rate lower than that of the magnetosensitive layer; a contact layer having a lower contact resistance with metal than the magnetosensitive layer, the contact layer being formed on the etching stop layer so as to expose a portion of the etching stop layer; a protective layer formed to cover the top surface on which the magneto-sensitive layer, the etching stop layer, and the contact layer are formed, except for an exposed portion of the etching stop layer; a metal electrode layer formed on the protective layer and in contact with the contact layer through an opening formed in the protective layer; Including, a magnetoelectric conversion element in which the magnetosensitive layer, the etching stop layer and the contact layer contain the compound semiconductor, and the exposed portion of the etching stop layer is oxidized to become an insulator;

2. 2. The magnetoelectric transducer according to claim 1, wherein the compound semiconductor includes a III-V group semiconductor.

3. 3. The magnetoelectric transducer according to claim 2, wherein the III-V group semiconductor includes at least one of GaAs, InSb, and InAs.

4. 2. The magnetoelectric transducer according to claim 1, wherein at least one of Si and Te is added to the magnetosensitive layer.

5. 2. The magnetoelectric transducer according to claim 1, wherein the etching stop layer contains Al and Te.

6. 2. The magnetoelectric transducer according to claim 1, wherein the contact layer is doped with Te.

7. forming a magnetosensitive layer on a top surface of a substrate comprising a compound semiconductor; forming an etching stop layer on the magnetosensitive layer, the etching rate of which is lower than that of the magnetosensitive layer; forming a contact layer on the etching stop layer, the contact layer having a lower contact resistance with a metal than the magnetosensitive layer; forming a protective layer on the contact layer such that a portion of the contact layer is exposed; etching the contact layer exposed from the protective layer to expose a portion of the etching stop layer; oxidizing the exposed portion of the etch stop layer to an insulator; forming a metal electrode layer on the protective layer; Including, A method for manufacturing a magnetoelectric conversion element, wherein the magnetosensitive layer, the etching stop layer and the contact layer all contain the compound semiconductor.

8. 8. The method for producing a magnetoelectric conversion element according to claim 7, wherein the compound semiconductor includes a III-V group semiconductor.

9. 9. The method for producing a magnetoelectric transducer according to claim 8, wherein the III-V group semiconductor includes at least one of GaAs, InSb, and InAs.

10. 8. The method for producing a magnetoelectric transducer according to claim 7, wherein at least one of Si and Te is added to the magneto-sensitive layer.

11. The method for producing a magnetoelectric transducer according to claim 7 , wherein the etching stop layer contains Al and Te.

12. The method for manufacturing a magnetoelectric transducer according to claim 7 , wherein the contact layer is doped with Te.

13. The method for manufacturing a magnetoelectric conversion element according to claim 7 , further comprising the step of removing a portion of the magnetosensitive layer, the etching stop layer and the contact layer so that the magnetosensitive layer, the etching stop layer and the contact layer form a predetermined pattern on the top surface.

14. The method for manufacturing a magnetoelectric transducer according to claim 7 , further comprising the step of forming an opening in the protective layer on the contact layer, the metal electrode layer being in contact with the contact layer through the opening.

15. The method for manufacturing a magnetoelectric transducer according to claim 7 , further comprising the step of forming a protective layer on the top surface of the substrate so as to cover at least the exposed etching stop layer.

Images