JP5940639B2 - Strain detector - Google Patents

Description

  Embodiments described herein relate generally to a strain detection apparatus.

  There is a need for a strain sensor that can measure strain with high sensitivity even in a minute region. For example, there is a configuration in which a semiconductor sensor chip having an acoustic detection unit that detects pressure fluctuation by vibration and a control circuit chip are electrically connected by a bonding wire. However, in this configuration, it is difficult to reduce the size of the apparatus, and it is difficult to measure strain with high sensitivity in a minute region.

JP 2009-5077 A

  Embodiments of the present invention provide a strain detection device that can detect strain with high sensitivity in a minute region.

According to the embodiment of the present invention, a strain detection apparatus including a semiconductor circuit unit and a detection unit is provided. The semiconductor circuit unit includes a semiconductor substrate and a transistor provided on the main surface of the semiconductor substrate. The detection unit is provided on the semiconductor circuit unit. The detection unit includes a cavity provided above the transistor and a non-cavity juxtaposed with the cavity in a plane parallel to the main surface. The detection unit includes a movable beam, a strain detection element unit, a first wiring, and a second wiring. The movable beam has a fixed part fixed to the non-cavity part, and a movable part extending from the fixed part to the cavity part and spaced apart from the transistor and having a variable distance between the transistors. The strain sensing element portion is provided in the movable part, and includes a first magnetic layer, a second magnetic layer, a nonmagnetic intermediate layer provided between the first magnetic layer and the second magnetic layer, A first bias layer juxtaposed with the first magnetic layer and applying a bias magnetic field to the first magnetic layer . The first wiring includes a portion that is provided in the non-hollow portion and intersects the main surface, and electrically connects the first magnetic layer and the semiconductor circuit portion. The second wiring includes a portion provided in the non-hollow portion and intersecting the main surface, and electrically connects the second magnetic layer and the semiconductor circuit portion.

It is a typical perspective view which shows the distortion | strain detector which concerns on 1st Embodiment. It is a typical perspective view which shows a part of distortion detection apparatus which concerns on 1st Embodiment. FIG. 3A to FIG. 3C are schematic perspective views showing the operation of the strain sensing device according to the first embodiment. It is a typical perspective view which shows a part of distortion detection apparatus which concerns on 1st Embodiment. It is a typical perspective view which shows a part of distortion detection apparatus which concerns on 1st Embodiment. FIG. 6A to FIG. 6C are schematic views showing a part of the strain detection apparatus according to the first embodiment. FIG. 7A to FIG. 7C are schematic views showing a part of the strain detection apparatus according to the first embodiment. FIG. 8A to FIG. 8C are schematic views illustrating a part of the strain detection apparatus according to the first embodiment. It is a typical perspective view which shows another distortion detection apparatus which concerns on 1st Embodiment. It is a typical perspective view which shows a part of another distortion detection apparatus which concerns on 1st Embodiment. It is a typical perspective view which shows a part of another distortion detection apparatus which concerns on 1st Embodiment. FIG. 12A to FIG. 12C are schematic views illustrating another strain detection device and electronic apparatus according to the first embodiment. FIG. 13A and FIG. 13B are schematic views showing a method for manufacturing the strain sensing device according to the first embodiment. FIG. 14A and FIG. 14B are schematic views showing a method for manufacturing the strain sensing device according to the first embodiment. FIG. 15A and FIG. 15B are schematic views showing a method for manufacturing the strain sensing device according to the first embodiment. FIG. 16A and FIG. 16B are schematic views showing a method for manufacturing the strain sensing device according to the first embodiment. FIG. 17A and FIG. 17B are schematic views showing a method for manufacturing the strain sensing device according to the first embodiment. FIG. 18A and FIG. 18B are schematic views showing a method for manufacturing the strain sensing device according to the first embodiment. FIG. 19A and FIG. 19B are schematic views showing a method for manufacturing the strain sensing device according to the first embodiment. FIG. 20A and FIG. 20B are schematic views showing a method for manufacturing the strain sensing device according to the first embodiment. FIG. 21A and FIG. 21B are schematic views showing a method for manufacturing the strain sensing device according to the first embodiment. FIG. 22A and FIG. 22B are schematic views showing a method for manufacturing the strain sensing device according to the first embodiment. FIG. 23A and FIG. 23B are schematic views showing a method for manufacturing the strain sensing device according to the first embodiment. FIG. 24A and FIG. 24B are schematic views showing a method for manufacturing the strain sensing device according to the first embodiment. FIG. 25A to FIG. 25C are schematic views illustrating a part of the strain detection apparatus according to the first embodiment. FIG. 26A and FIG. 26B are schematic views showing a method for manufacturing the strain sensing device according to the first embodiment. FIG. 27A and FIG. 27B are schematic views showing a method for manufacturing the strain sensing device according to the first embodiment. FIG. 28A and FIG. 28B are schematic views showing a method for manufacturing the strain sensing device according to the first embodiment. FIG. 29A and FIG. 29B are schematic views showing a method for manufacturing the strain sensing device according to the first embodiment. FIG. 30A and FIG. 30B are schematic views showing a method for manufacturing the strain sensing device according to the first embodiment. FIG. 31A and FIG. 31B are schematic views showing a method for manufacturing the strain sensing device according to the first embodiment. FIG. 32A and FIG. 32B are schematic views showing a method for manufacturing the strain sensing device according to the first embodiment. FIG. 33A and FIG. 33B are schematic views showing a method for manufacturing the strain sensing device according to the first embodiment. It is a typical perspective view which shows another distortion detection apparatus which concerns on 1st Embodiment. It is a flowchart figure which shows the manufacturing method of the distortion | strain detector which concerns on 2nd Embodiment.

Each embodiment will be described below with reference to the drawings.
Note that the drawings are schematic or conceptual, and the size ratio between the parts is not necessarily the same as the actual one. Further, even when the same part is represented, the dimensions and ratios may be represented differently depending on the drawings.
Note that, in the present specification and each drawing, the same elements as those described above with reference to the previous drawings are denoted by the same reference numerals, and detailed description thereof is omitted as appropriate.

(First embodiment)
FIG. 1 is a schematic perspective view illustrating the configuration of the strain detection apparatus according to the first embodiment.
In FIG. 1, in order to make the drawing easier to see, the insulating portion is omitted and the conductive portion is mainly drawn.

  As illustrated in FIG. 1, the strain detection device 310 according to the present embodiment includes a semiconductor circuit unit 110 and a detection unit 120.

The semiconductor circuit unit 110 includes a semiconductor substrate 111 and a transistor 112.
The semiconductor substrate 111 has a main surface 111 a of the semiconductor substrate 111. The semiconductor substrate 111 has an element region 111b provided on the main surface 111a. The transistor 112 is provided in the element region 111b.

  The semiconductor circuit unit 110 may include a processing circuit 113. The processing circuit 113 may be provided in the element region 111b or may be provided in other regions. The processing circuit 113 is provided at an arbitrary location in the semiconductor circuit unit 110. The processing circuit 113 may include a transistor 112 provided in the element region 111b.

  The detection unit 120 is provided on the semiconductor circuit unit 110.

  The detection unit 120 includes a cavity part 70 and a non-cavity part 71. The cavity 70 is provided above the transistor 112. The cavity 70 is provided at least on the element region 111b. Non-hollow part 71 is juxtaposed with cavity part 70 in a plane parallel to main surface 111a.

  The cavity portion 70 is a portion where the material forming the non-cavity portion 71 is not provided. The cavity 70 may be in a vacuum (a low pressure state lower than 1 atm), and the cavity 70 may be filled with a gas such as air or an inert gas. Further, the hollow portion 70 may be filled with a liquid. In the hollow portion 70, a deformable substance may be arranged so that a movable part described later can move.

  Here, a plane parallel to the main surface 111a is defined as an XY plane. A direction perpendicular to the XY plane is taken as a Z-axis direction. The detection unit 120 is stacked with the semiconductor circuit unit 110 along the Z-axis direction.

  The non-cavity portion 71 may surround the cavity portion 70.

  The detection unit 120 includes a movable beam 60, a strain detection element unit 50, a first embedded wiring 61c, and a second embedded wiring 62c.

  The movable beam 60 has a fixed part 63 and a movable part 64. The movable beam 60 includes a first wiring layer 61 and a second wiring layer 62.

  The fixed portion 63 is fixed to the non-hollow portion 71. The movable part 64 extends from the fixed part 63 to the cavity 70. The movable part 64 is separated from the transistor 112. The distance between the movable part 64 and the transistor 112 is variable. The first wiring layer 61 and the second wiring layer 62 extend from the fixed portion 63 toward the movable portion 64.

  In this example, the movable beam 60 extends along the X-axis direction (one direction in the XY plane). That is, the direction from the fixed portion 63 toward the movable portion 64 is along the X-axis direction. An axis perpendicular to the X-axis direction and perpendicular to the Z-axis direction is taken as a Y-axis direction.

  The strain sensing element unit 50 is fixed to the movable part 64. One end of the strain sensing element unit 50 is electrically connected to the first wiring layer 61. The other end of the strain sensing element unit 50 is electrically connected to the second wiring layer 62. The strain sensing element unit 50 includes a first magnetic layer described later.

  The first embedded wiring 61 c is provided in the non-hollow part 71. The first embedded wiring 61 c electrically connects the end of the first wiring layer 61 on the fixed portion 63 side and the semiconductor circuit unit 110.

  The second embedded wiring 62 c is provided in the non-hollow part 71. The second embedded wiring 62 c electrically connects the end of the second wiring layer 62 on the fixed portion 63 side and the semiconductor circuit unit 110.

  For example, the first embedded wiring 61c and the second embedded wiring 62c have portions along the Z-axis direction.

  In the strain sensing device 310 according to the present embodiment, the distance between the movable part 64 and the transistor 112 can be changed. The amount of strain applied to the strain sensing element unit 50 changes according to the change in the distance, and the magnetization direction of the first magnetic layer changes according to the change in the amount of strain. As the magnetization direction changes, the electrical resistance between one end and the other end of the strain sensing element unit 50 changes. This change in electrical resistance is based on, for example, the MR effect. Thereby, distortion can be detected with high sensitivity in a minute region.

  In this example, the movable portion 64 has a diaphragm portion 61 b laminated with the first wiring layer 61. In this example, the first wiring layer 61 extends on a part of the diaphragm portion 61b.

  In the present specification, the state of being stacked includes not only the state of being directly stacked but also the state of being stacked with another element inserted therebetween. Moreover, the state provided on top includes the state arrange | positioned on another element inserted in addition to the state arrange | positioned above in contact.

  The area of the diaphragm portion 61 b is larger than the area of the first wiring layer 61. By providing the diaphragm portion 61b, external force from the outside is efficiently transmitted to the strain sensing element portion 50. Thereby, the sensitivity of distortion detection increases. In addition, since the diaphragm portion 61b is provided, it is possible to detect the strain on the structure whose shape is defined, so that the relationship between the external force and the strain is constant. For example, the conversion from the strain amount to the external force is unique and easy to use.

  In this example, the strain sensing element unit 50 is provided with a strain resistance changing unit 50s and bias layers 55a and 55b (for example, a hard bias layer) for applying a bias magnetic field to the strain resistance changing unit 50s. The bias layers 55a and 55b are provided as necessary, and may be omitted in some cases. The bias layers 55a and 55b will be described later. Hereinafter, the strain resistance changing unit 50s will be described.

FIG. 2 is a schematic perspective view illustrating the configuration of a part of the strain detection device according to the first embodiment.
As illustrated in FIG. 2, the strain resistance change unit 50 s (strain detection element unit 50) includes, for example, the first magnetic layer 10, the second magnetic layer 20, the first magnetic layer 10, and the second magnetic layer 20. And an intermediate layer 30 provided therebetween. The intermediate layer 30 is a nonmagnetic layer.

  In this example, the first magnetic layer 10 is a magnetization free layer. The second magnetic layer 20 is, for example, a magnetization fixed layer or a magnetization free layer.

  Hereinafter, an example of the operation of the strain sensing element unit 50 will be described in the case where the second magnetic layer 20 is a magnetization fixed layer and the first magnetic layer 10 is a magnetization free layer. In the strain sensing element unit 50, the “inverse magnetostriction effect” of the ferromagnetic material and the “MR effect” developed in the strain resistance change unit 50s are used.

  The “MR effect” is a phenomenon in which, in a laminated film having a magnetic material, when an external magnetic field is applied, the value of the electric resistance of the laminated film changes due to a change in magnetization of the magnetic material. There are GMR (Giant magnetoresistance) effect, TMR (Tunneling magnetoresistance) effect and the like. By flowing a current through the strain resistance changing portion 50s, the MR effect is manifested by reading the change in the relative angle of the magnetization direction as a change in electrical resistance. For example, based on the stress applied to the strain sensing element unit 50, a tensile stress is applied to the strain resistance change unit 50s. When the magnetization direction of the first magnetic layer 10 (magnetization free layer) and the direction of the tensile stress applied to the second magnetic layer 20 are different, the MR effect is manifested by the inverse magnetostriction effect. ΔR / R is referred to as “MR change rate”, where R is the resistance in the low resistance state and ΔR is the amount of change in electrical resistance that changes due to the MR effect.

FIG. 3A to FIG. 3C are schematic perspective views illustrating the operation of the strain detection apparatus according to the first embodiment.
These drawings illustrate the state of the strain sensing element unit 50. These drawings illustrate the relationship between the direction of magnetization in the strain sensing element unit 50 and the direction of tensile stress.

  FIG. 3A shows a state in which no tensile stress is applied. At this time, in this example, the magnetization direction of the second magnetic layer 20 (magnetization fixed layer) is the same as the magnetization direction of the first magnetic layer 10 (magnetization free layer).

  FIG. 3B shows a state where tensile stress is applied. In this example, tensile stress is applied along the X-axis direction. For example, due to the deformation of the movable portion 64, for example, a tensile stress along the X-axis direction is applied. That is, the tensile stress is applied in a direction orthogonal to the magnetization directions (Y-axis direction in this example) of the second magnetic layer 20 (magnetization fixed layer) and the first magnetic layer 10 (magnetization free layer). At this time, the magnetization of the first magnetic layer 10 (magnetization free layer) rotates so as to be in the same direction as the direction of the tensile stress. This is called “reverse magnetostriction effect”. At this time, the magnetization of the second magnetic layer 20 (magnetization fixed layer) is fixed. Accordingly, the magnetization of the first magnetic layer 10 (magnetization free layer) and the magnetization direction of the second magnetic layer 20 (magnetization fixed layer) and the magnetization direction of the first magnetic layer 10 (magnetization free layer) are rotated. And the relative angle changes.

  In this figure, the direction of magnetization of the second magnetic layer 20 (magnetization fixed layer) is shown as an example, and the direction of magnetization may not be the direction shown in this figure.

  In the inverse magnetostriction effect, the easy axis of magnetization changes depending on the sign of the magnetostriction constant of the ferromagnetic material. Many materials exhibiting a large inverse magnetostrictive effect have a positive sign for the magnetostriction constant. When the magnetostriction constant has a positive sign, the direction in which tensile stress is applied as described above is the easy axis of magnetization. At this time, as described above, the magnetization of the first magnetic layer 10 (magnetization free layer) rotates in the direction of the easy axis of magnetization.

  For example, when the magnetostriction constant of the first magnetic layer 10 (magnetization free layer) is positive, the magnetization direction of the first magnetic layer 10 (magnetization free layer) is set to a direction different from the direction in which tensile stress is applied. To do.

On the other hand, when the magnetostriction constant is negative, the direction perpendicular to the direction in which the tensile stress is applied becomes the easy axis of magnetization.
FIG. 3C illustrates a state where the magnetostriction constant is negative. In this case, the magnetization direction of the first magnetic layer 10 (magnetization free layer) is set to a direction different from the direction perpendicular to the direction in which the tensile stress is applied (X-axis direction in this example).
In this figure, the direction of magnetization of the second magnetic layer 20 (magnetization fixed layer) is shown as an example, and the direction of magnetization may not be the direction shown in this figure.

  Depending on the angle between the magnetization of the first magnetic layer 10 and the magnetization of the second magnetic layer 20, the electrical resistance of the strain sensing element unit 50 (strain resistance changing unit 50s) changes due to, for example, the MR effect.

  The magnetostriction constant (λs) indicates the magnitude of the shape change when an external magnetic field is applied and the ferromagnetic layer is saturated and magnetized in a certain direction. If the length is L in the absence of an external magnetic field and changes by ΔL when an external magnetic field is applied, the magnetostriction constant λs is expressed by ΔL / L. Although the amount of change varies depending on the magnitude of the magnetic field, the magnetostriction constant λs is expressed as ΔL / L in a state where a sufficient magnetic field is applied and magnetization is saturated.

  For example, when the second magnetic layer 20 is a fixed magnetization layer, for example, a CoFe alloy, a CoFeB alloy, a NiFe alloy, or the like can be used for the second magnetic layer 20. The thickness of the second magnetic layer 20 is, for example, not less than 2 nanometers (nm) and not more than 6 nm.

A metal or an insulator can be used for the intermediate layer 30. For example, Cu, Au, Ag, or the like can be used as the metal. In the case of metal, the thickness of the intermediate layer 30 is, for example, 1 nm or more and 7 nm or less. As the insulator, for example, magnesium oxide (such as MgO), aluminum oxide (such as Al ₂ O ₃ ), titanium oxide (such as TiO), and zinc oxide (such as ZnO) can be used. In the case of an insulator, the thickness of the intermediate layer 30 is, for example, not less than 0.6 nm and not more than 2.5 nm.

In the case where the first magnetic layer 10 is a magnetization free layer, for example, an FeCo alloy, a NiFe alloy, or the like can be used for the first magnetic layer 10. In addition, the first magnetic layer 10 includes an Fe—Co—Si—B alloy, a Tb—M—Fe alloy exhibiting λs> 100 ppm (M is Sm, Eu, Gd, Dy, Ho, Er), Tb— M1-Fe-M2 alloy (M1 is Sm, Eu, Gd, Dy, Ho, Er, M2 is Ti, Cr, Mn, Co, Cu, Nb, Mo, W, Ta), Fe-M3-M4- B alloy (M3 is Ti, Cr, Mn, Co, Cu, Nb, Mo, W, Ta, M4 is Ce, Pr, Nd, Sm, Tb, Dy, Er), Ni, Al-Fe and ferrite ( Fe ₃ O ₄ , (FeCo) ₃ O ₄ ) and the like can be used. The thickness of the first magnetic layer 10 is, for example, 2 nm or more.

The first magnetic layer 10 may have a two-layer structure. In this case, the first magnetic layer 10 may include an FeCo alloy layer and the following layers stacked with the FeCo alloy layer. Stacked with the FeCo alloy layer is an Fe—Co—Si—B alloy, a Tb—M—Fe alloy (M is Sm, Eu, Gd, Dy, Ho, Er), Tb— M1-Fe-M2 alloy (M1 is Sm, Eu, Gd, Dy, Ho, Er, M2 is Ti, Cr, Mn, Co, Cu, Nb, Mo, W, Ta), Fe-M3-M4- B alloy (M3 is Ti, Cr, Mn, Co, Cu, Nb, Mo, W, Ta, M4 is Ce, Pr, Nd, Sm, Tb, Dy, Er), Ni, Al-Fe and ferrite ( Fe ₃ O ₄ , (FeCo) ₃ O ₄ ), etc.).

  For example, when the intermediate layer 30 is a metal, a GMR (Giant Magnetoresistance) effect appears. When the intermediate layer 30 is an insulator, a TMR (Tunneling Magnetoresistance) effect appears. For example, in the strain sensing element unit 50, for example, a CPP (Current Perpendicular to Plane) -GMR effect is used in which a current flows along the stacking direction of the strain resistance change unit 50s.

  Further, as the intermediate layer 30, a CCP (Current-Confined-Path) spacer layer in which a plurality of metal current paths having a width (for example, a diameter) of about 1 nm to about 5 nm are formed through a part of the insulating layer in the film thickness direction. Can be used. Again, the CCP-GMR effect is used.

  Thus, in this embodiment, the inverse magnetostriction phenomenon in the strain sensing element unit 50 is used. Thereby, highly sensitive detection becomes possible. When the inverse magnetostriction effect is used, for example, the magnetization direction of at least one of the first magnetic layer 10 and the second magnetic layer 20 is changed with respect to externally applied strain. The relative angles of the magnetizations of the two magnetic layers change depending on the strain (existence / absence and degree thereof) applied from the outside. Since the electrical resistance changes due to externally applied strain, the strain sensing element unit 50 functions as a strain sensor.

FIG. 4 is a schematic perspective view illustrating the configuration of a part of the strain detection device according to the first embodiment.
As illustrated in FIG. 4, the strain sensing element unit 50 includes, for example, a first electrode 51 and a second electrode 52. A strain resistance changing portion 50 s is provided between the first electrode 51 and the second electrode 52. In this example, in the strain resistance changing unit 50 s, the buffer layer 41 (also a seed layer, thickness of several nm) and the antiferromagnetic layer 42 (thickness of several) are directed from the first electrode 51 side toward the second electrode 52. nm), magnetic layer 43 (thickness several nm), Ru layer 44, second magnetic layer 20 (thickness several nm), intermediate layer 30 (thickness several nm), first magnetic layer 10 and cap layer 45 (thickness). Several nm) are provided in this order.

  For example, a magnetic multilayer film is used for the second magnetic layer 20. The first magnetic layer 10 includes a magnetic laminated film 10a (thickness of about 1 nm) and a high magnetostrictive magnetic film 10b (thickness of several nm) provided between the magnetic laminated film 10a and the cap layer 45.

For the first electrode 51 and the second electrode 52, for example, a non-magnetic material such as Au, Cu, Ta, or Al can be used. By using a soft magnetic material as the first electrode 51 and the second electrode 52, it is possible to reduce external magnetic noise that affects the strain resistance changing portion 50s. For example, permalloy (NiFe alloy) or silicon steel (FeSi alloy) can be used as the soft magnetic material. The strain sensing element unit 50 is covered with an insulator such as aluminum oxide (for example, Al ₂ O ₃ ) or silicon oxide (for example, SiO ₂ ).

The magnetization direction of at least one of the first magnetic layer 10 and the second magnetic layer 20 changes according to the stress. The absolute value of the magnetostriction constant of at least one of the magnetic layers (magnetic layer whose magnetization direction changes according to stress) is set to 10 ⁻⁵ or more, for example. Thereby, the direction of magnetization changes according to the strain applied from the outside by the inverse magnetostriction effect. For example, at least one of the first magnetic layer 10 and the second magnetic layer 20 is made of a metal such as Fe, Co, Ni, or an alloy containing them. The magnetostriction constant is set to be large depending on the element used and the additive element.

For example, an oxide such as MgO is used for the intermediate layer 30. The magnetic layer on the MgO layer generally has a positive magnetostriction constant. For example, when the first magnetic layer 10 is formed on the intermediate layer 30, a magnetization free layer having a laminated structure of CoFeB / CoFe / NiFe is used as the first magnetic layer 10. When the uppermost NiFe layer is Ni-rich, the magnetostriction constant of the NiFe layer is negative and its absolute value increases. In order to suppress the cancellation of the positive magnetostriction on the oxide layer, the Ni composition of the uppermost NiFe layer is not made Ni rich as compared with the permalloy composition of Ni ₈₁ Fe ₁₉ which is generally used. Specifically, the Ni ratio in the uppermost NiFe layer is preferably less than 80 atomic percent (atomic%). When the first magnetic layer 10 is a magnetization free layer, the thickness of the first magnetic layer 10 is preferably, for example, 1 nm or more and 20 nm or less.

  In the case where the first magnetic layer 10 is a magnetization free layer, the second magnetic layer 20 may be a magnetization fixed layer or a magnetization free layer. When the second magnetic layer 20 is a fixed magnetization layer, the direction of magnetization of the second magnetic layer 20 does not substantially change even when strain is applied from the outside. The electrical resistance changes depending on the relative magnetization angle between the first magnetic layer 10 and the second magnetic layer 20. The presence or absence of distortion is detected by the difference in electrical resistance.

  When both the first magnetic layer 10 and the second magnetic layer 20 are magnetization free layers, for example, the magnetostriction constant of the first magnetic layer 10 is set to be different from the magnetostriction constant of the second magnetic layer 20. The

  Whether the second magnetic layer 20 is a magnetization fixed layer or a magnetization free layer, the thickness of the second magnetic layer 20 is preferably, for example, 1 nm or more and 20 nm or less.

  For example, when the second magnetic layer 20 is a magnetization fixed layer, for example, a synthetic AF structure using a laminated structure of a diamagnetic layer / magnetic layer / Ru layer / magnetic layer is used for the second magnetic layer 20. Can do. For example, IrMn is used for the diamagnetic layer. Further, as will be described later, a hard bias layer may be provided.

  In the strain sensing element unit 50, the spin of the magnetic layer is used. An extremely small size is sufficient for the area required for the strain sensing element unit 50. The area of the strain sensing element 50 is, for example, about 10 nm × 10 nm to 20 nm × 20 nm or less.

  For example, the length along the X-axis direction (the first direction from the fixed portion 63 toward the movable portion 64) of the strain sensing element unit 50 is 20 nm or more and 10 μm or less. The length along the X-axis direction of the strain sensing element unit 50 is preferably 100 nm or more and 3 μm or less.

  For example, the length of the strain sensing element unit 50 along the Y-axis direction (direction perpendicular to the X-axis direction and parallel to the XY plane) is 20 nm or more and 10 μm or less. The length along the Y-axis direction of the strain sensing element unit 50 is preferably 100 nm or more and 3 μm or less.

  For example, the length along the Z-axis direction (direction perpendicular to the XY plane) of the strain sensing element unit 50 is 20 nm or more and 100 nm or less.

  The length of the strain sensing element unit 50 along the X-axis direction may be the same as or different from the length of the strain sensing element unit 50 along the Y-axis direction. Shape magnetic anisotropy occurs when the length of the strain sensing element unit 50 along the X-axis direction is different from the length of the strain sensing element unit 50 along the Y-axis direction. Thereby, the same effect as that obtained in the hard bias layer can be obtained.

  The direction of the current flowing in the strain sensing element unit 50 may be the direction from the first magnetic layer 10 toward the second magnetic layer 20 or the direction from the second magnetic layer 20 toward the first magnetic layer 10.

FIG. 5 is a schematic perspective view illustrating the configuration of a part of the strain detection device according to the first embodiment.
As shown in FIG. 5, in this example, the strain sensing element unit 50 further includes bias layers 55a and 55b (hard bias layers). The bias layers 55a and 55b are provided to face the strain resistance change unit 50s.

  In this example, the second magnetic layer 20 is a magnetization fixed layer. The bias layers 55 a and 55 b are juxtaposed with the second magnetic layer 20. Between the bias layers 55a and 55b, the strain resistance changing unit 50s is disposed. An insulating layer 54a is provided between the bias layer 55a and the strain resistance changing portion 50s. An insulating layer 54b is provided between the bias layer 55b and the strain resistance changing portion 50s.

  The bias layers 55 a and 55 b apply a bias magnetic field to the first magnetic layer 10. Thereby, the magnetization direction of the first magnetic layer 10 can be biased to an appropriate position, and a single magnetic domain can be formed.

  Each of the bias layers 55a and 55b (in this example, the length along the Y-axis direction) is, for example, not less than 100 nm and not more than 10 μm.

  The size of each of the insulating layers 54a and 54b (in this example, the length along the Y-axis direction) is, for example, 1 nm or more and 5 nm or less.

  In the strain sensing device 310 according to the present embodiment, the strain sensing element unit 50 is formed above the substrate on which the transistor 112 is formed. The transistor 112 and the strain sensing element unit 50 are connected not by a wire used in the mounting process but by a wiring layer that is consistently formed in the wafer manufacturing process. As a result, the strain detection device can be downsized, and the strain can be detected with high sensitivity in a minute region.

  By forming a transistor and a strain sensing element on a common substrate, for example, a circuit (processing circuit 113, etc.) that processes information obtained by a sensor, such as an arithmetic circuit, an amplifier circuit, and a communication circuit, is detected. It can be formed on the same substrate as the element portion 50. By forming the high-sensitivity sensor integrally with the arithmetic circuit, it is possible to reduce the size of the system as a whole. Further, low power consumption can be realized.

  In the present embodiment, for example, a high-sensitivity sensor is used, and a circuit that performs arithmetic processing on a signal obtained by the sensor is realized as a system-on-chip on a common substrate.

  When the movable portion 64 (diaphragm portion 61b) is provided above the transistor 112, the practically obtained movable range (distance along the Z-axis direction) is 10 μm or less. In practice, a smaller movable range is easier to form. In order to accurately measure strain even in such a small movable range, a very sensitive sensor is required as a strain sensor. Further, in order to accurately measure the pressure even in a minute point contact state, it is desirable that the area of the diaphragm is small. If the diaphragm is small, the amount of deflection will be small unless the film thickness of the diaphragm is reduced, and measurement with high sensitivity will not be possible. In order to be used as a pressure sensor in a state that is not easily broken in the external environment, the film thickness of the diaphragm cannot be reduced too much. Therefore, when the diaphragm diameter is reduced, the sensitivity of the pressure sensor is also deteriorated.

  As described above, in order to realize the two situations of the diaphragm having a small vertical movable range and a diaphragm having a small diameter, a strain sensor having high sensitivity is desired. Since the strain sensing element unit 50 according to the embodiment satisfies this requirement, this is possible.

  In the strain sensing element unit 50 according to the embodiment, a high strain sensitivity α can be realized even with a small element area without substantially depending on the size of the element. The strain sensitivity α is expressed by, for example, α = (ΔR / Rmin) / ε. Rmin is a resistance in a low state, and ΔR is a resistance change amount. ε is strain and is expressed by Δl / l. Here, l is an initial length, and Δl is a displacement amount.

For example, in the case of a piezoresistive strain sensor using Si, the strain sensitivity α is determined by the material used. For example, the strain sensitivity α is about 130. In the case of a piezoresistive strain sensor using Si, an element area of about 100 μm per side is required. The strain sensitivity α per unit area is, for example, 130/100 μm ² and is about 10 ¹⁰ .

On the other hand, in the case of the strain sensing element 50 (spin strain sensor) according to the present embodiment, there is no upper limit to the strain sensitivity α, and a strain sensitivity of about 1000 can be easily realized. The element area necessary for realizing the strain sensitivity α is about 20 nm on a side. For this reason, for example, the strain sensitivity α per unit area is about 10 ¹⁷ . As described above, in the embodiment, the sensitivity per unit area can be improved by about 7 digits as compared with the pressure sensor of the conventional MEMS structure (Si-MEMS: Micro Electro Mechanical Systems) using Si. Become.

  According to the present embodiment, high strain sensitivity can be obtained by using the spin strain sensor technology, and for example, a strain / pressure sensor in which an arithmetic circuit is embedded can be realized.

FIG. 6A to FIG. 6C are schematic views illustrating the configuration of a part of the strain detection device according to the first embodiment.
These drawings illustrate the configuration of the detection unit 121 which is an example of the detection unit 120. FIG. 6A is a perspective view. FIG. 6B is a plan view. FIG. 6C is a cross-sectional view taken along line A1-A2 of FIG.

  As shown in FIG. 6A, the movable portion 64 moves along the Z-axis direction in the cavity 70. The thickness Lz (length along the Z-axis direction) of the detection unit 121 (detection unit 120) is, for example, not less than 1 μm and not more than 10 μm. In this example, a diaphragm portion 61b is provided. The size of the movable portion 64 is the size of the diaphragm portion 61b.

  As shown in FIG. 6B, the movable portion 64 includes a diaphragm portion 61b. The width of the diaphragm portion 61b along the Y-axis direction (direction perpendicular to the X-axis direction from the fixed portion 63 toward the movable portion 64 and parallel to the main surface 111a) is the first wiring layer 61 and the second wiring. The width of the layer 62 is wider than the width along the Y-axis direction.

  The length Lx of the movable portion 64 along the X-axis direction (corresponding to the length along the X-axis direction of the diaphragm portion 61b) is 10 μm or more and 500 μm or less. The length Lx is preferably 50 μm or more and 200 μm or less. The length Ly of the movable portion 64 along the Y-axis direction (corresponding to the length of the diaphragm portion 61b along the Y-axis direction) is 10 μm or more and 500 μm or less. The length Ly is preferably 50 μm or more and 200 μm or less.

  The length Lx is preferably not less than the length Ly. For example, the length Lx is not less than 1.5 times and not more than 5 times the length Ly.

  A part of the diaphragm portion 61 b may be fixed to the non-hollow portion 71 as the fixed portion 63. The width L1 (width along the X-axis direction) of the portion fixed to the non-hollow portion 71 in the diaphragm portion 61b is, for example, 1/10 or more and 1/3 or less of the length Lx.

  As shown in FIG. 6C, the movable portion 64 (diaphragm portion 61b) bends along the Z-axis direction. A height Lz70 along the Z-axis direction of the cavity 70 is, for example, not less than 1 μm and not more than 10 μm. The movable part 64 moves in the cavity 70. The distance of movement along the Z-axis direction (distance along the Z-axis direction) of the tip of the movable portion 64 (diaphragm portion 61b) is, for example, 1 μm or more and 10 μm or less. The distance between the movable part 64 and the transistor 112 (semiconductor circuit part 110) varies, for example, in the range of 1 μm to 10 μm.

  Stress is applied to the strain sensing element portion 50 in accordance with the movement of the movable portion 64 (diaphragm portion 61b). The electrical resistance of the strain sensing element unit 50 changes according to this stress.

  A current is passed through the strain sensing element 50 through the first embedded wiring 61c, the second embedded wiring 62c, the first wiring layer 61, and the second wiring layer 62, and the electrical resistance is detected. Thereby, the stress applied to the movable part 64 (diaphragm part 61b) is detected. That is, the strain applied to the strain detection device 310 is detected.

  For the first embedded wiring 61c, the second embedded wiring 62c, the first wiring layer 61, and the second wiring layer 62, for example, a metal such as Cu and Al is used.

For the diaphragm portion 61b, for example, a single layer film or a laminated film of SiO ₂ , amorphous Si, various oxides, and various nitrides is used. As will be described later, the first wiring layer 61 (at least one of the first wiring layer 61 and the second wiring layer 62) can also function as the diaphragm portion 61b. In this case, a metal such as Cu and Al is used for the diaphragm portion 61b (first wiring layer 61). Thus, in the embodiment, a configuration of a diaphragm mixed with the transistor 112 is employed.

  On the other hand, SOI (Silicon on insulator) substrates are used in conventional Si-MEMS. In this case, the back surface of the substrate on which the SOI is provided (Si single crystal substrate) is selectively removed, the SOI oxide film becomes a diaphragm, and the SOI silicon film becomes an active part. Since the conventional configuration is based on the idea of using an SOI substrate, usable film materials are limited to an oxide film and a silicon film formed thereon. This is because etching using an RIE (Reactive Ion Etching) process or the like is necessary to use single crystal Si as a strain sensor. Since it is a process of etching from the back surface of the substrate, it is a conventional idea that it is extremely difficult to form a diaphragm on a transistor formed on the substrate. Further, when single crystal Si is used as a strain sensor in this way, the material of the diaphragm inevitably becomes a very limited material as described above.

  On the other hand, in the embodiment, a sacrificial layer described later is formed on the transistor 112, and the movable portion 64 is formed on the sacrificial layer. For example, a film formed on a sacrificial layer formed on the transistor 112 is used as the diaphragm portion 61b. Therefore, any material can be used for the diaphragm portion 61b. Thereby, the diaphragm characteristic can be improved by appropriately selecting the material, and further, for example, the stress of the diaphragm portion 61b can be made substantially zero. In addition, although it is extremely difficult to form single crystal Si on a diaphragm formed on a base other than an SOI substrate, it can be formed with a spin strain sensor.

  In the embodiment, a configuration in which the movable portion 64 is formed on the sacrificial layer and the sacrificial layer is removed from the upper surface of the sacrificial layer is employed. In this case, since it is difficult to increase the thickness of the sacrificial layer, the movable range of the movable portion 64 is limited compared to Si-MEMS using an SOI substrate. That is, the movable amount of the diaphragm is small, and the strain change amount is small. The present inventor has considered that a high strain sensitivity can be realized in a spin strain sensor, and therefore it can function sufficiently as a sensor even when the movable amount of the diaphragm is small.

  The thickness of the diaphragm part 61b is, for example, not less than 50 nm and not more than 1 μm. It is preferable that it is 100 nm or more and 500 nm or less.

As shown in FIG. 6C, an insulating layer 65 (for example, an SiO ₂ layer) is provided between the first wiring layer 61 and the second wiring layer 62. In addition, an insulating layer 66 (for example, a SiO ₂ layer) is provided in contact with the end of the first wiring layer 61 on the movable part 64 side and the end of the second wiring layer 62 on the movable part 64 side.

  By using the detection unit 120 (detection unit 121) having such a configuration, distortion can be detected with high sensitivity in a minute region.

  In this example, the shape of the movable part 64 (for example, the diaphragm part 61b) and the cavity part 70 when viewed along the Z-axis direction is substantially rectangular, but the embodiment is not limited thereto. These shapes are arbitrary.

FIG. 7A to FIG. 7C are schematic views illustrating the configuration of a part of the strain detection device according to the first embodiment.
These drawings show the configuration of the detection unit 122 which is one example of the detection unit 120. FIG. 7A is a perspective view. FIG. 7B is a plan view. FIG. 7C is a cross-sectional view taken along line A1-A2 of FIG.

As shown in FIGS. 7A to 7C, in this example, the shape of the movable portion 64 (for example, the diaphragm portion 61b) when viewed along the Z-axis direction is substantially circular (including a flat circle). ). The shape of the cavity 70 when viewed along the Z-axis direction is also substantially circular (including a flat circle).
Also in this case, distortion can be detected with high sensitivity in a minute region.

FIG. 8A to FIG. 8C are schematic views illustrating the configuration of a part of the strain detection device according to the first embodiment.
These drawings illustrate the configuration of a detection unit 123 that is one example of the detection unit 120. FIG. 8A is a perspective view. FIG. 8B is a plan view. FIG. 8C is a cross-sectional view taken along line A1-A2 of FIG.

As shown in FIGS. 8A to 8C, in this example, the end of the movable part 64 is connected to the fixed part 63, and the other end of the movable part 64 (three in this example) End) is fixed to the non-hollow part 71 by fixing parts 67a, 67b and 67c. The movable part 64 is supported at four places by the fixed part 63 and the three fixed parts. For the fixing parts 67a, 67b and 67c, for example, an insulating layer such as SiO ₂ is used.

  In this configuration, as shown in FIG. 8C, the central portion of the movable portion 64 moves along the Z-axis direction.

  In this example, the movable portion 64 is supported at four locations, but it can also be considered that the movable portion 64 is provided with a hole 64 h penetrating the movable portion 64.

  Thus, the movable part 64 may be supported by a plurality of locations. Also in this case, distortion can be detected with high sensitivity in a minute region.

  In the strain detection apparatus 310 according to the present embodiment, some action is applied from the outside to the movable portion 64 (for example, the diaphragm portion 61b), and the shape of the movable portion 64 (for example, the diaphragm portion 61b) changes. Along with this change in shape, distortion occurs in the strain detection element unit 50, and this distortion is detected as a change in electrical resistance. The strain detection device 310 can be used as a pressure sensor, for example. Further, the strain detection device 310 can be used as an acceleration sensor. Further, the strain detection device 310 can be used as a temperature sensor. When using as a temperature sensor, the movable part 64 (for example, the diaphragm part 61b) expands and contracts according to temperature, and the distortion by this is detected. For example, a highly sensitive temperature sensor can be provided by using a material having a large temperature expansion coefficient as the movable portion 64 (for example, the diaphragm portion 61b).

  FIG. 9 is a schematic perspective view illustrating the configuration of another strain detection apparatus according to the first embodiment. As shown in FIG. 9, the strain detection device 320 according to the present embodiment further includes a pressure transducer unit 130 provided on the detection unit 120.

  The pressure transducer part 130 has a sensor protection part 132 and a pressure transducer cavity part 131. The pressure transducer cavity 131 is, for example, a portion where a material for forming the sensor protection part 132 is not provided.

FIG. 10 is a schematic perspective view illustrating the configuration of a part of another strain detection apparatus according to the first embodiment.
FIG. 10 shows one example of the configuration of the pressure transducer unit 130.
For the sensor protection part 132, for example, an insulating material such as Al ₂ O ₃ and SiO ₂ is used. The shape of the pressure transducer cavity 131 when viewed in the Z-axis direction is, for example, along the shape of the cavity 70 of the detector 120 when viewed in the Z-axis direction. However, the shape of the pressure transducer cavity 131 is arbitrary. For example, air is filled in the pressure transducer cavity 131. The pressure transducer cavity 131 transmits, for example, air vibrations to the strain sensing element unit 50.

  By applying this configuration, it is possible to produce a microphone that detects sound. As described above, the strain detection device 320 according to the embodiment can be applied to a detection device that detects vibration in an arbitrary medium such as sound.

  By providing the pressure transducer part 130, a change in external pressure can be transmitted to the strain sensing element part 50 more efficiently. Thereby, more accurate and more stable detection is possible.

  In this example, the pressure transducer cavity 131 has a circular shape (including a flat circle) when viewed in the Z-axis direction, and its diameter 131w is, for example, not less than 1 μm and not more than 500 nm. The thickness t130 of the sensor protection part 132 is, for example, not less than 300 nm and not more than 100 μm. However, the embodiment is not limited to this. These shapes and sizes are arbitrary.

FIG. 11 is a schematic perspective view illustrating the configuration of a part of another strain detection apparatus according to the first embodiment.
FIG. 11 shows another example of the configuration of the pressure transducer unit 130.
In this example, for example, a pressure transducer material 133 is disposed inside the pressure transducer cavity 131. For the pressure transducer material 133, for example, gel or liquid such as silicone is used.

  In the case of using this configuration, for example, mounting is performed such that pressure is transmitted between the pressure transducer 130 and the outside in the mounting process of manufacturing the strain sensing device.

  The processing circuit 113 described with reference to FIG. 1 can perform, for example, amplification processing of signals obtained by the strain sensing element unit 50, A / D conversion processing of sensor signals, and the like. As described above, the semiconductor circuit unit 110 processes a signal based on the current flowing through the strain sensing element unit 50. The processing circuit 113 can further perform processing for transmitting sensor signal data to another electronic device. Furthermore, the processing circuit 113 can also perform data mining processing (for example, noise removal processing) for extracting meaningful information from the sensor signal.

FIG. 12A to FIG. 12C are schematic views illustrating the configurations of another strain detection device and an electronic device according to the first embodiment.
FIG. 12A is a schematic perspective view illustrating the configuration of another strain detection device 311 according to this embodiment. FIG. 12B shows an example of the transmission circuit 117 provided in the distortion detection device 311. FIG. 12C illustrates an example of the electronic device 118d used in combination with the strain detection device 311.

  As illustrated in FIG. 12A, the strain detection device 311 further includes an antenna 115 and an electrical wiring 116 in addition to the semiconductor circuit unit 110 and the detection unit 120. The antenna 115 is connected to the semiconductor circuit unit 110 via the electrical wiring 116.

  As illustrated in FIG. 12B, the transmission circuit 117 is provided in the distortion detection device 311. The transmission circuit 117 wirelessly transmits data based on the electrical signal flowing through the strain sensing element unit 50. At least a part of the transmission circuit 117 can be provided in the semiconductor circuit portion 110. The semiconductor circuit unit 110 can include a transmission circuit 117 that wirelessly transmits data based on an electrical signal flowing through the strain sensing element unit 50.

  As illustrated in FIG. 12C, the electronic device 118 d used in combination with the strain detection device 311 is provided with a receiving unit 118. For example, an electronic device such as a portable terminal is used as the electronic device 118d.

  For example, it is more convenient to use a combination of the distortion detection device 311 including the transmission circuit 117 and the electronic device 118d including the reception unit 118.

  In this example, as illustrated in FIG. 12B, the distortion detection device 311 is provided with a reception circuit 117r that receives a control signal from the electronic device 118d. For example, at least a part of the reception circuit 117r can be provided in the semiconductor circuit unit 110. By providing the receiving circuit 117r, the operation of the distortion detection device 311 can be controlled by operating the electronic device 118d, for example.

  As illustrated in FIG. 12B, in this example, the distortion detection device 311 includes, as the transmission circuit 117, for example, an AD converter 117a connected to the distortion detection element unit 50, a Manchester encoding unit 117b, Is provided. Further, a switching unit 117c is provided to switch between transmission and reception. This switching is controlled by the timing controller 117d. As the reception circuit 117r, a data correction unit 117e, a synchronization unit 117f, and a determination unit 117g are provided. Further, a voltage controlled oscillator 117h (VCO) is provided.

  On the other hand, as shown in FIG. 12C, the electronic device 118d includes a Manchester encoding unit 117b, a switching unit 117c, a timing controller 117d, a data correction unit 117e, a synchronization unit 117f, a determination unit 117g, and a voltage controlled oscillator 117h. And a storage unit 118a and a central processing unit 118b (CPU).

  Hereinafter, as an example of a manufacturing method of the strain detection device 310 according to the present embodiment, a strain detection device having a square diaphragm portion 61b like the detection unit 121 illustrated in FIGS. 6A to 6C is manufactured. An example of the method will be described.

13 (a), 13 (b), 14 (a), 14 (b), 15 (a), 15 (b), 16 (a), 16 (b), and 17 (A), FIG. 17 (b), FIG. 18 (a), FIG. 18 (b), FIG. 19 (a), FIG. 19 (b), FIG. 20 (a), FIG. 20 (b), FIG. ), FIG. 21B, FIG. 22A, FIG. 22B, FIG. 23A, FIG. 23B, FIG. 24A, and FIG. 24B are the first embodiment. It is a schematic diagram which illustrates the manufacturing method of the distortion | strain detector concerning this.
Fig.13 (a)-FIG.24 (a) are typical top views, and FIG.13 (b)-FIG.24 (b) are typical sectional drawings.

  As illustrated in FIGS. 13A and 13B, the semiconductor layer 112 </ b> M is provided on the surface portion of the semiconductor substrate 111. An element isolation insulating layer 112I is formed on the upper surface of the semiconductor layer 112M. A gate 112G is formed on the semiconductor layer 112M via an insulating layer (not shown). A source 112S and a drain 112D are formed on both sides of the gate 112G, and the transistor 112 is formed. An interlayer insulating film 114a is formed thereon, and an interlayer insulating film 114b is further formed.

  In the region to be the non-cavity 71, a trench and a hole are formed in a part of the interlayer insulating films 114a and 114b. The connection pillars 114c to 114e are formed by embedding a conductive material in the holes. In this example, the connection pillar 114c is connected to the source 112S of one transistor, and the connection pillar 114d is connected to the drain 112D. The connection pillar 114e is connected to the source 112S of another transistor. A conductive material is embedded in the trench to form the wiring part 114f and the wiring part 114g. The wiring part 114f is connected to the connection pillar 114c and the connection pillar 114d. The wiring part 114g is connected to the connection pillar 114e. An interlayer insulating film 114h is formed on the interlayer insulating film 114b.

As shown in FIGS. 14A and 14B, SiO ₂ to be the interlayer insulating film 114i is formed on the interlayer insulating film 114h by, for example, CVD. A hole is formed in a predetermined position of the interlayer insulating film 114i, a conductive material (metal material) is embedded, and the upper surface is planarized by CMP. Thereby, the connection pillar 114j connected to the wiring part 114f and the connection pillar 114k connected to the wiring part 114g are formed.

  As shown in FIGS. 15A and 15B, a groove is formed in a region to be the cavity 70 of the interlayer insulating film 114i, and a sacrificial layer 114l is embedded in the groove. For example, SiGe is used for the sacrificial layer 114l. A material that can be formed at a low temperature is used for the sacrificial layer 114l.

As shown in FIGS. 16A and 16B, an insulating film 61bf (SiO ₂ or the like) to be the diaphragm portion 61b is formed on the interlayer insulating film 114i and the sacrificial layer 114l. A hole is provided in the insulating film 61bf, and a conductive material (metal) is embedded in the hole to form the connection pillar 61fa and the connection pillar 62fa. The connection pillar 61fa is connected to the connection pillar 114k, and the connection pillar 62fa is connected to the connection pillar 114j.

  As shown in FIGS. 17A and 17B, the conductive layer 61f that becomes the first wiring layer 61 is formed on the insulating film 61bf, the connection pillar 61fa, and the connection pillar 62fa.

  As illustrated in FIG. 18A and FIG. 18B, a laminated film 50f that forms the strain sensing element unit 50 is formed on the conductive layer 61f.

As shown in FIGS. 19A and 19B, the laminated film 50f is processed into a predetermined shape, and an insulating film 65f (SiO ₂ or the like) to be the insulating layer 65 is formed thereon.

  As shown in FIGS. 20A and 20B, a part of the insulating film 65f is removed, and the conductive layer 61f is processed into a predetermined shape. Thereby, the shape of the first wiring layer 61 is formed. At this time, a part of the conductive layer 61f becomes the connection pillar 62fb connected to the connection pillar 62fa. Further, an insulating film 66f to be the insulating layer 66 is formed thereon.

  As shown in FIGS. 21A and 21B, an opening 66p is formed in the insulating film 66f. Thereby, the connection pillar 62fb is exposed.

  As shown in FIGS. 22A and 22B, a conductive layer 62f to be the second wiring layer 62 is formed thereon. A part of the conductive layer 62f is connected to the connection pillar 62fb.

  As shown in FIGS. 23A and 23B, the conductive layer 62f is processed into a predetermined shape. Thereby, the second wiring layer 62 is formed. The second wiring layer 62 is connected to the connection pillar 62fb.

As shown in FIGS. 24A and 24B, an opening 66o having a predetermined shape is formed in the insulating film 66f. The insulating film 61bf is processed through the opening 66o, and the sacrificial layer 114l is removed. Thereby, the cavity part 70 is formed. In removing the sacrificial layer 114l, for example, the sacrificial layer 114l is removed (for example, etched) from the upper surface of the sacrificial layer 114l (the surface of the sacrificial layer 114l opposite to the semiconductor substrate 111).
Thereby, the distortion | strain detector 310 which concerns on this embodiment can be formed.

FIG. 25A to FIG. 25C are schematic views illustrating the configuration of a part of the strain detection apparatus according to the first embodiment.
These drawings illustrate the configuration of a detection unit 124 that is one example of the detection unit 120. FIG. 25A is a perspective view. FIG. 25B is a plan view. FIG. 25C is a cross-sectional view taken along line A1-A2 of FIG.

  As shown in FIG. 25A, in this example, the diaphragm portion 61b is not provided, and the first wiring layer 61 performs the function of the diaphragm portion 61b.

  The first wiring layer 61 is provided below the second wiring layer 62. That is, the first wiring layer 61 is provided between the second wiring layer 62 and the semiconductor circuit unit 110 (not shown in FIG. 25A).

  The width along the Y-axis direction (the direction perpendicular to the X-axis direction from the fixed portion 63 toward the movable portion 64 and parallel to the main surface 111a) in the movable portion 64 of the first wiring layer 61 is the second wiring. The width of the movable portion 64 of the layer 62 is wider than the width along the Y-axis direction.

  When the diaphragm portion 61 b is not provided, the length Ly in the Y-axis direction of the movable portion 64 corresponds to the length in the Y-axis direction of the movable portion 64 of the first wiring layer 61. The length Lx in the X axis direction of the movable portion 64 corresponds to the length in the X axis direction of the movable portion 64 of the first wiring layer 61.

  The first wiring layer 61 fulfills the function of the diaphragm portion 61b, thereby simplifying the configuration and simplifying the manufacturing process. Such a detection unit 124 can also detect distortion with high sensitivity in a minute region.

  Hereinafter, an example of a method for manufacturing a strain detection apparatus having the detection unit 124 illustrated in FIGS. 25A to 25C will be described.

26 (a), 26 (b), 27 (a), 27 (b), 28 (a), 28 (b), 29 (a), 29 (b), and 30. (A), FIG. 30 (b), FIG. 31 (a), FIG. 31 (b), FIG. 32 (a), FIG. 32 (b), FIG. 33 (a) and FIG. It is a schematic diagram which illustrates the manufacturing method of the distortion | strain detector which concerns on embodiment.
Fig.26 (a)-FIG.33 (a) are typical top views, and FIG.26 (b)-FIG.33 (b) is typical sectional drawing. Below, the process after the process similar to having demonstrated regarding Fig.13 (a)-FIG.15 (b) is demonstrated.

  As shown in FIGS. 26A and 26B, a conductive layer 61f to be the first wiring layer 61 is formed on the connection pillar 114j, the connection pillar 114k, the interlayer insulating film 114i, and the sacrificial layer 114l. .

  As shown in FIGS. 27A and 27B, a laminated film 50f to be the strain sensing element unit 50 is formed on the conductive layer 61f.

As shown in FIGS. 28A and 28B, the laminated film 50f is processed into a predetermined shape, and an insulating film 65f (SiO ₂ or the like) to be the insulating layer 65 is formed thereon.

  As shown in FIGS. 29A and 29B, a part of the insulating film 65f is removed, and the conductive layer 61f is processed into a predetermined shape. Thereby, the shape of the first wiring layer 61 is formed. The first wiring layer 61 is connected to the connection pillar 114k. At this time, a part of the conductive layer 61f becomes the connection pillar 62fb connected to the connection pillar 114j. Further, an insulating film 66f to be the insulating layer 66 is formed thereon.

  As shown in FIGS. 30A and 30B, an opening 66p is formed in the insulating film 66f. Thereby, the connection pillar 62fb is exposed.

  As shown in FIGS. 31A and 31B, a conductive layer 62f to be the second wiring layer 62 is formed thereon. A part of the conductive layer 62f is connected to the connection pillar 62fb.

  As shown in FIGS. 32A and 32B, the conductive layer 62f is processed into a predetermined shape. Thereby, the second wiring layer 62 is formed. The second wiring layer 62 is connected to the connection pillar 62fb.

As shown in FIGS. 33A and 33B, an opening 66o having a predetermined shape is formed in the insulating film 66f. The sacrificial layer 114l is removed through the opening 66o. Thereby, the cavity part 70 is formed.
Thereby, a strain detection device having the detection unit 124 can be formed. In this configuration, the first wiring layer 61 performs the function of the diaphragm portion 61b, and the configuration is simple. Therefore, the manufacturing is also simplified.

FIG. 34 is a schematic perspective view illustrating the configuration of another strain detection apparatus according to the first embodiment.
As shown in FIG. 34, in another strain detection device 330 according to the present embodiment, the first embedded wiring 61 c and the second embedded wiring 62 c of the detection unit 120 include the transistor 112 provided below the cavity 70. And are electrically connected.

  In this example, the current flowing through the strain sensing element unit 50 is provided below the cavity 70 via the first wiring layer 61, the second wiring layer 62, the first embedded wiring 61c, and the second embedded wiring 62c. It flows to the transistor 112.

  With the configuration in which the transistor 112 provided under the strain sensing element unit 50 detects the resistance change of the strain sensing element unit 50, for example, the chip area can be further reduced.

(Second Embodiment)
The present embodiment relates to a method for manufacturing a strain detection device.
FIG. 35 is a flowchart illustrating the method for manufacturing the strain sensing device according to the second embodiment.
As shown in FIG. 35, in the method for manufacturing the strain sensing device according to the present embodiment, the transistor 112 is formed on the semiconductor substrate 111 (step S110). For example, the processing described with reference to FIGS. 13A and 13B is performed.

  In this manufacturing method, an interlayer insulating layer is formed on the semiconductor substrate 111, and a sacrificial layer 114l is formed on the transistor 112 (step S120). For example, the processing described with reference to FIGS. 14A to 15B is performed. This interlayer insulating layer includes, for example, an interlayer insulating film 114i.

  A first conductive layer (conductive layer 61f) to be the first wiring layer 61 is formed on the interlayer insulating layer (for example, the interlayer insulating film 114i) and the sacrificial layer 114l (step S130). For example, the processing described with reference to FIGS. 17A and 17B is performed. Prior to this, the diaphragm portion 61b may be formed.

  The strain sensing element unit 50 including the first magnetic layer 10 is formed on the first conductive layer (conductive layer 61f) on the sacrificial layer 114l (step S140). For example, the processing described with reference to FIGS. 18A to 19B is performed.

  A second conductive layer (conductive layer 62f) to be the second wiring layer 62 is formed on the strain sensing element unit 50 (step S150). For example, the processing described with reference to FIGS. 22A to 23B is performed.

  In the interlayer insulating layer, a first embedded wiring 61c that electrically connects the first conductive layer (conductive layer 61f) to the semiconductor substrate 111, and a second conductive layer (conductive layer 62f) that is electrically connected to the semiconductor substrate 111. A second embedded wiring 62c to be connected is formed (step S160). For example, with reference to FIGS. 13 (a), 13 (b), 14 (a), 14 (b), 16 (a), 16 (b), 20 (a) and 20 (b). Perform the process described. For example, step S160 is performed once or by a plurality of processes in at least one of the steps S110 to S150 and after step S150.

  Then, the sacrificial layer 114l is removed (step S170). For example, the processing described with reference to FIGS. 24A and 24B is performed.

  Thereby, the manufacturing method of the distortion | strain detection apparatus which can detect distortion | strain in a micro area | region with high sensitivity can be provided.

  In the step of removing the sacrificial layer 114l (step S170), for example, the sacrificial layer 114l is removed (for example, etched) from the upper surface of the sacrificial layer 114l (the surface of the sacrificial layer 114l opposite to the semiconductor substrate 111). Including.

  According to the embodiment, a strain detection device capable of detecting a strain with high sensitivity in a minute region and a manufacturing method thereof are provided.

  The embodiments of the present invention have been described above with reference to specific examples. However, embodiments of the present invention are not limited to these specific examples. For example, a semiconductor circuit unit, a semiconductor substrate, a transistor, a strain detection unit, a fixed part, a movable part, a strain detection element unit, a first magnetic layer, a second magnetic layer, an intermediate layer, a first wiring layer, included in the strain detection device, The specific configuration of each element such as the second wiring layer, the diaphragm section, the first embedded wiring, the second embedded wiring, and the transducer section is similarly selected by a person skilled in the art by appropriately selecting from a known range. It is included in the scope of the present invention as long as the same effect can be obtained.

  Moreover, what combined any two or more elements of each specific example in the technically possible range is also included in the scope of the present invention as long as the gist of the present invention is included.

  In addition, based on the strain detection device and its manufacturing method described above as an embodiment of the present invention, all strain detection devices and methods for manufacturing the same that can be implemented by those skilled in the art are also included in the gist of the present invention. As long as it is included, it belongs to the scope of the present invention.

  In addition, in the category of the idea of the present invention, those skilled in the art can conceive of various changes and modifications, and it is understood that these changes and modifications also belong to the scope of the present invention. .

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

  DESCRIPTION OF SYMBOLS 10 ... 1st magnetic layer, 10a ... Magnetic laminated film, 10b ... High magnetostrictive magnetic film, 20 ... 2nd magnetic layer, 30 ... Intermediate layer, 41 ... Buffer layer, 42 ... Antiferromagnetic layer, 43 ... Magnetic layer, 44 ... Ru layer, 45 ... cap layer, 50 ... strain detecting element part, 50f ... multilayer film, 50s ... strain resistance changing part, 51 ... first electrode, 52 ... second electrode, 54a, 54b ... insulating layer, 55a, 55b DESCRIPTION OF SYMBOLS ... Bias layer 60 ... Movable beam 61 ... 1st wiring layer 61b ... Diaphragm part 61bf ... Insulating film 61c ... 1st embedded wiring 61f ... Conductive layer 61fa ... Connection pillar 62 ... 2nd wiring layer, 62c ... second embedded wiring, 62f ... conductive layer, 62fa, 62fb ... connection pillar, 63 ... fixed part, 64 ... movable part, 64h ... hole, 65 ... insulating layer, 65f ... insulating film, 6 ... Insulating layer, 66f ... Insulating film, 66o, 66p ... Opening, 67a-67c ... Fixed part, 70 ... Hollow part, 71 ... Non-hollow part, 110 ... Semiconductor circuit part, 111 ... Semiconductor substrate, 111a ... Main surface, 111b ... element region 112 ... transistor 112D ... drain 112G ... gate 112I ... element isolation insulating layer 112M ... semiconductor layer 112S ... source 113 ... processing circuit 114a, 114b ... interlayer insulating film 114c-114e ... Connection pillar, 114f, 114g ... wiring section, 114h, 114i ... interlayer insulation film, 114j, 114k ... connection pillar, 114l ... sacrificial layer, 115 ... antenna, 116 ... electrical wiring, 117 ... transmission circuit, 117a ... AD converter, 117b ... Manchester encoding section, 117c ... switching section 117d: Timing controller, 117e: Data correction unit, 117f: Synchronization unit, 117g ... Determination unit, 117h ... Voltage controlled oscillator, 117r ... Reception circuit, 118 ... Reception unit, 118a ... Storage unit, 118b ... Central processing unit, 118d ... Electronic equipment, 120 to 124 ... detection unit, 130 ... pressure transducer, 131 ... pressure transducer cavity, 131w ... diameter, 132 ... sensor protector, 133 ... pressure transducer material, 310, 311, 320, 330 ... Strain detector, L1 ... width, Lx, Ly ... length, Lz ... thickness, Lz70 ... height, t130 ... thickness

Claims (9)

A semiconductor circuit unit having a semiconductor substrate and a transistor provided on the main surface of the semiconductor substrate;
A detection unit provided on the semiconductor circuit unit,
The detection unit includes a cavity provided above the transistor, and a non-cavity juxtaposed with the cavity in a plane parallel to the main surface,
The detector is
A fixed portion fixed to the non-cavity,
A movable part extending from the fixed part to the cavity and spaced apart from the transistor and having a variable distance between the transistors;
A movable beam having
Provided on the movable portion, a first magnetic layer, a second magnetic layer, an intermediate layer of non-magnetic disposed between said first magnetic layer and the second magnetic layer, the first magnetic layer A strain sensing element unit including a first bias layer juxtaposed to apply a bias magnetic field to the first magnetic layer ;
A first wiring that includes a portion that is provided in the non-hollow portion and intersects the main surface, and electrically connects the first magnetic layer and the semiconductor circuit portion;
A second wiring that includes a portion that is provided in the non-hollow portion and intersects the main surface, and electrically connects the second magnetic layer and the semiconductor circuit portion;
A strain detection device comprising the detection unit. 2. The magnetization direction of the first magnetic layer changes in accordance with a change in the distance of the movable part from the transistor, and the electrical resistance of the strain sensing element unit changes in accordance with the change in the magnetization direction. The strain detection apparatus described. The strain sensing element unit further includes a second bias layer that is provided in the movable part and applies a bias magnetic field to the first magnetic layer, and the first bias layer is interposed between the first bias layer and the second bias layer. A magnetic layer, the second magnetic layer and the intermediate layer are disposed;
The strain detection device according to claim 1, wherein a direction from the first bias layer toward the second bias layer is along an edge of the movable part in which the strain detection element unit is provided. The strain detection apparatus according to claim 1, wherein a magnetostriction constant of the first magnetic layer is 10 ⁻⁵ or more.   The strain detection apparatus according to claim 1, wherein the movable part has a hole penetrating the movable part.   The strain detection apparatus according to any one of claims 1 to 5, wherein a distance between the movable part and the transistor changes in a range of 1 micrometer or more and 10 micrometers or less.   The strain detection apparatus according to any one of claims 1 to 6, wherein a length of the movable part along a first direction from the fixed part toward the movable part is not less than 10 micrometers and not more than 500 micrometers.   The strain detection apparatus according to claim 1, wherein the semiconductor circuit unit includes a processing circuit that processes a signal based on a current flowing through the strain detection element unit.   The strain detection device according to claim 1, wherein the semiconductor circuit unit includes a transmission circuit that wirelessly transmits data based on an electrical signal flowing through the strain detection element unit.

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