JP2009246028A - Mems and its method for manufacturing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve electric characteristics of a MEMS including a piezoelectric layer on a piezo-resistor part. <P>SOLUTION: A method for manufacturing of the MEMS includes steps of forming the piezo-resistor part in a semiconductor layer by implanting impurities into the semiconductor layer; forming a conductive layer serving as a lower layer electrode on a flat region on the surface of an insulation layer coupling with the surface of the semiconductor layer, forming the piezoelectric layer on a flat region on the surface of the conductive layer serving as the lower layer electrode; forming a conductive layer serving as an upper layer electrode on the surface of the piezoelectric layer; and etching the conductive layer serving as the lower layer electrode, the piezoelectric layer and the conductive layer serving as the upper layer electrode, thereby forming a piezoelectric element. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to MEMS (Micro Electro Mechanical Systems) and a MEMS manufacturing method, and more particularly to a technique for forming a piezoelectric layer on a piezoresistive portion.

Conventionally, an acceleration sensor, a vibration gyroscope, a pressure sensor, a vibration sensor, a microphone, and a force sensor are known as MEMS using stacked piezoresistors and piezoelectric elements. The self-excited microphone described in Patent Document 1 is a MEMS that excites a diaphragm constituting a flexible portion with a piezoelectric element and detects the displacement of the diaphragm with a piezoresistor. The piezoelectric element includes a piezoelectric layer and two electrode layers sandwiching the piezoelectric layer. The crystal characteristics of the piezoelectric layer greatly affect the electrical characteristics of the MEMS.
JP 2001-25095 A

  However, the self-excited microphone described in Patent Document 1 has a problem that the crystal structure of the piezoelectric element is disturbed because the piezoelectric layer and the lower layer electrode of the piezoelectric element are formed on a stepped surface.

  The present invention has been created to solve such a problem, and an object thereof is to improve the electrical characteristics of a MEMS including a piezoelectric layer on a piezoresistive portion.

(1) In a MEMS manufacturing method for achieving the above object, a piezoresistive portion is formed in a semiconductor layer by injecting impurities into the semiconductor layer, and the surface of the insulating layer bonded to the surface of the semiconductor layer is flat. A conductive layer to be a lower layer electrode is formed in a region, a piezoelectric layer is formed to a flat region on the surface of the conductive layer to be a lower layer electrode, and a conductive layer to be an upper layer electrode is formed on the surface of the piezoelectric layer to be a lower layer electrode Forming a piezoelectric element by etching a conductive layer, a piezoelectric layer, and a conductive layer to be an upper electrode.
By forming a conductive layer as a lower layer electrode of the piezoelectric element on the flat region of the surface of the insulating layer separating the piezoresistive portion and the piezoelectric element, and forming the piezoelectric layer on the flat region of the surface of the conductive layer, the piezoelectric layer is formed. The crystal structure of the layer can be adjusted. Therefore, according to the present invention, it is possible to improve the electrical characteristics of the MEMS including the piezoelectric layer on the piezoresistive portion. In this specification, “flat” is used for a relatively macroscopic surface shape, in other words, there is no step, and “smooth” is used for a relatively microscopic surface shape. It means that minute unevenness is small.

(2) In the MEMS manufacturing method for achieving the above object, an insulating layer is formed in a flat region of the surface of the semiconductor layer, and an impurity is injected into the semiconductor layer through the insulating layer, thereby piezoresistive in the semiconductor layer. It is preferable to include.
By forming the insulating layer in a flat region on the surface of the semiconductor layer before injecting impurities into the semiconductor layer, a piezoelectric element can be formed in a smooth region on the surface of the insulating layer. As a result, the piezoresistive portion It is possible to further improve the electrical characteristics of the MEMS including the piezoelectric layer on the substrate.

(3) In the MEMS manufacturing method for achieving the above object, it is preferable to include forming the insulating layer by thermal oxidation.
By forming the insulating layer by thermal oxidation, an insulating layer having a smooth surface can be formed. As a result, the electrical characteristics of the MEMS including the piezoelectric layer on the piezoresistive portion can be further improved.

(4) In the MEMS manufacturing method for achieving the above object, the semiconductor layer is preferably a thinner semiconductor layer of the SOI wafer.
By forming the insulating layer on the surface of the flat and smooth thin semiconductor layer of the SOI wafer, the surface of the insulating layer serving as a base for forming the piezoelectric element can be formed smoothly. As a result, the piezoresistive portion It is possible to further improve the electrical characteristics of the MEMS including the piezoelectric layer on the substrate.

(5) In the MEMS manufacturing method for achieving the above object, it is preferable to form the wiring of the piezoresistive portion by injecting impurities into the semiconductor layer.
When a wiring is formed by implanting impurities into the semiconductor layer, stress generated by the formation of the wiring can be reduced as compared with a case where a conductive film to be a wiring is formed by deposition. Further, by forming the wiring of the piezoresistive portion in the semiconductor layer, the wiring of the piezoelectric element and the wiring of the piezoresistive portion can be formed in different layers separated by an insulating layer, so that the layout efficiency is increased.

(6) A MEMS for achieving the above object includes a flexible portion including a semiconductor layer, a piezoresistive portion formed in the semiconductor layer, and an insulating layer having a flat surface bonded to the surface of the semiconductor layer; A lower layer electrode that is bonded to the surface of the insulating layer and has a flat surface; a piezoelectric layer that is bonded to the surface of the lower layer electrode; and a piezoelectric element that includes an upper layer electrode bonded to the surface of the piezoelectric layer.
According to the present invention, since the surface of the insulating layer underlying the lower electrode and the surface of the insulating layer underlying the piezoelectric layer are flat, the electrical characteristics of the MEMS including the piezoelectric layer on the piezoresistive portion are as follows. Characteristics can be improved.

(7) In the MEMS for achieving the above object, it is preferable that the wiring of the piezoresistive portion is formed in the semiconductor layer.
By forming the wiring of the piezoresistive portion in the semiconductor layer, the wiring of the piezoelectric element and the wiring of the piezoresistive portion can be formed in different layers separated by an insulating layer, so that the layout efficiency is increased.

  In addition, in the claims, “to the upper” means both “without an intermediate on the top” and “with an intermediate on the upper” unless there is a technical obstruction factor. To do. Further, the order of the operations described in the claims is not limited to the order of description as long as there is no technical obstruction factor, and may be executed at the same time, may be executed in the reverse order of the description order, or may be continuous. It does not have to be executed in order.

Hereinafter, embodiments of the present invention will be described in the following order with reference to the accompanying drawings. In addition, the same code | symbol is attached | subjected to the corresponding component in each figure, and the overlapping description is abbreviate | omitted.
1. First embodiment (Configuration)
As a first embodiment of the MEMS of the present invention, a six-dimensional motion sensor is shown in FIGS. 1A, 1B, and 1C. The motion sensor 1 is a MEMS for detecting a triaxial acceleration component orthogonal to each other and a triaxial angular velocity component orthogonal to each other.

  The motion sensor 1 includes a flexible part F having a cross-shaped form in plan view, a support part S coupled to four ends of the flexible part F, and a weight part coupled to the center of the flexible part F. M, a piezoelectric element 30 for exciting the flexible portion F, and a piezoresistive portion 131 for detecting deformation or displacement of the flexible portion F.

  The flexible part F is mainly composed of the thinner semiconductor layer 13, insulating layer 20, and insulating layer 40 of the SOI wafer. The flexible portion F includes a piezoresistive portion 131 and a piezoelectric element 30.

  A piezoresistive portion 131 and a low resistance portion 132 are formed in the semiconductor layer 13. The remainder of the semiconductor layer 13 is made of single crystal silicon (Si). Boron (B) is implanted into the piezoresistive portion 131 as silicon impurities. Boron is implanted into the low resistance portion 132 as a silicon impurity at a higher concentration than the piezoresistive portion 131.

The insulating layer 20 is bonded to the surface of the semiconductor layer 13. The insulating layer 20 that insulates the piezoresistive portion 131 and the piezoelectric element 30 is made of silicon dioxide (SiO ₂ ). The surface of the insulating layer 20 (interface with the piezoelectric element 30) is formed flat and smooth. A contact hole H <b> 1 is formed in the insulating layer 20.

  The piezoresistive portion 131 and the surface wiring 51 are electrically connected by the internal wiring 31b connected to the low resistance portion 132 via the contact hole H1 and the low resistance portion 132 connected to the piezoresistance portion 131. ing.

  The piezoelectric element 30 is located on the piezoresistive portion 131 and is bonded to the flat and smooth surface of the insulating layer 20. Layout efficiency is enhanced by overlapping the piezoelectric element 30 and the piezoresistive portion 131 in the vertical direction. The piezoelectric element 30 includes a lower layer electrode 31a coupled to the insulating layer 20, a piezoelectric layer 32, and an upper layer electrode 33a. The lower layer electrode 31a is made of platinum (Pt). The surface of the lower electrode 31a (interface with the piezoelectric layer 32) is formed flat and smooth. The piezoelectric layer 32 is bonded to the surface of the lower layer electrode 31a. The piezoelectric layer 32 is made of PZT (lead zirconate titanate). The upper layer electrode 33a is made of platinum. The upper layer electrode 33 a is bonded to the surface of the piezoelectric layer 32. The lower layer electrode 31a and the surface wiring 51 are connected by a wiring 31c (see FIG. 1C). The upper layer electrode 33 a is directly connected to the surface wiring 51.

  The insulating layer 40 covers the piezoelectric element 30, the wiring 31 c of the lower layer electrode 31 a of the piezoelectric element 30, the internal wiring 31 b of the piezoresistive portion 131 and the entire insulating layer 20. The surface wiring 51 is connected to the internal wiring 31 b of the piezoresistive portion 131, the wiring 31 c of the lower layer electrode 31 a of the piezoelectric element 30, and the upper layer electrode 33 a of the piezoelectric element 30 through contact holes formed in the insulating layer 40.

  The plan view of the weight portion M has a form in which a rectangle is connected to each of the four corners of the center rectangle. The central part of the weight part M is coupled to the central part of the flexible part F. Except for the central part of the weight part M, neither the flexible part F nor the support part S overlaps. The weight portion M includes a bulk layer 11, a connection layer 12, a semiconductor layer 13, and an insulating layer 20. The bulk layer 11 is made of a single crystal silicon base wafer. The connection layer 12 that joins the bulk layer 11 and the semiconductor layer 13 is made of silicon dioxide.

  The support S has a rectangular frame shape. The support portion S includes a bulk layer 11, a connection layer 12, a semiconductor layer 13, an insulating layer 20, and an insulating layer 40.

  The motion sensor 1 is connected to a drive detection circuit (not shown) by external wiring connected to the surface wiring 51. A drive voltage for exciting the flexible portion F is applied to the piezoelectric element 30 by a drive detection circuit. The resistance value of the piezoresistive portion 131 is converted into a voltage signal indicating the deformation amount or displacement amount of the flexible portion F by the drive detection circuit. The vibration frequency of the displacement component of the flexible part due to the Coriolis force generated by the excitation of the flexible part F and the angular velocity coincides with the excitation frequency of the flexible part F. On the other hand, the displacement component of the flexible portion F due to acceleration is independent of the excitation frequency of the flexible portion F. Therefore, by setting the excitation frequency of the flexible portion F sufficiently higher than the frequency of the acceleration to be detected, the acceleration component and the angular velocity component can be extracted from the displacement of the flexible portion F. Since the flexible portion F has a form capable of three-dimensional vibration, the motion sensor 1 can detect the three-dimensional acceleration and the three-dimensional angular velocity.

(Production method)
First, as shown in FIG. 2, the insulating layer 20 is formed on the flat and smooth surface of the semiconductor layer 13 of the SOI wafer 10. As a result, an insulating layer 20 bonded to the surface of the semiconductor layer 13 is formed. In order to form the surface of the insulating layer 20 flat and smooth, the semiconductor layer 13 which is the base of the insulating layer 20 is the thinner semiconductor layer of the SOI wafer 10, and the insulating layer is thermally oxidized by the thinner semiconductor layer. It is desirable to form 20. The SOI wafer 10 includes, for example, a bulk layer 11 made of single crystal silicon having a thickness of 625 μm, a connection layer 12 made of silicon dioxide and having a thickness of 1 μm, and a semiconductor made of a bond wafer made of single crystal silicon and having a thickness of 10 μm. And the layer 13. Subsequently, a protective film R1 made of a photoresist is formed on the surface of the insulating layer 20. Further, a piezoresistive portion 131 is formed in the semiconductor layer 13 by implanting impurities into a part of the semiconductor layer 13 using the protective film R1. The impurity of the piezoresistive portion 131 is, for example, boron ion having a concentration of 2 × 10 ¹⁸ / cm ³ . The depth at which impurity ions are distributed is controlled by the acceleration voltage for ion implantation. That is, the impurity is implanted using an acceleration voltage that penetrates the insulating layer 20 and remains in the semiconductor layer 13.

Next, as shown in FIG. 3A, a contact hole H1 is formed in the insulating layer 20 using a protective film R2 made of a photoresist. Subsequently, impurities are implanted into part of the semiconductor layer 13 using the protective film R2 and the insulating layer 20. As a result, in the lower layer of the insulating layer 20, the low resistance portion 132 is formed in a region continuous with the piezoresistive portion 131 as shown in FIG. 3B. The region of the low resistance portion 132 and the region of the piezoresistive portion 131 are made continuous by the position of the contact hole H1 or by diffusion of impurities after implantation. The impurity of the low resistance portion 132 is, for example, boron ion having a concentration of 2 × 10 ²⁰ / cm ³ . The depth at which impurity ions are distributed is controlled by the acceleration voltage for ion implantation. Thereafter, the crystal structures of the semiconductor layer 13 and the insulating layer 20 are shaped by annealing, and the piezoresistive portion 131 and the low-resistance portion 132 are activated.

Next, as shown in FIG. 4, the conductive layer 31 that becomes the wiring of the piezoresistive portion 131 and the wiring of the lower layer electrode of the piezoelectric element is formed on the surface of the semiconductor layer 13 exposed from the contact hole H1 and the entire surface of the insulating layer 20. . In order to form the surface of the conductive layer 31 flat and smooth, it is desirable that the insulating layer 20 as a base is formed to be a flat and smooth surface, and a film of the conductive layer 31 is deposited on the surface. Specifically, as the conductive layer 31, for example, a film made of platinum having a thickness of 0.1 μm is formed by sputtering. Before depositing platinum, a 30 nm thick titanium (Ti) film may be formed as an adhesion layer. Alternatively, the conductive layer 31 may be formed of iridium (Ir), iridium dioxide (IrO ₂ ), SrRuO ₃ or the like.

Next, as shown in FIG. 5, the piezoelectric layer 32 is formed on the entire surface of the conductive layer 31. It is desirable to deposit the film of the piezoelectric layer 32 so that the crystal structure of the piezoelectric layer 32 and the crystal structure of the underlying conductive layer 31 are continuous (epitaxial growth). Specifically, as the piezoelectric layer 32, for example, a film made of PZT having a thickness of 3 μm is formed by sputtering. A sol-gel method may be used instead of sputtering. BLT (Bi _4-x La _x Ti ₃ O ₁₂ ), BaTiO ₃ , aluminum nitride (AlN), zinc oxide (ZnO), or the like may be used instead of PZT.

  Next, as shown in FIG. 6, a conductive layer 33 to be the upper electrode of the piezoelectric element is formed on the entire surface of the piezoelectric layer 32. For example, a film made of platinum having a thickness of 0.1 μm is formed as the conductive layer 33 by sputtering. A titanium film having a thickness of 30 nm may be formed as an adhesion layer before depositing platinum. The conductive layer 33 may be formed from iridium, iridium dioxide, gold (Au), or the like.

  Next, as shown in FIG. 7, the upper layer electrode 33a is formed by etching the conductive layer 33 using the protective film R3 made of a photoresist. For example, the conductive layer 33 made of platinum is etched by milling using argon (Ar) ions. The end surface of the protective film R3 may be formed on a slope using baking or a multi-tone mask, and the cross-sectional shape of the protective film R3 may be transferred to the upper electrode 33a by milling.

Next, as shown in FIG. 8, the piezoelectric layer 32 is etched using the protective film R3 or the upper layer electrode 33a. For example, the piezoelectric layer 32 made of PZT is etched by reactive ion etching using chlorine (Cl ₂ ) gas. The protective film R3 may be removed before the piezoelectric layer 32 is etched, or the protective film R3 may disappear during the etching of the piezoelectric layer 32.

  Next, as shown in FIGS. 9 and 10, the conductive layer 31 is etched using a protective film R4 made of a photoresist, whereby the internal wiring 31b of the piezoresistive portion 131 and the wiring 31c of the lower layer electrode 31a of the piezoelectric element 30 are formed. Form. As a result, the piezoelectric element 30 in which the lower electrode 31a is bonded to the surface of the insulating layer 20 and the piezoelectric layer 32 is bonded to the surface of the lower electrode 31a is formed together with the internal wirings 31b and 31c. For example, the conductive layer 31 made of platinum is etched by milling using argon ions. The conductive layer 31 may be etched by reactive ion etching.

  Next, as shown in FIGS. 11A and 11B, the insulating layer 40 is formed on the surface of the piezoelectric element 30, the internal wirings 31 b and 31 c, and the insulating layer 20. Subsequently, contact holes are formed in the insulating layer 40. At this time, for example, as shown in FIG. 11B, the contact hole is formed so that the insulating layer 40 is cut out in a region other than the flexible portion and the supporting portion, and the portion that becomes the weight portion of the insulating layer 20 is exposed. Other areas are also removed. For example, photosensitive polyimide is applied to a thickness of 10 μm, exposed, and developed to form the insulating layer 40 made of an organic substance. The insulating film 40 may be formed by forming an inorganic insulating film such as silicon dioxide, silicon nitride, or alumina and etching the inorganic insulating film. Subsequently, a surface wiring 51 connected to the upper layer electrode 33 a of the piezoelectric element 30 exposed from the contact hole and the internal wirings 31 b and 31 c is formed on the surface of the insulating layer 40. The surface wiring 51 is formed, for example, by forming a conductive film made of aluminum having a thickness of 0.5 μm by sputtering and etching the conductive film by reactive ion etching using chlorine gas. The surface wiring 51 may be formed from aluminum silicide (AlSi), AlSiCu, or the like. Before forming the surface wiring 51 made of aluminum, a titanium film having a thickness of 30 nm may be formed as an adhesion layer. The surface wiring 51 may be etched by milling using argon ions or wet etching using a mixed solution of phosphoric acid, nitric acid, acetic acid and the like.

Next, as shown in FIGS. 12A and 12B, the slit S1 is formed by etching the insulating layer 20 and the semiconductor layer 13 using a protective film made of a photoresist (not shown). The flexible part F is formed by forming the slit S1. The insulating layer 20 and the semiconductor layer 13 are etched by reactive ion etching using, for example, CF ₄ gas. The insulating layer 20 and the semiconductor layer 13 may be etched by wet etching using hydrofluoric acid (HF) or buffered hydrofluoric acid (BHF).

Next, as shown in FIG. 13, the surface of the work (surface on which the surface wiring is formed) is bonded to the reinforcing substrate 100. For example, a wax is used as the adhesive B. The workpiece may be bonded to the reinforcing substrate 100 with a photoresist, a double-sided adhesive tape, or the like. Subsequently, an annular slit S2 is formed by etching the bulk layer 11 using a protective film R5 made of a photoresist. As a result, a portion composed of the bulk layer 11 of the support portion S and the weight portion M is formed. The bulk layer 11 is etched by DeeP-RIE (so-called Bosch process) in which, for example, passivation with C ₄ F ₈ plasma and etching with SF ₆ plasma are repeated alternately.

  Next, as shown in FIG. 14, the connection layer 12 is etched using the protective film R5 or the bulk layer 11, and the semiconductor layer 13 is exposed. As a result, the region between the slit S1 and the slit S2 of the connection layer 12 is removed. For example, the connection layer 12 made of silicon dioxide is etched using buffered hydrofluoric acid.

  Thereafter, the adhesive B is peeled from the work, and when a post-process such as dicing is performed, the motion sensor 1 shown in FIG. 1 is completed.

  When the motion sensor 1 is manufactured by the method described above, the surface of the insulating layer 20 positioned on the piezoresistive portion 131 can be formed flat and smooth on the order of several nanometers. Thus, the flat and smooth insulating layer 20 can be formed. The lower electrode 31a and the piezoelectric layer 32 can be formed on the surface. Therefore, according to the present embodiment, the crystal structure of the piezoelectric layer 32 can be adjusted. As a result, the piezoelectric characteristics of the piezoelectric layer 32 are enhanced, and the electrical characteristics of the motion sensor 1 are improved.

2. Second embodiment (Configuration)
A six-dimensional motion sensor is shown in FIGS. 15A and 15B as a second embodiment of the MEMS of the present invention. The low resistance portion 132 of the semiconductor layer 13 of the motion sensor 2 is also a large part of wiring that connects the piezoresistive portion 131 and the surface wiring 51. That is, most of the wiring of the piezoresistive portion 131 is formed in the semiconductor layer 13. For this reason, layout efficiency increases, and for example, the piezoelectric element 30 can be enlarged without changing the outer dimensions of the motion sensor 2.

  The plan view of the piezoresistive portion 131 of the motion sensor 2 is bent and has a U shape. For this reason, the piezoresistive portion 131 can be lengthened without changing the outer dimensions of the motion sensor 2.

(Production method)
First, as shown in FIG. 16, a piezoresistive portion 131 is formed in the semiconductor layer 13 by implanting impurities using a protective film R6 made of a photoresist as in the first embodiment.

  Next, as shown in FIGS. 17A and 17B, as in the first embodiment, the low resistance portion 132 is formed as a semiconductor layer as most of the wiring of the piezoresistive portion 131 by implanting impurities using the protective film R7 made of photoresist. 13 to form. Since most of the wiring of the piezoresistive portion 131 is formed by implanting impurities into the semiconductor layer 13, the stress generated by forming the wiring of the piezoresistive portion 131 can be reduced.

  Next, as shown in FIG. 18, a contact hole H2 is formed in the insulating layer 20 by etching using a protective film R8 made of a photoresist. As shown in FIG. 19, the contact hole H2 includes an internal wiring 31b (see FIGS. 20A and 20B) for connecting the low resistance portion 132 as the majority of the wiring of the piezoresistive portion 131 and the terminal portion of the surface wiring. Is for connecting. FIG. 18 corresponds to a cross section taken along line AA in FIG.

  Next, as shown in FIG. 20, similarly to the first embodiment, the lower layer electrode 31a and the internal wiring 31b are simultaneously formed, the piezoelectric layer 32 is formed, and the upper layer electrode 33a is formed.

  Thereafter, when the process of forming the insulating layer 40 and the surface wiring 51 is performed as in the first embodiment, the motion sensor 2 is completed.

3. Other Embodiments The surface of the insulating layer 20 may be chemically smoothed in order to form a flat and smooth surface of the insulating layer 20 as a base of the piezoelectric element. After the insulating layer of silicon dioxide is formed by thermal oxidation of single crystal silicon, the insulating film may be removed, and the insulating layer 20 made of silicon dioxide may be formed again by thermal oxidation. Further, these processes for forming the surface of the insulating layer 20 flat and smooth may be performed after the piezoresistive portion 131 is formed as shown in FIG. With these treatments, the crystal structure of the lower electrode and the piezoelectric layer can be adjusted without forming an insulating layer before forming the piezoresistive portion 131. However, if these processes are performed after the piezoresistive portion 131 is formed, the number of steps increases and the manufacturing cost increases.
The insulating layer that insulates the piezoresistive portion from the piezoelectric element may be formed of a material such as silicon nitride (SiN), silicon oxynitride (SiO _x N _y ), or aluminum oxide (AlO _x ).
Further, the insulating layer 40 may be left on the exposed surface portion of the weight portion M.
The present invention can also be applied to MEMS such as an acceleration sensor, a vibration gyroscope, a pressure sensor, a vibration sensor, a microphone, and a force sensor.

  Furthermore, the technical scope of the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the present invention. For example, the materials, dimensions, film forming methods, and pattern transfer methods shown in the above embodiments are merely examples, and descriptions of addition and deletion of processes and replacement of process orders that are obvious to those skilled in the art are omitted. ing.

1A and 1B are cross-sectional views according to a first embodiment of the present invention. FIG. 1C is a plan view according to the first embodiment of the present invention. Sectional drawing concerning 1st embodiment of this invention. FIG. 3A is a sectional view according to the first embodiment of the present invention. FIG. 3B is a plan view according to the first embodiment of the present invention. Sectional drawing concerning 1st embodiment of this invention. Sectional drawing concerning 1st embodiment of this invention. Sectional drawing concerning 1st embodiment of this invention. Sectional drawing concerning 1st embodiment of this invention. Sectional drawing concerning 1st embodiment of this invention. Sectional drawing concerning 1st embodiment of this invention. The top view concerning a first embodiment of the present invention. FIG. 11A is a sectional view according to the first embodiment of the present invention. FIG. 11B is a plan view according to the first embodiment of the present invention. FIG. 12A is a sectional view according to the first embodiment of the present invention. FIG. 12B is a plan view according to the first embodiment of the present invention. Sectional drawing concerning 1st embodiment of this invention. Sectional drawing concerning 1st embodiment of this invention. FIG. 15A is a sectional view according to the second embodiment of the present invention. FIG. 15B is a plan view according to the second embodiment of the present invention. Sectional drawing concerning 2nd embodiment of this invention. FIG. 17A is a sectional view according to the second embodiment of the present invention. FIG. 17B is a plan view according to the second embodiment of the present invention. Sectional drawing concerning 2nd embodiment of this invention. The top view concerning 2nd embodiment of the present invention. FIG. 20A is a sectional view according to the second embodiment of the present invention. FIG. 20B is a plan view according to the second embodiment of the present invention. Sectional drawing concerning other embodiment of this invention.

Explanation of symbols

1: motion sensor, 2: motion sensor, 10: wafer, 11: bulk layer, 12: connection layer, 13: semiconductor layer, 20: insulating layer, 30: piezoelectric element, 30: piezoelectric element, 31: conductive layer, 31a : Lower layer electrode, 31b: internal wiring, 31c: wiring, 32: piezoelectric layer, 33: conductive layer, 33a: upper layer electrode, 40: insulating layer, 51: surface wiring, 100: reinforcing substrate, 131: piezoresistive part, 132 : Low resistance part, B: adhesive, F: flexible part, H1: contact hole, H2: contact hole, M: weight part, R1: protective film, R2: protective film, R3: protective film, R4: protective film , R5: protective film, R6: protective film, R7: protective film, S: support, S1: slit, S2: slit

Claims (7)

A piezoresistive portion is formed in the semiconductor layer by injecting impurities into the semiconductor layer,
Forming a conductive layer to be a lower layer electrode in a flat region of the surface of the insulating layer bonded to the surface of the semiconductor layer;
Forming a piezoelectric layer in a flat region of the surface of the conductive layer to be the lower electrode;
Forming a conductive layer to be an upper electrode on the surface of the piezoelectric layer;
A piezoelectric element is formed by etching the conductive layer to be the lower electrode, the piezoelectric layer, and the conductive layer to be the upper electrode;
MEMS manufacturing method including the above. Forming the insulating layer in a flat region of the surface of the semiconductor layer;
Forming the piezoresistive portion in the semiconductor layer by injecting impurities into the semiconductor layer through the insulating layer;
The MEMS manufacturing method according to claim 1. Forming the insulating layer by thermal oxidation;
The MEMS manufacturing method according to claim 1 or 2, further comprising: The semiconductor layer is the thinner semiconductor layer of the SOI wafer;
The MEMS manufacturing method as described in any one of Claim 1 to 3. Forming the wiring of the piezoresistive portion by injecting impurities into the semiconductor layer;
The MEMS manufacturing method as described in any one of Claim 1 to 4 including this. A flexible portion comprising a semiconductor layer, a piezoresistive portion formed in the semiconductor layer, and an insulating layer having a flat surface bonded to the surface of the semiconductor layer;
A piezoelectric element comprising a lower layer electrode bonded to the surface of the insulating layer and having a flat surface, a piezoelectric layer bonded to the surface of the lower layer electrode, and an upper layer electrode bonded to the surface of the piezoelectric layer;
A MEMS comprising: Wiring of the piezoresistive portion is formed in the semiconductor layer,
The MEMS according to claim 6.

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