JP5942582B2 - Method for manufacturing vibrator - Google Patents

Description

  The present invention relates to a method for manufacturing a vibrator.

  Timing devices using piezoelectric elements are widely used in information devices such as watches and cellular phones and personal computers. Among them, with improvement in performance, miniaturization, and power saving of information equipment, a clock module using a timing device is required to have excellent frequency characteristics and further miniaturization. For example, as described in Patent Document 1, a piezoelectric vibrator capable of forming a semiconductor circuit and a manufacturing method thereof are known for the purpose of reducing the size and performance of a clock module. In addition, for example, as described in Patent Document 2, a tuning fork vibrator that can replace a conventional tuning fork type crystal vibrator of several tens of kHz band and is capable of forming a semiconductor circuit and a manufacturing method thereof It has been known.

JP 2008-153944 A JP 2007-267109 A

  However, according to the vibrator manufacturing methods described in Patent Document 1 and Patent Document 2, when obtaining a highly accurate vibrator, it is difficult to further suppress variation in the manufacturing process, and it is stable and simple. However, it was difficult to manufacture. Specifically, in the case of the piezoelectric vibrator described in Patent Document 1, the problem is that the length of the vibration part is likely to vary due to wet etching. In the case of the tuning fork vibrator described in Patent Document 2, support for supporting the beam part is present. This is a problem that the length of the space below the portion is likely to vary due to wet etching. In other words, in the etching process that determines the length of the part that affects the vibration characteristics, in order to suppress variation in accuracy, strict management of the thickness variation of the etched layer, the concentration of the etching solution, temperature, etching time, etc. is required. Had to be done.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following application examples or forms.

  Application Example 1 A method of manufacturing a vibrator according to this application example includes a step of forming a first layer on one main surface of a substrate, a step of patterning the first layer to form a void forming portion, A step of laminating a second layer on one main surface of the substrate so as to cover at least a part of the gap forming portion, and when the substrate is viewed in plan from one main surface side of the substrate, at least the Forming a driving unit including an electrode and a piezoelectric layer so as to be stacked on the second layer in a region overlapping a part of the gap forming unit, patterning the second layer, Forming a vibration part extending from the support part and laminating the drive part, exposing a part of the gap formation part, removing the gap formation part, and forming the vibration part and the substrate. And a step of forming a gap between them.

According to the manufacturing method of this application example, the gap forming portion is formed by patterning the first layer formed on one main surface of the substrate, and the second layer including the portion covering the gap forming portion is patterned. The plane shape of the vibrator is created. The vibrator is configured to include a support part and a vibration part in which a driving part is extended from the support part and a vibration part having a gap part is formed between the substrate and the substrate by removing the gap formation part. The In other words, since the void forming portion functions as a die for forming the void portion, the void portion can be formed with high accuracy by patterning the void forming portion with high processing accuracy. Dimensional variation can be reduced. Specifically, the etching process for forming the void portion may be an etching process for removing the void forming portion, and can be performed by wet etching using the second layer as a stopper. Therefore, it is not necessary to strictly manage the concentration, temperature, etching time, etc. of the etching solution as in the case of the wet etching according to the conventional manufacturing method described above, and it is possible to manufacture a highly accurate vibrator stably and simply. it can.
Note that patterning means forming a pattern using a photolithography technique or the like generally used in a semiconductor manufacturing process.

  Application Example 2 In the method for manufacturing a vibrator according to the application example, the first layer is an oxide layer, and the second layer is a semiconductor layer.

  As in this application example, it is preferable that the first layer is an oxide layer and the second layer is a semiconductor layer. By comprising in this way, the etching of the 1st layer which forms a space | gap formation part can be performed by using a 2nd layer as a stopper. Further, since a semiconductor circuit can be formed in the second semiconductor layer, a clock module including a vibrator can be downsized.

  Application Example 3 In the method for manufacturing a vibrator according to the application example, a step of forming a third layer on one main surface of the substrate, a step of stacking a fourth layer on the third layer, Patterning a fourth layer to expose a portion of the third layer, wherein the first layer is stacked on the fourth layer and the exposed third layer, and the substrate When the substrate is viewed in plan from one main surface side, the gap forming portion is formed in a region overlapping at least a part of the exposed third layer, and the gap forming portion and the third layer are formed. A part is removed, and a gap is formed between the vibration part and the substrate.

  According to the manufacturing method of this application example, the gap forming portion and a part of the third layer are removed, and the gap portion is formed between the vibrating portion and the substrate. Can be configured large. As a result, for example, even when it is difficult to form the first layer with a sufficient thickness, the gap portion can be configured in combination with the third layer thickness, so that it is necessary for the vibrating portion. It is possible to more flexibly form a gap with a simple substrate.

  Application Example 4 In the method for manufacturing a vibrator according to the application example, the third layer is an oxide layer, and the fourth layer is a nitride layer.

  As in this application example, it is preferable that the third layer is an oxide layer and the fourth layer is a nitride layer. By comprising in this way, the 3rd layer which forms a space | gap formation part can be etched using a 4th layer as a mask. As a result, by utilizing the pattern by the fourth layer, the third layer can be selectively etched in accordance with the region of the gap forming portion by the first layer.

  Application Example 5 In the vibrator manufacturing method according to the application example described above, the electrode includes at least a first electrode and a second electrode, and the piezoelectric layer is formed of the first electrode and the second electrode. It is characterized by being sandwiched between them.

  According to this application example, the electrode includes at least the first electrode and the second electrode, and the piezoelectric layer is sandwiched between the first electrode and the second electrode. With this configuration, it is possible to configure a drive unit that vibrates the vibration unit by applying a drive electric field from the first electrode and the second electrode to the piezoelectric layer.

  Application Example 6 In the method for manufacturing a vibrator according to the application example, an insulating film is provided between the second layer and the electrode.

  According to this application example, the insulating film is provided between the second layer and the electrode. With this configuration, even when a plurality of electrodes are formed on the second layer or an integrated circuit is formed on the second layer, the charge of the electrodes does not leak through the second layer, and the piezoelectric layer A predetermined drive electric field can be applied to.

  Application Example 7 In the method for manufacturing a vibrator according to the application example, the piezoelectric layer is sandwiched between the second layer and the electrode.

  According to this application example, the piezoelectric layer is sandwiched between the second layer and the electrode. By doing in this way, the drive part which used the 2nd layer as the counter electrode can be comprised.

(A) The top view which shows typically the vibrator | oscillator concerning Embodiment 1, (b) AA cross-sectional schematic, (c) BB cross-sectional schematic. (A)-(f) The cross-sectional schematic explaining the manufacturing process of the vibrator | oscillator concerning Embodiment 1. FIG. (A) The top view which shows typically the vibrator | oscillator concerning Embodiment 2, (b) AA cross-sectional schematic, (c) BB cross-sectional schematic. (A)-(f) The cross-sectional schematic explaining the manufacturing process of the vibrator | oscillator concerning Embodiment 2. FIG. FIG. 4A is a schematic cross-sectional view illustrating a drive unit and a vibration unit of the vibrator according to the first embodiment. FIG. 5B is a schematic cross-sectional view illustrating a drive unit and the vibration part of the vibrator according to the first modification. (A), (b) The cross-sectional schematic which shows the drive part and vibration part of the vibrator | oscillator concerning the modification 2. FIG.

  DESCRIPTION OF EMBODIMENTS Embodiments embodying the present invention will be described below with reference to the drawings. The following is one embodiment of the present invention and does not limit the present invention. In the following drawings, the scale may be different from the actual scale for easy understanding. In particular, in the cross-sectional view, in order to make the laminated structure easy to understand, it is enlarged and displayed about 10 times in the lamination direction.

(Embodiment 1)
First, the vibrator 1 according to the first embodiment will be described.
1A is a plan view schematically showing the vibrator 1, FIG. 1B is a schematic cross-sectional view taken along line AA of FIG. 1A, and FIG. 1C is FIG. FIG.
The vibrator 1 includes a support portion 100 using a silicon substrate 10 and a polysilicon layer 12 as a second layer stacked on one main surface of the silicon substrate 10 as a base, and a driving portion 200 extending from the support portion 100. And a vibrating part 300 formed. The thickness of the polysilicon layer 12 is preferably 10 μm or less in order to reduce the size of the vibrator. In the case of the vibrator 1, the thickness is, for example, 1 to 2 μm. In addition, since various semiconductor circuits can be formed in the silicon substrate 10 and the polysilicon layer 12 in the region C shown in the drawing, the vibrator 1 and the semiconductor integrated circuit can be integrated.
In the following description, the direction on one main surface side of the silicon substrate 10, that is, the direction in which the polysilicon layer 12 is laminated on the silicon substrate 10 will be described as the upward direction, and the opposite direction will be described as the downward direction.

The support part 100 is, for example, a rectangular frame formed of the polysilicon layer 12 and supports the vibration part 300.
The vibration unit 300 is a cantilever formed of the polysilicon layer 12, and one end thereof is supported inside the frame-shaped support unit 100. That is, the polysilicon layer 12 constituting the vibration part 300 is formed so as to have the gap 90 between the silicon layer 10 and the polysilicon layer 12. The planar shape of the vibration unit 300 is, for example, a rectangle, the length L in the longitudinal direction is, for example, 300 μm, and the width W in the lateral direction is, for example, 3 μm.
The driving unit 200 is stacked on the upper surface of the vibration unit 300.
In the example shown in FIG. 1A, the two vibrating portions 300 extend in parallel from the supporting portion 100 inside the frame-shaped supporting portion 100, but the number of vibrating portions 300 is limited to two. Not what you want.

The drive unit 200 is composed of a pair of drive units of a first drive unit 200a and a second drive unit 200b. The first drive unit 200a and the second drive unit 200b extend along the longitudinal direction from the end (the base portion) where the vibration unit 300 is supported by the support unit 100 to the substantially central portion in the direction in which the vibration unit 300 extends. They are formed in parallel.
The first drive unit 200a and the second drive unit 200b are each configured by an electrode 201a as a first electrode, an electrode 201b as a second electrode, a piezoelectric layer 202, and the like, and an insulating layer between the vibration unit 300 and the first drive unit 200a and the second drive unit 200b. 203. The piezoelectric layer 202 is sandwiched between the electrode 201a and the electrode 201b, and is deformed by applying a driving electric field (alternating electric field) to the piezoelectric layer 202 from the electrode 201a and the electrode 201b. Vibrate. Note that a drive circuit and wiring (not shown) for applying a drive electric field can be appropriately configured corresponding to various modes in which the vibration unit 300 is vibrated.

As a suitable example, the insulating layer 203 is an insulating layer such as a silicon oxide (SiO ₂ ) layer or a silicon nitride (Si ₃ N ₄ ) layer, and may be composed of two or more composite layers. The thickness of the insulating layer 203 is, for example, 0.1 μm.
For the electrodes 201a and 201b, titanium nitride (TiN) is used as a preferred example, but the present invention is not limited to this. The thickness of the electrodes 201a and 201b may be any thickness as long as a sufficiently low electric resistance value can be obtained, and can be set to, for example, 10 nm to 1 μm.
The piezoelectric layer 202 uses aluminum nitride (AlN) as a preferred example, but is not limited thereto. For example, lead zirconate titanate (Pb (Zr, Ti) O ₃ : PZT), titanate niobate A piezoelectric material such as lead zirconate (Pb (Zr, Ti, Nb) O ₃ : PZTN) or zinc oxide (ZnO) may be used. The thickness of the piezoelectric layer 202 can be set to 0.1 μm to 1 μm, for example.
In the illustrated example, in the driving unit 200, only the piezoelectric layer 202 exists between the electrodes 201a and 201b, but a layer other than the piezoelectric layer 202 may be provided between the electrodes 201a and 201b. good. The film thickness of the piezoelectric layer 202 can be appropriately changed according to the resonance condition.

In the vibrator 1 having the above-described configuration, the vibration characteristics can be set according to the natural vibration characteristics of the vibration unit 300, the configuration of the drive unit 200, the mode of the drive electric field, and the like. In other words, for example, the vibration characteristics of the vibrator 1 vary due to variations in the natural vibration characteristics of the vibration unit 300 in the manufacturing stage. The natural vibration of the vibration part 300 is determined by the material forming the vibration part 300, the shape and size of the vibration part 300, the shape and structure of the coupling between the vibration part 300 and the support part 100, and so on. In order to obtain the child 1, it is necessary to suppress these variations. When forming a pattern using a photolithographic technique or the like used in a semiconductor manufacturing process, generally, when there is no boundary layer functioning as an etching stopper, processing by dry etching is better than wet etching, It is easy to increase the processing accuracy. For this reason, the processing of the portion related to the vibration characteristics is preferably performed by wet etching or dry etching in which an etching stopper is formed.
The vibration characteristics refer to LCR characteristics when the vibrator is represented by a general equivalent circuit, vibration frequencies determined by the characteristics, and the like.
Hereinafter, an example of a method for manufacturing the vibrator 1 according to the first embodiment will be described.

2A to 2F are an AA cross-sectional schematic diagram (FIG. 1A) and a BB cross-sectional schematic diagram of the vibrator 1 in the main manufacturing process.
FIG. 2A: First, a silicon substrate 10 is prepared, and a silicon oxide layer 11 as a first layer is formed on the main surface (upper side in the drawing) by a CVD (Chemical Vapor Deposition) method or the like. To do.
FIG. 2B: Next, the silicon oxide layer 11 is patterned to form a gap forming portion 11p. The patterning can be performed by a photolithography technique and an etching technique generally used in a semiconductor manufacturing process. Further, the gap forming portion 11p formed here functions as a die for forming the gap portion 90 in a process described later. Since the formation of the air gap forming portion 11p is processing of a portion related to vibration characteristics, it is necessary to suppress variations in processing dimensions. Therefore, it is performed by a method that can reduce variations, such as dry etching.
FIG. 2C: Next, a polysilicon layer 12 as a second layer (semiconductor layer) is laminated by a CVD method or the like so as to cover the silicon substrate 10 and the gap forming portion 11p. The polysilicon layer 12 is patterned in a process described later to form the support part 100, the vibration part 300, and the like.

FIG. 2D: Next, the drive unit 200 is formed so as to be stacked on the polysilicon layer 12. Specifically, the insulating layer 203, the electrode 201a, the piezoelectric layer 202, and the electrode 201b are sequentially formed on the polysilicon layer 12. Further, the position of the driving unit 200 is formed in a region that overlaps the gap forming portion 11p when the silicon substrate 10 is viewed from above the silicon substrate 10.
The insulating layer 203 is formed by being stacked by a thermal oxidation method, a CVD method, a sputtering method, or the like. The insulating layer 203 is patterned so as to have a shape constituting the lowermost layer of the driving unit 200 described above.
The electrode 201a can be formed over the insulating layer 203 by vapor deposition, sputtering, or the like. The electrode 201a is formed by patterning so as to have a shape that constitutes the drive unit 200 described above.
The piezoelectric layer 202 can be formed by various methods such as vapor deposition, sputtering, laser ablation, and CVD. The piezoelectric layer 202 is formed by patterning so as to have the shape constituting the driving unit 200 described above.
The electrode 201b can be formed on the piezoelectric layer 202 by vapor deposition, sputtering, or the like. The electrode 201b is formed by patterning so as to have a shape that constitutes the drive unit 200 described above.

  Note that the patterning of each layer for forming the driving unit 200 may be performed individually following the formation of each layer as described above, or may be performed after the layers are stacked. In addition, the insulating layer 203 for electrically insulating the electrode 201a is provided on the polysilicon layer 12. However, when the polysilicon layer 12 is formed with a sufficiently high resistance, the second layer is formed of polysilicon. In the case where the insulating layer 203 is not the layer 12 but made of some insulating material, the insulating layer 203 can be omitted.

  FIG. 2E: Next, the polysilicon layer 12 is patterned to form the support part 100 and the vibration part 300 in which the driving part 200 extending from the support part 100 is laminated, and the gap forming part 11p. Expose part. Since the patterning here is processing of a portion related to vibration characteristics that determines the shape of the support portion 100, the vibration portion 300, and the like, it is necessary to suppress these variations. Therefore, it is performed by a method that can reduce variations, such as dry etching.

  FIG. 2 (f): Next, the gap forming part 11 p is removed, and a gap part 90 is formed between the vibrating part 300 and the silicon substrate 10. Specifically, the gap forming portion 11p is removed by wet etching using the silicon substrate 10 and the polysilicon layer 12 as an etching stopper. For wet etching, for example, hydrofluoric acid or the like can be used as an etchant.

  The vibrator 1 can be formed by the manufacturing process described above. In the description of the above manufacturing process, the description of the process of forming the wiring to the electrodes 201a and 201b, the drive circuit, the semiconductor circuit, and the like is omitted.

As described above, according to the method for manufacturing a vibrator according to the present embodiment, the following effects can be obtained.
By patterning the silicon oxide layer 11 (first layer) formed on one main surface of the silicon substrate 10, a void forming portion 11p is formed, and a polysilicon layer 12 (second layer) including a portion covering the void forming portion 11p is formed. The planar shape of the vibrator 1 is created by patterning the layer. The vibrator 1 includes a support part 100 and a vibration part 300 in which a driving part 200 extending from the support part 100 is laminated. A gap is formed between the vibrator 1 and the silicon substrate 10 by removing the gap forming part 11p. A vibrating part 300 having a part 90 is formed. That is, since the gap forming portion 11p functions as a punching die for forming the gap portion 90, the gap portion 90 can be formed with high accuracy by patterning the gap forming portion 11p with high processing accuracy. It is possible to reduce the dimensional variation of the gap 90 in the process. Specifically, the etching process for forming the gap portion 90 may be an etching process for removing the gap formation portion 11p, and can be easily performed by wet etching using the polysilicon layer 12 as a stopper. Therefore, according to the method for manufacturing a vibrator according to the present embodiment, it is not necessary to strictly manage the concentration, temperature, etching time, etc. of the etching solution, and a more accurate vibrator can be manufactured stably and easily. Can do.

(Embodiment 2)
Next, an example of a method for manufacturing the vibrator 2 according to the second embodiment will be described. In the description, the same components as those in the above-described embodiment are denoted by the same reference numerals, and redundant description is omitted.

3A is a plan view schematically showing the vibrator 2, FIG. 3B is a schematic cross-sectional view taken along the line AA of FIG. 3A, and FIG. 3C is FIG. FIG.
In the vibrator 2, a third layer is further formed between the gap forming portion 11p and the silicon substrate 10, and a part of the gap forming portion 11p and the third layer is removed to form a deeper gap portion. It is characterized by forming.
As shown in FIGS. 3B and 3C, the vibrator 2 includes a silicon oxide layer 13 as a third layer and a silicon nitride as a fourth layer between the frame-shaped support portion 100 and the silicon substrate 10. The resonator 1 is the same as the vibrator 1 except that the gap 90 extends to the regions of the silicon oxide layer 13 and the silicon nitride layer 14.
Hereinafter, an example of a method for manufacturing the vibrator 2 according to the second embodiment will be described.

4A to 4G are schematic cross-sectional views taken along line AA of the vibrator 2 in the main manufacturing process (FIG. 3A).
FIG. 4A: First, a silicon substrate 10 is prepared, and a silicon oxide layer 13 as a third layer is laminated and formed on the main surface of the silicon substrate 10 by a CVD method or the like. Next, a silicon nitride layer 14 as a fourth layer is formed on the silicon oxide layer 13 by a CVD method or the like.
4B: Next, the silicon nitride layer 14 is patterned to remove the silicon nitride layer 14 in the central region, thereby forming a void forming window 14h through which the silicon oxide layer 13 is exposed. The region where the air gap forming window 14h is formed is a region slightly narrower than the air gap forming portion 11p formed in the subsequent steps. The patterning can be performed by a photolithography technique and an etching technique generally used in a semiconductor manufacturing process. Next, the silicon oxide layer 11 (the first layer in the first embodiment) is formed by being stacked by a CVD method or the like.
FIG. 4C: Next, the silicon oxide layer 11 is patterned to form the gap forming portion 11p. The gap forming portion 11p is formed to cover the gap forming window 14h. That is, in the gap forming window 14h, the gap forming portion 11p is formed so as to be laminated on the exposed silicon oxide layer 13.

4D to 4F: Next, the same process as that described with reference to FIGS. 2C to 2E in the first embodiment is performed. Specifically, with the gap forming portion 11p and the silicon oxide layer 13 sandwiched between the support portion 100 and the silicon substrate 10, the vibrating portion 300 extending from the support portion 100 and having the driving portion 200 stacked thereon is provided. Form.
FIG. 4G: Next, a part of the gap forming part 11 p and the silicon oxide layer 13 is removed, and a gap part 90 is formed between the vibrating part 300 and the silicon substrate 10. Specifically, the gap forming portion 11p and the silicon oxide layer 13 are partially removed by wet etching using the silicon substrate 10, the polysilicon layer 12, and the silicon nitride layer 14 as etching stoppers. For wet etching, for example, hydrofluoric acid or the like can be used as an etchant.

  In the etching of the silicon oxide layer 13, the lower silicon substrate 10 and the upper silicon nitride layer 14 function as etching stoppers, but there is no etching stopper in the lateral direction (plane direction). Therefore, it is necessary to set the etching time so that the silicon oxide layer 13 remains sufficiently between the frame-shaped support portion 100 and the silicon substrate 10. However, the dimensional accuracy of the silicon oxide layer 13 below the support part 100 is not a part that directly affects the vibration characteristics such as the support part 100 and the vibration part 300. Therefore, strict etching management is not required.

  The vibrator 2 can be formed by the manufacturing process described above. In the description of the above manufacturing process, the description of the process of forming the wiring to the electrodes 201a and 201b, the drive circuit, the semiconductor circuit, and the like is omitted.

As described above, according to the method for manufacturing a vibrator according to the present embodiment, the following effects can be obtained in addition to the effects of the first embodiment.
By removing a part of the air gap forming part 11p and the silicon oxide layer 13, the air gap part 90 is formed between the vibration part 300 and the silicon substrate 10. Therefore, the space of the air gap between the vibration part 300 and the silicon substrate 10 is reduced. It can be configured larger. As a result, for example, even when it is difficult to form the silicon oxide layer 11 (first layer) with a sufficient thickness, the void portion is combined with the layer thickness of the silicon oxide layer 13 (third layer). 90 can be configured, so that the gap between the vibration part 300 and the silicon substrate 10 can be formed more flexibly.

  Note that the present invention is not limited to the above-described embodiment, and various modifications and improvements can be added to the above-described embodiment. A modification will be described below. Here, the same components as those in the above-described embodiment are denoted by the same reference numerals, and redundant description is omitted.

(Modification 1)
5A is a schematic cross-sectional view showing the drive unit 200 and the vibration unit 300 of the vibrator 1, and FIG. 5B is a schematic cross-sectional view showing the drive unit and the vibration part of the vibrator according to the first modification. is there. Both are schematic cross-sectional views in the AA direction shown in FIG.
In the manufacturing methods of the first and second embodiments, as shown in FIG. 1B, FIG. 3B, or FIG. 5A, the driving unit 200 includes the insulating layer 203, the electrode 201a, Although it has been described that the piezoelectric layer 202 and the electrode 201b are sequentially stacked, the present invention is not limited to this configuration, and any configuration in which an electric field that generates a desired vibration in the vibration unit 300 is applied to the piezoelectric layer 202 is possible. It ’s fine.
For example, in the case where the vibration unit 300 is vibrated in a direction parallel to the main surface of the silicon substrate 10, that is, in the direction of the arrow illustrated in FIG. 5A, the first drive unit 200 a and the second drive are performed in the vibrator 1. An alternating electric field is applied to the part 200b in the relationship of polarity (+, −) as shown.

The vibrator according to the first modification (FIG. 5B) includes the drive unit 200v and the vibration unit 300.
The drive unit 200v includes a pair of drive units 200av and 200bv, and is formed by sequentially laminating a piezoelectric layer 202 and electrodes 201 (201av and 201bv) on the vibration unit 300. When the polysilicon layer 12 constituting the vibration unit 300 has conductivity, the interface between the vibration unit 300 and the piezoelectric layers 202 of the drive units 200av and 200bv is an intermediate potential between the electrode 201av and the electrode 201bv. Become. Therefore, by applying an alternating electric field with the polarity relationship shown in the figure, the vibrating unit 300 can be vibrated in the direction of the arrow shown in FIG. In FIG. 5B, the vibration unit 300 is connected to the ground potential, but it is not necessarily connected to the ground potential.

  As in this modification, the piezoelectric layer 202 may be manufactured so as to be sandwiched between the polysilicon layer 12 as the second layer and the electrode 201. By doing in this way, the drive part which used the polysilicon layer 12 as a counter electrode can be comprised, and in addition to the effect in embodiment mentioned above, a vibrator | oscillator can be comprised more simply.

(Modification 2)
6A and 6B are schematic cross-sectional views illustrating a drive unit and a vibration unit of a vibrator according to the second modification. Both are schematic cross-sectional views in the AA direction shown in FIG.
In the manufacturing method according to the first embodiment, as illustrated in FIGS. 1A and 1B, the driving unit 200 is configured by a pair of driving units including a first driving unit 200 a and a second driving unit 200 b. However, the present invention is not limited to this configuration. For example, as shown in FIGS. 6 (a) and 6 (b), it may be manufactured with a configuration including one drive unit (one set of electrodes and a piezoelectric layer). good.

In the example shown in FIG. 6A, the drive unit 200sa includes an electrode 201a as a first electrode, an electrode 201b as a second electrode, a piezoelectric layer 202, and the like. The layer 202 and the electrode 201b are sequentially stacked. In FIG. 6A, the insulating layer 203 is not formed between the vibrating portion 300, but the insulating layer 203 may be formed as necessary. The piezoelectric layer 202 is deformed by applying a drive electric field (AC electric field) to the piezoelectric layer 202 from the electrodes 201a and 201b, and vibrates the vibration unit 300 in the direction of the arrow shown in the drawing.
In the example shown in FIG. 6B, the drive unit 200sb includes the electrode 201b as the second electrode, the piezoelectric layer 202, and the like, and is formed by sequentially stacking the piezoelectric layer 202 and the electrode 201b on the vibration unit 300. doing. The polysilicon layer 12 constituting the vibration part 300 has conductivity, and the piezoelectric layer 202 is deformed by applying a driving electric field (alternating current electric field) to the piezoelectric layer 202 from the electrode 201b and the vibration part 300 and vibrates. The part 300 is vibrated in the direction of the arrow shown in the figure.
Even with the vibrator as in this modification, it is possible to provide a vibrator manufacturing method that can achieve the effects of the above-described embodiments.

  DESCRIPTION OF SYMBOLS 1, 2 ... Vibrator, 10 ... Silicon substrate, 11 ... Silicon oxide layer, 11p ... Air gap formation part, 12 ... Polysilicon layer, 13 ... Silicon oxide layer, 14 ... Silicon nitride layer, 14h ... Air gap formation window, 90 ... Gap part, 100 ... support part, 200 ... drive part, 200a ... first drive part, 200b ... second drive part, 201, 201a, 201b ... electrode, 202 ... piezoelectric layer, 203 ... insulating layer, 300 ... vibration part .

Claims (9)

Forming a first layer on one main surface of the substrate;
Patterning the first layer to form a void forming portion;
Wherein on one major surface of the substrate, forming a second layer so as to cover at least a portion of said gap forming portion,
In a plan view of a prior SL substrate, at least a portion is heavy Do Tsu and before Symbol least a first electrode on the second layer regions and the gap forming portion and said second layer overlaps the second electrode, and Forming a drive unit including a piezoelectric layer disposed between the first electrode and the second electrode ;
Patterning the second layer, forming a supporting portion connected to the one main surface of the substrate, and a vibration unit for the drive unit is laminated not extend from the support portion When,
Removing the gap forming portion, and forming a gap portion between the vibrating portion and the substrate.   The method for manufacturing a vibrator according to claim 1, wherein the first layer is an oxide layer, and the second layer is a semiconductor layer. Forming a third layer wherein on one major surface of the substrate before the step of forming the first layer,
Laminating a fourth layer on the third layer;
Patterning the fourth layer to expose a portion of the third layer;
Thereafter, the first layer in the step of forming the first layer, laminated on the fourth layer and the exposed third layer on,
Wherein said substrate in a plan view at the step of forming the gap forming portion, the gap forming portion, is formed in a region overlapping at least a portion of the exposed third layer,
The gap forming portions and removing a portion of the third layer, the oscillator according to claim 1 or claim 2, characterized in that to form the air gap between the vibrating portion and the substrate Production method.   The method for manufacturing a vibrator according to claim 3, wherein the third layer is an oxide layer, and the fourth layer is a nitride layer. An insulating film is formed on the second layer after the step of forming the second layer and before the step of forming the driving unit ;
Method for manufacturing a vibrator according to any one of claims 1 to 4, characterized in that to form the driving portion on the insulating film at the step of forming the driving unit.   Forming a first layer on one main surface of the substrate;
  Patterning the first layer to form a void forming portion;
  Forming a second layer on the one main surface of the substrate so as to cover at least a part of the gap forming portion;
  In plan view of the substrate, overlaps at least a part of a region where the gap forming portion and the second layer overlap, and forms a piezoelectric layer on the second layer, and at least the first electrode, and Forming a driving unit in which a second electrode is disposed on the piezoelectric layer;
  Patterning the second layer to form a support part connected to one main surface of the substrate and a vibration part extending from the support part and laminating the drive part; ,
  Removing the gap forming portion, and forming a gap portion between the vibrating portion and the substrate.   The method for manufacturing a vibrator according to claim 6, wherein the first layer is an oxide layer and the second layer is a semiconductor layer.   Forming a third layer on the one main surface of the substrate;
  Laminating a fourth layer on the third layer;
  Patterning the fourth layer to expose a portion of the third layer;
  Laminating the first layer on the fourth layer and the exposed third layer;
  Forming the gap forming portion in a region overlapping at least a part of the exposed third layer in plan view of the substrate;
  8. The vibrator according to claim 6, wherein a part of the gap forming part and the third layer is removed, and the gap part is formed between the vibrating part and the substrate. Production method.   The method for manufacturing a vibrator according to claim 8, wherein the third layer is an oxide layer, and the fourth layer is a nitride layer.

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