JP2005311671A - Micro-resonator, manufacturing method thereof and electronic equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a micro-resonator with high performance for which the electric resistance of fixed electrodes and connection terminals, etc., is reduced, and a manufacturing method thereof. <P>SOLUTION: The micro-resonator 10 has a configuration in which a resonator 40 is disposed between a fixed electrode 22 having a comb tooth part 21 and a fixed electrode 32 having a comb tooth part 31. To the fixed electrodes 22 and 32, connection terminals 26 and 36 are respectively connected through lead wires 25 and 35. The resonator 40 has a movable electrode 24 disposed so that a comb tooth part 23 is engaged with the comb tooth part 21 of the fixed electrode 22 and a movable electrode 34 disposed so that a comb tooth part 33 is engaged with the comb tooth part 31 of the fixed electrode 32. Metal layers M1-M3 for resistance reduction are respectively formed on the fixed electrode 22, the lead wire 25 and the connection terminal 26, on the fixed electrode 32, the lead wire 35 and the connection terminal 36, and on the resonator 40. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a microresonator that applies a voltage between a fixed electrode and a movable electrode to cause the movable electrode to vibrate at a specific resonance frequency, a manufacturing method thereof, and an electronic device including the microresonator.

  In recent years, research and development for manufacturing ultra-compact and ultra-high-performance electronic components using MEMS (Micro Electro Mechanical System) technology has been actively conducted. There are a wide variety of electronic components using MEMS technology, and one type is a microresonator. In the microresonator, for example, an insulating film made of an oxide film is formed on a substrate such as a silicon substrate, and the comb teeth of the comb-shaped fixed electrode and the comb teeth of the comb-shaped movable electrode are formed on the insulating film. It is the structure formed so that it might mesh | engage in parallel with respect to.

  The comb-shaped movable electrode is coupled to a support portion having a spring property supported on a silicon substrate, and the comb-shaped fixed electrode and the comb-shaped movable electrode are engaged with each other. One set is arranged on each side of the support portion. The comb-shaped movable electrode and the support portion constitute a resonator. Further, two electrode terminals connected to each of the comb-shaped fixed electrodes and an electrode terminal as a ground electrode common to these two electrode terminals are provided on the insulating film. The above-described comb-shaped fixed electrode, comb-shaped movable electrode, support portion, and electrode terminal are formed on, for example, a polysilicon film formed on the above-described insulating film or an insulating film of an SOI (Silicon On Insulator) substrate. It is formed using a silicon layer that has been formed.

  Such a microresonator applies an alternating voltage between the electrode terminal of one of the comb-shaped fixed electrodes and the electrode terminal as a ground electrode, thereby moving the comb-shaped fixed electrode and the comb-shaped movable electrode. An electrostatic attractive force is generated between the electrodes, and the electrostatic attraction force causes the comb-like movable electrode to vibrate by being pushed and pulled planarly in the comb-tooth engagement direction (the comb tooth length direction). This vibration is transmitted to a support portion having a spring property integrated with the comb-shaped movable electrode, and the other comb-shaped movable electrode which is in the meshed state is vibrated planarly.

Resonance determined by the spring constant determined by the structure of the movable electrode and the mass of the movable electrode and the structure of the spring support, generated between the comb-shaped fixed electrode on the input side and the comb-shaped movable electrode A resonance phenomenon occurs when the frequency matches, and the resonance frequency is taken out from the electrode terminal of the other comb-shaped fixed electrode on the output side. The microresonator having such a configuration is used as an oscillator that oscillates an electric signal having a specific frequency or a filter that filters an electric signal having a specific frequency from an electric signal including a plurality of frequencies. By forming the resonator or the filter with a microresonator, these electronic components can be integrated with other electronic components, so that the electronic circuit can be downsized. For details of the microresonator, see, for example, Patent Documents 1 and 2 below.
US Pat. No. 5,025,346 (column 3, line 37-column 6, line 2, column 6, line 55-column 7, line 52, FIGS. 1-4) US Pat. No. 5,537,083 (column 4, line 43 to column 10, line 33, FIGS. 4 to 8)

  Incidentally, in recent years, attempts have been made to form the above-described fixed electrode and movable electrode with single crystal silicon. This is because the fixed electrode and the movable electrode made of single crystal silicon have more stable mechanical characteristics than the fixed electrode and the movable electrode formed using a polysilicon film formed by CVD (Chemical Vapor Deposition) or the like. Because it is. When the fixed electrode and the movable electrode are formed of single crystal silicon, it is necessary to make the fixed electrode and the movable electrode as low resistance as possible. For this purpose, it is necessary to use a material in which an impurity is previously added (doped) at a high concentration, or to dope impurities at a high concentration later on a material doped at a low concentration.

  However, a low-resistance material doped with impurities at a concentration high enough to withstand use as a fixed electrode and a movable electrode of a microresonator is manufactured because the concentration of impurities is too high to form a semiconductor integrated circuit. There is almost nothing. In addition, the fixed electrode and the movable electrode of the microresonator have a thickness of about several μm to several tens of μm, and it takes a long time and there is thermal damage to uniformly dope impurities up to this thickness. Therefore, it is also impractical to make the material low in resistance by doping the material later. Furthermore, the current fixed electrode and movable electrode formed by using a silicon layer crystallized on a polysilicon film or an insulating film of an SOI substrate also efficiently extract current changes at the time of resonance of the movable electrode. It is necessary to further reduce the resistance.

  The electrode terminal connected to the fixed electrode or the like is formed using Al (aluminum), which is a general electrode material, in order to take out a change in current when the movable electrode resonates. In the microresonator, in order to make the movable electrode float on the substrate, after forming the movable electrode, the fixed electrode, and the electrode terminal, an insulating film provided between the movable electrode and the substrate is formed with hydrofluoric acid. The process of removing by etching using is performed. When performing this process, there was a problem that Al (aluminum) used for the electrode terminal was dissolved by hydrofluoric acid.

  If the insulating film provided between the movable electrode and the substrate is removed by etching and then a film made of Al (aluminum) is formed on the electrode terminal, the above problem does not occur, but the movable electrode floats on the substrate. Therefore, it is difficult to form a metal layer by vapor deposition and pattern the metal layer in a predetermined shape because the mechanical strength is weak. In addition, a metal layer can be deposited in a desired shape using a mask, but if formed by this method, a metal layer having a fine shape cannot be formed. If a metal layer having an unnecessarily large area is formed, parasitic capacitance is generated, and the performance of the microresonator is degraded.

  The present invention has been made in view of the above circumstances, and provides a microresonator having high performance with reduced electrical resistance such as a fixed electrode and a connection terminal, and easily manufacturing such a microresonator having high performance. Another object of the present invention is to provide a microresonator manufacturing method that can be used, and to provide an electronic device including the microresonator or the microresonator manufactured by using the method.

In order to solve the above problems, a microresonator of the present invention includes a silicon substrate, a stacked portion including at least an insulating film formed on the silicon substrate, a fixed electrode, a movable electrode formed on the stacked portion, And an electrode terminal electrically connected to the fixed electrode, wherein the fixed electrode, the movable electrode, and at least a part on the electrode terminal are provided with a metal layer for reducing electric resistance. It is a feature.
According to this invention, since the metal layer for reducing the electrical resistance is provided on at least a part of the fixed electrode, the movable electrode, and the electrode terminal, at least a part of the fixed electrode, the movable electrode, and the electrode terminal. Can be reduced, and a minute current generated by the vibration of the movable electrode can be efficiently taken out. Thereby, the performance of the microresonator can be improved.
In the microresonator of the present invention, the metal layer is provided on the electrode terminal.
According to the present invention, since the resistance of the electrode terminal can be reduced by providing the metal layer on the electrode terminal, it is possible to efficiently extract a minute current due to the vibration of the movable electrode.
The microresonator of the present invention is characterized in that the metal layer is provided in the fixed electrode, the electrode terminal, and a connection portion that connects the fixed electrode and the electrode terminal.
According to the present invention, since the resistance from the fixed electrode to the electrode terminal can be reduced by providing the metal layer on the fixed electrode, the electrode terminal, and the connection portion, the metal layer is generated by relative vibration of the movable electrode with respect to the fixed electrode. The current can be increased and the current can be efficiently extracted to the outside.
The microresonator of the present invention is characterized in that the metal layer is provided over the fixed electrode, the movable electrode, and the electrode terminal.
According to the present invention, by providing the metal layer over the fixed electrode, the movable electrode, and the electrode terminal, the voltage for vibrating the movable electrode can be efficiently applied, and the movable electrode The current generated by the vibration can be increased and can be efficiently taken out.
The microresonator of the present invention is characterized in that the metal layer is formed of a metal or alloy having corrosion resistance.
According to the present invention, since the metal layer is formed of a corrosion-resistant metal or alloy, it is not forced to significantly change the manufacturing process of the microresonator by forming the metal layer. The resistivity does not change due to the change.
The microresonator of the present invention is characterized in that the metal layer is made of gold or platinum.
According to the present invention, since the metal layer is formed of gold or platinum, there is no significant change in the manufacturing process of the microresonator and no change in resistivity. A layer can be formed.
In the microresonator of the present invention, the fixed electrode and the movable electrode are partially comb-shaped.
According to the present invention, since the fixed electrode and the movable electrode have a comb-teeth shape, the fixed electrode and the movable electrode have a structure in which the width is narrow and there are many places where the resistance becomes high. The resistance of the fixed electrode and the movable electrode on which the metal layer is provided can be reduced. In addition, it is possible to obtain a resonance mode such as vibration in the longitudinal direction of the comb teeth, or torsion of the resonator or vibration due to rotation of the resonator, which is preferable for widening the setting range of the resonance frequency of the microresonator. Of course, with such a configuration, a single resonance frequency can be obtained. However, the present invention is not intended to limit the resonator to a shape having a comb-like electrode. In addition to the shape having a comb-like electrode, the beam (beam) shape or disk A shape can also be adopted.
In order to solve the above problems, a method of manufacturing a microresonator of the present invention includes a silicon substrate, a stacked portion including at least an insulating film formed on the silicon substrate, a fixed electrode formed on the stacked portion, A method of manufacturing a microresonator comprising a movable electrode and an electrode terminal electrically connected to the fixed electrode, wherein the fixed electrode, the movable electrode, and the electrode terminal of a semiconductor layer formed on the stacked portion are formed Forming a metal layer on an upper portion of at least a part of a portion to be formed, and performing a predetermined treatment on the semiconductor layer to form the fixed electrode, the movable electrode, and the electrode terminal. It is a feature.
According to the present invention, the metal layer is formed on at least a part of the portion where the fixed electrode, the movable electrode, and the electrode terminal of the semiconductor layer formed on the silicon substrate are formed, and the semiconductor layer is subjected to predetermined processing. Since the fixed electrode, the movable electrode, and the electrode terminal are formed by applying the above, it is possible to manufacture a high-performance microresonator in which the resistance of at least a part of the fixed electrode, the movable electrode, and the electrode terminal is reduced. .
In addition, the method for manufacturing a microresonator according to the present invention includes a step of adding an impurity to a portion of the semiconductor layer where the metal layer is formed before the metal layer is formed.
According to the present invention, since the metal layer is formed after the impurity is added to the portion where the metal layer is formed, the impurity concentration in the portion where the metal layer is formed is increased, and the metal layer and the semiconductor layer are ohmic. A contact can be formed, and an increase in extra resistance can be prevented.
The method for manufacturing a microresonator according to the present invention is characterized in that a heat treatment is performed after forming a metal layer on the semiconductor layer, and the metal layer is alloyed with the semiconductor layer.
According to this invention, since the metal layer is alloyed with respect to the semiconductor layer by performing the heat treatment after forming the metal layer on the semiconductor layer, the adhesion of the metal layer to the semiconductor layer can be increased. In addition, it is suitable for making the metal layer and the semiconductor layer ohmic contact.
In the method for manufacturing a microresonator of the present invention, the step of alloying the metal layer with respect to the semiconductor layer is performed by setting the temperature during the heat treatment to 1000 ° C. or less.
According to the present invention, the metal layer is alloyed with respect to the semiconductor layer at a temperature of 1000 ° C. or less, and a significant heat load is not applied to the silicon substrate, which is suitable for preventing a decrease in yield.
In the method for producing a microresonator of the present invention, the step of forming the metal layer is a step of forming the metal layer with a metal having corrosion resistance.
According to the present invention, since the metal layer is formed of a metal having corrosion resistance, after the metal layer is formed, the semiconductor layer is subjected to a predetermined treatment to form the fixed electrode, the movable electrode, and the electrode terminal. It is possible to prevent the metal layer from being corroded. Further, by forming the metal layer with a corrosion-resistant metal or alloy, it is possible to prevent a change in resistivity due to a chemical change such as oxidation.
In the method for producing a microresonator of the present invention, the corrosion-resistant metal is gold or platinum.
According to this invention, since the metal layer is formed of gold or platinum, the metal layer can be formed at low cost by applying an existing process.
Further, in the method for manufacturing the microresonator of the present invention, the step of forming the fixed electrode, the movable electrode, and the electrode terminal includes forming the fixed electrode and the movable electrode in a shape having a comb-tooth shape in part. It is the process to perform.
According to the present invention, since the fixed electrode and the movable electrode are formed in a shape having a comb-teeth shape, the fixed electrode and the movable electrode have a structure in which the width is narrow and there are many places where the resistance becomes high. Since the metal layer is formed on the movable electrode, the resistance of the fixed electrode and the movable electrode can be reduced. In addition, it is possible to obtain a resonance mode such as vibration in the longitudinal direction of the comb teeth, or torsion of the resonator or vibration due to the rotation of the resonator, which is suitable for widening the setting range of the resonance frequency of the microresonator. Of course, with such a configuration, a single resonance frequency can be obtained. However, the present invention is not intended to limit the resonator to a shape having a comb-like electrode. In addition to the shape having a comb-like electrode, the beam (beam) shape or disk A shape can also be adopted.
An electronic apparatus according to the present invention includes any one of the above-described microresonators or a microresonator manufactured by using any one of the above-described microresonator manufacturing methods.
According to the present invention, since a microresonator having a desired resonance frequency can be formed on a silicon substrate by using a technique for manufacturing a semiconductor element, a filter, an oscillator, and the like using the microresonator are incorporated in a semiconductor chip. It can be integrated. As a result, for example, an electronic device including an ultra-compact and ultra-high performance semiconductor element such as a semiconductor element in which a receiving circuit including an oscillator, a filter, an amplifier, a mixer, a detector, and the like is integrated into one chip is provided. .

  Hereinafter, a microresonator, a manufacturing method thereof, and an electronic device according to embodiments of the present invention will be described in detail with reference to the drawings.

[Micro Resonator]
FIG. 1 is a plan view showing a microresonator according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view taken along line AA in FIG. The microresonator 10 shown in FIGS. 1 and 2 is configured as a filter that functions in the same manner as a transversal SAW (Surface Acoustic Wave) filter. In the following description, if necessary, an XYZ orthogonal coordinate system is set in the drawing, and the positional relationship of each member will be described with reference to this XYZ orthogonal coordinate system. The XYZ orthogonal coordinate system in FIGS. 1 and 2 is set so that the X axis and the Y axis are parallel to the surface of the silicon substrate 50, and the Z axis is set in a direction orthogonal to the surface of the silicon substrate 50. Has been.

  A microresonator 10 shown in FIG. 1 includes a transmission-side IDT (Inter Digital Transducer) 20 and a reception-side IDT 30 arranged along the X direction on an insulating film 51 including an oxide film formed on the surface of a silicon substrate 50. In this configuration, the resonator 40 is disposed between them. The transmission-side IDT 20, the reception-side IDT 30, and the resonator 40 are formed using, for example, a polysilicon (p-Si) film as a conductive layer formed on the silicon substrate 50. Alternatively, it is formed using a silicon layer crystallized on an insulating film of an SOI (Silicon On Insulator) substrate.

  The transmission-side IDT 20 includes a fixed electrode 22 having a comb tooth portion 21 and a movable electrode 24 having a comb tooth portion 23. The fixed electrode 22 of the transmission side IDT 20 is connected to the electrode terminal 26 via the lead wire 25. Similarly, the receiving side IDT 30 includes a fixed electrode 32 having a comb tooth portion 31 and a movable electrode 34 having a comb tooth portion 33. The fixed electrode 32 of the receiving side IDT 30 is connected to the electrode terminal 36 via a lead wire 35. Note that reference numeral 38 in FIG. 1 denotes an electrode terminal as a ground electrode that is set in common with respect to the electrode terminals 26 and 36.

  The movable electrode 24 and the movable electrode 34 are connected by a connecting beam 41 extending in the X direction. The resonator 40 includes the connection beam 41, the movable electrodes 24 and 34, and a beam portion 42 formed of a rectangular frame described later. The resonator 40 is configured so that the comb tooth portion 23 of the movable electrode 24 connected to the end portion in the −X direction of the connection beam 41 meshes with the comb tooth portion 21 of the fixed electrode 22 in a plane and + X of the connection beam 41. The comb teeth 33 of the movable electrode 34 connected to the end in the direction are arranged between the fixed electrode 22 and the fixed electrode 32 so as to mesh with the comb teeth 31 of the fixed electrode 32 in a plane.

  The comb teeth 21 of the fixed electrode 22 and the comb teeth 23 of the movable electrode 24 each have a plurality of comb teeth meshing in parallel with the surface of the silicon substrate 50 with a predetermined plane gap (comb gap). ing. Similarly, the comb tooth portion 31 of the fixed electrode 32 and the comb tooth portion 33 of the movable electrode 34 have a plurality of comb teeth meshing in parallel with the surface of the silicon substrate 50 with a gap on a predetermined plane. Since the movable electrode 24 having the comb-tooth portion 23 and the movable electrode 34 having the comb-tooth portion 33 are provided in the resonator 40, the longitudinal vibration of the comb-tooth portions 23, 33, or the twist or rotation of the resonator 40. This is suitable for widening the setting range of the resonance frequency. Of course, with such a configuration, a single resonance frequency can be obtained.

  The frame-shaped beam portion 42 formed integrally with the movable electrodes 24 and 34 is supported by a cantilever beam 43 coupled to the beam portion 42, and the support portion 44 of the cantilever beam 43 is a silicon substrate. The structure is fixed on 50. Since the support portion 44 is electrically connected to the electrode terminal 38 as a ground electrode, the potential of the resonator 40 is almost equal to the ground potential. The outer shape of the beam portion 42 is not particularly limited to a square shape, and can be set to an arbitrary shape such as a circular shape, an oval shape, or a spindle shape.

  As shown in FIG. 2, the coupling beam 41 is supported in a state of being lifted in parallel to the substrate surface above the surface of the insulating film 51 of the silicon substrate 50 (+ Z direction). Accordingly, the comb-like movable electrodes 24 and 34 connected to both ends of the connection beam 41 are also arranged in a state of floating in parallel to the substrate surface. Further, the comb-shaped fixed electrodes 22 and 32 meshing with the movable electrodes 24 and 34 are also supported in a state where the comb-shaped portions are lifted in parallel to the substrate surface. The flying height of the movable electrodes 24 and 34 and the fixed electrodes 22 and 32, that is, the distance from the insulating film 51 formed on the silicon substrate 50 is about 2 to 3 μm.

  As shown in FIGS. 1 and 2, the microresonator 10 of the present embodiment is provided with a metal layer M1 on the electrode terminal 26, the lead wire 25, and the fixed electrode 22, and the electrode terminal 36, the lead wire 35, and A metal layer M <b> 2 is provided on the fixed electrode 32. A metal layer M3 is provided on the resonator 40 including the movable electrodes 24 and 34. Further, a metal layer M4 is provided on a part of the electrode terminal 38. The metal layers M1 to M3 include electrode terminals 26 and 36, lead wires 25 and 35, fixed electrodes 22 and 32, which are formed using a silicon layer crystallized on an insulating film of polysilicon or an SOI substrate, and It is provided to reduce the electrical resistance of the resonator 40 including the movable electrodes 24 and 34.

  That is, since the overall size of the microresonator 10 shown in FIG. 1 is about 100 μm square in the plane, the electrode terminals 26 and 36, the lead wires 25 and 35, the fixed electrodes 22 and 32, and the movable electrode The electric resistance of the resonator 40 including 24 and 34 is increased. In particular, since the comb teeth 21 and 31 of the fixed electrodes 22 and 32, the comb teeth 23 and 33 of the movable electrodes 24 and 34, and the lead wires 25 and 35 are structurally narrow, the resistance value increases.

  If there is no metal layer M1 to M3 and an alternating current is applied between the electrode terminal 26 and the electrode terminal 38, the output is output from the electrode terminal 36 even when the resonator 40 is resonating. The current is a weak current on the order of nA (nanoampere), and the performance as a filter that passes only an electric signal in a specific frequency region is not so good. The metal layers M1 to M3 reduce the electric resistance of the resonator 40 including the electrode terminals 26 and 36, the lead wires 25 and 35, the fixed electrodes 22 and 32, and the movable electrodes 24 and 34, thereby improving the performance of the microresonator 10. Provided to improve. Further, the metal layer M1 on the electrode terminal 26, the metal layer M2 on the electrode terminal 36, and the metal layer M4 on the electrode terminal 38 efficiently input an external current to the microresonator 10 or within the microresonator 10 Is provided to efficiently output the current flowing through the outside.

  The metal layers M1 to M4 are formed of a metal or alloy having corrosion resistance, and are formed of a metal such as gold (Au) or platinum (Pt). These metals are also used for forming wiring of semiconductor elements and the like, and are easy to form because the manufacturing process has been established. In addition, electrode terminals 26 and 36, lead wires 25 and 35, and fixing Adhesiveness to the resonator 40 including the electrodes 22 and 32 and the movable electrodes 24 and 34 is sufficiently obtained. As will be described later, in this embodiment, the metal layer M1 is applied to the resonator 40 including the electrode terminals 26 and 36, the lead wires 25 and 35, the fixed electrodes 22 and 32, and the movable electrodes 24 and 34 by heat treatment. -M4 is alloyed to further increase the adhesion, and the metal layer and the semiconductor layer are in ohmic contact.

  When the microresonator 10 having the above-described configuration is used as an oscillator, for example, an AC voltage is applied between the electrode terminal 26 of the comb-like fixed electrode 22 and the electrode terminal 38 as a ground electrode. When an alternating voltage is applied between these electrode terminals, an electrostatic attractive force is generated between the comb tooth portion 21 of the fixed electrode 22 and the comb tooth portion 23 of the movable electrode 24. As a result, the movable electrode 24 is pulled and vibrated through the beam portion 42 having spring properties in the meshing direction of the comb teeth (the length direction of the comb teeth, that is, the X direction). This vibration is transmitted to a beam portion 42 having a spring property integrated with the movable electrode 24, and the movable electrode 34 having the comb tooth portion 33 in mesh with the comb tooth portion 31 of the fixed electrode 32 is X similarly. Vibrate in the direction.

  When the vibration generated between the one comb-shaped fixed electrode 22 on the input side and the movable electrode 24 reaches the natural frequency of the resonator 40, the resonator 40 resonates at that frequency. When the resonator 40 resonates, an electric signal having an oscillation frequency corresponding to the natural frequency is output from the electrode terminal 36 connected to the fixed electrode 32 having the other comb tooth portion 31. The oscillation frequency (resonance frequency) is determined by the mass of the resonator 40 including the movable electrodes 24 and 34 and the restoring force against the displacement determined by the spring constant of the beam portion 42 (elastic force of the beam portion 42).

Here, when the mass of the resonator 40 is m and the spring constant of the beam portion 42 is k, the oscillation frequency f ₀ of the electric signal output from the fixed electrode 32 is expressed by the following equation (1).
f ₀ = (1 / (2 · π)) · (k / m) ^1/2 (1)
When the microresonator 10 shown in FIGS. 1 and 2 is used as an oscillator, for example, 16 kHz, 32 kHz, 72 kHz or the like is set as a design target value of the oscillation frequency.

In the case of using the micro-resonator 10 as a filter, as shown in FIG. 3, it is used as a filter having a pass band width of the resonance width W centered on the natural frequency f ₀ of the resonator 40. FIG. 3 is a diagram illustrating an example of pass characteristics when the microresonator 10 is used as a filter. When the microresonator 10 is used as a filter, an AC voltage is applied between the electrode terminal 26 of the comb-like fixed electrode 22 and the electrode terminal 38 as a ground electrode.

  If the frequency of the alternating voltage applied between these electrode terminals is a frequency included in the bandwidth W shown in FIG. 3, the resonator 40 vibrates in the X direction by electrostatic force, and an electric signal having the frequency Is output from the electrode terminal 36. On the other hand, when an AC voltage having a frequency not included in the bandwidth W is input, the resonator 30 does not resonate. As a result, that frequency is removed. With this operation, the microresonator 10 is used as a filter.

  In the microresonator 10 according to the embodiment of the present invention described above, the resonator 40 includes the movable electrode 24 having the comb-tooth portion 23 and the movable electrode 34 having the comb-tooth portion 33 so that the movable electrodes 24 and 34 are sandwiched therebetween. A fixed electrode 22 having a comb-tooth portion 21 and a fixed electrode 32 having a comb-tooth portion 31 are arranged, and the metal layer M1, the electrode terminal 36, the lead wire 35, and the electrode terminal 26, the lead wire 25, and the fixed electrode 22 The metal layer M2 is provided on the fixed electrode 32, and the metal layer M3 is provided on the resonator 40. As the form of the resonator 40 of the microresonator 10, a form of a beam (disk) shape or a disk shape can be adopted in addition to such a form. Even when these forms are adopted, a metal layer is formed on the resonator and the fixed electrode provided close to the resonator, and the resistance value between the resonator (movable electrode) and the fixed electrode is set. Can be reduced.

[Manufacturing Method of Micro Resonator]
4 to 6 are process diagrams showing a method for manufacturing a microresonator according to an embodiment of the present invention. 4 to 6, the same members as those shown in FIGS. 1 and 2 are denoted by the same reference numerals. In the following description, the case of manufacturing the microresonator 10 using an SOI substrate will be described as an example, but by forming an insulating film and a polysilicon (p-Si) film on the silicon substrate 50, The microresonator 10 can be manufactured by the same process as that in the case of using the SOI substrate.

In this embodiment, as shown in FIG. 4A, an oxide film 51 made of silicon dioxide (SiO ₂ ) as an insulating film and a low pressure vapor deposition (low pressure CVD (Chemical Vapor Deposition)) method are used on a silicon substrate 50. An SOI substrate in which a silicon layer 52 as a semiconductor layer is sequentially formed is used. The silicon substrate 50 is polished on both sides and has a thickness of about 500 μm. The oxide film 51 is formed to a thickness of about 0.1 μm, and the silicon layer 52 is formed to a thickness of about 10 to 29 μm.

First, a thermal oxidation process is performed on the SOI substrate shown in FIG. 4A, and silicon dioxide (SiO ₂ ) is formed on the back surface of the silicon substrate 50 and the surface of the silicon layer 52 as shown in FIG. 4B. Thus, a diffusion mask 53 is formed. The diffusion mask 53 is subjected to a process using PECVD (Plasma Enhanced Chemical Vapor Deposition) in addition to the thermal oxidation process. : Si (OC ₂ H ₅ ) ₄ : TEOS) may be formed.

  When the diffusion mask 53 is formed, a photoresist (not shown) is applied over the entire upper surface of the diffusion mask 53 formed on the silicon layer 52, and an exposure process and a development process are performed on the photoresist. As shown in FIG. 4C, a resist pattern having a predetermined shape is formed. The resist pattern formed by this process includes electrode terminals 26 and 36 formed using the silicon layer 52, lead wires 25 and 35, and openings H1 and H2 along the outer shape of the fixed electrodes 22 and 32, and This is a shape having an opening H3 along the outer shape of the resonator 40 including the movable electrodes 24 and 34.

Next, as shown in FIG. 5A, impurities are doped (added) and diffused into the silicon layer 52 from the openings H <b> 1 to H <b> 3 formed in the diffusion mask 53, so that the impurity added region 54 is formed in the silicon layer 52. A forming step is performed. The impurity used here is, for example, B (boron). By this process, the resonator 40 including the electrode terminals 26 and 36 formed using the silicon layer 52, the lead wires 25 and 35, the fixed electrodes 22 and 32, and the movable electrodes 24 and 34 is formed. Impurities are doped and diffused in the part. After doping and diffusing impurities, a diffusion mask formed on the back surface of the silicon substrate 50 and the surface of the silicon layer 52 using a BHF (buffered hydrofluoric acid) solution (HF: NH ₄ F = 1: 6). A step of removing 53 is performed. FIG. 5B shows a state where the diffusion mask 53 is removed.

  When the above steps are completed, a photoresist (not shown) is applied over the entire silicon layer 52 including the impurity-added region 54, and an exposure process and a development process are performed on the photoresist. Along the outer shape of the resonator 40 including the electrode terminals 26 and 36, the lead wires 25 and 35, the openings along the outer shape of the fixed electrodes 22 and 32, and the movable electrodes 24 and 34. A resist pattern having a shape having an opening is formed. The resist pattern formed here has substantially the same shape as the diffusion mask 53 shown in FIG.

  When the resist pattern is formed, a metal film made of platinum (Pt) and gold (Au) is formed on the surface on which the resist pattern is formed using a vacuum deposition method or a sputtering method, and the resist pattern is peeled off using a stripping solution. Then, the metal film formed on the resist pattern is removed and a lift-off process is performed. When this step is finished, as shown in FIG. 5C, a first metal layer 55a made of platinum (Pt) and a second metal layer 55b made of gold (Au) are formed on the silicon layer 52.

  The first metal film 55a and the second metal film 55b formed at the positions where the electrode terminal 26, the lead wire 25, and the fixed electrode 22 are formed become the metal layer M1 shown in FIGS. The first metal film 55a and the second metal film 55b formed at the position where the fixed electrode 32 is formed become the metal layer M2 shown in FIGS. 1 and 2, and the system integrity of the resonator 40 including the movable electrodes 24 and 34 is obtained. The first metal film 55a and the second metal film 55b formed in the step become the metal film M3 shown in FIGS.

  When the metal layers M1 to M3 are formed on the silicon layer 52 by the above steps, the silicon substrate 50 on which the metal layers M1 to M3 are formed is placed in a heat treatment furnace and heat treated in a reducing atmosphere. Each of the first metal films 55a made of platinum (Pt) of the metal layers M1 to M3 is alloyed with respect to the impurity added region 54. By performing this treatment, the adhesion between the metal layers M1 to M3 and the silicon layer 52 can be further increased, and the metal layers M1 to M3 and the silicon layer 52 can be in ohmic contact. The temperature in the heat treatment furnace when performing this treatment is preferably set to 1000 ° C. or less, more preferably about 800 to 900 ° C. to reduce thermal damage.

  When the above processing is completed, next, a photoresist (not shown) is applied over the entire silicon layer 52 including the metal layers M1 to M3, and exposure processing and development processing are performed on the photoresist. The outer shapes of the electrode terminals 26 and 36, the lead wires 25 and 35, and the fixed electrodes 22 and 32 formed by using the silicon layer 52, and the outer shape of the resonator 40 including the movable electrodes 24 and 34, respectively. A resist pattern is formed. When the resist pattern is formed, the silicon layer 20 is dry-etched, and finally the fixed electrodes 22 and 32, the resonator 40 (the coupling beam 41, the movable electrodes 24 and 34, and the beam portion 42), and the cantilever beam. 43, the portions to be the electrode terminals 26 and 36 and the lead portions 25 and 35 are left, and the other portions are removed. When the etching process is finished and the resist pattern formed on the silicon layer 52 including the metal layers M1 to M3 is removed, the state shown in FIG. As the dry etching process used here, etching by RIE (Reactive Ion Etching) or ICP (Inductively Coupled Plasma) can be used.

  Next, the comb-tooth portion 21 of the fixed electrode 22, the comb-tooth portion 31 of the fixed electrode 32, the resonator 40 (movable electrodes 24 and 34, the coupling beam 41, and the beam portion 42), and the insulating film below the cantilever 43 51 is removed by etching. Such etching is possible by controlling the etching time. By performing such etching, as shown in FIG. 6B, the resonator 40 can be formed on the silicon substrate 50 in a state of being levitated with an interval of about 2 to 3 μm.

  As described above, in the present embodiment, the metal film M1 is formed on the electrode terminal 26, the lead wire 25, and the fixed electrode 22, and the metal film M2 is formed on the electrode terminal 36, the lead wire 35, and the fixed electrode 32. Since the metal layer M3 is formed on the resonator 40 including the movable electrodes 24 and 34, the electrical resistance can be reduced by about two orders of magnitude. Further, since the metal layers M1 to M3 are formed after the impurity addition region 54 is provided by adding impurities to the silicon layer 52, the metal layers M1 to M3 and the silicon layer 52 can be in ohmic contact, An increase in excess resistance can be prevented.

  Further, since the metal layers M1 to M3 are formed using corrosion-resistant gold (Au) and platinum (Pt), the comb tooth portion 21 of the fixed electrode 22, the comb tooth portion 31 of the fixed electrode 32, and the resonator 40 are formed. Preventing the metal layers M1 to M3 from being corroded when the insulating film 51 under the movable electrodes 24 and 34, the connecting beam 41, and the beam portion 42 and the cantilever beam 43 is removed by etching. Can do. Further, by forming the metal layers M1 to M3 with corrosion-resistant gold (Au) and platinum (Pt), it is possible to prevent a change in resistivity due to a chemical change such as oxidation.

  In the embodiment described above, the metal film M1 is formed on the electrode terminal 26, the lead wire 25, and the fixed electrode 22, and the metal film M2 is formed on the electrode terminal 36, the lead wire 35, and the fixed electrode 32. Although the metal layer M3 is formed on the resonator 40 including the movable electrodes 24 and 34, it is not always necessary to form a metal film over these entire portions. For example, in the microresonator 10, there is a problem that the current for extracting the current generated by the vibration of the resonator 40 is extremely small. Therefore, only the metal film M <b> 1 is formed on the electrode terminal 26, the lead wire 25, and the fixed electrode 22. It may be formed. Furthermore, a metal film may be formed on the upper portion of at least one of the electrode terminals 26, 36, and 38 connected to the outside.

  Furthermore, in the above embodiment, the configuration in which the metal layer M3 is provided on the resonator 40 (the movable electrodes 24 and 34 and the coupling beam 41) has been described as an example. However, the beam portion 42 that forms a part of the resonator 40 is described. A metal layer may be provided thereon, and further, a metal layer may be provided on the upper portion of the cantilever 43. By providing a metal layer on these parts, the potential difference between the resonator 40 and the electrode terminal 38 can be reduced. In the above embodiment, the first metal layer 55a is formed of platinum (Pt) and the second metal layer 55b is formed of gold (Au). However, the first metal layer 55a is formed of chromium (Cr). The second metal layer 55b may be formed of gold (Au).

  Although the microresonator 10 is manufactured through the steps described above, the resonant frequency of the resonator 40 may vary in the manufactured microresonator 10. The metal layer M3 formed on the resonator 40 can also be used to fine tune the resonance frequency of the resonator 40. FIG. 7 is a diagram showing how the resonance frequency is finely adjusted using the metal layer M3. As shown in FIG. 7, the weight of the metal layer M3 (resonator 40) is adjusted by irradiating the metal layer M3 with laser light emitted from the laser 70 and partially evaporating the metal layer M3. The amount of adjustment of the weight of the metal layer M3 varies depending on the variation in the weight of the formed resonator 40 and the spring constant of the cantilever 43. Therefore, the weight of the resonator 40 is adjusted while measuring the resonance frequency of the resonator 40 while vibrating the resonator 40.

  In order to measure the resonance frequency of the resonator 40 while vibrating the resonator 40, a measuring device including an amplifier 71, a sensor head 72, a laser Doppler vibrometer 73, and a frequency analyzer 74 is used as shown in FIG. The amplifier 71 amplifies an AC signal having a predetermined frequency (resonant frequency of the resonator 40 or a frequency in the vicinity thereof) output from the signal output terminal (signal) of the frequency analyzer 74 with a predetermined amplification factor, and supplies it to the electrode terminal 36. Give.

  The sensor head 72 includes a light source such as a He—Ne laser, and irradiates the comb tooth portion 23 of the movable electrode 24 provided on the resonator 40 with laser light emitted from the light source, and reflects the reflected light. It receives the interference light obtained by interfering with the reference light and outputs a light reception signal obtained by photoelectric conversion. The intensity of the laser light emitted from the sensor head 72 is set to be much lower than the intensity of the laser light emitted from the laser 70, and the weight of the movable electrode 24 changes due to the irradiation of the laser light. Does not have any effect.

  The laser Doppler vibrometer 73 outputs a detection signal obtained by detecting the vibration frequency / vibration speed of the resonator 40 by frequency-modulating the light reception signal output from the sensor head 72. The frequency analyzer 74 outputs an AC signal having a variable frequency, a detection signal output from the laser Doppler vibrometer 73 and input to the input terminal (ch1), and an output output from the signal output terminal (signal). The resonance frequency of the resonator 40 is obtained using the AC signal input to the end (ch2), and the result is visually displayed on a display device 75 such as a CRT (Cathod Ray Tube) or a liquid crystal display device.

  In the above configuration, the weight of the metal layer M3 (resonator 40) is adjusted, for example, according to the following procedure. First, the resonance frequency of the resonator 40 is measured in a state where the laser light from the laser 70 is not irradiated onto the metal layer M3. For this measurement, an electric signal having a predetermined frequency is output from the signal output terminal (signal) of the frequency analyzer 74 and amplified by the amplifier 71 and then applied to the electrode terminal 36. Further, laser light is irradiated from the sensor head 72 to the comb teeth portion 23 of the movable electrode 24 provided on the resonator 40.

  If the frequency of the electrical signal applied to the electrode terminal 36 is a frequency away from the resonance frequency of the resonator 40, the amplitude of the resonator 40 is small, and therefore vibration of the detection signal output from the laser Doppler vibrometer 73. The value of the signal indicating the speed is small. On the other hand, if the frequency of the electric signal applied to the electrode terminal 36 approaches the resonance frequency of the resonator 40, the amplitude of the resonator 40 increases, and therefore the vibration speed of the detection signal output from the laser Doppler vibrometer 73. The value of the signal indicating becomes larger.

  Such measurement is performed while changing the frequency of the electrical signal output from the signal output terminal of the frequency analyzer 74. Thereby, the resonance frequency of the resonator 40 in a state where the weight of the metal layer M3 is not adjusted is measured. As described above, since the metal layer M3 is formed slightly heavier than the weight capable of obtaining the target resonance frequency, the resonance frequency obtained by the above measurement is lower than the target resonance frequency. .

  Next, in a state where an electric signal from the signal output terminal of the frequency analyzer 74 is applied to the electrode terminal 36, the metal layer M3 is irradiated with laser light emitted from the laser 70, and the metal layer M3 is partially evaporated. Let At this time, the laser light from the sensor head 72 is irradiated to the comb teeth portion 23 of the movable electrode 24 provided on the resonator 40 to constantly measure the resonance frequency of the resonator 40. Note that it takes time to measure the resonance frequency of the resonator 40 because it is necessary to change the frequency of the electrical signal from the frequency analyzer 74. For this reason, it is desirable to stop the irradiation of the laser 70 until the measurement is completed. Of course, if the evaporation of the metal layer M3 is small, the resonance frequency can be measured while irradiating the laser 70.

  Thus, the operation of measuring the resonance frequency of the resonator 40 while irradiating the metal layer M3 with the laser light from the laser 70 and partially evaporating the metal layer M3 is repeated, and the resonance frequency of the resonator 40 to be measured is measured. When the frequency reaches the target resonance frequency, the irradiation of the laser beam from the laser 70 is stopped. As a result, the microresonator 10 including the resonator 40 having the target resonance frequency is obtained.

  When the weight of the metal layer M3 (resonator 40) is adjusted, the resonator is changed when the resonance frequency is changed in a state where only the longitudinal vibration of the comb teeth portions 23 and 33 is generated. Desirably, the metal layer M3 is evaporated symmetrically with respect to the center of gravity of 40 and adjusted symmetrically with respect to the center of gravity of the resonator 40. On the other hand, when it is desired to obtain a resonance mode due to torsion or rotation of the resonator 40, the metal layer M3 is evaporated asymmetrically with respect to the center of gravity of the resonator 40 and adjusted asymmetrically with respect to the center of gravity of the resonator 40. Is desirable. Thus, in the present embodiment, the metal layer 40 formed on the resonator 40 can be used to reduce the electrical resistance of the resonator 40, and the resonance frequency and resonance mode of the resonator 40 can be set. It can also be used to adjust.

  According to the manufacturing method of the microresonator of the present embodiment described above, the weight of the resonator 40 is adjusted by adjusting the weight of the metal layer M3 formed on the top of the resonator 40. The weight of the resonator 40 can be adjusted even when there is a variation in weight due to a manufacturing error of the resonator 40 or the like. As a result, the microresonator 10 having the target resonance frequency can be manufactured at a high yield and at a low cost.

  In addition, the method for manufacturing the microresonator of the present embodiment described above includes a resonator 40 having movable electrodes 24 and 34 that are partly comb-shaped and a microelectrode that includes fixed electrodes 22 and 32 that are partly comb-shaped. In addition to the resonator, the present invention can also be applied to manufacturing a microresonator including a beam-shaped or disk-shaped resonator.

〔Electronics〕
FIG. 8 is a perspective view showing an appearance of a mobile phone as an electronic apparatus according to an embodiment of the present invention. A cellular phone 100 shown in FIG. 8 includes an antenna 101, a receiver 102, a transmitter 103, a liquid crystal display unit 104, an operation button unit 105, and the like. FIG. 9 is a block diagram showing an electrical configuration of an electronic circuit provided in the mobile phone 100 shown in FIG.

  The electronic circuit shown in FIG. 9 shows a basic configuration of an electronic circuit provided in the mobile phone 100, and includes a transmitter 110, a transmission signal processing circuit 111, a transmission mixer 112, a transmission filter 113, a transmission power amplifier 114, and a transmission / reception amount. It includes a wave filter 115, antennas 116a and 116b, a low noise amplifier 117, a reception filter 118, a reception mixer 119, a reception signal processing circuit 120, a receiver 121, a frequency synthesizer 122, a control circuit 123, and an input / display circuit 124. The In addition, since the cellular phone currently in practical use performs frequency conversion processing a plurality of times, its circuit configuration is more complicated.

  The transmitter 110 is realized by, for example, a microphone that converts sound waves into an electric signal, and corresponds to the transmitter 103 in FIG. The transmission signal processing circuit 111 is a circuit that performs processing such as D / A conversion processing and modulation processing on the electrical signal output from the transmitter 110. The transmission mixer 112 uses the signal output from the frequency synthesizer 122 to mix the signal output from the transmission signal processing circuit 111. The frequency of the signal supplied to the transmission mixer 112 is, for example, about 380 MHz. The transmission filter 113 passes only a signal having a frequency that requires an intermediate frequency (IF) and cuts a signal having an unnecessary frequency. The signal output from the transmission filter 113 is converted into an RF signal by a conversion circuit (not shown). The frequency of this RF signal is, for example, about 1.9 GHz. Transmission power amplifier 114 amplifies the power of the RF signal output from transmission filter 113 and outputs the amplified signal to transmission / reception demultiplexer 115.

  The transmitter / receiver demultiplexer 115 outputs the RF signal output from the transmission power amplifier 114 to the antennas 116a and 116b, and transmits the RF signal from the antennas 116a and 116b in the form of radio waves. Further, the transmitter / receiver demultiplexer 115 demultiplexes the received signals received by the antennas 116 a and 116 b and outputs the demultiplexed signals to the low noise amplifier 117. The frequency of the reception signal output from the transmission / reception duplexer 115 is, for example, about 2.1 GHz. The low noise amplification 117 amplifies the reception signal from the transmission / reception duplexer 115. The signal output from the low noise amplifier 117 is converted into an intermediate signal (IF) by a conversion circuit (not shown).

  The reception filter 118 passes only a signal having a required frequency of an intermediate frequency (IF) converted by a conversion circuit (not shown), and cuts a signal having an unnecessary frequency. The reception mixer 119 mixes the signal output from the transmission signal processing circuit 111 using the signal output from the frequency synthesizer 122. The intermediate frequency supplied to the reception mixer 119 is about 190 MHz, for example. The reception signal processing circuit 120 is a circuit that performs processing such as A / D conversion processing and demodulation processing on the signal output from the reception mixer 119. The receiver 121 is realized by, for example, a small speaker that converts an electrical signal into a sound wave, and corresponds to the receiver 102 in FIG.

  The frequency synthesizer 122 is a circuit that generates a signal to be supplied to the transmission mixer 112 (for example, a frequency of about 380 MHz) and a signal to be supplied to the reception mixer 119 (for example, a frequency of 190 MHz). The frequency synthesizer 122 includes a PLL circuit that oscillates at an oscillation frequency of 760 MHz, for example, divides the signal output from the PLL circuit to generate a signal having a frequency of 380 MHz, and further divides the frequency to 190 MHz. Generate a signal. The control circuit 123 controls the overall operation of the mobile phone by controlling the transmission signal processing circuit 111, the reception signal processing circuit 120, the frequency synthesizer 122, and the input / display circuit 124. The input / display circuit 124 is for displaying the state of the device to the user of the mobile phone 100 and inputting an instruction from the operator. For example, the liquid crystal display unit 104 and the operation button unit shown in FIG. This corresponds to 105.

  In the electronic circuit having the above configuration, the above-described microresonator is used as the transmission filter 113 and the reception filter 118. The frequencies filtered by the transmission filter 113 and the reception filter 118 (frequency bands to be passed) are transmitted according to the required frequency in the signal output from the transmission mixer 112 and the frequency required by the reception mixer 119. These are set individually for the filter 113 and the reception filter 118.

  Further, the above-described microresonator is used as a part of the PLL circuit provided in the frequency synthesizer 122. Since the PLL circuit provided in the frequency synthesizer 122 is a circuit that oscillates at a specific frequency as described above, the microresonator provided as a part of the PLL circuit resonates in a single resonance mode, and the above specific The Q value is set to be higher at the frequency of. Note that the above-described microresonator is also used in a conversion circuit (not shown) provided between the transmission filter 113 and the transmission power amplifier 114 and between the low noise amplifier 117 and the reception filter 118.

  Since conventional components corresponding to the transmission filter 113, the reception filter 118, the frequency synthesizer 122, and the like cannot be integrated with the reception mixer 119, etc., they are separated from the integrated reception mixer 119, etc. on the substrate. It was mounted on. On the other hand, in the electronic circuit shown in FIG. 9, since the microresonator is used for the transmission filter 113, the reception filter 118, the frequency synthesizer 122, and the like, it can be integrated together with the reception mixer 119 and the like. Thus, the mobile phone 100 can be reduced in size and weight.

  FIG. 10 is a perspective view showing an appearance of a wristwatch as an electronic apparatus according to another embodiment of the present invention. A wristwatch 200 shown in FIG. 10 includes the microresonator 10 described above as an oscillator. The oscillation frequency of the microresonator 10 is set to about 32 kHz, for example. Currently, wristwatches that are generally provided include a quartz (crystal) oscillator as an oscillator. However, by using the microresonator 10 as an oscillator, the wristwatch 200 can be further reduced in size and weight.

  The microresonator, the manufacturing method thereof, and the electronic device according to the embodiment of the present invention have been described above. However, the present invention is not limited to the above embodiment, and can be freely changed within the scope of the present invention. For example, in the above-described embodiment, a mobile phone and a wristwatch have been described as examples of electronic devices. However, the electronic device of the present invention is not limited to a mobile phone and a wristwatch, and includes various electronic devices such as a computer having a timekeeping function, a radio timepiece, a digital camera, and various home appliances.

  Further, not only electronic devices having portability such as mobile phones but also communication devices used in a stationary state such as tuners that receive BS broadcasts and CS broadcasts are included. Furthermore, not only communication devices that use radio waves propagating in the air as communication carriers, but also electronic devices such as HUBs that use high-frequency signals propagating in coaxial cables or optical signals propagating in optical cables. In these electronic devices, a microresonator is used for filtering a predetermined frequency and for realizing a clocking function.

It is a top view which shows the microresonator by one Embodiment of this invention. It is a cross-sectional arrow view along the AA line in FIG. It is a figure which shows an example of the passage characteristic in the case of using the microresonator 10 as a filter. It is process drawing which shows the manufacturing method of the microresonator by one Embodiment of this invention. It is process drawing which shows the manufacturing method of the microresonator by one Embodiment of this invention. It is process drawing which shows the manufacturing method of the microresonator by one Embodiment of this invention. It is a figure which shows a mode that a resonant frequency is finely adjusted using the metal layer M3. It is a perspective view which shows the external appearance of the mobile telephone as an electronic device by one Embodiment of this invention. It is a block diagram which shows the electrical constitution of the electronic circuit provided in the inside of the mobile telephone 100 shown in FIG. It is a perspective view which shows the external appearance of the wristwatch as an electronic device by other embodiment of this invention.

Explanation of symbols

10 …… Microresonator 22 …… Fixed electrode 24 …… Moving electrode 25 …… Lead wire (connection part)
26 …… Electrode terminal 32 …… Fixed electrode 34 …… Moving electrode 35 …… Lead wire (connection part)
36 ... Electrode terminal 40 ... Resonator 50 ... Silicon substrate 51 ... Insulating film (laminated part)
M1 to M3 ...... Metal layer

Claims (15)

A microresonator comprising a silicon substrate, a stacked portion including at least an insulating film formed on the silicon substrate, a fixed electrode formed on the stacked portion, a movable electrode, and an electrode terminal electrically connected to the fixed electrode. There,
A microresonator comprising a metal layer for reducing electric resistance at least on a part of the fixed electrode, the movable electrode, and the electrode terminal.   The microresonator according to claim 1, wherein the metal layer is provided on the electrode terminal.   2. The microresonator according to claim 1, wherein the metal layer is provided in the fixed electrode, the electrode terminal, and a connection portion that connects the fixed electrode and the electrode terminal. 3.   2. The microresonator according to claim 1, wherein the metal layer is provided over the fixed electrode, the movable electrode, and the electrode terminal.   The microresonator according to any one of claims 1 to 4, wherein the metal layer is formed of a metal or an alloy having corrosion resistance.   6. The microresonator according to claim 5, wherein the metal layer is made of gold or platinum.   The micro-resonator according to any one of claims 1 to 6, wherein a part of the fixed electrode and the movable electrode has a comb-teeth shape. A microresonator comprising a silicon substrate, a stacked portion including at least an insulating film formed on the silicon substrate, a fixed electrode formed on the stacked portion, a movable electrode, and an electrode terminal electrically connected to the fixed electrode. A manufacturing method comprising:
Forming a metal layer on top of at least a part of a portion where the fixed electrode, the movable electrode, and the electrode terminal of the semiconductor layer formed on the stacked portion are formed;
And a step of performing a predetermined treatment on the semiconductor layer to form the fixed electrode, the movable electrode, and the electrode terminal.   9. The method of manufacturing a microresonator according to claim 8, further comprising a step of adding an impurity to a portion of the semiconductor layer where the metal layer is formed before the metal layer is formed.   The method for manufacturing a microresonator according to claim 9, further comprising a step of performing heat treatment after forming a metal layer on the semiconductor layer, and alloying the metal layer with respect to the semiconductor layer.   The method for producing a microresonator according to claim 10, wherein the step of alloying the metal layer with respect to the semiconductor layer is performed by setting a temperature during the heat treatment to 1000 ° C. or less.   The method for producing a microresonator according to any one of claims 8 to 11, wherein the step of forming the metal layer is a step of forming the metal layer with a metal having corrosion resistance.   13. The method of manufacturing a microresonator according to claim 12, wherein the metal having corrosion resistance is gold or platinum.   9. The step of forming the fixed electrode, the movable electrode, and the electrode terminal is a step of forming the fixed electrode and the movable electrode in a shape having a comb tooth shape in part. The manufacturing method of the microresonator as described in any one of Claim 13 from. A microresonator manufactured according to any one of claims 1 to 7, or a microresonator manufactured using the method of manufacturing a microresonator according to any one of claims 8 to 14. Electronic equipment characterized by

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