JP2009006428A - Mems device equipped with getter film formed in sealed space - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce volume of a sealed space and simplify a manufacturing process, while maintaining performance of a MEMS (Micro Electronic Mechanical System) device formed in the sealed space. <P>SOLUTION: This MEMS device in the sealed space is formed by recessed parts 34, 36a, 36b and 36c of a glass substrate. The MEMS device is a vibrator 10 provided with a movable part (a ring or a suspension, for instance) and a fixed part (an electrode for detecting primary vibration, for instance), and is provided with getter films 40a, 40b, 40c and 40d formed on a surface of only the fixed part. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a MEMS device including a getter film formed in a sealed space.

  The technical field to which MEMS (Micro Electro Mechanical Systems) devices using silicon are applied is steadily expanding, and in recent years, the technology has been applied not only to micro turbines and sensors but also to information communication field and medical field. Yes. One of the main elemental technologies that support this MEMS technology is a technology related to getters. The getter is one of the important members for stabilizing the performance of the MEMS device formed in the sealed space. Especially in the field of sensors and the like that are becoming smaller, various technologies related to the getter are described. Development is essential.

  Conventionally used getters are formed by vapor deposition on the bottom of a recess provided in advance on a glass substrate. For example, a sealed space is formed by anodic bonding of the glass substrate and silicon, and the gas remaining after anodic bonding is appropriately absorbed by the presence of the getter (see, for example, Patent Document 1).

On the other hand, in the above-mentioned Patent Document 1, there is a description suggesting that a getter is provided on the surface of a silicon substrate. However, the specific configuration is not disclosed or suggested at all.
JP-A-10-122869

  By the way, the position where the getter is formed in the sealed space is one of the factors that influence various performances of the MEMS device. For example, if the position where the getter is formed in the sealed space is inappropriate, the difference in thermal expansion coefficient between the getter and the base material on which the getter region is formed and the residual stress may cause malfunction of the MEMS device. There is. In addition, if the distance between the getter and the electrode part formed on the MEMS device is too short, even if they do not contact, the electrode for detection or driving via the getter capacitively coupled with electrical noise Encroaching can adversely affect the operation of the MEMS device.

Such a problem appears particularly prominently in a miniaturized MEMS device having an area of 100 mm ² or less in a front view of a chip of a vibrating gyroscope having a substantially square shape as shown in FIG. Specifically, as the device becomes more compact, the volume of the sealed space also decreases accordingly.However, if the volume decreases, the gas released into the sealed space or the residual gas during the manufacturing process is reduced in the sealed space. The effect on the internal pressure is increased. As a result, for example, in the case of a MEMS sensor, the detection sensitivity is significantly reduced. Accordingly, although the technical significance of providing a getter region is particularly increased in a small-sized MEMS device, it is very difficult to form a getter in which the above-described problems are solved as long as a getter having an existing gas absorption performance is employed.

  The present invention greatly contributes to the optimization of the positional relationship between a MEMS device formed in a sealed space and a getter that helps maintain the performance by solving such technical problems. The inventors first paid attention to the depth of digging of the recess when the substrate is provided with a recess in advance to form a sealed space and the getter region is formed on the bottom surface thereof. As a result of various investigations, it became clear that there is a technical dilemma based on the relationship between the position of the getter region and the depth of digging.

  Specifically, when the digging depth is shallow, even if a getter film can be formed only on the bottom surface of the recess using a mask, the position of the getter film approaches each electrode of the MEMS device. Noise enters a detection or drive electrode through a getter film capacitively coupled. On the other hand, a technical problem when the digging depth is increased will be described by taking a conventional MEMS device as an example. FIG. 7 is a cross-sectional view of a part of a conventional ring-type vibrating gyroscope 300 (corresponding to the BB cross section in FIG. 2). When the digging depth is increased, it seems that it is easy to form a getter film only at the bottom of the recess 74 if a mask is used, but this is not the case. As shown in this figure, when an existing method such as sputtering is used, a getter film 73 is formed not only on the bottom surface of the recess 74 but also on the side surface. Accordingly, it is difficult to secure a sufficient distance such that the getter film 73 and the primary vibration detection electrode 75 do not affect each other, and as a result, the same problem as when the digging depth is shallow may occur. . Further, if the digging depth is deep, a process disadvantage for the digging formation (for example, an increase in process time and a decrease in yield) is caused.

  Inventors repeated earnest research based on the above-mentioned situation. As a result, by abandoning the existing idea of securing the getter area using the bottom surface of the recess provided on the substrate, changing the way of thinking about the getter area, and taking into account newly discovered technical issues A structure has been created that solves the above problems all at once. The present invention is based on such knowledge.

  One MEMS device of the present invention is a MEMS device formed in a sealed space, and the MEMS device includes a movable part and a fixed part, and a getter film formed on the surface of only the fixed part. I have.

  By adopting this structure, the difference in thermal expansion coefficient between the base material forming the MEMS device and the getter film is obtained by forming the getter film on the surface of only the fixed part while avoiding the surface of the movable part in the MEMS device. It is possible to prevent deterioration of device performance (for example, vibration characteristics and / or temperature characteristics in the case of a vibration gyroscope) caused by residual stress. In addition, the digging depth of the concave portion of the glass substrate for forming the sealed space is significantly shallower than before, so that the process time can be shortened and the manufacturing process can be simplified and the manufacturing cost can be greatly reduced. Is done.

  Another MEMS device of the present invention is a MEMS device formed in a sealed space, and the MEMS device includes a movable portion and a fixed portion, and a plurality of regions on the surface of only the fixed portion. The getter film is divided into two, and the getter film in each region is connected to any one electrode of the MEMS device or the ground potential via the base material of the MEMS device.

  If this structure is adopted, the digging depth of the concave portion of the substrate for forming the sealed space can be made significantly shallower than in the prior art. Further, a device that is generated by a stress difference between a base material forming the MEMS device and a getter film by forming a film-like getter on the surface of only the fixed portion while avoiding the surface of the movable portion in the MEMS device. It is possible to prevent deterioration of performance (for example, vibration characteristics and / or temperature characteristics in the case of a vibration gyro). In addition, since the film-like getter is formed by being dispersed on the surface of only the fixing portion, it is easy to obtain a sufficient surface area of the getter film while alleviating the warping of the fixing portion due to the formation of the getter film. Furthermore, since each region of the getter film divided into a plurality is connected to any one electrode of the MEMS device or the ground potential via the base material of the MEMS device, the potential of the getter film itself is determined. In other words, the potential does not enter a floating state. As a result, it is possible to prevent electrical noise from entering the detection or driving electrode via the getter film capacitively coupled.

  By the way, in any of the above inventions, the material of the getter film is a non-evaporable type titanium, zirconium, vanadium, aluminum, tantalum, from the viewpoint of the suction performance of the released gas or residual gas into the sealed space. It is preferably at least one metal selected from the group consisting of tungsten and molybdenum.

  According to one MEMS device of the present invention, the getter film is formed only on the surface of the fixed part while avoiding the surface of the movable part in the MEMS device, so that the base material that forms the MEMS device and the getter film are formed. It is possible to prevent deterioration in device performance caused by a difference in thermal expansion coefficient or residual stress. In addition, since the digging depth of the concave portion of the glass substrate for forming the sealed space is significantly shallower than the conventional one, the process time can be shortened and the manufacturing process can be simplified and the manufacturing cost can be greatly increased. Reduced.

  Next, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In this description, common parts are denoted by common reference symbols throughout the drawings unless otherwise specified. In the drawings, the elements of the present embodiment are not necessarily shown to scale.

<First Embodiment>
FIG. 1 is a front view of a structure that plays a central role in a ring-type vibrating gyroscope 100 that is one of the MEMS devices according to the present embodiment. FIG. 2 is an AA partial enlarged view of the structure shown in FIG. 3 is a cross-sectional view taken along the line BB in FIG. 2, and FIG. 4 is an exploded perspective view of the ring-type vibrating gyroscope 100 of the present embodiment including the package.

  The MEMS device according to this embodiment shown in FIGS. 1 to 4 is a ring-type vibrating gyroscope 100. First, as shown in FIG. 3, in this ring-type vibrating gyroscope 100, the upper glass substrate 30 in which the recesses 36a, 36b, and 36c are formed in advance and the lower glass substrate 32 in which the recess 34 is formed are trench-etched. It has a structure in which a silicon vibrator (hereinafter simply referred to as a vibrator) 10 processed by a process or the like is sandwiched. Here, the opposing surfaces of the glass substrates 30 and 32 and the vibrator 10 are anodically bonded to form a sealed space including the concave portions 34, 36a, 36b, and 36c as a part.

  As shown in FIG. 4, the concave portion formed in the lower glass substrate 32 is formed in an annular shape, and a columnar structure 39 having no concave portion is formed in the center thereof. The columnar structure 39 supports a part of the vibrator 10 by finally joining the central portion 24 of the vibrator 10. On the other hand, other portions of the vibrator 10 that are not supported by the columnar structure 39 (for example, the natural frequency adjusting electrodes 20 a, 20 b,..., 20 s) are joined to the upper glass substrate 30. , Suspended from the upper glass substrate 30.

  In the upper glass substrate 30, through holes represented by through holes 37 for wires connected to the electrode pads 38 a, 38 b, 38 c, 38 d, etc. are formed in order to drive the ring-type vibrating gyroscope 100. Yes. Specifically, as shown in FIG. 4, after the glass substrates 30 and 32 and the vibrator 10 are joined, they are connected to output pins of a vibration gyro installation base 44 (not shown) by wires drawn from the electrodes. . Thereafter, the ring-type vibrating gyroscope 100 is sealed by welding the lid 42 and the vibrating gyroscope mounting base 44 by resistance welding under a dry nitrogen atmosphere. Since the ring-type vibrating gyroscope 100 is shielded from the outside air by this joining, it is possible to prevent the occurrence of malfunction due to the ingress of moisture or the like.

  Here, in the MEMS device of the present embodiment, the getter films 40 a, 40 b, 40 c, 40 d are formed on one surface of the fixed part in the vibrator 10. Specifically, the getter films 40a and 40b are formed on the surfaces of the primary vibration detection electrodes 18c and 18g, the natural frequency adjustment electrodes 20a, 20b,..., 20s, and the remaining etching portions 22,. Is formed. It should be noted that the etching remaining portions 22,..., 22 are left as a part of the vibrator 10, thereby widening the formation region of the getter film. In the present embodiment, the getter film is a titanium thin film having a thickness of 0.1 μm or more and 2 μm or less.

  As described above, the getter films 40a, 40b, 40c, and 40d of the present embodiment are formed on the surface of the fixed portion of the vibrator 10, so that even if there is a stress difference between silicon and titanium, ring-type vibrations are obtained. Does not affect the operation of the gyro. In other words, when the getter film is formed on the surface of the ring 14 which is the movable portion of the vibrator 10 and the zigzag-shaped (dog leg-shaped) suspensions 16,... Due to the difference in thermal expansion coefficient between silicon and titanium and residual stress, normal operation cannot be obtained at the time of ring resonance.

  In addition, the conventional getter film is formed on the bottom surface of the recess 34 formed in the lower glass substrate 32. In this case, since the getter film itself serves as a floating electrode, if the concave portion does not have a sufficient digging depth (for example, 200 μm or more), capacitive coupling with each electrode of the vibrator 10 Electrical noise enters one of the detection or drive electrodes. On the other hand, since the getter film of this embodiment is formed only on the surface of the fixed portion of the vibrator 10 that is determined in terms of potential, the getter film does not enter a floating state in terms of potential. Specifically, the getter films 40c and 40d formed on the surfaces of the natural frequency adjusting electrodes 20a, 20b,..., 20s and the primary vibration detecting electrodes 18c and 18g are applied to the respective electrodes. And substantially the same potential. On the other hand, the unetched portions 22,..., 22 defined by the trenches 26 are integrated with the ring 14 including the suspensions 16,. Molded. That is, the unetched portions 22,..., 22 are electrically connected to the suspensions 16,. Therefore, the getter films 40a and 40b formed on the surfaces of the unetched portions 22,..., 22 are applied to the central portion 24 to which a DC voltage is applied from a DC power source (not shown) together with the ring 14. Since the potential is substantially shared, the floating state is not achieved.

As described above, in the MEMS device of this embodiment, even when the digging depth (d ₁ ) of the recess 34 shown in FIG. 3 is 30 μm, electrical noise due to capacitive coupling does not enter the getter film. . In the MEMS device as in this embodiment in which the movable part moves substantially on the same plane with respect to the fixed part, the digging depth (d ₁ ) may be 5 μm or more. On the other hand, in the MEMS device in which the moving surface of the movable portion and the formation surface of the fixed portion are substantially perpendicular, the digging depth (d ₁ ) is preferably 10 μm or more. In addition, although the upper limit of the digging depth is not particularly defined, in order to reduce the process burden for forming the recess 34, and further to reduce the amount of released gas that is considered to depend on the inner wall area of the sealed space, It is preferable that it is 60 micrometers or less. Thus, since the digging depth can be made shallower than in the prior art, the process time can be shortened and the manufacturing process can be simplified. The digging depth of each recess formed in the upper glass substrate 30 is the same as that of the lower glass substrate 32 or shallower than that so long as the operation of the vibrator 10 is not hindered.

  In addition, in order to prevent an excessively high vacuum in the sealed space and adjust the Q value of the vibrating gyroscope, a rare gas (for example, argon gas) that is not absorbed by the getter film in the sealed space is a pressure of 1 Pa or more. It is sealed so as to be 20 Pa or less. As described above, since the digging depth of the concave portion 34 formed in the lower glass substrate 32 is remarkably shallow compared to the conventional case, the glass thickness is greatly increased even in consideration of the strength of the entire MEMS device. Can be thinned. For example, the conventional glass thickness is 600 μm, but the glass thickness of the present embodiment is 450 μm. In addition, a more compact MEMS device can be provided. As a result, the manufacturing cost can be greatly reduced as compared with the conventional case.

  By the way, in this embodiment, although a getter film is formed on the surface of each above-mentioned electrode etc., it is not limited to this. A getter film may be formed on the surface of the primary vibration driving electrodes 18a and 18e, the secondary vibration detection electrodes 18b and 18f, or the secondary vibration canceling electrodes 18d and 18h, which are other fixed portions. . Also in this case, since the potential of the getter film is set to a certain value, it does not enter a floating state.

  Next, the manufacturing method of the MEMS device of this embodiment will be described based on FIGS. 5A to 5F. For convenience, the manufacturing method will be described while taking up the portion corresponding to FIG.

  First, the concave portions of the upper glass substrate 30 and the lower glass substrate 32 are formed by a wet etching process using a known glass etching solution. Specifically, after the glass substrates 30 and 32 are patterned by a known photolithography technique, the glass substrates 30 and 32 are made of 10% hydrofluoric acid at a liquid temperature of 30 ° C., depending on the etching depth. By dipping in the solution for 5 to 30 minutes, recesses as shown in FIGS. 5A and 5B are formed. The upper glass substrate 30 is etched from one surface to form a sealed space, and then etched or sandblasted to form the through hole 37 from the other surface.

  Next, the silicon substrate (S) serving as the base of the vibrator 10 that plays a central role in the MEMS device of the present embodiment and the upper glass substrate 30 are described in known conditions (for example, JP-A-2005-16965). (Fig. 5C).

  Subsequently, a resist mask is formed on the silicon substrate by a known photolithography technique. Thereafter, trenches 26 and 28 are formed in the silicon substrate (S) by a known anisotropic etching technique, whereby the vibrator 10 is formed on the upper glass substrate 30 (FIG. 5D). This etching technique and related techniques are disclosed in a plurality of patent applications (for example, Japanese Patent Application Laid-Open No. 2007-35929, Japanese Patent Application Laid-Open No. 2002-158214, Japanese Patent Application Laid-Open No. 2004-228556, or Japanese Patent Application Laid-Open No. 2004-228556). 2004-296474).

  Next, getter films 40a, 40b, 40c, and 40d made of titanium films are formed on the surface of the vibrator 10 by a known sputtering method or vacuum deposition method using a metal mask (FIG. 5E).

  Thereafter, similarly to the above, the vibrator 10 is bonded to the lower glass substrate 32 by anodic bonding using a known condition (for example, the condition described in JP-A-2005-16965). Finally, electrode pads 38a, 38b, 38c, 38d made of Al, Al alloy, or Au film are formed by a known sputtering method or vacuum deposition method (FIG. 5F).

  The ring-type vibrating gyroscope 100 manufactured in this way is then illustrated by drawing wires from the electrode pads 38a, 38b, 38c, 38d, etc. using the through holes represented by the through holes 37. Not connected to each power supply. Further, thereafter, the ring-type vibrating gyroscope 100 is sealed under a nitrogen atmosphere by the lid portion 42 and the vibrating gyroscope mounting base 44 as described above.

  Next, the operation of the ring-type vibrating gyroscope 100 of this embodiment will be described. As described above, a DC voltage is applied to the central portion 24 of the ring-type vibrating gyroscope 100 from a DC power supply (not shown), and AC voltages are applied to the primary vibration driving electrodes 18a and 18e from an AC power supply (not shown). Is done. In the present embodiment, in addition to the primary vibration driving electrodes 18a and 18e, the primary vibration detection electrodes 18c and 18g, the secondary vibration detection electrodes 18b and 18f, the secondary vibration cancellation electrodes 18d and 18h, and The natural frequency adjusting electrodes 20a, 20b,..., 20s are provided. The secondary vibration canceling electrodes 18d, 18h are connected to an AC power source, and the natural frequency adjusting electrodes 20a, 20b,..., 20s are connected to a DC power source. Further, the peripheral portion 12 physically and electrically separated from the ring 14 and the respective electrodes 18a, ..., 18h on the outer periphery of the ring 14 by the trench 28 is connected to the ground potential.

First, when an AC voltage is applied to the primary vibration driving electrodes 18a and 18e, the primary vibration of the ring-type vibration gyro 100 using the electrostatic attractive force between the ring 14 and the primary vibration driving electrodes 18a and 18e is generated. This occurs and is detected by the primary vibration detection electrodes 18c and 18g. After that, when a certain angular velocity is applied, Coriolis force is generated and secondary vibration is generated.
This is detected by the secondary vibration detection electrodes 18b and 18f. The natural frequency adjusting electrodes 20a, 20b,..., 20s are adjusted in advance so that the natural frequency of the primary vibration and the natural frequency of the secondary vibration coincide with each other by giving a potential difference to the ring 14. Has been. Thereafter, the current generated by the change in capacitance according to the applied angular velocity is detected by the secondary vibration detection electrodes 18b and 18f, and the output voltage for canceling the current is canceled by the feedback circuit. It is applied to the cutting electrodes 18d and 18h. By monitoring this output voltage, the angular velocity is detected.

<Second Embodiment>
FIG. 6 is a cross-sectional view of a part of another ring-type vibrating gyroscope 200 according to this embodiment. This sectional view corresponds to FIG. 3 of the first embodiment. The ring-type vibrating gyroscope 200 of this embodiment has the same configuration as that of the first embodiment except for the recess 60 formed in the lower glass substrate 32 and the formation position of the getter film. The manufacturing method and operation method are the same as those in the first embodiment. Therefore, the description which overlaps with 1st Embodiment is abbreviate | omitted.

  As shown in FIG. 6, the recessed part 60 formed in the lower glass substrate 32 has spread in the peripheral direction rather than the recessed part 34 of 1st Embodiment. Specifically, a part of the peripheral portion 12 physically and electrically separated from the ring 14 and the respective electrodes 18a, ..., 18h on the outer periphery of the ring 14 by the trench 28 is formed in the recess 60 or the upper glass substrate. It is in contact with a sealed space formed by 30 recesses 36a, 36b, 36c and the like. Further, a getter film 40 m is formed on a part of the surface of the peripheral portion 12. On the other hand, 40e, 40f, 40g, 40h, 40j, and 40k are formed on the surface of the other fixed portion.

  As a result, even if the volume of the sealed space of the present embodiment is increased as compared with that of the first embodiment, it is released into the sealed space due to the presence of a new getter region represented by the getter film 40m. The goal of absorbing gas or residual gas to maintain the performance of the MEMS device is achieved.

  Further, in the present embodiment, unlike the first embodiment, the getter films 40e, 40f, 40g, and 40h are formed by being divided into a plurality of regions on the surface of one etching remaining portion 22,. ing. By being divided in this way, it is possible to alleviate the warpage of the fixed portion caused by the difference in thermal expansion coefficient between the silicon and the getter film and the residual stress. Even on the surface of the fixed portion, it is preferable from the above viewpoint that the getter film is divided into a plurality of regions rather than integrally formed.

  The getter film may have different gas absorption performance depending on its material and formation conditions, or the amount of released gas may vary depending on anodic bonding conditions, etc., so that the above object can be achieved even without the getter film 40m. The However, it is preferable for maintaining the performance of the MEMS device that a part of the surface of the peripheral portion 12 can be a candidate as a place where the getter film 40m is formed. In particular, in the present embodiment, the peripheral portion 12 is connected to the ground potential in the same manner as in the first embodiment, so that the getter film 40m is not in a potential floating state. Therefore, it is possible to prevent electrical noise from entering the detection or driving electrode via the getter film 40m capacitively coupled.

Therefore, in this embodiment, even if the digging depth (d ₂ ) of the recess 60 shown in FIG. 6 is 20 μm, electrical noise caused by capacitive coupling does not enter the getter film. In the MEMS device as in this embodiment in which the movable part moves substantially on the same plane with respect to the fixed part, the digging depth (d ₂ ) may be 5 μm or more. On the other hand, in the MEMS device in which the moving surface of the movable portion and the formation surface of the fixed portion are substantially perpendicular, the digging depth (d ₂ ) is preferably 10 μm or more. Further, although the upper limit of the digging depth is not particularly defined, in order to reduce the process burden for forming the recess 60, and further to reduce the amount of released gas that is considered to depend on the inner wall area of the sealed space, It is preferable that it is 60 micrometers or less. In this embodiment as well, the depth of the recesses formed in the upper glass substrate 30 is the same as that of the lower glass substrate 32 or within a range that does not hinder the operation of the vibrator 10. Shallower.

  As described above, in the MEMS device of each embodiment, since the getter film is formed avoiding the surface of the movable part of the MEMS device, the gap between silicon and the getter film that is a base material for forming the MEMS device is formed. Degradation of device performance caused by the difference in stress is prevented. More specifically, the vibration that is considered to be caused by the residual stress generated by the difference in thermal expansion coefficient between silicon and the getter film, or the change in the stress state of each member caused by the temperature change in the usage environment of the MEMS device. It is possible to prevent deterioration of characteristics. Furthermore, the MEMS device of each of the embodiments described above has a significantly shallower digging depth of the concave portion of the glass substrate for forming the sealed space, so that the process time can be shortened and the manufacturing process can be simplified. Achieving and significantly reducing manufacturing costs. Further, the entire MEMS device formed in the sealed space including the package can be further reduced in size.

  In each of the above-described embodiments, the ring-type vibrating gyroscope is taken up as an example of the MEMS device. However, the MEMS device to which the present invention can be applied is not limited to this. The present invention also applies to other MEMS devices that are preferably formed in an enclosed space. Specifically, a micromirror or an RF switch is a typical example of a MEMS device to which the present invention can be applied.

  In addition, the area of the surface of the fixed part where the getter film is formed is increased or decreased according to the specifications of various MEMS devices. Therefore, as in the above-described embodiments, it is not always necessary to form a getter film on the surface of each electrode or etching residue, and a getter film may be formed on only a part of the surface. In consideration of potential stability, it is preferable that a getter film be formed in a region that is a ground potential in the MEMS device (in the above-described embodiments, the region of the peripheral portion 12).

  Moreover, in this embodiment, although titanium is employ | adopted as a material of a getter film | membrane, it is not limited to this. For example, the getter film may be made of at least one metal selected from the group consisting of zirconium, vanadium, aluminum, tantalum, tungsten, and molybdenum. Furthermore, in this embodiment, a ring-type vibrating gyroscope using silicon as a base material is employed, but the present invention is not limited to this. For example, the base material of the MEMS device may be germanium or silicon germanium. As described above, modifications that exist within the scope of the present invention are also included in the claims.

  The present invention is suitable for a MEMS device such as an acceleration sensor, an angular velocity sensor, a micromirror, or an RF switch formed in a sealed space.

It is a front view of the MEMS device in one embodiment of the present invention. It is the AA partial enlarged view of the MEMS device shown in FIG. It is BB sectional drawing in FIG. 1 is an exploded perspective view of a MEMS device including a package in one embodiment of the present invention. It is sectional drawing which shows one process of the manufacturing process of the MEMS device in one Embodiment of this invention. It is sectional drawing which shows one process of the manufacturing process of the MEMS device in one Embodiment of this invention. It is sectional drawing which shows one process of the manufacturing process of the MEMS device in one Embodiment of this invention. It is sectional drawing which shows one process of the manufacturing process of the MEMS device in one Embodiment of this invention. It is sectional drawing which shows one process of the manufacturing process of the MEMS device in one Embodiment of this invention. It is sectional drawing which shows one process of the manufacturing process of the MEMS device in one Embodiment of this invention. FIG. 6 is a partial cross-sectional view of a MEMS device according to another embodiment of the present invention. It is sectional drawing of the part of the conventional MEMS device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Vibrator 14 Ring 16 Suspension 18a, 18e Primary vibration drive electrode 18b, 18f Secondary vibration detection electrode 18c, 18g, 75 Primary vibration detection electrode 18d, 18h Secondary vibration cancellation electrode 22 Etching remaining part 24 Center Portions 26, 28 Trench 30, 71 Upper glass substrate 32, 72 Lower glass substrate 34, 36a, 36b, 36c, 60, 74 Recess 37 Through hole 38a, 38b, 38c, 38d Electrode pads 40a, 40b, 40c, 40d, 40e, 40f, 40g, 40h, 40j, 40k, 40m, 73 Getter film 42 Lid 44 Vibrating gyro installation table 100, 200, 300 Ring-type vibrating gyro

Claims (7)

A MEMS device formed in a sealed space,
The MEMS device includes a movable part and a fixed part, and a getter film formed on a surface of only the fixed part. The MEMS device according to claim 1, wherein the getter film is connected to any one electrode of the MEMS device or a ground potential via a base material of the MEMS device. A MEMS device formed in a sealed space,
The MEMS device includes a movable portion and a fixed portion, and includes a getter film formed by being divided into a plurality of regions on the surface of only the fixed portion,
A MEMS device in which the getter film in each region is connected to any one electrode of the MEMS device or a ground potential via a base material of the MEMS device. The distance from the surface of the MEMS device to the wall surface of the sealed space facing the surface is not less than 5 μm and not more than 60 μm, and the movable portion moves substantially on the same plane with respect to the fixed portion. Or the MEMS device according to claim 3. 2. The moving surface of the movable part and the forming surface of the fixed part are substantially perpendicular, and the distance from the surface of the MEMS device to the wall surface of the sealed space facing the surface is 10 μm or more and 60 μm or less. Or the MEMS device according to claim 3. At least a part of the movable part and the fixed part are integrally formed via a fixed end of the movable part;
The MEMS device according to claim 1 or 3. The MEMS device according to claim 1, wherein the getter film is made of at least one metal selected from the group consisting of titanium, zirconium, vanadium, aluminum, tantalum, tungsten, and molybdenum.

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