WO2018026031A1

WO2018026031A1 - Mems apparatus with improved impact characteristics, mems package comprising same, computing system, and method for manufacturing same

Info

Publication number: WO2018026031A1
Application number: PCT/KR2016/008586
Authority: WO
Inventors: 김덕수; 문상희; 서평보; 이종성
Original assignee: (주)스탠딩에그
Priority date: 2016-08-04
Filing date: 2016-08-04
Publication date: 2018-02-08
Also published as: KR20180016219A

Abstract

A MEMS apparatus, a MEMS package comprising the same, a computing system, and a method for manufacturing the same are provided. The MEMS apparatus comprises: a substrate; a mass structure which is arranged on the substrate and is movable while rotatable with respect to a rotary shaft which is perpendicular to the direction of acceleration; and a support structure which connects the substrate and the mass structure, wherein the substrate has formed thereon a plurality of trench structures which correspond to both ends of the mass structure, the plurality of trench structures comprising a plurality of trenches which are formed to be parallel with the rotary shaft, and a bridge formed between the plurality of trenches, and the both ends of the mass structure can be brought into contact with the bridge of the plurality of trench structures of the substrate.

Description

MEMS device with improved impact characteristics, MEMS package including the same, computing system, and method for manufacturing same

The present invention relates to a MEMS device, a MEMS package including the same, a computing system, and a method of manufacturing the same.

MEMS (Micro Electro Mechanical Systems) is used for military applications such as satellites, missiles, and unmanned aerial vehicles, and for hand shake prevention, mobile phones, cameras, camcorders, etc. It is used for various purposes such as motion sensing and navigation for game consoles.

If an excessive impact is applied to the MEMS device, a stiction phenomenon may occur in which the mass structure is broken or the mass structure sticks to a substrate or another plate, which may cause a problem of reliability.

[Technical Document] US Patent Publication No. 991575, 2015.10.06

An object of the present invention is to provide an MEMS device with improved impact characteristics, a MEMS package including the same, a computing system, and a method of manufacturing the same.

Problems to be solved by the present invention are not limited to the above-mentioned problems, and other problems not mentioned will be clearly understood by those skilled in the art from the following description.

MEMS device according to an aspect of the present invention for solving the above problems, a mass body structure disposed on the substrate, the upper portion of the substrate, rotatable about a rotation axis perpendicular to the direction of the acceleration, and the substrate and the mass structure A plurality of trench structures are formed on the substrate to correspond to both ends of the mass structure, and the plurality of trench structures are formed in parallel with the rotation axis. A bridge formed between the trenches, wherein both ends of the mass structure are each in contact with the bridge of the plurality of trench structures of the substrate.

In some embodiments, each of the two ends of the mass structure may be formed by extending at least one stopper.

In addition, three or more stoppers may be formed at both ends of the mass structure to extend at a center portion and at both corner portions, respectively.

In some other embodiments, the width of the plurality of trench structures may be smaller than the width of the mass structure, and both corners of both ends of the mass structure may be in contact with the substrate.

In some other embodiments, the width of the plurality of trench structures may be greater than the width of the mass structure, and both edge portions of both ends of the mass structure may not be in contact with the substrate.

MEMS package according to another aspect of the present invention for solving the above problems includes any one of the above-described MEMS device.

A computing system according to another aspect of the present invention for solving the above problems includes any one of the above-described MEMS device.

MEMS device manufacturing method according to another aspect of the present invention for solving the above problems, the first silicon layer, the silicon oxide layer formed on the first silicon layer and the second silicon layer formed on the silicon oxide layer Providing a substrate comprising: etching the silicon oxide layer and the second silicon layer to form a plurality of holes on both sides of the substrate; and etching the first silicon layer below the plurality of holes to form the plurality of holes. Forming a plurality of trench structures on both sides of the substrate, forming a mass structure pattern by etching the second silicon layer, and removing a portion of the silicon oxide layer with respect to a rotation axis perpendicular to the direction of acceleration. Completing a rotatable mass structure.

Other specific details of the invention are included in the detailed description and drawings.

According to the present invention, even if excessive impact is applied to the MEMS device, the stiction phenomenon can be prevented and the problem of unreliability can be eliminated.

Effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the following description.

1 is a plan view schematically showing the structure of a MEMS device according to an embodiment of the present invention.

2 is a cross-sectional view schematically showing the structure of a MEMS device according to an embodiment of the present invention.

3 to 9 are diagrams schematically showing a method of manufacturing a MEMS device according to an embodiment of the present invention.

10 is a plan view schematically showing the structure of a MEMS device according to another embodiment of the present invention.

11 is a plan view schematically showing the structure of a MEMS device according to another embodiment of the present invention.

12 is a diagram schematically illustrating a MEMS package including a MEMS device according to an embodiment of the present invention.

13-14 are schematic diagrams of sensor hubs including MEMS devices in accordance with embodiments of the present invention.

15 is a diagram schematically illustrating a computing system including a MEMS device according to an embodiment of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. Advantages and features of the present invention and methods for achieving them will be apparent with reference to the embodiments described below in detail with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but can be embodied in various different forms, and the present embodiments only make the disclosure of the present invention complete, and those of ordinary skill in the art to which the present invention belongs. It is provided to fully inform those skilled in the art of the scope of the invention, which is defined only by the scope of the claims.

Although the first, second, etc. are used to describe various elements, components and / or sections, these elements, components and / or sections are of course not limited by these terms. These terms are only used to distinguish one element, component or section from another element, component or section. Therefore, the first device, the first component, or the first section mentioned below may be a second device, a second component, or a second section within the technical spirit of the present invention.

When elements or layers are referred to as "on" or "on" of another element or layer, intervening other elements or layers as well as intervening another layer or element in between. It includes everything. On the other hand, when a device is referred to as "directly on" or "directly on" indicates that no device or layer is intervened in the middle. The spatially relative terms " below ", " beneath ", " lower ", " above ", " upper " It may be used to easily describe the correlation of a device or components with other devices or components. Spatially relative terms are to be understood as including terms in different directions of the device in use or operation in addition to the directions shown in the figures. For example, when flipping a device shown in the figure, a device described as "below or beneath" of another device may be placed "above" of another device. Thus, the exemplary term "below" can encompass both an orientation of above and below. The device may be oriented in other directions as well, in which case spatially relative terms may be interpreted according to orientation.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. In this specification, the singular also includes the plural unless specifically stated otherwise in the phrase. As used herein, "comprises" and / or "comprising" does not exclude the presence or addition of one or more other components in addition to the mentioned components. Like reference numerals refer to like elements throughout.

Unless otherwise defined, all terms (including technical and scientific terms) used in the present specification may be used in a sense that can be commonly understood by those skilled in the art. In addition, terms that are defined in a commonly used dictionary are not ideally or excessively interpreted unless they are specifically defined clearly.

Hereinafter, in order to describe an embodiment of the present invention, an acceleration sensor among various MEMS devices will be described as an example. However, the present invention is not limited thereto, and a person of ordinary skill in the art to which the present invention pertains is not limited to the technical idea or essential to any MEMS device such as a gyro sensor, a pressure sensor, a microphone, as well as an acceleration sensor. It will be appreciated that the same may be applied substantially without changing the feature.

1 is a plan view schematically showing the structure of a MEMS device according to an embodiment of the present invention, Figure 2 is a cross-sectional view schematically showing the structure of a MEMS device according to an embodiment of the present invention.

1 to 2, a MEMS device 1 according to one embodiment of the present invention is shown.

The MEMS device 1 includes a mass structure 190 that is movable in accordance with an external force (or an inertial force due to an external force). Mass structure 190 is rotatable about a predetermined axis of rotation. Mass structure 190 is disposed on top of substrate 110 and is connected to substrate 110 by support structure 195.

An opening is formed by removing a predetermined area inside the mass structure 190. In addition, the support structure 195 may be formed in the opening. The support structure 195 can include a pedestal 191 and one or more torsion bars 192. The torsion bar 195 may extend from both sides of the pedestal 191 and be connected to the mass structure 190. Although not explicitly illustrated, unlike the illustrated in FIG. 1, the torsion bar 192 may extend from one or more surfaces of the pedestal 191.

The torsion bar 192 may define a rotation axis in which the mass structure 190 rotates with respect to the pedestal 191 and the substrate 110. By the rotation axis, the mass structure 190 may be divided into a plurality of regions. For example, the axis of rotation may be defined such that the moment of the first region (left region of FIG. 1) of the mass structure 190 is smaller than the moment of the second region (right region of FIG. 1) of the mass structure 190. However, it is not limited thereto. Since an empty space exists between the mass structure 190 and the substrate 110, the mass structure 190 is rotatable. Although not explicitly illustrated, a wire providing a predetermined voltage may be connected to the pedestal 191 for driving the mass structure 190.

A plurality of trench structures 160 are formed in the substrate 110 corresponding to both ends of the mass structure 190 (that is, at least a portion thereof overlaps). Each trench structure 160 includes a plurality of trenches 161 and a bridge 162 formed between the plurality of trenches 161. The plurality of trenches 161 may be formed in parallel with the axis of rotation of the mass structure 190.

The substrate 110, the mass structure 190, and the support structure 195 may include silicon, but are not limited thereto.

Although not clearly illustrated, a plurality of sensing electrodes may be disposed above or below the mass structure 190. The sensing electrode may be disposed on the substrate 110 or the cap wafer 200. The sensing electrode may include a metal, but is not limited thereto. The first sensing electrode may constitute a first capacitor together with the first region of the corresponding mass structure 190, and the second sensing electrode may constitute a second capacitor together with the second region of the corresponding mass structure 190. have. In order to drive the sensing electrode, a wire providing a predetermined voltage may be connected to the sensing electrode.

1 to 2, the mass structure 190 may be used for z-axis acceleration sensing. The direction of acceleration and the axis of rotation of the mass structure 190 are perpendicular. When the acceleration is applied, the mass structure 190 rotates about the axis of rotation according to the direction and magnitude of the acceleration, and the capacitance of the first capacitor and the capacitance of the second capacitor may increase or decrease in opposite directions. That is, when the capacitance of the first capacitor is increased, the capacitance of the second capacitor is decreased, and when the capacitance of the first capacitor is decreased, the capacitance of the second capacitor may be increased. When no acceleration is applied, the mass structure 190 and the plurality of sensing electrodes may be parallel to each other. The direction and magnitude of acceleration may be determined by using the change in capacitance.

On the other hand, when an excessive impact is applied to the MEMS device 1, one end of either end of the mass structure 190 may be in contact with the substrate 110. At this time, the end portion of the mass structure 150 contacts the bridge 162 of the corresponding trench structure 160 of the substrate 110, whereby the contact area between the mass structure 190 and the substrate 110 is reduced, Since the distance between the mass structure 190 and the upper surface of the substrate 110 is increased, the stiction phenomenon can be prevented and the problem of poor reliability of the MEMS device can be eliminated.

First, referring to FIG. 3, a substrate is provided. The substrate includes a first silicon layer 110, a silicon oxide layer 120, and a second silicon layer 130. The silicon oxide layer 120 is formed on the first silicon layer 110, and the second silicon layer 130 is formed on the silicon oxide layer 120. The silicon oxide layer 120 may function as an insulating layer. The substrate may be provided by oxidizing the silicon substrate 110 to form the silicon oxide layer 120, and depositing the silicon layer 130 on the silicon oxide layer 120. Alternatively, a silicon-on-insulator (SOI) substrate may be provided.

Subsequently, referring to FIG. 4, a portion of the silicon oxide layer 120 and the second silicon layer 130 are etched to form a plurality of holes 150 on both sides of the substrate. Reference numeral 140 illustrates a mask pattern for etching the silicon oxide layer 120 and the second silicon layer 130. The mask pattern 140 may include silicon oxide, but is not limited thereto. For example, a deep reactive ion etching (DRIE) process may be used for etching the second silicon layer 130, but is not limited thereto.

Subsequently, referring to FIG. 5, an etching protection layer 151 is formed on the bottom and sidewalls of the plurality of holes 150. Subsequently, referring to FIG. 6, the etch protection film 151 on the bottom surface of the plurality of holes 150 is etched, and the first silicon layer 110 below the plurality of holes 150 is etched to form an amount of the substrate. A plurality of trench structures 160 are formed to each side. In order to etch the etching protection layer 151 on the bottom surface of the plurality of holes 150, a blanket etching process is used, and the etching of the first silicon layer 110 below the plurality of holes 150 is performed. To this end, a wet etching process may be used, but is not limited thereto.

Subsequently, referring to FIG. 7, etching protection layers 152 and 163 are formed in the inner spaces of the plurality of holes 150 and the sidewalls of the trench structure 160, respectively. In order to form the

etch protection layers

152 and 163, an oxidation process may be used, but is not limited thereto. Subsequently, referring to FIG. 8, a metal pad 170 is formed on the second silicon layer 130. For example, the metal pad 170 may include germanium (Ge), but is not limited thereto. The metal pad 170 may also function as a bonding pad bonding the sensor wafer and the cap wafer 200. The metal pads 170 may be bonded by eutectic bonding. A portion of the second silicon layer 130 is etched to form the mass structure pattern 180. For example, a depth reactive ion etching (DRIE) process may be used for etching the second silicon layer 130, but is not limited thereto. Next, referring to FIG. 9, a portion of the silicon oxide layer 120 and the etching protection layers 152 and 163 of the lower portion of the mass structure pattern 180 are removed to complete the mass structure 190. A gas etching process may be used to remove the silicon oxide layer 120 below the mass structure pattern 180, but is not limited thereto. Referring again to FIG. 2, the cap wafer 200 is bonded onto the metal pad 170, thereby completing the MEMS device 1 according to an embodiment of the present invention.

10 is a plan view schematically showing the structure of a MEMS device according to another embodiment of the present invention. For convenience of explanation, the differences from the MEMS device 1 of FIG. 1 will be described with emphasis.

Referring to FIG. 10, the MEMS device 2 according to another embodiment of the present invention further includes one or more stoppers 196 as compared to the MEMS device 1 described with reference to FIG. 1. The stoppers 196 may be formed to extend at both ends of the mass structure 190. As shown, three or more stoppers 196 may be formed at both ends of the mass structure 190 to extend, respectively, at the center and both corners thereof, but is not limited thereto. The stopper 196 may prevent excessive movement of the mass structure 190 and thereby damage.

11 is a plan view schematically showing the structure of a MEMS device according to another embodiment of the present invention. For convenience of explanation, the differences from the MEMS device 2 of FIG. 10 will be described with emphasis.

Referring to FIG. 11, the width of the plurality of trench structures 160 is increased in the MEMS device 3 according to another embodiment of the present invention compared to the MEMS device 2 described with reference to FIG. 10. That is, in the MEMS device 2 of FIG. 10, since the widths of the plurality of trench structures 160 are smaller than the widths of the mass structures 190, not only the centers of both ends of the mass structures 190 but also the corners thereof may be formed on the substrate ( 110, but in the MEMS device 3 according to another embodiment of the present invention, the sizes of the plurality of trenches 165 may be deformed so that the plurality of trench structures 160 may be larger than the width of the mass structure 190. Since the width is large, both edge portions of both ends of the mass structure 190 may not be in contact with the substrate 110, respectively. As a result, since the contact area between the mass structure 190 and the substrate 110 is further reduced, the stiction phenomenon can be further prevented and the problem of poor reliability of the MEMS device can be eliminated.

Although not clearly illustrated, the sizes of the plurality of trenches 161 of the MEMS device 1 described with reference to FIG. 1 are also the sizes of the plurality of trenches 165 of the MEMS device 3 according to another embodiment of the present invention. And may be modified substantially the same as

Referring to FIG. 12, the MEMS package 1000 includes a PCB substrate 1100, a MEMS device 1200 stacked on the PCB substrate 1100, and an ASIC device 1300. The MEMS device 1200 may be formed in substantially the same manner as the

MEMS devices

1, 2, and 3 described with reference to FIGS. 1 to 2, 10, and 11. 12 illustrates a wire bonding method, but the present invention is not limited thereto, and a flip chip method may be used.

Referring to FIG. 13, the sensor hub 2000 may include a processing device 2100, a MEMS device 2200, and an application specific integrated circuit (ASIC) device 2300. The MEMS device 2200 may be formed in substantially the same manner as the

MEMS devices

1, 2, and 3 described with reference to FIGS. 1 to 2, 10, and 11. The ASIC device 2300 may process the sensing signal of the MEMS device 2200. The processing device 2100 may function as a coprocessor for professionally performing sensor data processing on behalf of the application processor.

Referring to FIG. 14, the sensor hub 3000 may include a plurality of

MEMS devices

3200 and 3400 and a plurality of ASIC devices 3300 and 3500. At least one of the plurality of

MEMS devices

3200 and 3400 may be formed in substantially the same manner as the

MEMS devices

1, 2 and 3 described with reference to FIGS. 1 to 2, 10, and 11. The first MEMS device 3200 may be an acceleration sensor, and the second MEMS device 3400 may be a gyro sensor, but is not limited thereto. The plurality of ASIC devices 3300 and 3500 may process sensing signals of the

corresponding MEMS devices

3200 and 3400, respectively. The processing device 3100 may function as a coprocessor for professionally performing sensor data processing on behalf of the application processor. Unlike shown, three or more MEMS devices and ASIC devices may be provided within the sensor hub 3000.

Referring to FIG. 15, the computing system 4000 includes a wireless communication unit 4100, an A / V input unit 4200, a user input unit 4300, a sensing unit 4400, an output unit 4500, a storage unit 4600, The interface unit 4700 includes a control unit 4800 and a power supply unit 4900.

The wireless communication unit 4100 may wirelessly communicate with an external device. The wireless communication unit 4100 may wirelessly communicate with an external device using various wireless communication methods such as mobile communication, WiBro, Wi-Fi, Bluetooth, Zigbee, ultrasonic wave, infrared ray, and RF (Radio Frequency). Can be. The wireless communication unit 4100 may transmit data and / or information received from the external device to the controller 4800, and may transmit data and / or information transmitted from the controller 4800 to the external device. To this end, the wireless communication unit 4100 may include a mobile communication module 4110 and a short range communication module 4120.

In addition, the wireless communication unit 4100 may include the location information module 4130 to obtain location information of the computing system 4000. Location information of the computing system 4000 may be provided from, for example, a GPS positioning system, a WiFi positioning system, a cellular positioning system, or a beacon positioning system, but is not limited to any positioning system. Location information may be provided. The wireless communication unit 4100 may transfer the location information received from the positioning system to the controller 4800.

The A / V input unit 4200 is for inputting a video or audio signal and may include a camera module 4210 and a microphone module 4220. The camera module 4210 may include, for example, an image sensor such as a complementary metal oxide semiconductor (CMOS) sensor, a charge coupled device (CCD) sensor, or the like.

The user input unit 4300 receives various information from the user. The user input unit 4300 may include input means such as a key, a button, a switch, a touch pad, and a wheel. When the touch pad has a mutual layer structure with the display module 4510 described later, a touch screen may be configured.

The sensor unit 4400 detects a state of the computing system 4000 or a state of a user. The sensing unit 4400 may include sensing means such as a touch sensor, a proximity sensor, a pressure sensor, a vibration sensor, a geomagnetic sensor, a gyro sensor, an acceleration sensor, and a biometric sensor. The sensing unit 240 may be used for user input.

The output unit 4500 notifies the user of various information. The output unit 4500 may output information in the form of text, video or audio. To this end, the output unit 4500 may include a display module 4510 and a speaker module 4520. The display module 4510 may be provided in a PDP, LCD, TFT LCD, OLED, flexible display, three-dimensional display, electronic ink display, or any form well known in the art. The output unit 4500 may further comprise any form of output means well known in the art.

The storage unit 4600 stores various data and commands. The storage unit 4600 may store system software and various applications for operating the computing system 4000. The storage unit 4600 may include a RAM, a ROM, an EPROM, an EEPROM, a flash memory, a hard disk, a removable disk, or any type of computer readable recording medium well known in the art.

The interface unit 4700 serves as a path to an external device connected to the computing system 4000. The interface unit 4700 receives data and / or information from an external device or receives power and transmits the data and / or information to components inside the computing system 4000, or transmits data and / or information inside the computing system 4000 to an external device. It can transmit power or supply internal power. The interface unit 4700 includes, for example, a wired / wireless headset port, a charging port, a wired / wireless data port, a memory card port, a universal serial bus (USB) port, and an identification module. Port may be connected to a connected device, an audio input / output (I / O) port, a video input / output (I / O) port, or the like.

The controller 4800 controls other components to control the overall operation of the computing system 4000. The controller 4800 may execute system software and various applications stored in the storage 4600. The controller 2800 may include an integrated circuit such as a microprocessor, a microcontroller, a digital signal processing core, a graphics processing core, an application processor, or the like.

The power supply unit 4900 may include a wireless communication unit 4100, an A / V input unit 4200, a user input unit 4300, a sensor unit 4400, an output unit 4500, a storage unit 4600, an interface unit 4700, Supply power for the operation of the controller 4800. The power supply 4900 may include an internal battery.

MEMS devices

1, 2, and 3 described with reference to FIGS. 1 to 2, 10, and 11 or

sensor hubs

2000 and 3000 described with reference to FIGS. 13 to 14 may be provided in the sensor unit 4400. Can be.

The method described in connection with an embodiment of the present invention may be implemented as a software module performed by a processor. The software module may reside in RAM, ROM, EPROM, EEPROM, flash memory, hard disk, removable disk, CD-ROM, or any form of computer readable recording medium well known in the art. .

Although the embodiments of the present invention have been described above with reference to the accompanying drawings, those skilled in the art to which the present invention belongs may be embodied in other specific forms without changing the technical spirit or essential features of the present invention. You will understand that. Therefore, it should be understood that the embodiments described above are exemplary in all respects and not restrictive.

Claims

Board;

A mass structure disposed on the substrate and rotatable about a rotation axis perpendicular to the direction of acceleration; And

A support structure connecting the substrate and the mass structure;

The substrate is provided with a plurality of trench structures corresponding to both ends of the mass structure,

The plurality of trench structures includes a plurality of trenches formed in parallel with the rotation axis and a bridge formed between the plurality of trenches,

Both ends of the mass structure are each in contact with the bridge of the plurality of trench structures of the substrate,

MEMS device.
The method of claim 1,

At least one stopper is formed to extend in each of the both ends of the mass structure,

MEMS device.
The method of claim 2,

The two ends of the mass structure is formed by extending at least three stoppers disposed in the center and both corners, respectively,

MEMS device.
The method of claim 1,

The width of the plurality of trench structures is smaller than the width of the mass structure, and both edge portions of both ends of the mass structure are respectively in contact with the substrate.

MEMS device.
The method of claim 1,

The width of the plurality of trench structures is greater than the width of the mass structure, and both corner portions of both ends of the mass structure are not in contact with the substrate, respectively.

MEMS device.
A MEMS device according to any one of claims 1 to 5,

MEMS package.
A MEMS device according to any one of claims 1 to 5,

Computing system.
Providing a substrate comprising a first silicon layer, a silicon oxide layer formed on the first silicon layer, and a second silicon layer formed on the silicon oxide layer;

Etching the silicon oxide layer and the second silicon layer to form a plurality of holes on both sides of the substrate;

Etching the first silicon layer below the plurality of holes to form a plurality of trench structures on both sides of the substrate, respectively;

Etching the second silicon layer to form a mass structure pattern; And

Removing a portion of the silicon oxide layer to complete a mass structure that is rotatable about an axis of rotation perpendicular to the direction of acceleration;

Method of manufacturing MEMS device.