WO2017061636A1

WO2017061636A1 - Mems device preparation method, mems package and user terminal

Info

Publication number: WO2017061636A1
Application number: PCT/KR2015/010526
Authority: WO
Inventors: 서평보; 문상희; 이종성
Original assignee: 주식회사 스탠딩에그
Priority date: 2015-10-06
Filing date: 2015-10-06
Publication date: 2017-04-13

Abstract

Provided are a MEMS device preparation method, a MEMS package and a user terminal. The MEMS device preparation method comprises the steps of: providing a substrate comprising a silicon oxide layer and a silicon layer which is formed on the silicon oxide layer; forming a hard mask pattern on the silicon layer; reducing the thickness of an area requiring a step-shaped portion in the hard mask pattern; forming a MEMS structure pattern by means of primary etching the silicon layer by using the hard mask pattern; forming a step-shaped portion on the MEMS structure pattern by means of secondary etching the MEMS structure pattern by using the hard mask pattern; and completing a movable MEMS structure by means of removing a part of the silicon oxide layer.

Description

MEMS device manufacturing method, MEMS package and user terminal

The present invention relates to a method for manufacturing a MEMS device, and more particularly, to a method for manufacturing a parallel-plate based MEMS device, a MEMS package and a user terminal.

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.

In a MEMS device that senses capacitance between a plurality of plates, the parallel plate method must form a step in the plurality of plates. Conventionally, by forming a step using a plurality of masks (such as a hard mask or a photoresist mask), it is difficult to realize alignment characteristics between a plurality of plates in the same manner as design conditions. In addition, due to the difference in the gap space between the plurality of plates, as the capacitance in the unintended direction is sensed, there is a problem in that the axial sensitivity is deteriorated.

An object of the present invention is to provide a method for manufacturing a MEMS device that can improve the alignment characteristics between a plurality of plates of a parallel plate-based MEMS device.

Another technical problem of the present invention is to provide a method for manufacturing a MEMS device capable of improving the axial sensitivity characteristic of a parallel plate-based MEMS device.

Another technical problem of the present invention is to provide a MEMS package and a user terminal including a MEMS device manufactured by the above-described method.

The technical problems of 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 manufacturing method according to an aspect of the present invention for solving the above technical problem, providing a substrate comprising a silicon oxide layer and a silicon layer formed on the silicon oxide layer, a hard mask on the silicon layer Forming a pattern, reducing a thickness of a region requiring a step among the hard mask patterns, forming a MEMS structure pattern by first etching the silicon layer using the hard mask pattern, and forming the hard mask pattern Forming a step in the MEMS structure pattern by performing secondary etching on the MEMS structure pattern, and removing a portion of the silicon oxide layer to complete a movable MEMS structure.

In some embodiments of the present invention, the hard mask pattern may include silicon oxide.

In some embodiments of the present disclosure, reducing the thickness of a region requiring a step among the hard mask patterns may include: a photoresist pattern exposing a region requiring a step among the hard mask patterns on the silicon layer and the hard mask pattern; And forming a portion of the hard mask pattern to be etched using the photoresist pattern.

In some embodiments, the step of forming a step on the MEMS structure pattern, the portion of the hard mask pattern is reduced in thickness, the second etching the MEMS structure pattern using the remaining hard mask pattern. Thus, a step may be formed in the MEMS structure pattern.

In some embodiments of the present disclosure, the method may further include forming a metal pad on the silicon layer, and forming the hard mask pattern may include forming a hard mask pattern on the silicon layer and the metal pad. have.

In some embodiments of the present invention, the MEMS structure may have a parallel plate-based structure.

In addition, the pattern portion having the first thickness of the MEMS structure may correspond to the movable plate, and the pattern portion having the second thickness may correspond to the fixed plate.

MEMS device manufacturing method according to another aspect of the present invention for solving the above technical problem, providing a substrate comprising a silicon oxide layer and a silicon layer formed on the silicon oxide layer, a hard mask on the silicon layer Forming a pattern, reducing a thickness of a portion of the hard mask pattern, forming a MEMS structure pattern by first etching the silicon layer using the hard mask pattern, using the hard mask pattern Second etching the MEMS structure pattern to reduce the thickness of a portion of the MEMS structure pattern; and removing a portion of the silicon oxide layer to complete a movable MEMS structure.

MEMS package according to another aspect of the present invention for solving the above technical problem includes a MEMS device manufactured by any one of the methods described above.

A user terminal according to another aspect of the present invention for solving the above technical problem includes a MEMS device manufactured by any one of the methods described above.

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

According to the manufacturing method of the MEMS device of the present invention, since the MEMS structure pattern is formed using one hard mask pattern, the alignment between the plurality of plates of the parallel plate-based MEMS device is not affected by the alignment between the plurality of masks. Properties can be improved.

In addition, as alignment characteristics between the plurality of plates are improved, capacitance in an unintended direction may not be sensed, and the axial sensitivity characteristic of the parallel plate-based MEMS device may be improved.

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 flowchart schematically illustrating a method of manufacturing a MEMS device according to an embodiment of the present invention.

2 to 7 are cross-sectional views schematically showing a method of manufacturing a MEMS device according to an embodiment of the present invention.

8 is a view schematically showing a MEMS device manufactured by the method of manufacturing a MEMS device according to an embodiment of the present invention.

9 is a diagram schematically illustrating a MEMS package including a MEMS device manufactured by the method of manufacturing a MEMS device according to an embodiment of the present invention.

10 to 11 are diagrams schematically showing a sensor hub including a MEMS device manufactured by the method of manufacturing a MEMS device according to an embodiment of the present invention.

12 is a diagram schematically illustrating a user terminal including a MEMS device manufactured by a method of manufacturing 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 may be embodied in various different forms, and the present embodiments merely make the disclosure of the present invention complete, and are common 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. Like reference numerals refer to like elements throughout.

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.

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.

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.

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 skilled in the art of the present invention is not only an acceleration sensor, but also a capacitance between a plurality of plates based on parallel plates such as a gyro sensor, a pressure sensor, a microphone, and the like. It will be appreciated that any MEMS device that senses A may be applied substantially the same without changing its technical spirit or essential features.

1 is a flowchart schematically illustrating a method of manufacturing a MEMS device according to an embodiment of the present invention, and FIGS. 2 to 5 are cross-sectional views schematically illustrating a method of manufacturing a MEMS device according to an embodiment of the present invention.

1 to 5, first in step S10, a substrate is provided. The substrate may include a lower silicon layer 110, an upper silicon layer 130, a silicon oxide layer 120 interposed between the lower silicon layer 110 and the upper silicon layer 130. 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. The MEMS structure described later may be formed on the device layer 130 of the SOI substrate.

Subsequently, in step S20, the metal pad 140 is formed on the silicon layer 130. For example, the metal pad 140 may include germanium (Ge), but is not limited thereto. The metal pad 140 may function as a bonding pad bonding the sensor wafer 100 and the cap wafer 200. The metal pad 140 may be bonded by eutectic bonding. As shown, the metal pad 140 may be formed together with the MEMS structure within the manufacturing process of the sensor wafer 100, or may be formed after the manufacturing of the sensor wafer 100 is completed, although not clearly illustrated.

Subsequently, in step S30, a hard mask pattern 155 is formed on the silicon layer 130 and the metal pad 140. For example, the hard mask pattern 155 may include silicon oxide, but is not limited thereto. In order to form the hard mask pattern 155, the silicon oxide layer 150 is formed on the silicon layer 130 and the metal pad 140, and the photoresist pattern 160 is formed on the silicon oxide layer 150. The silicon oxide layer 150 may be etched using the photoresist pattern 160.

Subsequently, in step S40, the thickness of the area in which the step is necessary in the hard mask pattern 155 is reduced. In order to form a portion 151 having a different thickness (that is, a smaller thickness) of the hard mask pattern 155, a step of the hard mask pattern 155 is formed on the silicon layer 130 and the hard mask pattern 155. A photoresist pattern 170 may be formed to expose a desired region, and an area requiring a step among the hard mask patterns 155 may be etched using the photoresist pattern 170.

Subsequently, in step S50, the silicon layer 130 is first etched using the hard mask pattern 155 to form the MEMS structure pattern 135. For example, the primary etching may be a deep reactive ion etching (DRIE) process, but is not limited thereto. Subsequently, in step S60, the MEMS structure pattern 135 is secondly etched using the hard mask pattern 155 to form a step in the MEMS structure pattern 135. Specifically, only the portion 151 for forming the step of the hard mask pattern 155 is removed and the remaining portion is retained to expose a portion of the MEMS structure pattern 135 covered by the portion 151. In order to remove the portion 151, a blanket etching process or the like may be used. The MEMS structure pattern 135 is etched using only the remaining hard mask patterns 155 to form portions 136 having different thicknesses among the MEMS structure patterns 135. For example, the second etching may be a recess etching process, but is not limited thereto.

Subsequently, in step S70, a portion of the silicon oxide layer 120 below the MEMS structure pattern 135 is removed to form the silicon oxide pattern 125, thereby completing a movable MEMS structure. A gas etching process may be used to remove the silicon oxide layer 120, but is not limited thereto. The MEMS structure may have a parallel plate based structure. The pattern portion 136 having the first thickness (relatively small) of the MEMS structure functions as a movable plate, and the pattern portion having the second thickness (same thickness as the other portion) is fixed. Can function as a fixed plate.

Referring to FIG. 8, the MEMS device 1 includes a sensor wafer 100 and a cap wafer 200.

The sensor wafer 100 may be manufactured by the method of manufacturing the MEMS device described with reference to FIGS. 1 to 7. The sensor wafer 100 may comprise a MEMS structure having a parallel plate based structure. Some of the MEMS structures are used for z-axis (ie, vertical axis) sensing (right side in FIG. 8), and others may be used for x and / or y-axis (ie horizontal axis) sensing (left side in FIG. 8). ). Although not explicitly shown, a mass may be connected to the movable plate 136 of the MEMS structure. The mass can move in accordance with an external force (or an inertial force due to external force). When an external force is applied to the MEMS device 1, the overlapping area between the movable plate 136 and the fixed plate 135 changes according to the movement of the mass, and the acceleration is made by using the change of capacitance according to the change of the area. Can be sensed.

The cap wafer 200 may be formed on the sensor wafer 100. The sensor wafer 100 and the cap wafer 200 may be bonded by a bonding pad.

Referring to FIG. 9, 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 substantially the same as the MEMS device described with reference to FIG. 8. 9 illustrates a wire bonding method, but the present invention is not limited thereto, and a flip chip method may be used.

Referring to FIG. 10, 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 substantially the same as the MEMS device 1 described with reference to FIG. 8. 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. 11, 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 device 1 described with reference to FIG. 8. 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. 12, the user terminal 200 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, and the like. 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 user terminal 4000. Location information of the user terminal 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 thereto. 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 user terminal 4000 or a state of the 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 the operation of the user terminal 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 user terminal 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 user terminal 4000, or transmits data and / or information inside the user terminal 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 user terminal 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.

The MEMS device 1 described with reference to FIG. 8 or the

sensor hubs

2000 and 3000 described with reference to FIGS. 10 to 11 may be provided in the sensor unit 4400.

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 pertains may implement the present invention in other specific forms without changing the technical spirit or essential features thereof. You will understand that. Therefore, it should be understood that the embodiments described above are exemplary in all respects and not restrictive.

Claims

Providing a substrate comprising a silicon oxide layer and a silicon layer formed on the silicon oxide layer;

Forming a hard mask pattern on the silicon layer;

Reducing the thickness of an area requiring a step among the hard mask patterns;

First etching the silicon layer using the hard mask pattern to form a MEMS structure pattern;

Forming a step on the MEMS structure pattern by second etching the MEMS structure pattern using the hard mask pattern; And

Removing a portion of the silicon oxide layer to complete the moveable MEMS structure.
The method of claim 1,

And the hard mask pattern comprises silicon oxide.
The method of claim 1,

Reducing the thickness of the region requiring the step of the hard mask pattern,

Forming a photoresist pattern on the silicon layer and the hard mask pattern to expose a region requiring a step among the hard mask patterns;

And etching a region requiring a step among the hard mask patterns by using the photoresist pattern.
The method of claim 1,

Forming a step in the MEMS structure pattern,

Removing the portion of which the thickness is reduced among the hard mask patterns, and secondly etching the MEMS structure pattern using the remaining hard mask pattern to form a step in the MEMS structure pattern.
The method of claim 1,

Forming a metal pad on the silicon layer;

The forming of the hard mask pattern comprises forming a hard mask pattern on the silicon layer and the metal pad.
The method of claim 1,

Wherein the MEMS structure has a parallel plate-based structure.
The method of claim 6,

Wherein the patterned portion having the first thickness of the MEMS structure corresponds to the movable plate and the patterned portion having the second thickness corresponds to the fixed plate.
Providing a substrate comprising a silicon oxide layer and a silicon layer formed on the silicon oxide layer;

Forming a hard mask pattern on the silicon layer;

Reducing a thickness of a portion of the hard mask pattern;

First etching the silicon layer using the hard mask pattern to form a MEMS structure pattern;

Second etching the MEMS structure pattern using the hard mask pattern to reduce a thickness of a portion of the MEMS structure pattern; And

Removing a portion of the silicon oxide layer to complete the moveable MEMS structure.
A MEMS package comprising a MEMS device made by the method of any one of claims 1 to 8.
A user terminal comprising a MEMS device manufactured by the method of any one of claims 1 to 8.