CN-121672409-B - MEMS device and preparation method thereof

CN121672409BCN 121672409 BCN121672409 BCN 121672409BCN-121672409-B

Abstract

The present disclosure relates to the technical field of semiconductor manufacturing, and in particular relates to a MEMS device and a method for manufacturing the same, wherein the MEMS device comprises a substrate, a device layer and a cap layer which are sequentially adjacent along a first direction; the semiconductor device comprises a substrate, a sealing cap layer, a device layer, a first driving electrode, a first movable driving comb tooth, a first beam, a first anchor point, a second beam, a first movable detection comb tooth and a first detection electrode, wherein the cavity grooves and the supporting columns are alternately arranged along a second direction, the sealing cap layer comprises the substrate and a plurality of semiconductor columns penetrating through the substrate along a first direction, the semiconductor columns are isolated from the substrate through isolating rings surrounding the semiconductor columns, the device layer comprises the first driving electrode, the first movable driving comb tooth, the first beam, the first anchor point, the second beam, the first movable detection comb tooth and the first detection electrode, and the first movable driving comb tooth is connected with the first anchor point through the first beam. At least, the MEMS device with excellent electrical isolation performance, good thermal matching and high electromechanical conversion sensitivity can be provided, and signal crosstalk caused by overlarge parasitic capacitance is avoided while the vertical interconnection and extraction of multiple paths of independent signals are realized.

Inventors

ZHAO QIANCHENG
TANG YI
SUN ZHIYU
LIU JIAXU

Assignees

北京大学

Dates

Publication Date: 20260508
Application Date: 20260205

Claims (10)

1. The MEMS device is characterized by comprising a substrate, a device layer and a sealing cap layer which are sequentially adjacent along a first direction; The substrate comprises cavity grooves and support columns which are alternately arranged along a second direction; The sealing cap layer comprises a substrate and a plurality of semiconductor columns penetrating through the substrate along the first direction, wherein the semiconductor columns are isolated from the substrate through isolating rings surrounding the semiconductor columns, the isolating rings are formed by etching annular grooves on the substrate, then carrying out glass reflow filling and chemical mechanical polishing; The device layer comprises a first driving electrode, a first movable driving comb tooth, a first beam, a first anchor point, a second beam, a first movable detection comb tooth and a first detection electrode which are sequentially arranged along the second direction; the first movable driving comb teeth are connected with the first anchor point through the first beam, the first movable detection comb teeth are connected with the first anchor point through the second beam, and the first movable driving comb teeth and the first movable detection comb teeth move under the drive of electric field force between the first driving electrode and the first detection electrode; The first driving electrode, the first anchor point and the first detection electrode are respectively bonded with the support column and the semiconductor column adjacent to the first driving electrode, the first anchor point and the first detection electrode along the first direction.
2. The MEMS device of claim 1, wherein inner sidewalls and bottom surfaces of the cavity recess are covered with a dielectric layer.
3. The MEMS device of claim 1, wherein a dielectric layer is included between the device layer and the support posts.
4. The MEMS device, as recited in claim 1, wherein a surface of the substrate facing away from the cavity recess is provided with alignment marks.
5. The MEMS device, as recited in claim 1, wherein a surface of the cap layer facing away from the cavity recess is provided with an insulating layer, the insulating layer comprising a plurality of contacts therethrough; the plurality of contact portions are correspondingly connected with the plurality of semiconductor pillars.
6. The MEMS device of claim 1, wherein the plurality of semiconductor pillars are eutectic bonded to the device layer via a conductive layer.
7. The MEMS device of claim 1, wherein the device layer further comprises a first sensor structure, a support structure, a second sensor structure arranged in sequence along the second direction; The first sensor structure comprises a first driving electrode, a first movable driving comb tooth, a first beam, a first anchor point, a second beam, a first movable detection comb tooth and a first detection electrode which are sequentially arranged along the second direction; The second sensor structure comprises a second driving electrode, a second movable driving comb tooth, a third beam, a second anchor point, a fourth beam, a second movable detection comb tooth and a second detection electrode which are sequentially arranged along the second direction, wherein the second movable driving comb tooth is connected with the second anchor point through the third beam; the second movable driving comb teeth and the second movable detection comb teeth are driven by electric field force between the second driving electrode and the second detection electrode to move.
8. The MEMS device of claim 7, comprising at least one of the following features: The first sensor structure, the supporting structure and the second sensor structure are prepared synchronously in the same process step; the movement directions of the first movable driving comb teeth and the first movable detection comb teeth are the same; The movement directions of the first movable driving comb teeth and the first movable detection comb teeth are opposite; the movement directions of the second movable driving comb teeth and the second movable detection comb teeth are the same; the second movable driving comb teeth and the second movable detection comb teeth have opposite movement directions.
9. A method of fabricating a MEMS device, comprising: Providing a substrate, wherein the substrate comprises a bonding surface and a bottom surface which are opposite along a first direction, cavity grooves and support columns which are alternately arranged along a second direction are formed in the substrate, and the cavity grooves are recessed towards the substrate through the bonding surface; Bonding a semiconductor layer with the top surface of the support column, and forming a first driving electrode, a first movable driving comb tooth, a first beam, a first anchor point, a second beam, a first movable detection comb tooth and a first detection electrode which are sequentially arranged along the second direction on the semiconductor layer to form a device layer, wherein the first movable driving comb tooth is connected with the first anchor point through the first beam, the first movable detection comb tooth is connected with the first anchor point through the second beam, and the first movable driving comb tooth and the first movable detection comb tooth move under the driving of electric field force between the first driving electrode and the first detection electrode; Providing a sealing cap layer, wherein the sealing cap layer comprises a substrate and a plurality of semiconductor columns penetrating through the substrate along the first direction, and the semiconductor columns are isolated from the substrate through isolating rings surrounding the semiconductor columns, wherein the isolating rings are formed by carrying out glass reflow filling and chemical mechanical polishing after etching annular grooves on the substrate; Bonding the sealing cap layer with the device layer, bonding the first driving electrode, the first anchor point and the first detection electrode with the support column and the semiconductor column adjacent to the first driving electrode, the first anchor point and the first detection electrode along the first direction respectively, isolating the isolation rings adjacent to the second direction through isolation grooves, and communicating the cavity grooves adjacent to the first direction with the isolation grooves.
10. The method of manufacturing a MEMS device according to claim 9, wherein the providing a substrate comprises: providing an initial substrate, wherein the initial substrate comprises a bonding surface and a bottom surface which are opposite along a first direction; Etching the bonding surface of the initial substrate based on the alignment mark to form cavity grooves and support columns which are alternately arranged along the second direction, wherein the cavity grooves are recessed towards the inside of the substrate through the bonding surface; and forming a dielectric layer covering the inner surface of the cavity groove and the top surface of the support column.

Description

MEMS device and preparation method thereof Technical Field The disclosure relates to the technical field of semiconductor manufacturing, in particular to an MEMS device and a preparation method thereof. Background In the manufacturing and packaging process of Micro Electro MECHANICAL SYSTEM, MEMS (Micro Electro) devices, wafer level packaging technology is one of key technologies for realizing miniaturization, high performance, high reliability and low-cost mass production of devices. With the continuous improvement of the requirements of various application scenes on the performance, the reliability and the cost control of devices, the traditional MEMS manufacturing and packaging process is faced with increasingly serious challenges. In terms of device structure, the gap between the movable structure and the substrate of the conventional MEMS device is small and difficult to control, so that the detection parasitic capacitance is large and the electromechanical conversion sensitivity is reduced. Vertical interconnection of electrical signals is a key element for realizing three-dimensional integration and high-density packaging, and the through silicon via (Through Silicon Via, TSV) technology is easy to cause interface cracking or insulating layer failure. Disclosure of Invention According to various embodiments of the present disclosure, a MEMS device and a method for manufacturing the same are provided, which can at least provide a MEMS device with excellent electrical isolation performance, good thermal matching, and high electromechanical conversion sensitivity, and avoid signal crosstalk caused by excessive parasitic capacitance while realizing vertical interconnection and extraction of multiple independent signals. According to some embodiments, a first aspect of the disclosure provides an MEMS device, which comprises a substrate, a device layer and a cap layer, wherein the substrate, the device layer and the cap layer are sequentially adjacent along a first direction, a cavity groove and a support column are alternately arranged along a second direction in the substrate, the cap layer comprises a substrate and a plurality of semiconductor columns penetrating through the substrate along the first direction, the semiconductor columns are isolated from the substrate through isolating rings surrounding the semiconductor columns, the device layer comprises a first driving electrode, a first movable driving comb tooth, a first beam, a first anchor point, a second beam, a first movable detection comb tooth and a first detection electrode, which are sequentially arranged along the second direction, the first movable driving comb tooth is connected with the first anchor point through the first beam, the first movable detection comb tooth is connected with the first anchor point through the second beam, the first movable driving comb tooth and the first movable detection comb tooth move under the driving of an electric field force between the first driving electrode and the first detection electrode, and the first driving electrode and the first anchor point and the first detection electrode are respectively bonded with the support column and the semiconductor columns adjacent along the first direction. In the MEMS device in the above embodiment, the plurality of semiconductor pillars are defined by the plurality of isolation rings extending along the direction perpendicular to the substrate and penetrating through the substrate, and the vertical signal extraction channel is provided, so that not only can the thermal stress mismatch between the substrate and the isolation rings be effectively reduced, but also the problem of poor electrical insulation can be effectively avoided, and the parasitic capacitance is reduced while the electrical isolation performance is improved. The substrate comprises cavity grooves and supporting columns which are alternately arranged along the second direction, and the gap between the movable structure of the MEMS device and the substrate can be accurately controlled at least by accurately controlling the concave depth of the cavity grooves, so that the detection parasitic capacitance is reduced, and meanwhile, the electromechanical conversion sensitivity is improved. The first driving electrode, the first anchor point and the first detection electrode are respectively bonded with the support column and the semiconductor column adjacent to the first anchor point along the first direction, so that the movable structure of the MEMS device can be twisted or vibrated conveniently under the driving of electric field force while good support is provided for the movable structure of the MEMS device, and the performance and reliability of the MEMS device are improved. According to some embodiments, the isolation rings adjacent along the second direction are isolated by the isolation grooves, and the cavity grooves adjacent along the first direction are communicated with the isolation