CN-122002200-A - MEMS device, method for manufacturing the same, and method for reading output signal of MEMS device

CN122002200ACN 122002200 ACN122002200 ACN 122002200ACN-122002200-A

Abstract

The application provides a MEMS device, a manufacturing method thereof and a method for reading an output signal of the MEMS device, wherein the MEMS device comprises a first substrate, a second substrate and a first substrate, wherein a back cavity is formed in the first substrate; the device comprises a first substrate, a first movable film layer, a first isolation layer, a first fixed electrode layer, a second isolation layer, a third movable film layer, a fifth isolation layer, a fourth movable film layer, a fourth isolation layer, a second fixed electrode layer, a third isolation layer and a second movable film layer, a first cavity, a second cavity, a first connecting column, a second connecting column and a release hole, wherein the first movable film layer, the first isolation layer, the first fixed electrode layer, the second isolation layer, the third movable film layer, the third isolation layer, the third movable film layer, the fifth isolation layer, the third movable film layer, the fourth movable film layer are arranged on the first substrate, the second cavity is arranged between the first movable film layer and the third movable film layer, the second cavity is arranged between the second movable film layer and the fourth movable film layer, the first connecting column is arranged in the first cavity and connected with the third movable film layer and the first movable film layer, the second connecting column is arranged in the second cavity and connected with the second movable film layer, and the release hole penetrates through the third movable film layer, the fifth isolation layer and the fourth movable film layer. The scheme of the application can improve the sensitivity and the signal to noise ratio of the device.

Inventors

JIN YI
DONG YANG
ZHANG BING
LI SHAOPING
GAO DUODUO
RONG GENLAN
ZHU ENCHENG
JIN WENCHAO
YANG GUOQING
YAN KAI
WANG JIE

Assignees

无锡华润微电子有限公司

Dates

Publication Date: 20260508
Application Date: 20241104

Claims (10)

1. A MEMS device, comprising: A first substrate in which a back cavity penetrating the first substrate is formed; The first movable film layer is positioned on the first substrate, and part of the surface of the first movable film layer is exposed out of the back cavity; A first isolation layer located on a portion of the first movable film layer; A first fixed electrode layer located on the first isolation layer; a second isolation layer on a part of the first fixed electrode layer; The third movable film layer is positioned on the second isolation layer; a fifth isolation layer located on the third movable film layer; a fourth movable film layer located on the fifth isolation layer; A fourth isolation layer located on a portion of the fourth movable membrane layer; The second fixed electrode layer is positioned on the fourth isolation layer; A third isolation layer on a part of the second fixed electrode layer; The second movable film layer is positioned on the third isolation layer; A first cavity located between the first movable membrane layer and the third movable membrane layer; the second cavity is positioned between the second movable film layer and the fourth movable film layer; The first connecting columns are positioned in the first cavity, and the upper ends and the lower ends of the first connecting columns are respectively connected with the third movable film layer and the first movable film layer; the second connecting columns are positioned in the second cavity, and the upper ends and the lower ends of the second connecting columns are respectively connected with the second movable film layer and the fourth movable film layer; The release holes penetrate through the third movable film layer, the fifth isolation layer and the fourth movable film layer, and the first cavity and the second cavity are mutually communicated through the release holes to form a cavity.
2. The MEMS device of claim 1, wherein the first movable film layer and the first fixed electrode layer constitute a first variable capacitance structure, the second movable film layer and the second fixed electrode layer constitute a second variable capacitance structure, the third movable film layer and the first fixed electrode layer constitute a third variable capacitance structure, and the fourth movable film layer and the second fixed electrode layer constitute a fourth variable capacitance structure, wherein output signals of adjacent variable capacitance structures have a phase difference of 180 °.
3. The MEMS device of claim 1, wherein the structures of the third movable film layer, the fifth isolation layer, and the fourth movable film layer comprise any one of ：Poly/A-Si/poly、Poly/SiN/Poly、Poly/SiO2/Poly、Poly/SiN/A-si/SiN/Poly、Poly/A-si/SiN/A-si/Poly、Poly/SiO2/A-si/SiO2/Poly、Poly/A-si/SiO2/A-si//Poly、Poly/SiN/SiO2/SiN/Poly and Poly/SiO2/SiN/SiO2/Poly; The fifth isolation layer is made of TiO2 or TaO2, and the third movable film layer and the fourth movable film layer are made of silicon, germanium, metal, a second-generation semiconductor or a third-generation semiconductor.
4. The MEMS device of claim 1, wherein the first and second connection posts are cylindrical in shape, the first and second connection posts have diameters in the range of 1um-3um, and/or The materials of the first connecting column and the second connecting column comprise SiN, siO2 wrapped by SiN or Poly wrapped by SiN.
5. The MEMS device of claim 1, wherein a spacing between the first movable membrane layer and the first fixed electrode layer, between the third movable membrane layer and the first fixed electrode layer, between the second movable membrane layer and the second fixed electrode layer, and between the fourth movable membrane layer and the second fixed electrode layer is in a range of 1um-3um, and/or The thickness of the first movable film layer, the second movable film layer, the third movable film layer and the fourth movable film layer is in the range of 0.1um to 1.5um, and/or The MEMS device has a thickness in the range of 8um to 15um except for the substrate.
6. The MEMS device of claim 1, further comprising a first metal wiring layer, a second metal wiring layer, a third metal wiring layer, a fourth metal wiring layer, a fifth metal wiring layer, and a sixth metal wiring layer, wherein the first metal wiring layer is electrically connected to the first movable film layer, the second metal wiring layer is electrically connected to the second movable film layer, the third metal wiring layer is electrically connected to the third movable film layer, the fourth metal wiring layer is electrically connected to the fourth movable film layer, the fifth metal wiring layer is electrically connected to the first fixed electrode layer, and the sixth metal wiring layer is electrically connected to the second fixed electrode layer, or comprising A first bonding pad positioned on the first movable film layer, a second bonding pad positioned on the second movable film layer, a third bonding pad positioned on the third movable film layer, a fourth bonding pad positioned on the fourth movable film layer, a fifth bonding pad positioned on the first fixed electrode layer and a sixth bonding pad positioned on the second fixed electrode layer.
7. A method of manufacturing a MEMS device, the method comprising: Providing a first substrate, wherein a first movable film layer, a first isolation layer, a first fixed electrode layer, a second isolation layer and a first bonding layer are sequentially formed on the first surface of the first substrate, a first cavity is formed between the first bonding layer and the first substrate, a plurality of first connecting columns are formed in the first cavity, the upper end and the lower end of each first connecting column are respectively connected with the first bonding layer and the first movable film layer, and a plurality of first release holes exposing the first cavity are formed in the first bonding layer; providing a second substrate, wherein a second movable film layer, a third isolation layer, a second fixed electrode layer, a fourth isolation layer and a second bonding layer are sequentially formed on the first surface of the second substrate, a second cavity is formed between the second bonding layer and the second substrate, a plurality of second connecting columns are formed in the second cavity, the upper end and the lower end of each second connecting column are respectively connected with the second bonding layer and the second movable film layer, and a plurality of second release holes exposing the second cavity are formed in the second bonding layer; Bonding the first bonding layer and the second bonding layer to enable the first bonding layer and the second bonding layer to form a third movable film layer, a fifth isolation layer and a fourth movable film layer, wherein the third movable film layer, the fifth isolation layer and the fourth movable film layer are arranged in a stacked mode and connected with the first connecting column, the fourth movable film layer is connected with the second connecting column, and the first cavity and the second cavity are mutually communicated through the first release hole and the second release hole to form a cavity; removing the second substrate to expose the second movable film layer; A portion of the first substrate corresponding to the cavity is removed from a second surface of the first substrate to form a back cavity exposing a portion of the first movable film layer.
8. The method according to claim 7, wherein the first bonding layer includes a first movable sub-layer, the second bonding layer includes the fourth movable sub-layer, the fifth separator layer on the fourth movable sub-layer, and a second movable sub-layer on the fifth separator layer, the first movable sub-layer and the second movable sub-layer are bonded in the bonding step, the first movable sub-layer and the second movable sub-layer constitute the third movable sub-layer, or The first bonding layer comprises the third movable film layer, the second bonding layer comprises the fourth movable film layer and the fifth isolation layer positioned on the fourth movable film layer, the fifth isolation layer and the third movable film layer are bonded in the bonding step, or The first bonding layer comprises the third movable film layer and a first sub-isolation layer positioned on the third movable film layer, the second bonding layer comprises the fourth movable film layer and a second sub-isolation layer positioned on the fourth movable film layer, the first sub-isolation layer and the second sub-isolation layer are bonded in the bonding step, and the first sub-isolation layer and the second sub-isolation layer form the fifth isolation layer, or The first bonding layer comprises the third movable film layer and the fifth isolation layer positioned on the third movable film layer, the second bonding layer comprises the fourth movable film layer, and the fifth isolation layer and the fourth movable film layer are bonded in the bonding step, or The first bonding layer comprises a third movable film layer, a fifth isolation layer positioned on the third movable film layer and a third movable film layer positioned on the fifth isolation layer, the second bonding layer comprises a fourth movable film layer, the third movable film layer and the fourth movable film layer are bonded in the bonding step, and the third movable film layer and the fourth movable film layer form the fourth movable film layer.
9. The method of manufacturing according to claim 7, wherein the bonding step is performed using a low temperature bonding process.
10. A method of reading an output signal of a MEMS device, comprising: Providing a MEMS device as claimed in any one of claims 1 to 6 or a MEMS device manufactured by a manufacturing method as claimed in any one of claims 7 to 9; Reading an output signal of the MEMS device: applying a first bias voltage to a first fixed electrode layer of the MEMS device and a second bias voltage to a second fixed electrode layer of the MEMS device; Connecting the first and fourth movable membrane layers with the non-inverting input of a first amplifier and the second and third movable membrane layers with the inverting input of the first amplifier, or connecting the first and fourth movable membrane layers with the inverting input of the first amplifier and the second and third movable membrane layers with the non-inverting input of the first amplifier; Reading the signal at the output of the first amplifier, or Applying a first bias voltage to the first movable film layer and the fourth movable film layer, and applying a second bias voltage to the second movable film layer and the third movable film layer; connecting the first fixed electrode layer and the second fixed electrode layer with a non-inverting input end and an inverting input end of the first amplifier respectively; Reading the signal at the output of the first amplifier, or Applying a first bias voltage to the first fixed electrode layer and a second bias voltage to the second fixed electrode layer; Connecting the second movable membrane layer and the fourth movable membrane layer with the non-inverting input terminal and the inverting input terminal of the first amplifier respectively, and connecting the first movable membrane layer or the third movable membrane layer with the input terminal of the second amplifier, or connecting the first movable membrane layer and the third movable membrane layer with the non-inverting input terminal and the inverting input terminal of the first amplifier respectively, and connecting the second movable membrane layer or the fourth movable membrane layer with the input terminal of the second amplifier; and reading signals at the output ends of the first amplifier and the second amplifier.

Description

MEMS device, method for manufacturing the same, and method for reading output signal of MEMS device Technical Field The application relates to the technical field of semiconductors, in particular to an MEMS device, a manufacturing method thereof and a method for reading output signals of the MEMS device. Background With the continuous development of semiconductor technology, in the market of sensor products, MEMS microphones prepared based on Micro-Electro-MECHANICAL SYSTEM, MEMS (Micro-Electro-MECHANICAL SYSTEM, MEMS) technology are widely applied due to the advantages of small volume, low cost, stable performance and the like compared with the traditional microphones. The capacitive MEMS microphone generally includes a single-layer diaphragm and a single-layer back plate, where the single-layer diaphragm and the single-layer back plate form a capacitive structure, and when an external sound signal acts on the diaphragm, the diaphragm vibrates to cause capacitance change, and the capacitance change is used to perform operation and work to complete conversion between the sound signal and the electrical signal. However, the capacitive MEMS microphone in the related art has a problem in that sensitivity and signal-to-noise ratio are low. Disclosure of Invention In the summary, a series of concepts in a simplified form are introduced, which will be further described in detail in the detailed description. The summary of the application is not intended to define the key features and essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter. In view of the problems existing at present, an aspect of the present application provides a MEMS device, including: A first substrate in which a back cavity penetrating the first substrate is formed; The first movable film layer is positioned on the first substrate, and part of the surface of the first movable film layer is exposed out of the back cavity; A first isolation layer located on a portion of the first movable film layer; A first fixed electrode layer located on the first isolation layer; a second isolation layer on a part of the first fixed electrode layer; The third movable film layer is positioned on the second isolation layer; a fifth isolation layer located on the third movable film layer; a fourth movable film layer located on the fifth isolation layer; A fourth isolation layer located on a portion of the fourth movable membrane layer; The second fixed electrode layer is positioned on the fourth isolation layer; A third isolation layer on a part of the second fixed electrode layer; The second movable film layer is positioned on the third isolation layer; A first cavity located between the first movable membrane layer and the third movable membrane layer; the second cavity is positioned between the second movable film layer and the fourth movable film layer; The first connecting columns are positioned in the first cavity, and the upper ends and the lower ends of the first connecting columns are respectively connected with the third movable film layer and the first movable film layer; the second connecting columns are positioned in the second cavity, and the upper ends and the lower ends of the second connecting columns are respectively connected with the second movable film layer and the fourth movable film layer; The release holes penetrate through the third movable film layer, the fifth isolation layer and the fourth movable film layer, and the first cavity and the second cavity are mutually communicated through the release holes to form a cavity. Illustratively, the first movable film layer and the first fixed electrode layer constitute a first variable capacitance structure, the second movable film layer and the second fixed electrode layer constitute a second variable capacitance structure, the third movable film layer and the first fixed electrode layer constitute a third variable capacitance structure, and the fourth movable film layer and the second fixed electrode layer constitute a fourth variable capacitance structure, wherein a phase difference of output signals of adjacent variable capacitance structures is 180 °. Illustratively, the structures of the third movable film layer, the fifth isolation layer, and the fourth movable film layer include any one of ：Poly/A-Si/poly、Poly/SiN/Poly、Poly/SiO2/Poly、Poly/SiN/A-si/SiN/Poly、Poly/A-si/SiN/A-si/Poly、Poly/SiO2/A-si/SiO2/Poly、Poly/A-si/SiO2/A-si//Poly、Poly/SiN/SiO2/SiN/Poly and Poly/SiO2/SiN/SiO2/Poly; The fifth isolation layer is made of TiO2 or TaO2, and the third movable film layer and the fourth movable film layer are made of silicon, germanium, metal, a second-generation semiconductor or a third-generation semiconductor. The first and second connection posts are illustratively cylindrical, the first and second connection posts have diameters in the range of 1um-3um, and/or The materials of the first connecting co