WO-2026092443-A1 - MEMS DEVICE AND MANUFACTURING METHOD THEREFOR, AND METHOD FOR READING OUTPUT SIGNAL OF MEMS DEVICE

WO2026092443A1WO 2026092443 A1WO2026092443 A1WO 2026092443A1WO-2026092443-A1

Abstract

The present application provides a MEMS device and a manufacturing method therefor, and a method for reading an output signal of the MEMS device. The MEMS device comprises: a first substrate, wherein a back cavity is formed in the 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 located on the first substrate; a first cavity located between the first movable film layer and the third movable film layer; a second cavity located between the second movable film layer and the fourth movable film layer; a first connecting column located in the first cavity and connecting the third movable film layer and the first movable film layer; a second connecting column located in the second cavity and connecting the second movable film layer and the fourth movable film layer; and release holes passing through the third movable film layer, the fifth isolation layer and the fourth movable film layer.

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: 20260507
Application Date: 20251028
Priority Date: 20241104

Claims (15)

A MEMS device, characterized in that it comprises: A first substrate, wherein a back cavity is formed therethrough the first substrate; A first movable film layer is located on the first substrate, and the back cavity exposes a portion of the surface of the first movable film layer; A first isolation layer is located on a portion of the first movable membrane layer; The first fixed electrode layer is located on the first isolation layer; A second isolation layer is located on a portion of the first fixed electrode layer; The third movable membrane layer is located on the second isolation layer; The fifth isolation layer is located on the third movable membrane layer; The fourth movable membrane layer is located on the fifth isolation layer; The fourth isolation layer is located on a portion of the fourth movable membrane layer; The second fixed electrode layer is located on the fourth isolation layer; A third isolation layer is located on a portion of the second fixed electrode layer; The second movable membrane layer is located on the third isolation layer; The first cavity is located between the first movable membrane layer and the third movable membrane layer; The second cavity is located between the second movable membrane layer and the fourth movable membrane layer; Multiple first connecting posts are located in the first cavity, and the upper and lower ends of the first connecting posts are respectively connected to the third movable membrane layer and the first movable membrane layer; Multiple second connecting posts are located in the second cavity, and the upper and lower ends of the second connecting posts are respectively connected to the second movable membrane layer and the fourth movable membrane layer; Multiple release holes penetrate the third movable membrane layer, the fifth isolation layer, and the fourth movable membrane layer. The first cavity and the second cavity are interconnected through the release holes to form a cavity.
According to claim 1, the MEMS device is characterized in that the first movable film layer and the first fixed electrode layer constitute a first variable capacitor structure, the second movable film layer and the second fixed electrode layer constitute a second variable capacitor structure, the third movable film layer and the first fixed electrode layer constitute a third variable capacitor structure, and the fourth movable film layer and the second fixed electrode layer constitute a fourth variable capacitor structure, wherein the phase difference of the output signals of adjacent variable capacitor structures is 180°.
The MEMS device according to claim 1, wherein the structure of the third movable film layer, the fifth isolation layer and the fourth movable film layer comprises any one of the following: Poly/A-Si/poly, Poly/SiN/Poly, Poly/SiO 2 /Poly, Poly/SiN/A-si/SiN/Poly, Poly/A-si/SiN/A-si/Poly, Poly/SiO 2 /A-si/SiO 2 /Poly, Poly/A-si/SiO 2 /A-si//Poly, Poly/SiN/SiO 2 /SiN/Poly and Poly/SiO 2 /SiN/SiO 2 /Poly; The fifth isolation layer is made of TiO2 or TaO2 , and the third and fourth movable film layers are made of silicon, germanium, metal, second-generation semiconductor or third-generation semiconductor.
According to claim 1, the MEMS device is characterized in that the first connecting post and the second connecting post are cylindrical, and the diameter of the first connecting post and the second connecting post is in the range of 1um-3um.
The MEMS device according to claim 1 is characterized in that the material of the first connecting post and the second connecting post includes SiN, SiO2 wrapped by SiN, or Poly wrapped by SiN.
The MEMS device according to claim 1 is characterized in that the spacing between the first movable film layer and the first fixed electrode layer, between the third movable film layer and the first fixed electrode layer, between the second movable film layer and the second fixed electrode layer, and between the fourth movable film layer and the second fixed electrode layer is in the range of 1um-3um.
The MEMS device according to claim 1 is characterized in that the thickness range of the first movable film layer, the second movable film layer, the third movable film layer and the fourth movable film layer is 0.1um-1.5um.
According to claim 1, the MEMS device is characterized in that the sum of the thicknesses of the MEMS device excluding the substrate ranges from 8µm to 15µm.
The MEMS device according to claim 1, characterized in that it further comprises: 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.
The MEMS device according to claim 1 is characterized in that it further comprises: a first pad located on the first movable film layer, a second pad located on the second movable film layer, a third pad located on the third movable film layer, a fourth pad located on the fourth movable film layer, a fifth pad located on the first fixed electrode layer, and a sixth pad located on the second fixed electrode layer.
The MEMS device according to claim 1, characterized in that it further comprises: a first support layer located between the first fixed electrode layer and the first isolation layer, a second support layer located between the first fixed electrode layer and the second isolation layer, a third support layer located between the second fixed electrode layer and the third isolation layer, and a fourth support layer located between the second fixed electrode layer and the fourth isolation layer.
A method for manufacturing a MEMS device, characterized in that the method includes: A first substrate is provided, on the first surface of which 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. A first cavity is formed between the first bonding layer and the first substrate. A plurality of first connecting pillars are formed in the first cavity. The upper and lower ends of the first connecting pillars are respectively connected to the first bonding layer and the first movable film layer. A plurality of first release holes are formed in the first bonding layer that expose the first cavity. A second substrate is provided, on the first surface of which 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. A second cavity is formed between the second bonding layer and the second substrate. A plurality of second connecting pillars are formed in the second cavity. The upper and lower ends of the second connecting pillars are respectively connected to the second bonding layer and the second movable film layer. A plurality of second release holes are formed in the second bonding layer that expose the second cavity. The first bonding layer and the second bonding layer are bonded together so that the first bonding layer and the second bonding layer constitute a third movable film layer, a fifth isolation layer and a fourth movable film layer connected to the first connecting post, which are stacked and connected to the first connecting post. The first cavity and the second cavity are interconnected through the first release hole and the second release hole to form a cavity. Remove the second substrate to expose the second movable film layer; The portion of the first substrate corresponding to the cavity is removed from the second surface of the first substrate to form a back cavity that exposes a portion of the first movable film layer.
According to the manufacturing method of claim 12, the first bonding layer comprises a first sub-movable film layer, the second bonding layer comprises the fourth movable film layer, the fifth isolation layer located on the fourth movable film layer, and the second sub-movable film layer located on the fifth isolation layer, wherein the first sub-movable film layer and the second sub-movable film layer are bonded together in the bonding step, and the first sub-movable film layer and the second sub-movable film layer constitute the third movable film layer; or, The first bonding layer includes the third movable film layer, and the second bonding layer includes the fourth movable film layer and the fifth isolation layer located on the fourth movable film layer. In the bonding step, the fifth isolation layer and the third movable film layer are bonded together; or... The first bonding layer includes the third movable film layer and a first sub-isolation layer located on the third movable film layer; the second bonding layer includes the fourth movable film layer and a second sub-isolation layer located on the fourth movable film layer; in the bonding step, the first sub-isolation layer and the second sub-isolation layer are bonded together, and the first sub-isolation layer and the second sub-isolation layer constitute the fifth isolation layer; or... The first bonding layer includes the third movable film layer and the fifth isolation layer located on the third movable film layer; the second bonding layer includes the fourth movable film layer; and in the bonding step, the fifth isolation layer and the fourth movable film layer are bonded together; or, The first bonding layer includes the third movable film layer, the fifth isolation layer located on the third movable film layer, and the third sub-movable film layer located on the fifth isolation layer. The second bonding layer includes the fourth sub-movable film layer. In the bonding step, the third sub-movable film layer and the fourth sub-movable film layer are bonded together, and the third sub-movable film layer and the fourth sub-movable film layer constitute the fourth movable film layer.
The manufacturing method according to claim 12 is characterized in that a low-temperature bonding process is used to perform the bonding step.
A method for reading the output signal of a MEMS device, characterized in that it includes: Provide a MEMS device as described in any one of claims 1-11 or a MEMS device manufactured using the manufacturing method as described in any one of claims 12-14; Read the output signal of the MEMS device; The process of reading the output signals of MEMS devices includes: A first bias voltage is applied to the first fixed electrode layer of the MEMS device, and a second bias voltage is applied to the second fixed electrode layer of the MEMS device; Connect the first movable diaphragm layer and the fourth movable diaphragm layer to the non-inverting input terminal of the first amplifier, and connect the second movable diaphragm layer and the third movable diaphragm layer to the inverting input terminal of the first amplifier; or connect the first movable diaphragm layer and the fourth movable diaphragm layer to the inverting input terminal of the first amplifier, and connect the second movable diaphragm layer and the third movable diaphragm layer to the non-inverting input terminal of the first amplifier. Read the signal at the output of the first amplifier; Alternatively, read the output signals of the MEMS device, including: A first bias voltage is applied to the first movable film layer and the fourth movable film layer, and a second bias voltage is applied to the second movable film layer and the third movable film layer; The first fixed electrode layer and the second fixed electrode layer are respectively connected to the non-inverting input terminal and the inverting input terminal of the first amplifier; Read the signal at the output of the first amplifier; Alternatively, read the output signals of the MEMS device, including: A first bias voltage is applied to the first fixed electrode layer, and a second bias voltage is applied to the second fixed electrode layer; The second movable diaphragm layer and the fourth movable diaphragm layer are respectively connected to the non-inverting input terminal and the inverting input terminal of the first amplifier, and the first movable diaphragm layer or the third movable diaphragm layer is connected to the input terminal of the second amplifier; or, the first movable diaphragm layer and the third movable diaphragm layer are respectively connected to the non-inverting input terminal and the inverting input terminal of the first amplifier, and the second movable diaphragm layer or the fourth movable diaphragm layer is connected to the input terminal of the second amplifier. Read the signals from the output terminals of the first amplifier and the second amplifier.

Description

MEMS devices and their manufacturing methods, and methods for reading the output signals of MEMS devices. Cross-reference of related applications This patent application claims priority to Chinese Patent Application No. 202411564197.1, filed on November 4, 2024, entitled "MEMS Device and Manufacturing Method Thereof, Method for Reading Output Signal of MEMS Device", the entire contents of which are incorporated herein by reference. Technical Field This application relates to the field of semiconductor technology, and more specifically to a MEMS device and its manufacturing method, and a method for reading the output signal of a MEMS device. Background Technology With the continuous development of semiconductor technology, MEMS microphones, which are fabricated based on micro-electro-mechanical systems (MEMS) technology, are widely used in the sensor product market due to their advantages such as small size, low cost and stable performance compared with traditional microphones. A typical condenser MEMS microphone consists of a single-layer diaphragm and a single-layer backplate. The single-layer diaphragm and the single-layer backplate constitute a capacitor structure. When an external sound signal acts on the diaphragm, the diaphragm vibrates, causing a change in capacitance. The change in capacitance is used for calculation and operation to complete the conversion between sound signals and electrical signals. Summary of the Invention The summary section introduces a series of simplified concepts, which will be further explained in detail in the detailed description section. This summary section is not intended to limit the key and essential technical features of the claimed technical solution, nor is it intended to determine the scope of protection of the claimed technical solution. This application provides a MEMS device, including: A first substrate, wherein a back cavity is formed therethrough the first substrate; A first movable film layer is located on the first substrate, and the back cavity exposes a portion of the surface of the first movable film layer; A first isolation layer is located on a portion of the first movable membrane layer; The first fixed electrode layer is located on the first isolation layer; A second isolation layer is located on a portion of the first fixed electrode layer; The third movable membrane layer is located on the second isolation layer; The fifth isolation layer is located on the third movable membrane layer; The fourth movable membrane layer is located on the fifth isolation layer; The fourth isolation layer is located on a portion of the fourth movable membrane layer; The second fixed electrode layer is located on the fourth isolation layer; A third isolation layer is located on a portion of the second fixed electrode layer; The second movable membrane layer is located on the third isolation layer; The first cavity is located between the first movable membrane layer and the third movable membrane layer; The second cavity is located between the second movable membrane layer and the fourth movable membrane layer; Multiple first connecting posts are located in the first cavity, and the upper and lower ends of the first connecting posts are respectively connected to the third movable membrane layer and the first movable membrane layer; Multiple second connecting posts are located in the second cavity, and the upper and lower ends of the second connecting posts are respectively connected to the second movable membrane layer and the fourth movable membrane layer; Multiple release holes penetrate the third movable membrane layer, the fifth isolation layer, and the fourth movable membrane layer. The first cavity and the second cavity are interconnected through the release holes to form a cavity. For example, the first movable film layer and the first fixed electrode layer constitute a first variable capacitor structure, the second movable film layer and the second fixed electrode layer constitute a second variable capacitor structure, the third movable film layer and the first fixed electrode layer constitute a third variable capacitor structure, and the fourth movable film layer and the second fixed electrode layer constitute a fourth variable capacitor structure, wherein the phase difference of the output signals of adjacent variable capacitor structures is 180°. For example, the structures of the third movable film layer, the fifth isolation layer, and the fourth movable film layer include any one of the following: Poly/A-Si/poly, Poly/SiN/Poly, Poly/SiO 2 /Poly, Poly/SiN/A-si/SiN/Poly, Poly/A-si/SiN/A-si/Poly, Poly/SiO 2 /A-si/SiO 2 /Poly, Poly/A-si/SiO 2 /A-si//Poly, Poly/SiN/SiO 2 /SiN/Poly, and Poly/SiO 2 /SiN/SiO 2 /Poly; The fifth isolation layer is made of TiO2 or TaO2 , and the third and fourth movable film layers are made of silicon, germanium, metal, second-generation semiconductor or third-generation semiconductor. For example, the first connecting post and the