MEMS inertial sensor and forming method therefor

A Micro-Electro-Mechanical-System (MEMS) inertial sensor, comprising a first substrate and a second substrate,

• wherein the first substrate has a first surface and a second surface opposite to the first surface;
• wherein the first substrate comprises a first base substrate, the first base substrate comprises a monocrystalline material, and the first surface and the second surface are located at two opposite sides of the first base substrate;
• herein the first substrate further comprises a first conductive layer, an insulating layer, a second conductive layer and a conductive via, wherein the first conductive layer, the insulating layer and the second conductive layer are formed on one side of the first base substrate closer to the first surface of the first substrate, the first conductive layer is located between the first base substrate and the second conductive layer and the insulating layer is located between the first conductive layer and the second conductive layer, and the conductive via is formed between the first conductive layer and the second conductive layer and/or between the second conductive layer and the first base substrate;
• wherein the second substrate has a third surface and a fourth surface opposite to the third surface;
• wherein the first surface of the first substrate and the third surface of the second substrate are bonded together to form a first substrate bonding interface;
• wherein all or part of the first base substrate forms a movable element of the MEMS inertial sensor;
• and
• wherein the second conductive layer comprises a shielding layer and the shielding layer is located between the first base substrate and the first substrate bonding interface in such a way that there is no substrate bonding interface located between the first substrate bonding interface and the first base substrate.

A method for forming a Micro-Electro-Mechanical-System (MEMS) inertial sensor, comprising:

• providing a first substrate having a first surface and a second surface opposite to the first surface, wherein providing the first substrate comprises:
• providing a first base substrate with the first surface and the second surface being located at two opposite sides of the first base substrate, forming a first conductive layer, an insulating layer and a second conductive layer on one side of the first base substrate closer to the first surface of the first substrate, wherein the first conductive layer is located between the first base substrate and the second conductive layer and the insulating layer is located between the first conductive layer and the second conductive layer, and forming a conductive via between the first conductive layer and the second conductive layer and/or between the second conductive layer and the first base substrate, wherein the first base substrate comprises a monocrystalline material, and wherein forming the first conductive layer and the second conductive layer comprises forming the first conductive layer and the second conductive layer via a deposition process respectively;
• providing a second substrate having a third surface and a fourth surface opposite to the third surface;
• bonding the first surface of the first substrate and the third surface of the second substrate together to form a first substrate bonding interface;
• thinning the first base substrate from a side of the second surface of the first substrate to remove part of the first base substrate;
• and
• forming a movable element of the MEMS inertial sensor, wherein the movable element comprises all or part of the thinned first base substrate.

A Micro-Electro-Mechanical-System (MEMS) inertial sensor, comprising a first substrate and a second substrate,

• wherein the first substrate has a first surface and a second surface opposite to the first surface;
• wherein the first substrate comprises a first base substrate, the first base substrate comprises a monocrystalline material, and the first surface and the second surface are located at two opposite sides of the first base substrate;
• wherein the first substrate further comprises a first conductive layer, a silicon nitride layer and a second conductive layer that are located on one side of the first base substrate closer to the first surface of the first substrate, and a conductive via, wherein the first conductive layer is located between the first base substrate and the second conductive layer, the silicon nitride layer is located between the first conductive layer and the second conductive layer, and the conductive via is located between the first conductive layer and the second conductive layer and/or between the second conductive layer and the first base substrate;
• wherein the second substrate has a third surface and a fourth surface opposite to the third surface;
• wherein the first surface of the first substrate and the third surface of the second substrate are bonded together to form a first substrate bonding interface;
• and
• herein all or part of the first base substrate forms a movable element of the MEMS inertial sensor.