MEMS (micro-electro mechanical system) pressure sensor and forming method thereof

Abstract

The invention discloses an MEMS (micro-electro mechanical system) pressure sensor and a forming method thereof. The forming method comprises steps as follows: a first substrate comprising a first surface and a second surface is provided and comprises at least one conductive layer which is located on one side of the first surface of the first substrate; a second substrate comprising a third surface and a fourth surface is provided and comprises a second base, a pressure-sensitive electrode and a pressure sensing area, and the pressure-sensitive electrode is located in the pressure sensing area and is located on one side of the third surface of the second substrate; the first surface of the first substrate is fixed with the third surface of the second substrate, and a hollow cavity is formed between the first substrate and the pressure sensing area of the second substrate; the second base is removed, and a fifth surface opposite to the third surface of the second substrate is formed; a first conductive plug penetrating to the at least one conductive layer is formed on one side of the fifth surface of the second substrate, so that the at least one conductive layer and the pressure-sensitive electrode are electrically connected. According to the MEMS pressure sensor and the forming method thereof, the performance and the reliability of the MEMS pressure sensor are improved, the size is reduced, and the processing cost is reduced.

Description

technical field [0001] The invention relates to the technical field of semiconductor manufacturing, in particular to a MEMS pressure sensor and a forming method thereof. Background technique [0002] Micro-Electro Mechanical System (MEMS for short) is an integrated device that acquires information, processes information and performs operations. Sensors in MEMS can receive external information such as pressure, position, velocity, acceleration, magnetic field, temperature or humidity, and convert the obtained external information into electrical signals for processing in MEMS. Common microelectromechanical systems include temperature sensors, pressure sensors, and humidity sensors. [0003] For the MEMS pressure sensor, its size is smaller, and its process precision, and its manufacturing process can be compatible with the manufacturing process of integrated circuit chips, thus greatly improving the cost performance. Current MEMS pressure sensors include piezoresistive pres...

AI Technical Summary

Problems solved by technology

[0007] In the existing manufacturing methods of MEMS pressure sensors, the process of integrating the pressure sensor chip and the signal processing circuit is quite different, and it is difficult to achieve monolithic integration.

At the same time, when the integrated circuit and the pressure sensor are fabricated on a single substrate, the existence of the pressure sensor has hindered the development of the integrated circuit, and the existence of the integrated circuit on the same substrate has also caused difficulties in the manufacture of small-sized pressure sensors.

Therefore, the manufacturing process of using a single substrate as an integrated circuit and a pressure sensor is more complicated, and the size of the formed device is larger, resulting in an increase in manufacturing cost

[0008] When making an integrated pressure sensor and circuit on a single substrate, if the components of the pressure sensor are made first, and then the circuit is made, the process of the pressure sensor often affects the substrate, resulting in a decrease in the yield of integrated circuits that is difficult to make

If the integrated circuit is made first, and then the pressure sensor is made, the existence of the integrated circuit has great restrictions on the choice of pressure sensor material and the temperature of the processing process, which will seriously reduce the performance of the pressure sensor

Images