Pressure sensor and preparation method thereof

Abstract

The invention discloses a pressure sensor and a preparation method therefor. The method comprises the steps: providing a semiconductor substrate, forming a first trench and a second trench on the front surface of the semiconductor substrate, and forming a step at the intersection of the first and second trenches; forming a first induction layer in the second trench, forming a second induction layer in the first trench, and forming a first cavity between a part of the bottom wall of the second trench and the first induction layer, wherein the first induction layer on the first cavity is provided with a first opening array; forming a second cavity between the second induction layer and the first induction layer, wherein the back surface of the semiconductor substrate is provided with a third opening communicated with the first cavity; forming a third induction layer, and forming a third cavity between the third induction layer and the second induction layer, wherein the third induction layer on the third cavity is provided with a second opening array; enabling a dielectric layer to cover the third induction layer the remaining front surface of the semiconductor substrate; enabling a first electrode to be electrically connected with the first induction layer, enabling a second electrode to be electrically connected with the second induction layer, and enabling a third electrode to be electrically connected with the third induction layer.

Description

technical field [0001] The invention relates to the technical field of micro-electromechanical systems, in particular to a pressure sensor and a preparation method thereof. Background technique [0002] Microelectromechanical systems (MEMS for short) is a multi-disciplinary frontier research field developed on the basis of microelectronics technology. It is a technology that uses semiconductor technology to manufacture microelectromechanical devices. Compared with traditional electromechanical devices, MEMS devices have obvious advantages in high temperature resistance, small size, and low power consumption. After decades of development, it has become one of the world's major scientific and technological fields. It involves electronics, machinery, materials, physics, chemistry, biology, medicine and other disciplines and technologies, and has broad application prospects. [0003] A pressure sensor is a MEMS that converts a pressure signal into an electrical signal. Accordi...

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Problems solved by technology

[0004] The object of the present invention is to provide a pressure sensor and its preparation method, which solves the problem of low detection sensitivity of the pressure sensor in the prior art

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