How to make a pressure sensor

Abstract

The invention provides a method for manufacturing a pressure sensor. The method includes the steps of providing a semiconductor substrate, wherein a CMOS circuit, an interconnection circuit and a bottom electrode plate which are laminated are embedded in the periphery of the semiconductor substrate, and the portion, on the periphery of the bottom electrode plate, of the interconnection circuit is exposed out of the semiconductor substrate; forming a sacrificial layer at the position, corresponding to the bottom electrode plate, of the semiconductor substrate; forming pressure induction layers on the sacrificial layer and the semiconductor substrate; removing the sacrificial layer, wherein a cavity is defined by the pressure induction layers and the semiconductor substrate; forming pressure conduction layers on the pressure induction layers, wherein the pressure conduction layers are located above the cavity. The pressure induction layers is formed through the steps of forming a germanium-silicon layer on the sacrificial layer and conducting laser pulse irradiation on the germanium-silicon layer to enable the germanium-silicon layer to be in the melting state. Compared with the prior art, through the arrangement of the pressure induction layers, the stress can be reduced through the method, the stress is accordingly and greatly reduced, and the device performance is improved.

Description

technical field [0001] The invention relates to the field of semiconductor manufacturing, in particular to a manufacturing method of a pressure sensor. Background technique [0002] Microelectromechanical systems (MEMS for short) is a cutting-edge multidisciplinary 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 transducer that converts a pressure signal into an electrical signal. According to differ...

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Problems solved by technology

[0005] In the prior art, when forming the pressure sensing layer, such as Figure 1a As shown, the excessive stress often causes the formed cavity to deform, the two plates of the capacitor are not parallel, and even the wafer is deformed and bent, which seriously affects the performance and yield of the pressure sensor formed.

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