A kind of low drift pressure sensor and its manufacturing method

Abstract

The invention discloses a low drifting pressure sensor and a manufacturing method thereof. The low drifting pressure sensor comprises a substrate, a first piezoresistor, a second piezoresistor, a third piezoresistor, a fourth piezoresistor, a metal lead and PAD points. The four piezoresistors form a Wheatstone bridge through the metal lead and are placed at a thin film area formed by manufacturing a back cavity in the same direction. The manufacturing method comprises the manufacturing steps of manufacturing a thick boron area and a thin boron area on the front face of the substrate through the micromachining photoetching and injection process, manufacturing lead holes, the metal lead and the PAD points on the front face of the substrate, manufacturing the cavity in the back face of the substrate to form a thin film layer, and scribing. The pressure sensor can effectively reduce electric leakage, zero drift of the pressure sensor can be lowered, the manufacturing method is compatible with the machining process of a standard body silicon piezoresistive type pressure sensor, the device machining process is simple and low in cost, the rate of finished products is high, and batch production can be realized.

Description

technical field [0001] The invention relates to a microelectromechanical system (MEMS) device and a manufacturing method thereof, in particular to a low-drift pressure sensor and a manufacturing method thereof, belonging to the field of microelectronics. Background technique [0002] The development of microelectromechanical systems (MEMS) has opened up a new technical field and industry, which can not only reduce the cost of electromechanical systems, but also complete many tasks that cannot be completed by large-scale electromechanical systems. It is precisely because MEMS devices and systems have advantages that traditional sensors cannot match, such as small size, light weight, low power consumption, low cost, high reliability, excellent performance, and powerful functions. There are very broad application prospects in monitoring, military affairs and almost all fields that people come into contact with. [0003] Silicon-based piezoresistive pressure sensors have been w...

AI Technical Summary

Problems solved by technology

At present, it is believed that the important factor affecting the zero drift is the varistor, which is generally prepared by diffusion or ion implantation, and the temperature drift of the resistance is relatively large.

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