Mems piezoresistive pressure sensor with no strain film structure and manufacturing method thereof

Abstract

The invention relates to an MEMS (Micro Electro Mechanical System) piezoresistive pressure transducer without a strain membrane structure. The MEMS piezoresistive pressure transducer comprises four groups of piezoresistors which are manufactured on a substrate and form a Wheatstone bridge, wherein two groups of opposite piezoresistors are arranged along a (100) crystal orientation, and the other two groups of opposite piezoresistors are arranged along a (110) crystal orientation. The manufacture method of the MEMS piezoresistive pressure transducer comprises the following steps: on the front of the substrate, adopting the required dose of the doping concentration of the piezoresistors to carry out P type ion implantation light doping and high temperature thermal annealing; on the front of the substrate, defining the lead contact region of P type heavy doping through photoetching, and carrying out heavy doping and high temperature thermal annealing through ion implantation; manufacturing a lead hole and a metal lead; defining the shape of the piezoresistors and a contact zone through the photoetching, and manufacturing piezoresistor stripes through an etching way; and performing scribing. The pressure transducer does not have the strain membrane structure, can reduce the chip size of the transducer, and can increase the anti-overload ability. The manufacture method is compatible with the process of a standard silicon piezoresistive pressure transducer, so that the cost is low, and the yield is high.

Description

technical field [0001] The invention belongs to the field of micro-electro-mechanical system (MEMS) sensor design, and relates to a MEMS piezoresistive pressure sensor and a method for manufacturing the pressure sensor on a single wafer by using a MEMS processing technique. Background technique [0002] MEMS (Micro Electro Mechanical System) is an emerging interdisciplinary high-tech research field. The piezoresistive pressure sensor based on MEMS technology is widely used in the modern market due to its excellent accuracy and reliability and relatively cheap manufacturing cost. Silicon-based piezoresistive pressure sensors have been widely used since the discovery of the piezoresistive properties of silicon materials in the mid-1950s. The working principle of a typical piezoresistive pressure sensor is to make four pressure-sensitive resistors in the stress concentration area by diffusion or ion implantation on a square or circular silicon strained film, and the four resis...

AI Technical Summary

Problems solved by technology

Due to the existence of the strain film, limited by the fracture strength of the silicon material, the traditional piezoresistive pressure sensor has limited anti-overload ability, and the piezoresistive pressure sensor in the high-pressure application field has the disadvantage of low anti-overload ability.

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