T-shaped cross beam cross island film pressure sensor chip and preparation method thereof

Abstract

The invention relates to a T-shaped cross beam cross island film pressure sensor chip and a preparation method, the sensor chip comprises a film in the middle of a substrate, the upper surface of thefilm is connected with a T-shaped cross beam, the T-shaped cross beam is composed of four T-shaped beams with the same size, the tails of the narrow ends of the T-shaped beams are connected, and the heads of the wide ends of the T-shaped beams are connected with the substrate; a cross-shaped mass block is attached to the center of the lower surface of the film in the etching cavity on the back surface of the substrate, and corresponds to the T-shaped cross beam up and down; pressure-sensitive relief resistor strips are respectively arranged on the upper surfaces of the wide end heads of the T-shaped beams; the four pressure-sensitive embossment resistor strips are sequentially connected through the five P type heavily-doped silicon embossment blocks to form a semi-open-loop Wheatstone bridge. The preparation method comprises the following steps: manufacturing the pressure-sensitive embossment resistor strips, the P type heavily doped silicon embossment blocks and a point electrode foran SOI silicon wafer, then bonding the silicon wafer with the front surface of the glass, and finally etching the back cavity cross-shaped mass block of the sensor; the sensor chip has the characteristics of 300 DEG C high temperature resistance, corrosion resistance, high linearity and the like, and is convenient to process and low in cost.

Description

technical field [0001] The invention relates to the technical field of MEMS piezoresistive micro-pressure sensors, in particular to a T-shaped cross-beam cross-island film pressure sensor chip and a preparation method. Background technique [0002] Microelectromechanicalsystems (MEMS for short) technology has the characteristics of small size, light weight, low power consumption, high reliability and excellent performance. Among them, micro pressure sensors are the most mature type of MEMS devices and are widely used. Used in petrochemical, aerospace, energy and power, transportation, metallurgy, machinery manufacturing, medical and health industries, the development of micro pressure sensors based on MEMS technology has become an eye-catching development direction. [0003] There are many types of miniature pressure sensors, mainly capacitive, resonant and piezoresistive. Capacitive pressure sensors are susceptible to signal interference, and special signal processing circ...

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Problems solved by technology

[0005] At present, most sensors use oil-filled packaging, but the working temperature of oil-filled packaging cannot be higher than 200 ° C, and the corrugated sheet is not corrosion-resistant, so there is a certain hysteresis

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