0-100Pa monolithic silicon based SOI high-temperature low drift micropressure sensor and processing method thereof

Abstract

The invention relates to a super-low micro-pressure sensor of 0-100pa single-chip silicon based SOI, which has the advantages of comparatively high sensitivity and linearity, high-temperature resistance, simple technique, good consistency, low production cost and being suitable for mass production. Therefore, the invention also provides a method for processing the sensor. The chips includes an N-shaped or P-shaped silicon substrate (1), two sides of which are covered with an insulation layer (2), a polysilicon layer (3) is deposited on the surface of the insulation layer (2); the surface of the polysilicon layer is a silicon dioxide layer (4), the surface of which is a polysilicon film layer which can generate polysilicon piezo-resistance (5); polysilicon inner lead (6) doped with dense boron is connected with the resistance (5); the surface of the polysilicon internal lead (6) is covered with aluminum lead (7); the back of the chip is provided with a square-shaped opening (10); polysilicon is taken as the substrate (1), which then goes through the processes of photoetching, depositing, injecting by adopting an ion beam machine, annealing, feeding dry oxygen-wet oxygen-dry oxygen, photoetching, TMAH wet etching or RIE dry etching, photoetching, dense-boron dispreading, front steaming and plating aluminm film, leading-out weld feet and wet-etching, etc.

Description

(1) Technical field [0001] The invention relates to the technical field of force-sensitive sensors, in particular to a 0-100pa monolithic silicon-based SOI high-temperature low-drift micro-pressure sensor and a processing method thereof. (2) Background technology [0002] At present, domestic ultra-low and micro-pressure sensors are very scarce and expensive, and almost all of them are imported from abroad. In 2000, domestic scholars completed the research project "Silicon Micro Pressure Sensor" of the National Ninth Five-Year Science and Technology Research Project "96-748 Sensor Technology". (Sub-topic 96-748-02-01- / 02) The completed technical indicators are: range 0-300pa, N L <0.5%, accuracy 1.0%, V FS >30mv, V CC 6 volts, overload damage pressure > 140 times. And after the scientific and technological novelty check (December 22, 1999) (management number of the novelty check central station: SJTU99-037), the novelty check result: this achievement reached the...

AI Technical Summary

Problems solved by technology

At present, micro-pressure sensors with a range of 1kpa are produced in small batches in laboratories in the industry, but due to the limitation of equipment conditions, it is impossible to form large-scale production

The 300pa micro-pressure sensor invented in the industry is a diffused silicon pressure sensor using bulk micromachining technology. The bridge resistors are isolated by PN junctions, so it is obviously affected by temperature, and its zero-point stability is far less than that of SOI structures.

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