Miniature feedback cavity sensor and its manufacturing method

Abstract

A micro feedback-chamber sensor comprises: a semiconductor base having a sensing circuit; a bonding structure layer disposed on the semiconductor base; and a sensing member chip having a low-resistance semiconductor body, a first end portion and a second end portion. The semiconductor body has free-standing Si posts, the first end portion is formed with a sensing member structure, the second end portion is connected to the semiconductor base through the bonding structure layer, and a micro feedback-chamber structure is formed between the sensing member structure, the semiconductor base and the semiconductor body. The sensing member structure is electrically connected to the sensing circuit through the free-standing Si posts. The sensing member structure and the micro feedback-chamber structure collaboratively react to an externally inputted physical signal to generate a sensing signal outputted to the sensing circuit. A method of manufacturing the micro feedback-chamber sensor is also provided.

Description

technical field [0001] The invention relates to a miniature feedback cavity sensor and a manufacturing method thereof, in particular to a miniature feedback cavity sensor for sound waves and / or pressure and a manufacturing method thereof. Background technique [0002] Piezoelectric, piezoresistive and capacitive are currently common micro sensor technologies. Piezoelectric sensors use the characteristics of piezoelectric materials to output current or voltage after being disturbed by external forces, and convert input physical signals into electrical signals, while piezoresistive sensors use piezoresistive materials to change the resistance characteristics after being stressed. One of the most common sensing methods is capacitive sensing, which has excellent characteristics such as easy manufacturing, high sensitivity, and low power consumption, and is currently the mainstream of market development. [0003] In particular, a sensor with a feedback cavity design, such as a m...

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Problems solved by technology

In addition, special attention must be paid to the fact that the space in the back cavity must be completely sealed (only the connection to the outside world is reserved through the diaphragm); if the back cavity is not properly sealed and connected to the front cavity space, the frequency response curve will be in the Sensitivity reduction occurs in the low frequency range

In the known technology, a package lid (package lid) is usually used to cover the MEMS chip to provide a huge back cavity. However, this packaging method is not suitable for the integration of the chip, and the volume of the miniature microphone produced is also large. Quite bulky and cannot be mass-produced with wafer-level manufacturing

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