Capacitive silicon miniature microphone and manufacturing method thereof

Abstract

The invention provides a capacitive silicon miniature microphone and a manufacturing method thereof. The capacitive silicon miniature microphone comprises a substrate, a backing plate and a supporting structure. A tunneling layer is arranged on the substrate, a dielectric layer is arranged on the tunneling layer and serves as a storage layer, a barrier layer is arranged on the storage layer, a cavity is formed in the position under the substrate, the substrate, the tunneling layer, the storage layer and the barrier layer, located over the cavity, form a vibrating diaphragm together, the backing plate is arranged above the substrate, through holes are formed in the backing plate, the backing plate is connected with the vibrating diaphragm through the supporting structure, and a gap is formed over the vibrating diaphragm. An additional power supply is not needed by the capacitive silicon miniature microphone, and the capacitive silicon miniature microphone is compatible with a CMOS process, has the advantages of being easy to microminiaturize, low in cost, high in precision and high in reliability and can be applied to severe environments such as a high-temperature environment and a high-humidity environment.

Description

technical field [0001] The present invention relates to a capacitive silicon micro-microphone based on CMOS technology and MEMS technology and a manufacturing method thereof, in particular to a capacitive silicon micro-microphone that uses charges stored in a charge trap type non-volatile memory to provide a bias voltage and its production method. Background technique [0002] Miniature microphones are widely used in electronic products such as mobile phones, digital cameras, notebook computers, and hearing aids. At present, the micro microphone is showing the development trend of miniaturization, low cost, high precision and integration. The traditional microphone formed by assembly method is not only bulky, but also has low precision, so it is difficult to meet the above-mentioned development trend. Compared with traditional microphones, silicon micro-microphones based on CMOS technology and MEMS technology can realize high-precision batch manufacturing with the help of ...

AI Technical Summary

Problems solved by technology

This kind of silicon micro-microphone based on floating gate non-volatile memory is compatible with CMOS process, but, compared with electret, since the floating gate is a conductor, the charge stored in the floating gate can move freely, when the subsequent process causes the memory to generate When there is a leakage channel, all the charges stored in the floating gate will be lost through this leakage channel, causing the microphone to fail to work, so the reliability needs to be improved

In addition, the charges stored in the electret and floating-gate nonvolatile memory are easily lost in high-temperature, high-humidity environments, so it is difficult for silicon micromics based on electret or floating-gate nonvolatile memory to Applications in harsh environments such as high temperature and high humidity

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