Manufacturing method of inertia micro-electro-mechanical sensor

Abstract

An inertia MEMS sensor and a manufacturing method are provided. The inertia MEMS sensor includes a main body and a weight block relatively removable. The main body includes a first main body with a first surface and a second main body vertically connecting with the first surface. A first electrode parallel to the first surface is in the first main body. A second electrode perpendicular to the first surface is in the second main body. The weight block is suspended in a space defined by the first and second main bodies. The weight block includes a third electrode parallel to the first surface, a forth electrode is perpendicular to the first surface, and a weight layer. The third electrode connects with the forth electrode to form a U-shaped groove for accommodating the weight layer, thereby increasing the weight block weight, improving precision and reducing the cost.

Description

technical field [0001] The invention relates to the technical field of semiconductor manufacturing, in particular to an inertial micro-electromechanical sensor and a manufacturing method thereof. Background technique [0002] MEMS (Microelectromechanical System) technology refers to the technology of designing, processing, manufacturing, measuring and controlling micro / nano (micro / nanotechnology) materials. MEMS is a micro system that integrates mechanical components, optical systems, drive components, and electronic control systems into an integral unit. MEMS are commonly used in position sensors, rotation devices or inertial sensors, such as acceleration sensors, gyroscopes and sound sensors. [0003] An existing conventional inertial micro-electromechanical sensor usually includes a main body and one or more inertial mass blocks. The inertial mass block is a separate structure suspended relative to the main body. The inertial mass block can be supported by a cantilever t...

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Problems solved by technology

[0005] However, as the process size decreases, the thickness of the film layer becomes thinner, so it becomes more and more difficult to fabricate capacitive inertial MEMS sensors on semiconductor substrates with CMOS devices.

Usually the inertial mass is formed by an integral conductive material, which requires good conductivity, stable properties, and high density. For example, silicon germanium is commonly used, but the conductive materials of the above properties are very expensive.

Moreover, for capacitive inertial MEMS sensors, the greater the weight of the inertial mass, the greater the inertia, and the higher the accuracy of the inertial MEMS sensor; and in order to make the inertia of the inertial mass greater, it is necessary to use a lot of the conductive material, which results in a very high cost of the inertial MEMS sensor

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