Method for manufacturing laminated composite MEMS(Micro-electromechanical Systems)chips and laminated composite MEMS chip

Abstract

The invention discloses a laminated composite MEMS(Micro-electromechanical Systems)chip and a manufacturing method thereof. The method comprises the following steps: firstly, manufacturing a first MEMS wafer and a silicon perforation wafer, and bonding the first MEMS wafer and the silicon perforation wafer to obtain a sealing wafer; manufacturing an insulating layer and a metal layer on the sealing wafer to form a metalized sealing wafer, and bonding a second MEMS wafer onto the metalized sealing wafer to obtain a laminated composite MEMS wafer; finally, and cutting the laminated composite MEMS wafer to obtain the laminated composite MEMS chip. The method fully utilizes the area of the silicon perforation wafer, and at least one upper sealing cavity and at least one lower sealing cavity are respectively formed in the upper side and the lower side of the silicon perforation wafer. MEMS structures are arranged in the sealing cavities, the signals of the MEMS structures in the sealing cavities are led out through the metal layer, and shield metal layers are arranged among signal lines and are used for isolating interference among the electric signals of different MEMS structures. The laminated composite MEMS chip can meet the requirement of a composite motion sensor chip on different pressures and has the advantages of small size, high integration level, flexible design and low cost.

Description

technical field [0001] The invention belongs to the technical field of MEMS chip manufacturing, and in particular relates to a laminated combined MEMS chip, and also relates to a manufacturing method of the laminated combined MEMS chip. Background technique [0002] MEMS (Micro-Electro-Mechanical Systems) is the abbreviation of micro-electro-mechanical systems. MEMS manufacturing technology uses micro-fabrication technology, especially semiconductor wafer manufacturing technology, to manufacture various micro-mechanical structures, combined with application-specific control integrated circuits (ASICs), composed of Intelligent micro sensors, micro actuators, micro optical devices and other MEMS components. MEMS components have the advantages of small size, low cost, high reliability, strong resistance to harsh environments, low power consumption, high intelligence, easy calibration, and easy integration, and are widely used in consumer electronics products (such as mobile pho...

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Problems solved by technology

However, in existing products, different MEMS structures are fabricated on the same MEMS layer, that is, accelerometers and gyroscopes, or two gyroscopes with different ranges are arranged horizontally, such as Invensense, Bosch, STMicroelectronics and other products, due to different The MEMS structure is made by the same MEMS layer, and the design flexibility is poor. Moreover, the working principles of the MEMS gyroscope and the accelerometer are different. The working performance is best under high pressure, generally above 0.1 atmospheric pressure, which requires MEMS chips to meet both requirements at the same time, that is, the MEMS gyroscope structure is fabricated in a lower air pressure, and the MEMS accelerometer structure is fabricated in a higher air pressure.

The existing dual pressure MEMS chip wafer-level packaging method was proposed by K. Reimer, Ch. Schr? A getter is made in one sealed cavity, and there is no getter in the other sealed cavity. When they are bonded to the wafer, a mixture of active gas and inert gas is sealed in the sealed cavity, and then heated and post-processed, there is a getter The active gas in the sealed cavity of the getter is absorbed, leaving only the inert gas, and the internal pressure is low. According to the ratio of the mixed gas, the pressure can be close to vacuum; while the active gas in the sealed cavity without the getter will not be absorbed. The gas pressure will not change, and the pressure is high, so as to achieve the purpose of dual-pressure wafer-level packaging. This method requires the use of getters, and the getters also need to be patterned, and the cost is high

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