Micromechanical structure and integrated circuit monolithic integrated processing method

Abstract

The invention relates to a micromechanical structure and integrated circuit monolithic integrated processing method which comprises the following steps of dividing the device layer of the substrate of an SOI (silicon on insulator) into an integrated circuit region, an MEMS structural region and an isolation region; processing an integrated circuit in the integrated circuit region and arranging an electrode striding the isolation region; sequentially removing a substrate layer and an oxide buried layer corresponding to the MEMS (electronic mechanical system) structural region and the isolation region in positions from one side of the substrate layer of the SOI substrate, so as to form a carinal cavity; and removing single crystal silicon on the device layer at the isolation region from one side of the carinal cavity, so as to accomplish the processing to an isolation groove; photoengraving the surface of the SOI substrate, defining an MEMS structural pattern, and carrying out mechanical erosion on a dielectric layer on the MEMS structural region so as to obtain the mask of the MEMS structure; and performing silicone anisotropy mechanical erosion on the device layer according to the mask of the MEMS structure until the device layer is penetrated through, so as to accomplish the processing to the MEMS structure. The method meets the precondition of foundry factory production of integrated circuits, has low difficulty in process difficulty and higher quality of the finished product.

Description

technical field [0001] The invention relates to a method for processing an integrated chip, in particular to a method for monolithically integrating a micromechanical structure and an integrated circuit. Background technique [0002] Capacitive sensors such as inertial sensors implemented with Microelectromechanical Systems (MEMS) technology have the advantages of small size, light weight, and low cost, and have broad application prospects in military, automotive, and consumer electronics. Limited by size, the signals of MEMS sensors are generally weak and easily affected by parasitic capacitance. Integrating the MEMS sensor header structure and the signal processing circuit on the same chip can effectively reduce the adverse effects of parasitic effects, and at the same time reduce the device volume and reduce manufacturing costs. It is one of the important directions for the development of MEMS technology. To complete the processing of integrated circuits and MEMS structu...

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Problems solved by technology

However, this method also has defects: when the silicon isotropic etching method is used to remove the single crystal silicon in the air isolation groove, a part of the MEMS device structure will also be etched laterally; on the other hand, dielectric materials such as silicon oxide The floating electrodes made of metal and metal have a large stress, which will affect the reliability of the device

However, in the process of anisotropic etching of the MEMS structure, residues are likely to rema

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