Redistribution layer manufacturing method and mems device manufacturing method

Abstract

The invention provides a redistribution layer manufacturing method and an MEMS (Micro-Electro-Mechanical Systems) device manufacturing method. The redistribution layer manufacturing method comprises the following steps: performing dry etching on a conductive metal layer which is made of Al and the like and is not covered with any photoresist to reduce the conductive metal layer to a certain thickness; and switching to wet etching within Q-Time set in a process in order to remove the residual thickness of the conductive metal layer which is not covered with the photoresist. The etching can well be stopped on the surface of an etching barrier layer. Through the wet etching process, the fence defect of the side wall of the redistribution layer which is subjected to the dry etching is overcome, and over-etching consumption of a top interconnection structure is avoided. Meanwhile, the thickness of the wet etching is small, so that the key size of the redistribution layer which is subjected to the wet etching can fully meet a requirement; the accumulation of a large quantity of etching residues is avoided; the quality of the redistribution layer is ensured; and the device performance is enhanced finally.

Description

technical field [0001] The invention relates to the field of semiconductor manufacturing, in particular to a method for manufacturing a rewiring layer and a method for manufacturing a MEMS device. Background technique [0002] Micro-Electro-Mechanical Systems (MEMS for short) refers to a micro-device or system made of micro-fabrication technology, integrating micro-sensors, micro-components, micro-actuators, signal processing, and control circuits. Its manufacturing process is A micromachining process that uses thin film deposition, photolithography, epitaxy, oxidation, diffusion, implantation, sputtering, evaporation, etching, scribing, and packaging as basic process steps to manufacture complex three-dimensional shapes, usually in the micron or nanometer range . In the MEMS device manufacturing process, in order to realize the internal or external electrical connection of the MEMS device, a redistribution layer (Redistribution Layer, RDL, redistribution interconnection la...

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Problems solved by technology

However, when the RDL layer is directly formed by the dry etching process, it is difficult to stop the etching on the surface of the etch barrier layer TiN, and it is easy to over-etch and cause the loss of the TM layer. At the same time, the lateral etching during dry etching is not good. Uniform, easy to form Al fence defect (Al fence defect); and when the RDL layer is directly formed by wet etching process, due to the effect of gravity, the etchant at the bottom of the etching window is more corrosive, which is easy to cause the critical dimension of Al at the bottom (CD) shrinks (shrink), and there will be more residues gathered at the bottom

Obviously, the reliability of the rewiring layer formed by the above dry etching or wet etching process is low, which affects the performance and yield of the final packaged chip

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