Method for manufacturing semiconductor micro electromechanical structure

Abstract

The invention discloses a method for manufacturing a semiconductor micro electronmechanical structure, which comprises the steps: firstly, at least one insulation circuit layer internally provided with a micro electronmechanical structure is produced on the upper surface of a silicon substrate, and a sacrifice layer and a blocking layer are sequentially produced on the upper surface of the insulation circuit layer from interior to exterior; secondly, an etching blocking layer is made on the lower backface of the silicon substrate, and deep reactive ion etching or wet etching is carried out tothe lower backface of the silicon substrate so as to form a space corresponding to the micro electronmechanical structure; and finally etching is carried out to the insulation circuit layer and the sacrifice layer in sequence to lead the micro electronmechanical structure to be suspended. Therefore, lateral erosion can be effectively avoided, the probability of exposure and damage of the micro electronmechanical structure is low, and the final encapsulation cost can be reduced by being integrated with common integrated circuit packaging technologies.

Description

Technical field [0001] The invention relates to a semiconductor manufacturing method, in particular to a manufacturing method of a semiconductor microelectromechanical structure. Background technique [0002] The existing semiconductor microelectromechanical system includes a variety of different semiconductor microstructures, such as: immovable probes, flow channels, hole structures, or some movable springs, connecting rods, gears (rigid body movement or flexible deformation) ) And other structures. [0003] The above-mentioned different structures and related semiconductor circuits are integrated with each other to form various semiconductor applications. Therefore, how to improve the various functions of the micromechanical structure through manufacturing methods is a key indicator of the future semiconductor microelectromechanical system, and it is also a serious challenge for further research on chips in the future. If we can develop and improve the known technology, the fut...

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Problems solved by technology

[0007] One is that it uses anisotropic dry chemical etching to remove the insulating layer material by means of chemical reaction. However, after passing through the side edges of the microelectromechanical structure, it is still necessary to perform isotropic chemical etching to remove the material. A large amount of silicon-based substrates are etched away, so this technology will cause serious undercuts;

[0008] The second is that in the process of this common technology, the MEMS structure is exposed to the process from the beginning. After a long period of multi-layer process processing, the MEMS structure is often polluted and damaged, resulting in a low yield;

[0009] The third is that after the etching operation is completed in this process technology, the MEMS structure can already operate in suspension, but the surface of the MEMS structure must be encapsulated with special mechanical tools to block the air, but since the MEMS structure must be guaranteed to be suspended In the past, a special mold cover was used to set the surface of the product, and then a packaging protective film that did not touch the suspended MEMS structure was precisely manufactured. However, this surface packaging technology is more complicated and costly, and it cannot be compared with the packaging of general integrated circuits. to integrate

[0010] The development of micro-electromechanical structure manufacturing technology is very rapid. In order to improve the above-mentioned problems, the US patent specification US6712983B2 (authorization date: March 30, 2004) proposed the use of ion etching (Reactive Ion Etching, hereinafter referred to as RIE) technology, which Although this technique can greatly reduce the undercut phenomenon (under cut), it is also etched layer by layer from top to bottom, and the last large amount of silicon substrate etching work must be achieved by lateral etching technology, so this The improved technology is too cumbersome and complicated, and there will still be under cut through a large amount of etching and lateral etching through the MEMS structure, and the above-mentioned problems that the MEMS structure is exposed and difficult to package have not yet been solved. improve

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