A low-cost preparation method of micro-cantilever beam based on stress peeling technology

Abstract

The invention discloses a low-cost preparation method of a micro-cantilever beam based on stress stripping technology. The method includes two implementation modes: one is stripping first and then photolithography, and the other is stripping after photolithography. The present invention can replace the base material with low-cost materials, only the micro cantilever beam is made of single crystal silicon material, the material consumed in one-time production of the AFM probe cantilever is only the height of the needle tip plus the thickness of the cantilever, which is about 20 microns, and the remaining silicon The crystal can also be used after polishing. Considering that the silicon crystal consumed by re-polishing is about 80 microns, only 100 microns of silicon crystals are consumed in one production; if traditional methods are used, a 1mm thick silicon crystal can only support one production, while The invention can increase the utilization rate of materials by 10 times, greatly improve the utilization rate of single crystal silicon materials, and reduce the cost; the invention has high utilization rate and low cost of the raw materials of the bulk micro-cantilever beam, and only a small amount of chemical reagents are used. for etching thin films.

Description

technical field [0001] The invention relates to a preparation method of a micro-cantilever beam, in particular to a low-cost preparation method of a micro-cantilever beam based on stress stripping technology. Background technique [0002] Micro-cantilever is an important component in the field of MEMS (Micro-Electro-Mechanical System, Micro-Electro-Mechanical System), and is widely used in the sensor field because of its low cost, small size, and high performance. Micro-cantilever beams refer to beams with one end fixed and the other suspended, and are generally prepared by bulk silicon processing technology and surface processing technology. Changes in correlated signals are detected by measuring tiny bends in the microcantilever. Typical applications are atomic force microscope (Atomic Force Microscope, AFM) probes, accelerometers, resonators, molecular detectors, etc. The width and thickness of the micro-cantilever are generally in the order of several microns, and the ...

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Problems solved by technology

But for AFM probe cantilever, if it is made by etching silicon wafer, 300 micron thick wafer usually has thickness variation of + / - 1 micron, to get 1 micron thick cantilever, 299 micron of silicon must be etched

However, due to the uneven thickness of the silicon wafer, in mass production, the material removal of 299 microns will result in a 1 micron thick cantilever in the 300 micron area, and a 2 micron thick cantilever in the 301 micron area, and the product consistency is difficult. Guaranteed, the yield is only about 30%

If the SOI (Silicon-On-Insulator, silicon-on-insulator) wafer whose thickness of the top layer of silicon is equal to the sum of the height of the probe tip and the thickness of the micro-cantilever is used to make it, although the consistency of the product can be guaranteed, there will still be problems that require engraving. The problem of etching silicon in a large area to obtain the substrate, the material utilization rate is low, and the cost of SOI wafer is high, resulting in high cost of AFM probe

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