Method for preparing straight Si {111} and Si {110} surface intersection line on Si (100) wafer

Abstract

The invention discloses a method for preparing a straight Si {111} and Si {110} surface intersection line on a Si (100) wafer. The implementation step comprises the following steps: preparing an etching solution added with an additive for reducing the surface etching rate; placing the Si (100) wafer for preparing the straight Si {111} and Si {110} surface intersection line in the etching solutionfor etching, and periodically adding the additive to the etching solution so that the component concentration of the etching liquid is constant; and after the etching operation of the Si (100) wafer reaches the specified time, the Si (100) wafer is taken out. According to the method for preparing the straight Si {111} and Si {110} surface intersection line on the Si (100) wafer disclosed by the invention, the Si {111} surface and the over-etched Si {110} surface can be smooth and flat, and the straightness of the surface intersection line of the Si {111} surface and the over-etched Si {110} reaches an ideal state, thereby reducing stress concentration and deformation of silicon structural components caused by a convex angle and rough surfaces, improving the symmetry and balance of the MEMSdevice structure, reducing the error of the MEMS devices and improving the performance and the sensitivity of the MEMS devices.

Description

technical field [0001] The invention relates to the MEMS device structure manufacturing technology in the field of semiconductors, in particular to a method for preparing straight Si{111} and Si{110} plane intersection lines on a Si(100) wafer. Background technique [0002] Fabrication of MEMS devices often involves fabricating silicon structures through etching processes. The silicon etching process is divided into dry etching and wet etching. Compared with dry etching, wet etching has lower requirements on equipment, better in-chip uniformity, process stability and repeatability, and is suitable for mass production. The silicon structure is mainly etched anisotropically by alkaline solutions such as TMAH, KOH, NaOH, etc. on the Si(100) wafer, and the platform formed by the Si{111} plane and the Si{100} plane constitutes the quality block, beam, frame, etc. of the MEMS device. Components, where {100} and {111} both refer to crystal planes. At present, 25%wtTMAH is used f...

AI Technical Summary

Problems solved by technology

[0003] The technical problem to be solved in the present invention: for the above-mentioned problem of prior art, in order to reduce the error of MEMS device, improve its performance, provide a kind of Si{111} and Si{110} plane on Si (100) wafer The preparation method of the intersection line can make the Si(111) surface and the over-etched surface smooth and smooth by the preparation method of the straight Si{111} and Si{110} plane intersection lines on the Si(100) wafer of the present invention, and the Si{ The flatness of the intersection line between the 111} plane and the over-etched Si {110} plane reaches an ideal state, reducing stress concentration and deformation of silicon structural components caused by convex corners and rough surfaces, and improving the symmetry and balance of the MEMS device structure performance, which further reduces the error of MEMS devices and improves the performance and sensitivity of MEMS devices

Images