The process of metal etching

One of the key steps in integrated circuit manufacturing is to remove the thin film layer not covered by the resist and obtain a pattern on the thin film that is completely consistent with the resist film.
In the manufacturing process of integrated circuits, a series of fine operations such as mask alignment, exposure, and development are first required to accurately replicate the desired pattern on the resist film. In addition, high-precision electron beams can also be directly used to draw the desired pattern on the resist film.
After completing this step, the pattern is immediately transferred to the dielectric thin film (such as silicon oxide, silicon nitride, polycrystalline silicon) or metal thin film (such as aluminum and its alloys) below the resist with extremely high precision, thereby creating a thin layer pattern on the thin film layer that is completely consistent with the design requirements.

The etching process plays a crucial role in this process, selectively removing the unprotected thin film layer through chemical, physical, or a combination of both methods, forming a pattern on the thin film that is identical to that on the resist film. The core of etching technology lies in its selectivity, that is, only removing the parts not covered by the resist while retaining the parts protected by the resist.
Etching technology is mainly divided into two types: dry etching and wet etching. Dry etching mainly uses reactive gases and plasma for etching, while wet etching mainly achieves etching through chemical reactions between chemical reagents and the material being etched, usually in a liquid environment, using chemical solutions to selectively dissolve thin film materials.
These two etching methods each have their own advantages and disadvantages. In practical applications, they should be selected and optimized according to specific needs to ensure that the final thin layer pattern obtained meets the design requirements.