Cryogenic etching has become a crucial technology in semiconductor manufacturing, particularly for high aspect ratio structures, low-k materials, black silicon (b-Si), and various sensor applications. This technique effectively addresses issues such as scalloping and notching that occur in the Bosch process, while also minimizing plasma-induced damage. In cryogenic environments, the formation of SiO_xF_y passivation layers enables anisotropic etching, allowing for the creation of complex and highly precise microstructures. For b-Si, the nanostructures formed on the surface enhance light absorption, significantly improving the performance of applications such as solar cells, photonic sensors, and infrared detectors. Additionally, cryogenic etching helps preserve the electrical properties of porous low-k materials, which is essential for maintaining the reliability of next-generation high-performance devices. As semiconductor manufacturing evolves, cryogenic etching will play a key role in overcoming the limitations of conventional processes and enabling more precise and reliable devices.

Keywords: Cryogenic etching, Silicon deep etching, Low-k materials, Anisotropic etching, Black silicon