In the manufacturing of MEMS devices and Through-Silicon Vias (TSVs), technology capable of forming high-aspect-ratio, vertical structures in silicon with high repeatability is indispensable. However, minimizing sidewall roughness and bottom residue while increasing the aspect ratio—all while balancing mass-production-level uniformity and throughput—remains a major challenge in process development.

This report provides comprehensive insights for equipment selection and process design regarding the Bosch process, the representative method for Si deep etching. It covers everything from its fundamental principles—alternating between polymer deposition and etching cycles—to the essential hardware components required to achieve it, including plasma sources, bias RF systems, and high-speed gas switching mechanisms.

Specifically, this report highlights case studies using the Predeus Si deep reactive ion etching system, which achieved trench etching with an aspect ratio of over 60 on sub-micron patterns, as well as processing examples on large-opening patterns exceeding 1 mm. In addition, it outlines the key features of the Proxion system—engineered for ultra-high-speed etching (up to 30 µm/min or more)—along with proven performance across diverse substrates such as bonded and SOI wafers, and wafer size scalability ranging from 4 inches to 300 mm. We hope this report serves as a valuable resource for your process evaluations across a wide range of needs, from R&D to high-volume manufacturing.