A review on the mainstream through-silicon via etching methods

Currently, 3D integration is considered to be the most promising development direction forchip industry. It relies on the through-silicon via (TSV) structure to achieve mechanical and electrical interconnection in the vertical direction. The manufacturing of TSV is usually accomplished by etching technique, which can produce a hole with high aspect ratio by removing the material from a specific area physically or chemically. At present, the mainstream TSV manufacturing methods include KOH wet etching, laser drilling, deep reactive ion etching and photo-assisted electrochemical etching. However, a cross-sectional comparison of their characteristic was lacking in the literature. This review aims to provide a comprehensive summary for four kinds of mainstream TSV etching methods, i.e., KOH wet etching, laser drilling, deep reactive ion etching and photo-assisted electrochemical etching, including their etching mechanism, process, parameters and hole structure. Finally, this paper summarizes and prospects the four methods for TSV etching, providing researchers and engineers with an extensive and updated understanding of the principles and applications for these four mainstream TSV etching methods.