A Review of Through-Silicon Via Inspection and Metrology Technology for Advanced Semiconductor Packaging

Abstract This article presents a comprehensive summary of the through-silicon via (TSV) technology, primarily focused on its metrology and inspection for advanced semiconductor packaging. With the rapid advancement of electronic technology, the size of integrated circuits (ICs) continues to decrease while the functionality of components continually enhances. Three-dimensional ICs (3D ICs) packaging is an essential method for improving both the integration and performance of components. TSVs are one of the key technologies used to achieve 3D ICs, as they enable efficient vertical electrical connections between different layers and significantly increase the device density, being recognized as a vital technology for high performance, miniaturization, and multifunctionality of semiconductor devices. Due to the small and complicated features of TSVs, various types of defects could be observed during manufacturing and operation. These defects affect the performance and reliability of the devices, further leading to potential system failure. Therefore, accurate and effective TSV metrology and inspection technology becomes a key factor in advanced semiconductor packaging, ensuring device performance and functionality. Various metrology technologies have been proposed, including optical inspection, X-ray inspection, scanning electron microscopy (SEM), atomic force microscopy (AFM), etc. Recently, new inspection technologies, such as via metrology based on edge diffraction and through-focus scanning optical microscopy (TSOM), have been continually developing, although those technologies still have potential issues and limitations. As applications of TSVs continue to expand, the need for fast and accurate metrology becomes increasingly important. Future trends include combining current methods with artificial intelligence (AI) to further achieve inspection automation. This article provides a comprehensive review of the main TSV metrology methods, discusses their capabilities, advantages, and limitations, and provides insight into the future TSV technology development trends.