TY - JOUR A1 - Bauer, Joachim A1 - Heinrich, Friedhelm A1 - Villasmunta, Francesco A1 - Villringer, Claus A1 - Reck, Johanna A1 - Peters, Sven A1 - Treffer, Alexander A1 - Kuhnt, Christian A1 - Marschmeyer, Steffen A1 - Fursenko, Oksana A1 - Stolarek, David A1 - Mai, Andreas A1 - Regehly, Martin T1 - Reflectometric method for measuring residual oxides in through-silicon vias for 3D chip integration JF - Optics Express N2 - A significant aspect of fabricating 3D chip architectures is ensuring proper contact between the different layers of the chip, which often requires removing the underside of isolation layers before filling vias with conductive material. Currently, scanning electron microscopy is the established method for investigating such structures. In this paper, we propose a rapid, non-destructive optical analysis technique for the simultaneous measurement of through-silicon vias (TSV) depths, silicon wafer thickness, and residual oxide thickness. The proposed method utilizes Fourier peak shift analysis (FPSA) of reflectance measurements in the near-infrared (1200 nm—2200 nm) spectral regions. The application of FPSA to representative samples taken from a commercial TSV integration process for MEMS and CMOS fabrication demonstrated good agreement with reference scanning electron microscopy measurements, confirming the feasibility of the method for in-line and in-situ metrology. The results indicate that FPSA has great potential for real-time process monitoring and control during 3D chip manufacturing. KW - effective refractive index KW - Fourier transforms KW - near infrared KW - ray tracing KW - scanning electron microscopy KW - thin film Y1 - 2025 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:526-opus4-20633 VL - 33 IS - 15 SP - 32175 EP - 32189 PB - Optica ER -