Wafer Thickness Measurement by Using Spectral Interferometry in Advanced Packaging

This study explores the application of spectral interferometry in wafer thickness measurement within the semiconductor industry. Spectral interferometry, a non-contact optical measurement technique, offers high precision and real time capabilities, making it ideal for semiconductor manufacturing processes. The system comprises essential components such as a high-resolution spectrometer, optical fibers, and a tungsten halogen light source, enabling accurate measurement of wafer thickness. Experimental results demonstrate the system's effectiveness in measuring wafer thickness with exceptional accuracy and repeatability. Comparative analysis with traditional measurement techniques highlights the superiority of spectral interferometry in terms of accuracy, efficiency, and versatility. The adoption of spectral interferometry offers numerous advantages, including enhanced quality control, process optimization, and compatibility with advanced semiconductor technologies. Therefore, this paper introduces the system architecture, measurement principles, measurement standards, and final experimental results, all of which demonstrate that spectral interferometry is highly suitable for high-precision wafer thickness measurements.