Substrate Yield Enhancement Enabled by Advanced Packaging Metrology System

Detecting dimensional errors in substrate fabrication induced by the manufacturing process is a challenge for high-density substrates. Such detection is especially important in advanced substrates that incorporate high-speed impedance-controlled circuits where a small change in linewidth and spacing can impact circuit performance. A 100% metrology inspection system has been developed that can detect these dimensional errors and provide the data needed to correct these errors. The Beltronics system can perform up to 10-billion line width, line space and pad diameter measurements on a 510mm x 515mm substrate in 5 minutes, to an accuracy of 0.15 microns. This new system provides real-time feedback to enable continuous inline process control to monitor the sizes of all features on the substrate during the fabrication process. The system compares the dimensions of features on the substrate to dimensions from the original CAD data to detect and classify defects. This paper presents an overview of this new technology and explains how it can be used to detect machine dependent distortions, such as non-linearities in the lithography lens or direct write exposure system, and design dependent distortions resulting from etch rates varying as a function of feature size, shape, and metal density in the neighborhood of each feature.