Novel photonics dielectric substrate process integration development cycle time reduction by inline Xe plasma FIB

Light-emitting diode (LED) photonics is a rapidly growing field that has applications in various domains, such as communication, lighting, display, and sensing. However, the fabrication and characterization of LED photonic devices pose several challenges that need to be addressed. Compared to the silicon semiconductor industry, LED devices are based on exotic substrates, such as sapphire (AlO), silicon carbide (SiC) and gallium arsenide (GaAs). One of the challenges in semiconductor process integration development and production control is checking the process quality through characterizing and analyzing defects at different process steps. Typically, wafers at different process steps are sent to the failure analysis laboratory (FA lab) for detailed analysis by transmission electron microscope (TEM), energydispersive X-ray spectroscopy (EDX), cross scanning electron microscope (XSEM), or gallium focus ion beam (GaFIB). These methods are destructive, slow, and expensive. As a result, having a non-destructive, fast, and low-cost method for full-wafer analysis can help speed up the integration cycle and improve process control and yield. This paper is a collaboration between ams-OSRAM international GmbH and Applied Materials Inc. The paper describes the benefits of inline Xenon Plasma FIB (XePFIB) and SEM in the fab for improving the cycle time of root cause analysis and process integration development. It explains the methods that are used to solve the problems of handling and analyzing special substrates, like transparent sapphire wafers in semiconductor manufacturing for LED and photonic products. Specifically, the paper describes the methodologies that are used to optimize the SEM image resolution and XePFIB cross-section quality by reducing the charging effects of the sapphire dielectric substrate.