Fiber-optic based distributed atomic absorption spectroscopy for film growth monitoring

Development of low-cost optical components for X-Ray microscopy and extreme ultraviolet lithography will facilitate the reduction of semiconductor chip features to a few nanometers and spur new frontiers in nanotechnology, microelectronics, neuroscience and cell biology and maintain the US position as a global leader in technology. The manufacturing of the required optical components by vacuum thin film deposition requires unprecedented precision and accuracy and presents a significant process control challenge. Currently no process control system provides the accuracy, portability and ease-of-use for adoption in the X-ray and EUVL optics. Multiple other new-generation thin film technologies require a solution to the same process control challenge in order to foster new frontiers in technology. The development of new superalloys and high entropy alloys, especially needed for the manufacturing of new generation jet turbines for commercial and military applications is another application that urgently needs a solution. During the SBIR Phase II project it was demonstrated that the Atomic absorption spectroscopy is a promising process control method, capable of accurately measuring deposition rate and composition of deposited thin films and overcoming many limitations of current methods. This SBIR Phase IIB project continues the effort to finalize the development of a novel process control system, installable on a variety of vacuum deposition systems for the manufacturing of high-precision thin films. The system provides accurate and reliable deposition rate, film composition and film uniformity measurements for dynamic feedback process control. The system comprises two major components – a hardware module located outside the deposition chamber with element specific light sources and a portable fiber-optic-based monitoring frame installed inside the deposition chamber in the area surrounding the substrate. The prefabricated and optically aligned frame, installed inside the deposition chamber, eliminates costly equipment refurbishing and allows flexibility and customization. The unique system design allows accurate measurement of the element concentration on the vicinity of the substrate. During this Phase IIB project a commercial in situ atomic spectroscopy system for thin film process control will be finalized. The system will be validated for multiple chemical elements, needed for the new generation semiconductor lithography, compound semiconductors and aerospace applications. These are all new generation applications where no commercial metrology solution is available today. Next, the system will be installed and integrated into mainstream manufacturing equipment for semiconductor and aerospace application. Validating the system for operation on equipment, widely used by real manufacturer will prepare the system for faster acceptance by the major manufacturers and will speed time to market.