A REAL-TIME PROCESS MONITOR FOR THE GROWTH OF HIGH TEMPERATURE SUPERCONDUCTOR THIN FILMS

High temperature superconductor (HTS) thin films promise to enhance a wide variety of commercial and defense related applications. In order to provide the necessary performance and reliability, the thin film fabrication process must be tightly controlled to ensure proper composition, uniform, thickness, and desired stress state in the HTS films. Pulsed laser deposition (PLD) is emerging as the process of choice for the deposition of the HTS thin films such as YBCO. Reactions in the PLD chamber often are governed by mechanisms that are complex functions of temperature, pressure, laser beam uniformity and plume dynamics. Process control is of paramount importance in order to achieve high quality HTS films with properties that are reproducible from run to run and which have lateral uniformity over the coated area. Phase I research will ential fabrication of several Raman optical probe assemblies/configurations and demonstration of their application for obtaining Raman spectra for in-situ real-time analysis of PLD growth of HTS thin films. Phase II will permit us to fabricate and deliver an advanced prototype Raman instrument with an advanced software system for process control in a HTS thin film PLD apparatus.