REAL TIME, SELF-DIRECTED MBE FLUX CONTROL INCORPORATING IN SITU ELLIPSOMETRY

MANY OF THE PERFORMANCE DRIVEN DEMANDS OF FUTURE AIR FORCE WEAPON SYSTEMS ARE DEPENDENT ON THE AVAILABILITY OF ADVANCED SEMICONDUCTOR, BANDGAP ENGINEERED DEVICES AND COMPONENTS. MOLECULAR BEAM EPITAXY (MBE) IS THE PREFERRED METHOD FOR CREATING THESE. BUT IN ORDER TO REACH THE REQUIRED GOAL OF HIGH PURITY, MONOLAYERS WITH ATOMICALLY ABRUPT HETEROJUNCTIONS, PROCESS CONTROL OF ALL DEPOSITION PARAMETERS IS ESSENTIAL. THE MOST IMPORTANT OF THESE IS BEAM FLUX. CONTROL OVER THE FLUX WILL BE ACHIEVED BY COMPLETING THE DEVELOPMENT OF A SELF-DIRECTED, AUTO-LEARNING SYSTEM THAT INCORPORATES REAL TIME, IN SITU ELLIPSOMETRY. DURING PHASE I OF THIS EFFORT, THE FEEDFORWARD TEMPERATURE AND SHUTTER CONTROL SYSTEM WILL BE COMPLETED, AND ELLIPSOMETRY WILL BE INTERFACED WITH AN MBE MACHINE IN ORDER TO ACHIEVE IN SITU MONITORING OF THE DEPOSITION PROCESS. A PHASE II WORK PLAN WILL BE COMPLETED DESCRIBING IN DETAIL HOW THE RESULTS OF THIS PHASE I EFFORT WILL BE INTEGRATED INTO THE CONTROL SYSTEM. A PLAN FOR TRANSFERRING THE CONTROL TECHNOLOGY TO INDUSTRY WILL BE COMPLETED BY INTRODUCING MBE SYSTEMS AND ELLIPSOMETER MANUFACTURERS TO THE CAPABILITY BEING DEVELOPED. THIS WILL INCLUDE A DEMONSTRATION OF THE CONTROL CAPABILITY AT THE END OF PHASE I.