ASPHERIC SURFACE FIGURING USING PLASMA ASSISTED CHEMICAL ETCHING

THIS PROJECT SHOULD PRODUCE AN AUTOMATED METHOD FOR THE DIRECT FABRICATION OF FINISHED, PRECISION, ASPHERIC SURFACES ON SILICON OPTICAL ELEMENTS, USING A PLASMA-ASSISTED CHEMICAL ETCHING (PACE) PROCESS. THIS METHOD WOULD MAKE POSSIBLE THE FIGURING OF SUCH SURFACES, BEGINNING WITH SIMPLE POLISHED, SPHERICAL SUBSTRATES IN A SINGLE OPERATION. THE PHASE I EFFORT WILL FOCUS ON THE SELECTION OF APPROPRIATE PLASMA PARAMETERS AND FLUORINATED GAS CHEMISTRIES THAT PRODUCE A SMOOTH SURFACE ETCHING WHILE PROVIDING A SMOOTH FIGURE USING THE FIRM'S AUTOMATED ASPHERIZING APPROACH. EXPERIMENTS WILL BE CONDUCTED USING SILICON WAFERS TO QUANTIFY REMOVAL RATES, FOOTPRINT CONTOURS, AND SURFACE ROUGHNESS USING CANDIDATE PACE CONFIGURATIONS. THESE EXPERIMENTS WILL USE AN EXISTING PROTOTYPE PACE ASPHERIC FIGURING SYSTEM. THE RESULTS OF PHASE I WILL DEFINE A PLASMA-ETCHING CONFIGURATION THAT CAN MEET THE REQUIREMENTS OF THE AUTOMATED, ONE-STEP OPTICAL-FIGURING PROCESS. THIS PROJECT SHOULD PRODUCE AN AUTOMATED METHOD FOR THE DIRECT FABRICATION OF FINISHED, PRECISION, ASPHERIC SURFACES ON SILICON OPTICAL ELEMENTS, USING A PLASMA-ASSISTED CHEMICAL ETCHING (PACE) PROCESS. THIS METHOD WOULD MAKE POSSIBLE THE FIGURING OF SUCH SURFACES, BEGINNING WITH SIMPLE POLISHED, SPHERICAL SUBSTRATES IN A SINGLE OPERATION. THE PHASE I EFFORT WILL FOCUS ON THE SELECTION OF APPROPRIATE PLASMA PARAMETERS AND FLUORINATED GAS CHEMISTRIES THAT PRODUCE A SMOOTH SURFACE ETCHING WHILE PROVIDING A SMOOTH FIGURE USING THE FIRM'S AUTOMATED ASPHERIZING APPROACH. EXPERIMENTS WILL BE CONDUCTED USING SILICON WAFERS TO QUANTIFY REMOVAL RATES, FOOTPRINT CONTOURS, AND SURFACE ROUGHNESS USING CANDIDATE PACE CONFIGURATIONS. THESE EXPERIMENTS WILL USE AN EXISTING PROTOTYPE PACE ASPHERIC FIGURING SYSTEM. THE RESULTS OF PHASE I WILL DEFINE A PLASMA-ETCHING CONFIGURATION THAT CAN MEET THE REQUIREMENTS OF THE AUTOMATED, ONE-STEP OPTICAL-FIGURING PROCESS.