MULTILAYER MEMBRANES FOR X-RAY LITHOGRAPHY MASKS

MULTILAYER COATINGS CONSTRUCTED OF MATERIALS OF LOW ATOMIC NUMBER WILL BE USED TO MAKE MEMBRANES FOR X-RAY LITHOGRAPHYMASKS. THE MULTILAYER MEMBRANES WILL THEN BE EVALUATED WITH RESPECT TO SUCH BENEFITS AS INCREASED OPTICAL TRANSMITTANCE FOR MASK ALIGNMENT,INCREASED WET ETCH RESISTANCE DURING MEMBRANE FABRICATION, IMPROVED STRESS CONTROL, INCREASED FRACTURE STRENGTH AND GREATER MEMBRANE SMOOTHNESS FOR IMPROVED PATTERNABLITY. THE COATING AND MEMBRANE DEVELOPMENTEFFORT WILL BE APPLIED TO MULTILAYER COMBINATIONS OF SILICON CARBIDE,SILICON NITRIDE, SILICON DIOXIDE, AND DIAMOND. AN ELECTRON CYCLOTRONRESONANCE CHEMICAL VAPOR DEPOSITION (ECR CVD) SYSTEM WILL BE USED TO DEPOSIT ALL THE LAYERS COMPRISING THE MULTILAYER COATINGS. THE ECT CVD COATING TECHNOLOGY HAS ALREADY BEEN SUCCESSFULLY APPLIED TO DEVELOPING SILICON CARBIDE MEMBRANES FOR X-RAY MASKS, AND ALL THE PROPOSED LAYERING MATERIALS HAVE BEEN TESTED AND DEVELOPED IN THE ECR CVD SYSTEM.THE REPRODUCIBILITY OF THE ECT CVD COATING PROCESS IS BETTER THAN 1%,MAKING THIS A PROMISING COMMERCIAL PROCESS FOR MANUFACTURING MULTILAYER COATINGS REQUIRING CONTROLLED LAYER THICKNESSES. THE INTEGRATION OFMULTILAYER MEMBRANES WITH THE REST OF THE X-RAY MASK MAKING PROCESS WILL BE FULLY EVALUATED. ANTICIPATED BENEFITS/POTENTIAL COMMERCIAL APPLICATIONS - ADVANCED AND IMPROVED X-RAY LITHOGRAPHY MASKS. THE KEY BENEFITS FOR MASKS ARE: IMPROVED MASK ALIGNMENT, IMPROVED PATTERNABILITY, AND HIGHER MANUFACTURING YIELDS. ALSO, IMPROVED X-RAY WINDOWS AND FILTERS HAVING GREATER BURST STRENGTH.