EVALUATION OF A DIAMOND-BASED X-RAY MASK FOR HIGH-RESOLUTION X-RAY PROXIMITY LITHOGRAPHY

A high resolution x-ray mask compatible with a commercial stepper has been realized with a diamond membrane and electroplated gold structure s. The membrane was optimized to satisfy all the requirements needed f or x-ray proximity lithography using soft x rays at the super-AGO sync hrotron facility. Patterning was optimized using a conventional 50 keV vector scan generator. High density high resolution gold gratings wer e obtained with linewidth down to 60 nm with periods as small as 120 n m. It was found that the resolution for our current studies was mainly limited by the resist thickness and not by the diamond surface morpho logy or the electrodeposition process. Alignment performance has been evaluated. Preliminary results show that diamond material with a 20 nm root-mean-square surface roughness is acceptable for good alignment p erformance. (C) 1995 American Vacuum Society.