大面积软X射线自支撑金透射光栅的研制

Abstract

To meet the need of soft X-ray self-supported transmission gratings for space detecting and plasma diagnostics,self-supported gold transmission gratings were successfully fabricated with the holographic lithography and plating technology.To obtain photo-resist mask patterns with steep sidewalls,a layer of Anti-reflection Coating(ARC) was used to attenuate standing wave resulting from the substrate with high reflectivity.Then,a plating mask was obtained by coating a protective chrome on the mask and using Reactive Ion Etching(RIE).In this process,the plating mask with desired duty cycle could be fabricated via changing the thickness of the protective coating.Finally,a self-supported transmission grating with a line density of 3 450 gr/mm(290 nm period),a duty cycle of 0.55 and 400 nm thick gold bars was fabricated by plating gold in grooves of plating mask.The grating size is up to 10 mm×15 mm,and its +1 order diffraction efficiency is about 5% in the soft X-ray band between 5 and 12 nm in the National Synchrotron Radiation Laboratory(NSRL).