High precision forming of masking coatings of X-ray masks directly on the membranes

X-ray masks have been made directly on 1.8-2.0 μm thick suspended membranes with ±0.02 μm positioning accuracy in the plane of gold masking coating with a thickness of 0.5-0.8 μm for 0.25-0.4 μm elements. This result has been achieved by implementing the mask after leaving it freely suspended. The mask etching was done by reactive ion etching with a magnetron type source and scanning linear ion beams. The stationary substrate holder on the basis of the Peltier effect allowed cooling the membrane with flowing helium.