A COLLIMATED X-RAY LITHOGRAPHY SOURCE USING A KUMAKHOV LENS

THE PURPOSE OF THE PROPOSED WORK IS TO DESIGN X-RAY OPTICS FOR THE COLLECTION AND REDISTRIBUTION OF THE ANNULAR X-RAY CONE GENERATED BY TRANSITION RADIATION SUCH THAT A UNIFORM X-RAY SPOT IS DELIVERED AT HIGH POWER DENSITY TO A MASK/WAFER TARGET. THIS WILL INCREASE THE POWER DENSITY FROM THE EXISTING 1 MW/CM(2) TO 5 MW/CM(2) PERMITTING TRANSITION RADIATION TO BE A COMPETITIVE SOURCE FOR X-RAY LITHOGRAPHY. TRANSITION RADIATION IS EMITTED IN CONICAL ANNULUS WHICH HAS A CENTRAL HOLE IN THE RADIATION PATTERN AND MORE THAN HALF OF THE X-RAYS ARE EMITTED AT ANGLES LARGER THAN THE ANGLE OF PEAK INTENSITY. HENCE, EFFICIENT COLLECTION OF THE X-RAYS AND THEIR PROPER COLLIMATION INTO AUNIFORM BEAM AREA ON THE SIZE OF THE MASK AND WAFER TARGET AREAS ARE REQUIRED FOR UNIFORM EXPOSURE OF X-RAY PHOTORESISTIN THE PROCESS OF MICROINTEGRATED CIRCUIT PRODUCTION. UNDER THE PROPOSED PROGRAM WE WILL DEMONSTRATE FEASIBILITY OF USING KUMA-KHOV X-RAY OPTICS TO COLLECT AND COLLIMATE X-RAYS FROM A TRANSITION RADIATION SOURCE OVER A ANGULAR RANGE OF UP TO 30 MRAD AND TO PROVIDE A QUASIPARALLEL BEAM SUITABLE OF X-RAY LITHOGRAPHY. THE DESIRED INTENSITY UNIFORMITY ACROSS THE OUTPUT X-RAY BEAM IS3%. A COMPLETE DESIGN OF A KUMAKHOV LENS BASED ON COMPUTER SIMULATION AND ON EXPERIMENTAL RESULTS WITH SINGLE CAPILLARIES AND POLYCAPILLARIES AND THEIR CORRELATION WITH THEORETICAL PREDICTIONS WILL BE DONE.