ACCURACY OF EXPOSURE DURING CONTINUOUS STAGE MOVEMENT IN A VARIABLE SHAPED VECTOR SCANNING EB LITHOGRAPHY SYSTEM

We have developed a variable shaped electron beam lithography system ' 'NOWEL-2'' [1,2]. Continuously moving stage exposure mode, which we ca ll CM exposure mode, is used in the system. To achieve high butting an d overlay accuracy in CM exposure mode, we measured the beam positioni ng error using the continuously moving mark detection method. Up to a stage velocity of 10 mm/sec, beam positioning error caused by eddy cur rent and system vibration was less than 0.04 mum. Total beam positioni ng drift during exposure was decreased to about 0.08 mum by keeping th e temperature of the electromagnetic deflectors and lenses constant.