An intensive study of the patterning performance of the EB-X3 revealed that the placement accuracy of a written image was degraded by the thermal effect originating from the temperature difference between the stage and the palette. An optimal writing procedure consisting of two temperature stabilization steps was developed. This procedure enables the EB-X3 to attain an image placement accuracy of better than 10 nm (3 sigma). A critical dimension control of 7.4 nm (3 sigma) has been confirmed over a 25-mm-square field.