We have devised a new mask format for low-energy electron-beam proximity-projection lithography (LEEPL) that enables faster and more accurate image transfer from the mask to a wafer, in comparison with the single-membrane mask as originally proposed. Simultaneous exposure over four adjacent complementary quadrants of the mask, synchronized with step-and-repeat motion of the wafer stage, yields one complete pattern with the throughput of similar to30 wafers/h. Mechanical analysis has demonstrated that the new format also offers better controllability of image placement owing to smaller membranes, even though the gravitational deformation of the mask, for example, must still be corrected for. (C) 2003 American Vacuum Society.