Abstract
The role of maskless lithography in industry, research and emerging applications in nanoscale science and engineering is discussed. Various forms of maskless lithography with emphasis on zone-plate-array lithography (ZPAL) are also described. Interference lithography (IL) and scanning electron-beam lithography (SEBL) represents highly effective forms of maskless lithography, especially for research and low-volume, special purpose manufacturing. SEBL can write patterns of arbitrary geometry but suffers from problems of low throughput, high cost and pattern placement inaccuracy.