“…By using current state-of-the art step-and-repeat exposure tools it is possible, for example, to achieve a minimum transistor gate length of 20 nm and a dynamic random access memory (DRAM) periodicity (half-pitch) of 50 nm [5]. Scanning beams of high-energy particles comprising atoms, ions, and electrons also have evolved into robust and mature technologies which are being used for micro-and nanofabrication purposes [6,7]. Each of these techniques can create arbitrary features at very high resolution (e.g., 5 nm and below), but their serial nature limits the scope of applications to selected, low-volume fabrication tasks.…”