Massively parallel electron-beam systems are equipped with a large number of beams to improve the writing throughput. It is unavoidable that some of the beams are abnormal, e.g., always on or off, spatial and temporal fluctuations of beam current, beam-positioning error, etc. A practical approach to improve the writing quality is to spread the negative effects of abnormal beams spatially. The multirow writing (MRW) was introduced, which uses each beam to expose pixels over multiple rows in each writing path minimizing the localization of pixels affected by an abnormal beam. In another method, the single-row writing (SRW), each beam exposes pixels in one row in each writing path localizing the affected pixels in a row. To spread the negative effects, especially for the single-row writing, each row of pixels may be exposed through multiple passes, i.e., multipass writing. In this study, the multirow and multipass writing methods in various combinations with the MRW and SRW are compared in terms of their effectiveness in reducing the negative effects of abnormal beams. The results from an extensive simulation study are analyzed in detail.

While electron-beam (e-beam) lithography is widely used in transferring fine-feature patterns onto a substrate, its major drawback is the low throughput, especially for large-scale patterns. To increase the writing throughput, e-beam machines with massively-parallel beams were recently developed. In such a system, it is highly likely that some beams may not be normal, e.g., permanently on or off, a significant current fluctuation, beam-positioning error, etc. Therefore, it is crucial to understand how abnormal beams affect writing qualities. In this study, the effects of abnormal beams on the writing qualities are analyzed through an extensive simulation, comparing three different writing methods, single-row writing I, single-row writing II, and multirow writing, to suggest ways of reducing their negative effects.

Massively parallel electron-beam (e-beam) systems (MPESs) were developed to increase the writing throughput and demonstrated to be able to write large-scale patterns significantly faster compared to conventional single-beam systems. However, such systems still suffer from the inherent proximity effect due to the electron scattering in the resist. The proximity effect correction (PEC) has been investigated for a long time, and several PEC schemes have been proposed. Though most of the PEC schemes may be employed for an MPES, their direct application would be subject to the system’s constraints, e.g., a relatively large beam size, a fixed exposing interval, and the same deflection angle for all beams, which may lead to nonoptimal correction results. In this work, practical methods for realizing various types of spatial dose distributions required for the PEC and implementing both shape and dose corrections under the MPES constraints have been developed. It has been shown that, with these methods, the proximity effect correction can be performed effectively with the critical dimension error, line edge roughness, and total dose taken into account.