Shape and dose control for proximity effect correction on massively parallel electron-beam systems

Abstract

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.