Multi-scale modeling of the multi beam mask writer writing process

Abstract

In the rapidly evolving landscape of semiconductor manufacturing, the Multi Beam Mask Writer (MBMW) has emerged as a critical tool in the fabrication of photomasks. Photomasks are essential for the fabrication of constantly shrinking semiconductor devices. Developed by the High Performance Computing (HPC) group at IMS Nanofabrication, the MBMW simulator has significantly contributed to understanding and improving data processing and writing techniques during mask production. However, a key challenge in the current MBMW simulation methodologies is the limited capacity to accurately represent large-scale effects such as back-scattering, which is essential for high-fidelity mask writing. This thesis addresses this gap by developing and implementing a comprehensive multi- scale modeling framework within the MBMW simulator. The primary aim is to accurately and efficiently simulate back-scattering effects, thus enhancing the simulator’s predictive capabilities for electron beam behavior during the mask writing process. The focus lies in developing a model which captures the effect of back-scattering at varying scales - from nanometer to micrometer levels. One primary goal is that the design of the framework is both modular and extendable. This flexibility ensures adaptability to future technological advancements and the inclusion of additional simulation models. The implementation process begins with a one-dimensional representation of back-scattering and progresses to a more sophisticated two-dimensional model. This phased approach not only provides a foundational understanding of the back- scattering dynamics but also allows for iterative refinement and validation of the model. A thorough benchmarking and error analysis follows, where the model’s performance is tested. Here, the accuracy and efficiency of the multi-scale approach, particularly in scenarios where back-scattering play a significant role, is demonstrated. This thesis makes a significant contribution to the field of semiconductor manufacturing, particularly in the realm of simulations of the writing process using multi-beam mask writer. The modular and scalable nature of the developed framework not only ensures current applicability but also lays the groundwork for future advancements in this domain.