Novel dose assignment method in grayscale electron beam lithography for 3D patterning

Grayscale electron beam lithography is a powerful technique for fabricating high-resolution three-dimensional (3D) patterns in a single processing step, with applications in photonics, optics, and microelectronics. This study focuses on optimizing 3D fabrication by addressing challenges such as proximity effects and the need for high pattern fidelity at feature sizes ranging from a few hundred nanometers to a few micrometers. A novel dose assignment methodology is introduced using electron beam exposure simulations. This allows for improved modeling of the energy distribution and, therefore, improved resist profile prediction. To perform this, the approach integrates a refined contrast curve and the point spread function, calibrated with experimental data, which allows to model the energy distribution. The proposed dose optimization is validated by comparing the fabricated structures with the predicted patterns, demonstrating both the proof of concept of this approach and the current limitations of the process. Additionally, this method has the potential to be integrated with nanoimprint lithography to enable a cost-effective, high-resolution manufacturing solution.