Modeling and implementation of a virtual lithography system for micromachines

This paper proposes the Litho3D, a virtual lithography system for micromachines. The system utilizes a Fourier optics imaging model, a photoresist espousing model, and a development model to simulate the projective optical lithography. Also, the system supports the input of GDSII and CIF format layout, and permits the interactive configuration of simulation parameters, including numerical aperture, wavelength, defocus, photoresist thickness, and surface reflection. The visualization of simulated results is based on the method of combining volume rendering with mesh rendering, which enhances the visibility. Additionally, the simulated results can be directly used as the masks of the etching process in the virtual process system, which implements the integrated simulation between lithography and other MEMS fabrication processes. A series of simulation results demonstrate the feasibility of the system.