Design of Micron Scale Digital Lithography Miniature Projection Objective

Micron-scale chips are widely used in large-scale industrial production because of their low cost and mature technology. However, in the manufacturing field, design studies on digital lithography projection objective lenses with micron-level resolution are relatively few. In this paper, a digital lithography micro-projection objective lens with micron resolution was designed using ZEMAX. For the commonly used 405 nm lithography light source, the system achieves a resolution of 0.625 μm, enabling more precise structural processing. The imaging distortion is reduced to 0.0159%, significantly improving overall image quality. The designed objective lens has a magnification of –0.0714 and a numerical aperture of 0.02, meeting the requirements for most micron-scale chip manufacturing processes. Additionally, a microlens array was designed to ensure uniform illumination, minimizing the effects of uneven lighting. Tolerance analysis shows that 90% of the manufactured lenses achieve an MTF greater than 0.7692, satisfying machining accuracy requirements.