Cost-Effective Laboratory Matrix Projection Micro-Lithography System

Micromachines (Basel). 2023 Dec 24;15(1):39. doi: 10.3390/mi15010039.

Abstract

This paper presents a home-built projection lithographer designed to transfer the image from a DLP (digital light processing) projector MEMS matrix onto the microscope objective's field of view, where a photoresist-covered substrate is placed. The photoresist is exposed using blue light with a wavelength of 450 nm. To calibrate the device and adjust focal lengths, we utilize a red light that does not affect the photoresist. The substrate is located on a movable platform, allowing the exposure field to be shifted, enabling the exposure of designs with lateral sizes of 1 × 1 cm2 at a resolution of a few micrometers. Our setup showcases a 2 μm resolution for the single frame 200 × 100 μm2, and a 5 μm resolution for 1 × 1 cm2 with field stitching. The exposure speed, approximately 1 mm2/100 s, proves to be sufficient for a variety of laboratory prototyping needs. This system offers a significant advantage due to its utilization of easily accessible and budget-friendly components, thereby enhancing its accessibility for a broader user base. The exposure speed and resolution meet the requirements for laboratory prototyping in the fields of 2D materials, quantum optics, superconducting microelectronics, microfluidics, and biology.

Keywords: DMD matrix; microfabrication; projection lithography.