A maskless photolithographic prototyping system using a low-cost consumer projector and a microscope

Lithographic processing has been the key technology responsible for the rapid advances in microelectronics, but is typically not accessible to undergraduates. We have developed a maskless photolithographic system that can be assembled from a consumer projector and a trinocular microscope. This system allows students to design and print custom patterns into photoresist in less than 30 min, without using a clean room, a mask facility, or a chrome-etch bath. Students can create and evaluate patterns, make changes to their design, or add additional layers of aligned patterns in a single laboratory session. The rapid turnaround time and low cost of ownership is useful for low-resolution $(∼10 μm)$ prototyping. Photoresist is spun in a modified food processor and baked on a standard hot plate. Mating pieces were machined from aluminum. Only the digital light processing projector and food processor are modified, so the microscope, camera, and computer need not be dedicated to the system. The entire system can be assembled for less than $5000.