Maskless Lithography Using Drop-On-Demand InkJet Printing Method

摘要

Writing process patterns directly on a substrate with small liquid droplets generated by Drop-On-Demand (DOD) inkjet devices offers a low cost, non-contact, low temperature, flexible, and data driven patterning approach. Existing inkjet printheads have a limited number of inkjet devices, which generate droplets on the scale of tens of microns. In our research, we have developed a monolithic inkjet printhead for maskless lithography based on silicon micro-machining technology. This printhead is composed of a large array of thermal bubble inkjet devices fabricated on a single silicon wafer. A high-resolution video imaging system has recorded stable generation of water droplets down to 3.5 μm. Au patterns as small as 8 μm have been formed on silicon substrates by printing with suspensions of Au nano-particles. Smaller droplet dimensions extending to the nano-scale is supported by theoretical analysis. This printhead technology can form the basis of a maskless lithography system with moderate throughput for building micro and nano-scale electronic circuits and MEMS devices.