Photolithography Process Optimization Starts With Ultrasonic Spraying

Photoresist, a high-cost core material in precision manufacturing, directly impacts total production costs and environmental benefits due to its utilization rate. In traditional spin coating processes, over 80% of the photoresist is wasted due to centrifugal force, resulting in a material utilization rate typically below 20%. Traditional two-fluid spraying also achieves a utilization rate of only 20%–40%, increasing production costs and generating more pollutants due to photoresist waste.

Ultrasonic atomization spraying technology, through the synergistic effect of low-pressure delivery and precise deposition, increases photoresist material utilization to over 90%, and even up to 95% in some scenarios. This saves 30%–50% of photoresist consumption compared to traditional spin coating, significantly reducing the cost of using high-cost specialty photoresists. Furthermore, the ultrasonic oscillation function of the equipment keeps the liquid channels unobstructed, reducing the probability of nozzle clogging and lowering downtime maintenance costs. Non-contact spraying avoids mechanical damage to fragile substrates such as wafers and optical substrates, improving product yield and further reducing overall production costs. Meanwhile, the improved material utilization reduces pollutant emissions from photoresist waste, eliminates excessive solvent evaporation pollution, and supports water-based solutions, aligning with the green and low-carbon development trend of the semiconductor and optical manufacturing industries.

As precision manufacturing moves towards miniaturization, high density, and three-dimensionality, the limitations of traditional coating technologies in handling complex structures, diverse substrate types, and various specifications are becoming increasingly apparent. Ultrasonic atomization spray photoresist, with its flexible process adjustment capabilities, achieves comprehensive adaptability to multiple scenarios and diverse needs.

In terms of substrate compatibility, its non-contact spraying method perfectly adapts to both rigid substrates (such as silicon wafers and glass lenses) and flexible substrates (such as flexible optical films), avoiding the risk of scratching fragile substrates caused by traditional contact coating and significantly reducing the breakage rate of fragile substrates such as thin silicon wafers. Regarding structural compatibility, tiny droplets can penetrate deep into high aspect ratio structures (such as deep trenches and TSV vias) with the help of a carrier gas. Combined with stage heating and curing technology, it significantly improves step coverage. In TSV structures with an aspect ratio of 10:1, the photoresist coverage at the bottom of the via can exceed 92%, effectively solving the problems of uneven coating and missing bottoms on three-dimensional structures caused by traditional spin coating. This provides reliable assurance for the manufacturing of complex structures such as 3D IC stacks, MEMS chambers, and optical waveguide devices.

In terms of material and specification compatibility, the equipment is compatible with various photoresists ranging from low viscosity (5-20 cps) to high viscosity (50-100 cps), including positive photoresists, negative photoresists, and high-performance photoresists such as polyimide-based photoresists. It adapts to all specifications from 2-inch laboratory samples to 12-inch mass production wafers, and can customize spraying paths and parameters according to different application scenarios (such as diffraction grating fabrication and anti-reflective coating preparation) to achieve differentiated process configurations.

Ultrasonic atomization spray photoresist, with its superior coating precision, ultra-high material utilization, wide application adaptability, and stable mass production capabilities, has completely broken through the limitations of traditional coating technologies. It not only reduces the production costs of precision manufacturing and enhances product competitiveness but also drives technological innovation in fields such as semiconductors, micro-nano optics, and MEMS. Against the backdrop of global semiconductor capacity expansion and accelerated domestic substitution, this technology will continue to play a core supporting role, providing a new path for the refined, green, and large-scale development of high-end precision manufacturing, and helping related industries achieve high-quality upgrading.