Plasmonic nanolithograph

As of now, the next-generation nano-manufacturing which can fulfill the cost, resolution, and throughput requirements for the fabrication of a wide range of nano-scale devices is still uncertain. Photolithography which served as the key manufacturing method in the past decades has the resolution limit, known as the diffraction limit. To reduce the features size, the employment of shorter wavelength light source has come to the turning point where the cost of the system and the cycle time for mask fabrication are critical. Plasmonics optics opens up potential to manipulate light at the length scale beyond the diffraction limit owing to the dispersive behavior of surface plasmons. Here I will report the potential of utilizing surface plasmons (SPs) in nano-scaled lithography applications. Numerous schemes such as parallel plasmonic lithography, plasmonic contact lithography, and maskless lithography utilizing flying head platform have been investigated. Parallel plasmonic lithography and plasmonic contact lithography were proposed to achieve high-resolution and density lithography. The former method utilizes propagating mode of SPs to enhance the transmission and contrast for near-field/contact lithography. The latter method utilizes localized SPs to increase the resolution and potentially to be applied for the fabrication of arbitrary patterns. High-throughput maskless lithography was also proposed to serve the emerging need of the next-generation manufacturing for a wide range of nano-scale device fabrication where the frequent design change is required. This unique method utilizes a plasmonic focusing lens to focus surface plasmons as the light source of the system. The focused spot size is well below 100 nm with a high optical enhancement ∼2 orders of magnitude. To achieve high-scanning speed while keeping a near-field distance between the lens and the recording medium, the scanning mechanism of the air bearing slider used in a hard disk drive was employed. In the lithography experiment, the patterning of a variety of structures including sub-100 nm line and arbitrary patterns at the writing speed of ∼8m/s was demonstrated, promising a high-resolution and throughput maskless lithography. The proposed lithography methods offer exciting avenues towards next-generation nano-manufacturing.