We demonstrated one-colour control of activation, excitation and deactivation of a fluorescent diarylethene derivative by using a 532 nm CW laser at a weak output power. This one-colour control method was applied to single-molecule tracking in polymer films over a total duration of a few hours at room temperature and PALM for the nanostructures of polymer systems.

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Fluorinated silicon-based resist materials have recently been applied as ultraviolet crosslinkable materials for nano imprint lithography. I report and demonstrate the step and flash nano imprint lithography process using the newly fluorinated silicon-based resist materials for next generation technologies. This paper presents progress in the formulation of advanced resist materials design, the development of suitable ultraviolet imprint conditions and etch processes to achieve thin residual resist layers, low volumetric shrinkage of the resist film, and low imprint pressures for defect reduction. High quality imprint images were produced with multiple pattern-structured templates on wafers using these developed fluorinated silicon-based resist materials.

A gas‐permeable cellulose template for microimprint lithography has been synthesized and characterized for the reduction of template damage and gas trapping caused by solvents and oxygen generated from cross‐linked materials. The 5 μm line‐pattern failure of the microimprinted UV cross‐linked liquid materials with 4.7 wt% acetone as a volatile solvent is solved by using the gas‐permeable cellulose template because of its increased oxygen permeability. The gas‐permeable cellulose template also allows the use of volatile solvents with high coating property and solubility into the microimprinted materials instead of the compounds and plastic resins conventionally used in mold injection.

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We investigated the eco-friendly electron beam (EB) lithography using a high-sensitive negative type of water-developable resist material derived from biomass on hardmask layer for tri-layer processes. A water developable, non-chemically amplified, high sensitive, and negative tone resist material in EB lithography was developed for environmental affair, safety, easiness of handling, and health of the working people, instead of the common developable process of trimethylphenylammonium hydroxide. The images of 200 nm line and 800 nm space pattern with exposure dose of 7.0 μC/cm2 and CF4 etching selectivity of 2.2 with hardmask layer were provided by specific process conditions.

An approach to ultraviolet (UV) nanoimprint lithography using a cyclodextrin-based porous template was investigated for the reduction of air trapping and template damage caused by gases such as nitrogen and oxygen generated from UV cross-linked materials. The accuracy of the printed pattern using UV nanoimprint lithography with the porous transparent template was improved because of enhanced material adsorption and increased permeability to gaseous species. The use of volatile solvents in the UV cross-linked materials for nanoimprint lithography has been limited because of high pattern failure rates. However, using the cyclodextrin-based porous template, the UV cross-linked materials with a 5 wt. % volatile solvent exhibited well-defined nanoscale patterns. Based on this study, acceptable chemistries for the UV cross-linked materials have been expanded, which will be beneficial for future device applications using UV nanoimprint lithography.

The via-first dual damascene process is the current manufacturing technology for copper/low-k interconnect fabrication. In the conventional via-first dual damascene process, metal trench patterning lithography is applied after filling the vias with sacrificial organic materials under the resist, such as gap fill materials and bottom antireflective coating. Resist poisoning has become a serious problem for the 65 nm technology node and beyond owing to the use of porous low-k dielectric materials. This study describes the newest method of evaluating resist poisoning. The dependence of film thickness on resist poisoning was observed, and the effects of the gap fill materials with different polymers were also clarified. One gap fill material was found to have an excellent resist poisoning blocking property as determined from the bias of trench patterning size between the center and edge areas. In addition, to evaluate the resist poisoning in lithography, a chemical approach using the developed gap fill materials can potentially allow the skipping of the additional thermal annealing process and achieve high throughput wafer processing by only coating the gap fill material on the substrates that generate resist poisoning. Continuing the via-first dual damascene process using porous low-k dielectric materials in an advanced lithography will be valuable in future studies based on this evaluation method, compared with the trench-first dual damascene process owing to the higher cost of the latter.