Study on vibration-assisted thermal nanoimprint lithography

In thermal nanoimprint lithography, polymethyl methacrylate (PMMA) with good thermoplasticity is often used as transferring media. However, due to the special properties of PMMA, the accuracy of microstructure transferred to the surface will be seriously affected. To address this problem, the micro-vibration by piezo-driven is introduced in conventional thermal nanoimprint lithography. Because of the micro-vibration will change the contact stress during the embossing process and reduce the contact time. This will improve the filling rate of PMMA during the embossing process and transfer the pattern of stamp to PMMA with excellent feature fidelity. Compared with the traditional nanoimprint lithography, the filling rate of PMMA is increased by 92% after the introduction of vibration by piezo-driven. Then, a new motion model is built to verify the rationality of introducing vibration. Besides, the effect of frequency and amplitude with filling rate is analyzed by finite element method to obtain the best frequency and amplitude for experiments. Finally, the transferred pattern is observed by experiment.