Pattern Distortion Analysis of Surface Plasmon Interference Lithography Using Line Grating Structure on Photoresist

Abstract

Photolithography has a resolution limit of the incident wavelength that is generated by the diffraction of light. Surface plasmon (SP) is a recently proposed nanolithography technology that overcomes this diffraction limit. In this paper, we focus on the fabrication process in order to utilize SP with a direct grating structure, and we compare the simulation and fabrication results: the pitch of the expected patterns is 120 nm in the simulation results and 121.5 nm in the calculation results. Therefore, the fabrication results establish that the period of the patterns is 115 nm. These results demonstrate that it is possible for photolithography to use SP. Furthermore, the random horizontal patterns in the fabrication results are analyzed, and it is found that the patterns result from the mask side distortion. Therefore, reducing the mask side distortion using other techniques could enable clearer line patterns in surface plasmon interference lithography.