Simulation for Submicron 3D-Structures based on Plane-pattern to the Cross-section Transfer (PCT) Technique

Abstract

In this paper, we investigate an influence of Fresnel diffraction to the Plane-pattern to Cross-section Transfer (PCT) technique. An analysis was performed by considering the X-ray intensity distribution. The mask pattern employed in this work was a set of right triangles placed in double rows facing each other. The design is based on the fact that when mask slit becomes narrow as it approaches the corner, the influence of the diffraction gradually becomes more significant. In X-ray lithography in optical applications, it has been realized that the Fresnel diffraction is an important factor for designing the shape of slits in submicron. The triangle mask pattern has a pitch of 1.48 μm and a height of 20 μm with Ta absorber thickness of 0.5 μm. Using PCT technique, the analysis was summarized by comparing Fresnel diffraction simulations and the data from experimental results. This work has proved that a submicron structure fabrication by PCT is possible with proximity gap of at least 200 μm.