Surface plasmon interference lithography using Al grating structure on glass

Abstract

Photolithography is used in the important technologies of the device fabrication process in the semiconductor industry. However, photolithography has a pattern resolution limit because of the diffraction of light. Using surface plasmon (SP) is one of the ways to overcome this limit, which is a recently proposed nanolithography technology. Using SP, we developed a fabrication process using an Al grating structure on glass (glass/Al grating/PR structure). A perfect contact between the photoresist and the Al grating increased the effects of the SP because the contact gap was reduced in the photolithography process. The pattern pitch of lithography result was 120 nm (simulation results) and 115 nm (fabrication results). In surface plasmon interference lithography (SPIL) it is possible to use SP in the photolithography area. And we analyzed irregular pattern trends in the shape of random horizontal patterns and found that the patterns result from Al line edge roughness. Therefore, techniques that reduce the Al line edge roughness could enable clearer Al line patterns in SPIL.