Shinobu Sugimura

Large Area Fabrication of Moth-Eye Antireflection Structures Using Self-Assembled Nanoparticles in Combination with Nanoimprinting

A moth-eye structure, which suppresses the reflection on a surface, was fabricated on the entire surface of a large silicon wafer by the formation of a self-assembled particle monolayer as a dry-etch mask formed by our embedded particle monolayer (EPM) method. We optimized the shape of moth-eye structures by optical calculation and improved the fabrication procedure to allow formation over a large area. As a result, we succeeded in fabricating a moth-eye structure on the entire surface of a 12-in. silicon wafer and the surface reflectance was reduced to less than 0.8% in the visible light range. A large nickel mold, which is able to transfer the pattern to an 8-in. display, could be formed using the 12-in. silicon substrate as a master. A moth-eye film was fabricated by UV nanoimprinting using the nickel mold and the high antireflection performance was confirmed. The fabrication cost of the moth-eye structure over a large area would be markedly reduced by the use of the self-assembly technique in combination with nanoimprinting.

Wide-range directed self-assembly lithography enabling wider range of applicable pattern size for both hexagonal multi-hole and line/space

One of technical issues of directed self-assembly lithography is extremely narrow patterning range. It is really difficult to make not only smaller patterns (pitch of less than 30nm) because of self-assembling limit but also middle patterns (pitch of more than 60nm) because of material synthesis issues. This paper describes wide–range directed self-assembly lithography which enables not only narrow patterns but also wide patterns using newly developed block copolymer. One block of the new block copolymer is easily metalized selectively by metalize technology and it is confirmed that dry etching resistance is markedly improved.

Sub-15nm patterning technology using directed self-assembly on nano-imprinting guide

In next generation lithography to make sub-15nm pattern, Directed self-assembly (DSA) and Nano-imprint lithography (NIL) are proposed. The current DSA process is complicated and it is difficult to decrease width and line edge roughness of a guide pattern for sub-15nm patterning. In the case of NIL, it is difficult to make the master template having sub- 15nm pattern. This paper describes cost-effective lithography process for making sub-15nm pattern using DSA on a guide pattern replicated by Nano-imprinting (NIL + DSA). Simple process for making sub-15nm pattern is proposed. The quartz templates are made and line/space patterns of half pitch (hp) 12nm and hp9.5nm are obtained by NIL + DSA.