Research on lithography using projection exposure of stereophonic surface

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K05293
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 28050:Nano/micro-systems-related
• Research Institution: Tokyo Denki University
• Principal Investigator: Horiuchi Toshiyuki 東京電機大学, 工学部, 研究員 (00297582)
• Co-Investigator(Kenkyū-buntansha): 小林 宏史 東京電機大学, 工学部, 教授 (80838855)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: 立体面投影露光 / 回転放物面ミラー / 曲面リソグラフィ / 大パターン / ヘルスモニタ

Outline of Final Research Achievements

A novel stereophonic lithography method for replicating 50-500 micron rough patterns on a gently curved reticle to curved articles with the same curvature was proposed. The stereophonic lithography was actually demonstrated using a handmade exposure system. In the system, a pair of parabolic mirrors were faced in the vertical direction, and apertures were opened at the both mirror centers. A curved reticle made with a transparent plastic spoon by pasting a seal with illustrations delineated by black emulsion was placed in the lower mirror aperture, and illuminated obliquely upward from one-side by a collimated LED light source. Owing to these ideas, very clear pattern images were projected on the surface of article coated with a resist film and paced just above the upper mirror. As a result, it was successfully demonstrated that projection lithography from a curved reticle to a curved article in a lump was practicable.

Free Research Field

光リソグラフィ

Academic Significance and Societal Importance of the Research Achievements

リソグラフィは通常、平面状のレチクルやマスクを原図として、半導体ウエハなどの平坦な被露光物上に微細パターンを形成する技術として用いられている。主に高開口数の投影露光や密着露光が使われており、原図基板および被露光物表面の平面度が良いことが必要とされ、少しでも凹凸があったり、傾いたり、曲がったりしているとパターンを形成できない。そのため、曲面レチクルのパターンを曲面に投影露光するという発想はこれまで全く無かった。本研究は、その新しい発想を実現するための方法を提案し、実際に可能であることを実証した。リソグラフィに新たな展開先、応用先を切り開いたという学術的意義、社会的意義は非常に大きい。