Sensor device using Si nanopillars by liquid Si nanoimprint

2020 Fiscal Year Final Research Report

• Project/Area Number: 17H04923
• Research Category: Grant-in-Aid for Young Scientists (A)
• Allocation Type: Single-year Grants
• Research Field: Electron device/Electronic equipment
• Research Institution: Japan Advanced Institute of Science and Technology
• Principal Investigator: Masuda Takashi 北陸先端科学技術大学院大学, 先端科学技術研究科, 講師 (70643138)
• Project Period (FY): 2017-04-01 – 2021-03-31
• Keywords: 液体シリコン / ナノインプリント / 半導体

Outline of Final Research Achievements

Si nanopillar arrays were obtained by liquid-Si nanoimprint. The nanopillars with gold electrodes deposited on the top had light absorption in the near-infrared region due to localized surface plasmon resonance. The absorbed photons were taken out as photocurrent. This light sensor required high accuracy in the dimensions of the pillars. High temperature annealing (400 C) is generally required for liquid-to-solid Si conversion. This annealing causes thermal expansion, which reduces the accuracy of the pillar dimensions and position. We investigated the liquid-to-solid Si conversion mechanism, and clarified that the conversion can be induced by electron beam irradiation instead of annealing. This result provided a technology for manufacturing well-defined nanostructures of semiconducting Si without heating/vacuuming. We enhanced the design accuracy of the nanopillar and realized to the improvement of the device quality.

Free Research Field

材料科学

Academic Significance and Societal Importance of the Research Achievements

液体Siという独自材料を舞台に、そのインプリントによって半導体Siのナノパターンを作製する初めての取り組みであった。材料・プロセス・デバイスの異なる視点から材料の課題に向き合い、最終的には非加熱・非真空でのSiナノパターンの直接製造という新たな微細加工技術の芽を生み出した。その学術的意義は、100 年続いた「固体Si工学」「気体Si工学」に続く第3のSi工学として、既存のSi素子の限界を突破するための新たな学術基盤として、「液体Si工学」を築くことにあった。その社会的意義は、非加熱・非真空のSiナノパターニング技術を確立し、ポストムーア時代に希求される精密工学の可能性を示した点にある。