Processing of wide-bandgap material with intense EUV light

2019 Fiscal Year Final Research Report

• Project/Area Number: 17K05727
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Plasma science
• Research Institution: Osaka University
• Principal Investigator: Tanaka Nozomi 大阪大学, レーザー科学研究所, 特任助教(常勤) (60581296)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: 極端紫外(EUV)光 / ワイドバンドギャップ材料 / 物質アブレーション / 薄膜

Outline of Final Research Achievements

We have shown possibilities of thin film synthesis by irradiation of intense pulsed extreme ultraviolet(EUV) radiation. We have mitigated debris accumulating on the target material by improving the EUV optical layouts. High EUV radiation energy of 5-8 mJ at the target was confirmed. Si, SiC, and AlN thin films were successfully deposited on Al2O3 substrates. The ablation spot on the target materials and synthesized thin films were compared with laser ablation deposition at a same irradiation condition. Our results showed EUV thin film synthesis had less heat effect on the target ablation and deposited particles for all materials. This can be considered as an advantageous characteristics for future application in industry. The x-ray reflectometry analysis showed deposition of 50-60 nm of layers for all materials, which are thick enough as films. Further, we showed that low intensity EUV irradiation on the SiC film sinters the particles to form SiC220 and SiC311 crystal structures.

Free Research Field

極端紫外光応用

Academic Significance and Societal Importance of the Research Achievements

近年パワーデバイスなどにワイドバンドギャップ(WBG)材料や、誘電体の薄膜の利用が着目されている。一方波長10-20 nmの極端紫外(EUV)光は光子エネルギーの高さと材料への吸収率の高さから、このような新規材料の加工へ応用が期待される光である。本研究では高強度パルスEUV光を用いた固体材料のアブレーションによる成膜に取り組んだ。EUV光により成膜したSi, SiC, AlNの薄膜は、従来光と比較してターゲット材や薄膜粒子への熱影響が抑えられることを示した。更にEUV焼結による膜の結晶化にも成功し、EUV光の成膜技術応用への可能性を示した。