Fabrication of thin-film transistor of crystallized silicon film on cellulose nanopaper

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K06257
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Electronic materials/Electric materials
• Research Institution: Japan Advanced Institute of Science and Technology
• Principal Investigator: Horita Susumu 北陸先端科学技術大学院大学, 先端科学技術研究科, 教授 (60199552)
• Co-Investigator(Kenkyū-buntansha): 能木 雅也 大阪大学, 産業科学研究所, 教授 (80379031)
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: セルロースナノペーパ / 結晶化シリコン / 薄膜トランジスタ / 低温作製 / イットリア安定化ジルコニア

Outline of Final Research Achievements

For poly-YSZ film deposition on cellulose nanopaper(CNP) by sputtering, not only coated films of organic Zeocoat and silicon oxide but also thermal compound between the sample and holder were used in order to reduce plasma and thermal damage to the CNP during the deposition. As a result, 70-nm-thick poly-YSZ film can be deposited on the CNP without its thermal damage. Also, a silicon oxide film for gate insulator was deposited by using silicone oil and ozone gas in atmospheric CVD method at less than 200 oC. OH bonds which remain in the oxide film degrade its electrical insulation. In order to reduce them by annealing, NH3 with Lewis base property was used instead of normal N2 as atmosphere gas. Then, it was found that the NH3 gas was more effective for reduction more than twice at less than 200 oC, compared with N2 gas.

Free Research Field

半導体デバイス

Academic Significance and Societal Importance of the Research Achievements

スパッタ堆積において、堆積中のプラズマにより基板を含めた試料温度は、基板加熱無しでも200℃程度に昇温する場合が多く、プラズマによる基板熱損傷も無視できない。それに対して、緩衝層や放熱グリスを用いることで、基板温度を実質100℃前後に維持して基板損傷無しで、結晶化YSZ膜の成膜を可能にした。また、酸化Si膜中に残留するOH基の除去は、通常のN2ガス雰囲気中アニール処理ならば、400℃程度の温度が必要であるが、NH3ガスを用いれば、200℃以下でもできる可能性を示した。これらの成果は、現高温プロセスから200℃以下の低温プロセスへの置換えを可能にし、省エネ、省資源化に貢献できる。