マイクロ熱プラズマジェット照射による四族半導体単結晶ナノ薄膜成長

• Project/Area Number: 22360126
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Electronic materials/Electric materials
• Research Institution: Hiroshima University
• Principal Investigator: 東 清一郎 Hiroshima University, 先端物質科学研究科, 教授 (30363047)
• Project Period (FY): 2010 – 2012
• Project Status: Completed (Fiscal Year 2011)
• Budget Amount: ¥13,390,000 (Direct Cost: ¥10,300,000、Indirect Cost: ¥3,090,000); Fiscal Year 2011: ¥7,280,000 (Direct Cost: ¥5,600,000、Indirect Cost: ¥1,680,000); Fiscal Year 2010: ¥6,110,000 (Direct Cost: ¥4,700,000、Indirect Cost: ¥1,410,000)
• Keywords: 大気圧プラズマジェット / 結晶化 / 薄膜トランジスタ / 固相結晶化 / 溶融ゾーン

Research Abstract

本年度は高速で高結晶性シリコン膜を作製するアプローチとして、高パワー密度化したマイクロ熱プラズマジェット(μ-TPJ)照射によるシリコン膜の相変化過程について調べ、アモルファスシリコン(a-Si)膜上に形成した溶融領域を高速走査することによる大粒径シリコン結晶成長の実現に注力した。
ノズル径(φ)を従来の4mmから0.8mmへ縮小し、更に陽極-陰極間距離(アークギャップ)を従来の1.0mmから2.0mmへ拡大した。この結果、従来～8kW/cm^2であったピークパワー密度を最大53kW/cm^2まで高めることができた。高パワー密度化したμ-TPJを用いて石英基板上に堆積したa-Si膜の結晶化を試みた。その場観測技術から、μ-TPJ照射によってa-Siはまず固相結晶化(SPC)し、その後、溶融・再結晶化の過程で横方向への長距離結晶成長が誘起される事が明らかになった。μ-TPJ照射によりa-Si膜中に発生した溶融ゾーンを高速操作(～4000mm/s)する事で横方向温度勾配を生成し、長さ～60μmに達する結晶成長が可能となった。高速横成長結晶化(HSLC)技術で得られた(111)優先配向大粒径結晶をチャネルに用いてTFTを作製した。SPCおよびHSLC条件において、それぞれ電界効果移動度μFE～10及び350cm^2V^<-1>s^<-1>の値が得られた。結晶粒径が20nm程度のSPCに対して、大幅な粒径増加を達成できるHSLCでは、4000mm/sという高い走査速度でも極めて高い移動度が得られ、本研究提案の結晶化手法が大面積に適用可能な結晶成長技術として高い可能性を有する事が実証された。

Research Products

• [Journal Article] Application of Thermal Plasma Jet Irradiation to Crystallization and Gate Insulator Improvement for High-Performance Thin-Film Transistor Fabrication (2011)
  • Author(s): S.Higashi, S.Hayashi, Y.Hiroshige, Y.Nishida, H.Murakami, S.Miyazaki
  • Journal Title: Jpn.J.Appl.Phys. Volume: 50
  • NAID: 210000070175
  • Peer Reviewed
• [Journal Article] Formation of High Quality SiO_2 and SiO_2/Si Interface using Thermal Plasma Jet Induced Millisecond Annealing and Post-Metallization Annealing (2010)
  • Author(s): Y.Hiroshige, S.Higashi, K.Matsumoto, S.Miyazaki
  • Journal Title: Jpn.J.Appl.Phys. Volume: 48
  • NAID: 110008001103
  • Peer Reviewed
• [Journal Article] Formation of High Crystallinity Silicon Films by High Speed Scanning of Melting Region Formed by Atmospheric Pressure DC Arc Discharge Micro-Thermal-Plasma-Jet and Its Application to Thin Film Transistor Fabrication (2010)
  • Author(s): S.Hayashi, S.Higashi, H.Murakami, S.Miyazaki
  • Journal Title: Appl.Phys.Express Volume: 3 Pages: 61401-61401
  • NAID: 10027015042
  • Peer Reviewed
• [Journal Article] Activation of B and As in Ultrashallow Junction During Millisecond Annealing Induced by Thermal Plasma Jet Irradiation (2010)
  • Author(s): K.Matsumoto, S.Higashi, H.Murakami, S.Miyazaki
  • Journal Title: Jpn.J.Appl.Phys. Volume: 49
  • NAID: 210000068160
  • Peer Reviewed
• [Journal Article] Characterization of Microcrystalline Silicon Thin Film Transistors Fabricated by Thermal Plasma Jet Crystallization Technique (2010)
  • Author(s): S.Higashi, K.Sugakawa, H.Kaku, T.Okada, S.Miyazaki
  • Journal Title: Jpn.J.Appl.Phys. Volume: 49
  • NAID: 210000068062
  • Peer Reviewed
• [Presentation] Improvement in Electrical Stress Endurance of Low-Temperature Deposited SiO_2 Films by Atmospheric Pressure Thermal Plasma Jet Annealing (2011)
  • Author(s): Y.Nishida, S.Hayashi, K.Matsumoto, S.Higashi
  • Organizer: 4^<th> Int.Conf. Plasma Nanotechnology and Science (IC-PLANTS 2011)
  • Place of Presentation: Takayama, Japan
• [Presentation] Fabrication of High performance TFTs Using Micro-Thermal-Plasma-Jet Crystallized Strip Amorphous Silicon Films (2011)
  • Author(s): S.Hayashi, M.Ikeda, Y.Nishida, R.Matsubara, S.Higashi
  • Organizer: 7^<th> Int.Thin-Film Transistor Conference (ITC 2011)
  • Place of Presentation: Cambridge, UK
• [Presentation] Characteristics of Thin Film Transistors Fabricated by Solid Phase Crystallization and High Speed Lateral Crystallization Induced by Micro-Thermal-Plasma-Jet Irradiation (2010)
  • Author(s): S.Hayashi, S.Higashi, H.Murakami, S.Miyazaki
  • Organizer: 17^<th> Int.Display Workshop (IDW'10)
  • Place of Presentation: Fukuoka, Japan
• [Presentation] Efficient Activation of As Atoms in Ultra Shallow Junction by Thermal Plasma Jet Induced Microsecond Annealing (2010)
  • Author(s): K.Matsumoto, S.Higashi, A.Ohta, H.Murakami, S.Miyazaki
  • Organizer: Int.Symp.Dry Process (DPS 2010)
  • Place of Presentation: Tokyo, Japan
• [Presentation] High Speed Lateral Crystallization of Amorphous Silicon Films Using Micro-Thermal-Plasma-Jet and Its Application to Thin Film Transistor (2010)
  • Author(s): S.Hayashi, S.Higashi, H.Murakami, S.Miyazaki
  • Organizer: 2010 Int.Conf Solid Sate Dev.Mat.(SSDM)
  • Place of Presentation: Tokyo, Japan
• [Presentation] Millisecond Annealing Induced by Atmospheric Pressure Thermal Plasma Jet Irradiation and Its Application to Ultra Shallow Junction Formation [Invited] (2010)
  • Author(s): S.Higashi
  • Organizer: 2010 Int.Workshop Junction Tech. (IWJT-2010)
  • Place of Presentation: Shanghai, China(招待講演)
• [Presentation] Growth of Large Crystalline Grains by High Speed Scanning of Melting Zone Formed by Micro-Thermal-Plasma-Jet Irradiation to Amorphous Silicon Films (2010)
  • Author(s): S.Hayashi, S.Higashi, S.Miyazaki
  • Organizer: 2010 Material Research Society Spring Meeting
  • Place of Presentation: San Francisco, U.S.A.