Laser-induced modification of diamond

• Project/Area Number: 17K18820
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Research Field: Mechanics of materials, Production engineering, Design engineering, and related fields
• Research Institution: Chiba University
• Principal Investigator: Morita Noboru 千葉大学, 大学院工学研究院, 教授 (30239660)
• Co-Investigator(Kenkyū-buntansha): 松坂 壮太 千葉大学, 大学院工学研究院, 准教授 (30334171) ; 比田井 洋史 千葉大学, 大学院工学研究院, 教授 (60313334)
• Project Period (FY): 2017-06-30 – 2019-03-31
• Project Status: Completed (Fiscal Year 2018)
• Budget Amount: ¥6,240,000 (Direct Cost: ¥4,800,000、Indirect Cost: ¥1,440,000); Fiscal Year 2018: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000); Fiscal Year 2017: ¥4,940,000 (Direct Cost: ¥3,800,000、Indirect Cost: ¥1,140,000)
• Keywords: レーザ / ダイヤモンド / 精密部品加工

Outline of Final Research Achievements

Diamond is expected to be utilized as a semiconductor material because it has excellent dielectric strength and thermal conductivity. Slicing a bulk diamond into wafers with small kerf loss is required. Therefore, a high-yield slicing method by etching laser-induced modified layer inside diamond has been studied. The modified layer was formed by scanning laser focus. However, this method had a problem that only a part of the modified area was etched because it was discontinuous. In this study, modified lines were formed under various processing conditions. Modified lines were evaluated by electric conductivity. As a result, higher electric conductivity modified line was obtained under a higher scanning rate and lower energy and with a higher NA lens and longer pulse duration laser.

Academic Significance and Societal Importance of the Research Achievements

ダイヤモンドは硬く脆いため，切断が困難である．そこで，小さい切りしろで切断する方法について，検討した．ダイヤモンドにレーザ光を照射し，照射した部分をグラファイトに変質する．グラファイトはある薬品に溶解するため，レーザを照射した部分のみを溶解できる．レーザ照射条件と変質のメカニズム，変質部分の評価を行った．

Research Products

• [Presentation] ピコ秒パルスレーザによるダイヤモンドの内部変質の研究 (2019)
  • Author(s): 佐藤正隆，比田井洋史， 松坂壮太，千葉明，森田昇
  • Organizer: 2019年度精密工学会卒業研究発表会発表論文集
• [Presentation] Processing of diamond by laser-induced graphitization and selective chemical etching (2017)
  • Author(s): Haruna Hirai, Hirofumi Hidai, Souta Matsusaka, Akira Chiba, Noboru Morita
  • Organizer: the 3rd International Conference on Inventions (ICI 2017)
  • Int'l Joint Research