An interview with Yohei Yamazawa (山澤 陽平) of TEL Miyagi, who works on the front lines of semiconductor micromachining using plasma, explaining the three core processes of etching, deposition and cleaning. It covers the discovery of reactive ion etching by Japanese researchers and TEL's approach to R&D. The interview also conveys the realities of next-generation equipment development and the training of young engineers.
Plasma, known as the “fourth state of matter” after solids, liquids and gases, is used in three semiconductor manufacturing processes: etching, which removes material from the wafer surface; deposition, which builds up thin films; and cleaning, which removes contamination after processing. Dry etching in particular can remove films precisely and vertically. Tokyo Electron Miyagi develops and manufactures this etching equipment. Plasma can also increase etching speeds by more than tenfold and is described as an essential technology for further miniaturization and higher performance.
Reactive ion etching, which combines the advantages of both ion bombardment and radicals, is cited as an advancement in plasma etching technology. It was discovered in 1973 by Naokichi Hosokawa (細川 直吉) and Reisaku Matsuzaki (松崎 励作) of NEC Varian, and is recognized as a contribution by Japanese researchers. This phenomenon made it possible to selectively remove only the film, contributing to cost-effective micromachining.
Yohei Yamazawa (山澤 陽平) joined the company in 1999 and leads RF plasma equipment R&D as a chief engineer in Miyagi. Since earning his PhD in 2001, he has worked on the research and development of measurement, control and plasma sources, and emphasizes a workplace culture that provides young engineers with research opportunities. He has achieved results including elucidating the principles of harmonics, and has also discussed his experience filing multiple patent applications after joining the company.
He currently serves as a chief engineer in the next-generation equipment development division, exploring opportunities to implement new technologies in society while considering the time remaining until retirement. TEL's R&D investment is high at 10% of sales, and he emphasizes the importance of development investment.
The interview was published in the form of a TEL web blog and portrays the appeal of plasma research, the speed of putting research into practical use and the organizational culture supporting research.