Measurement of ion energy distribution incident on substrate by retarding field energy analyzer

2022 Fiscal Year Final Research Report

• Project/Area Number: 19K03810
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 14030:Applied plasma science-related
• Research Institution: Nagasaki University
• Principal Investigator: Matsuda Yoshinobu 長崎大学, 工学研究科, 准教授 (60199817)
• Project Period (FY): 2019-04-01 – 2023-03-31
• Keywords: 負イオン / イオンエネルギー分布 / 反射電界型エネルギー分析器 / 磁気フィルタ / マグネトロン / スパッタリング / 透明導電膜 / 金属添加酸化亜鉛

Outline of Final Research Achievements

The energy distribution function of the substrate incident negative ions during the magnetron sputtering process of a metal-doped zinc oxide target was measured using a home-made retarding field energy analyzer (RFEA) with a magnetic field region.In the crossed magnetic field region ahead of the RFEA incident aperture, the bulk electron inflow into the RFEA is dramatically suppressed, while the inflow of negative ions emitted from the oxide target surface is hardly affected. Negative ions are emitted mainly from the target erosion region and are observed to enter the oncoming substrate with ion energy equivalent to the target applied voltage. Since no negative ion signal is observed at all in the magnetron sputtering of the copper target, the emission of oxygen negative ions was definitely observed.
Compared to energy-resolved mass spectrometers, magnetized RFEA is inexpensive, compact, and easy to sweep in space, although it does not provide mass separation.

Free Research Field

プラズマ理工学

Academic Significance and Societal Importance of the Research Achievements

磁化反射電界型エネルギー分析器（Retarding field energy analyzer: RFEA）を用いて、酸化物ターゲットのマグネトロンスパッタリング過程で酸素負イオンがターゲット表面から放出され高エネルギーで基板に入射することを明らかにした。差動排気を必要とし、大型で携帯性に劣るエネルギー分解型質量分析器に比べ、RFEAは安価でコンパクトで空間掃引が容易である。磁化RFEAは、成膜やエッチングなどの様々なプロセス環境下での正・負イオンの測定に展開可能である。半導体プロセスを含む各種真空・表面処理プロセスの診断・制御に、磁化RFEAを有効活用することで、社会に貢献できる。