Takahashi Ryosuke, Kito Seiya, Eriguchi Koji, Urabe Keiichiro
Department of Aeronautics and Astronautics, Kyoto University, Kyoto 615-8540, Japan.
Rev Sci Instrum. 2024 May 1;95(5). doi: 10.1063/5.0200138.
Controlling the ion velocity in an ion sheath by applying an alternating current (AC) voltage to an electrode and/or a substrate is critical in plasma material processes. To externally control the velocity distribution of incident ions on a substrate, the application of tailored-waveform AC voltages instead of sinusoidal voltages has garnered interest in recent years. In this study, to investigate temporal changes in ion-velocity distributions, we developed a time-resolved laser-induced fluorescence spectroscopy (LIF) system using a continuous-wave diode laser as an excitation-laser source. A time-resolved LIF system entails the capture of temporally continuous and spectrally discrete LIF spectra during an AC voltage cycle. By measuring temporal changes in the LIF signal intensity at various excitation-laser wavelengths, the argon-ion velocity distribution near the electrode following the AC voltage can be characterized. The results of applying sinusoidal, triangular, and rectangular bias waveforms indicate that the LIF measurement scheme proposed herein can be used to investigate the dynamic behavior of ion-velocity distributions controlled by tailored-waveform AC voltages.
在等离子体材料加工过程中，通过向电极和/或衬底施加交流（AC）电压来控制离子鞘层中的离子速度至关重要。为了从外部控制入射到衬底上的离子的速度分布，近年来，应用定制波形的交流电压而非正弦电压引起了人们的关注。在本研究中，为了研究离子速度分布的时间变化，我们开发了一种时间分辨激光诱导荧光光谱（LIF）系统，该系统使用连续波二极管激光器作为激发激光源。时间分辨LIF系统需要在交流电压周期内捕获时间上连续且光谱上离散的LIF光谱。通过测量在各种激发激光波长下LIF信号强度的时间变化，可以表征交流电压作用后电极附近的氩离子速度分布。施加正弦、三角和矩形偏置波形的结果表明，本文提出的LIF测量方案可用于研究由定制波形交流电压控制的离子速度分布的动态行为。
