40 years with studies on radiofrequency plasma and related theory

After introducing my relationship with the GEC, I will discuss the latest understanding of the mechanism and function in a low-temperature rf-plasma through expedients developed under us. These are DNP of the Boltzmann equation, RCT model, VicAddress, and spatiotemporal emission CT, etc.

For the purpose of the fundamental understanding of an rf-plasma, the electron transport with a finite phase delay with respect to the external field E(t) at fixed reduced frequency w/N has been studied from LF to UHF range by DNP of the B. Eq. RCT model, considering the relaxation times for momentum and energy of electrons, was proposed in the late 1980s and predicted, for example, that there exist an active and passive double layer in front of the electrode in an electronegative HF-CCP.

We here focus on some of interesting functions attributed to side-characters, negative ions and excited neutrals in a reactive CCP and ICP. General sustaining mechanism in CCPs with strong electronegativity is described as the minority electron swarm migrates and oscillates under collisions with gas molecules, including positive and negative ion productions, between both of electrodes covered with structural sheaths consisting of majority positive and negative ions. g(v,t) of electrons shows a temporally non-linear modulation in the bulk plasma. Injection of electrons to the instantaneous anode in a pulsed two-frequency CCP in electronegative gases and reduction of the bottom charging voltage on a high-aspect ratio SiO2 etching are simultaneously achieved by a time and space resolved optical emission CT and on the test chip. It is the active application of the double layer. The other is the spatiotemporally visualized ignition and extinction processes of an rf-ICP. The influence of long-lived neutrals with internal energy is experimentally revealed on the E-H-E transition.