Physics

Plasma processing

Torr

Atomic physics

Materials science

Computer science

Quantum mechanics

Plasma

Optoelectronics

Radio frequency

Telecommunications

Inductively coupled plasma

Thermodynamics

Chinese Physics B

Two classic radio-frequency (RF) plasmas, i.e., the capacitively and the inductively coupled plasmas (CCP and ICP), are widely employed in material processing, e.g., etching and thin film deposition, etc. Since RF plasmas are usually operated in particular circumstances, e.g., low pressures (mTorr–Torr), high-frequency electric field (13.56 MHz–200 MHz), reactive feedstock gases, diverse reactor configurations, etc., a variety of physical phenomena, e.g., electron resonance heating, discharge mode transitions, striated structures, standing wave effects, etc., arise. These physical effects could significantly influence plasma-based material processing. Therefore, understanding the fundamental processes of RF plasma is not only of fundamental interest, but also of practical significance for the improvement of the performance of the plasma sources. In this article, we review the major progresses that have been achieved in the fundamental study on the RF plasmas, and the topics include 1) electron heating mechanism, 2) plasma operation mode, 3) pulse modulated plasma, and 4) electromagnetic effects. These topics cover the typical issues in RF plasma field, ranging from fundamental to application.

Fundamental study towards a better understanding of low pressure radio-frequency plasmas for industrial applications