Comparison study of plasma properties generated by DC excitation and dual-source excitation with DC superimposed nanosecond pulse

Abstract Low-temperature plasma is widely used in thin-film deposition, circuit etching, material surface modification, and other applications in which plasma parameters can significantly affect the outcomes. Compared to single-source excitation, dual-source excitation can enhance the efficiency of energy utilization and expand the range of parameter variations. A low-pressure tube filled with a mixture of 95% Ar and 5% N 2 was developed to study the plasma properties under DC excitation and dual-source excitation with DC superimposed nanosecond pulse. The effects of different pulse amplitudes and pulse widths on the plasma properties were explored. The experimental results show that the superposition of pulses can enhance the electron density in the afterglow phase, and the enhancement of electron density in the afterglow phase is more sensitive to the pulse amplitude. The electron density can be maintained at a high level after the pulse ends, with a maximum value reaching 10 17 m −3 . In addition, the electron density in plasma under dual-source excitation can be two orders of magnitude higher than under single DC excitation, while the gas temperature decreases by approximately 40 K, thereby increasing the range of plasma parameters variations.