E-H transition in a pulsed inductively coupled argon plasma

Abstract

The plasma dynamics in a planar coil pulsed inductively coupled plasma system (ICPs) operated in argon is investigated using phase and space resolved optical emission spectroscopy. The measurements show the discharge initiation and E-H transition as the function of time. The results show that there is no delay in the discharge initiation and it starts due to capacitive coupling or in the E-mode. It transits to the H-mode later while the emission has a spike-like feature at the E-H transition i.e. it first achieves high emission which later decreases and finally rises again. The 2D images of the discharge reveal that at the time of high emission, the discharge structure is compact and bright, which later decreases in brightness and becomes diffusive. The results show that the spike like feature decreases with pressure until it finally disappears at the pressure of 600 mTorr.