Characteristics of NF₃/Ar remote plasma and etching behavior of Si and Si₃N₄ under industrial-relevant flow conditions

Abstract This study investigates the characteristics of NF₃/Ar remote plasma under industrial relevant flow condition (1000–7000 SCCM) and its etching behavior on Si and Si₃N₄. Experimental results demonstrate that increasing the NF₃ fraction leads to a rise in equivalent load impedance and a transition of electrical characteristics from inductive to resistive. By regulating the flow ratio in combination with a dynamic matching network, efficient dissociation of NF₃ can be achieved under lower power conditions. Optical emission spectroscopy (OES) further reveals a robust relationship between NF₃ fraction and emission intensity that remains stable across varying flow condition. This robust correlation confirms that OES is a good candidate for possible closed-loop control of the etching rates of thin films of various materials. The findings highlight both the fundamental insights into NF₃/Ar plasma behavior and its potential for guiding advanced plasma etching applications.