Etching Characteristics of Carbon Nanotube Thin Films in O-2/Ar Plasma

Abstract

In this work, we studied the influence of O-2/Ar mixing ratio on the etching characteristics of carbon nanotube (CNT) thin films in inductively coupled plasma at constant gas pressure (6 mTorr), input power (400 W), bias power (50 W), and total gas flow rate (40 sccm). The etching mechanism was analyzed based on both plasma diagnostics (optical emission spectroscopy, Langmuir probe) and plasma modeling. It was found that increasing the Ar mixing ratio in the range of 0-75% Ar lowered the O atom density but increased the CNT film etching rate (44.3-88.4 nm/min). It is proposed that the CNT film etching process is mainly driven by the chemical etching pathway, whereas an increase in the etching rate may be associated with increasing reaction probability.