A study on the etch characteristics of ITO thin film using inductively coupled plasmas

In this study, the high-density plasma etching of indium tin oxide (ITO) fi lms used for transparent electrodes in display devices have been investigat ed. The etch characteristics of ITO as a function of Ar/CH4 gas mixtures we re analyzed using quadrupole mass spectrometry (QMS), optical emission spec troscopy (OES), and electrostatic probe (ESP). ITO etch rates were increase d with the addition of moderate amount of CH4 to Ar due to the increased ch emical reaction between CH3 or H and ITO in addition to the physical sputte ring of ITO by Ar ion bombardment. However, the addition of excess amounts of CH4 decreased the ITO etch rates, possibly due to the increased polymer formation on the ITO surface. Also, the data obtained by QMS and OES sugges ted that CH3 radicals are more actively involved in the etching of ITO comp ared to H radicals. (C) 2000 Elsevier Science B.V. All rights reserved.