Etching Mechanism of Indium Tin Oxide Thin Films using Cl2/HBr Inductively Coupled Plasma

Abstract

Dry etching characteristics of indium tin oxide films and etch selectivities over photoresist films were investigated using Cl2/HBr inductively coupled plasma. From a Langmuir probe diagnostic system, it was observed that while the plasma temperature was kept nearly constant in spite of the change of the HBr mixing ratio, the positive ion density decreases rapidly with increasing the mixing ratio. On the other hand, a quadrupole mass spectrometer showed that the neutral HBr and Br species increased. The etching mechanism in the HBr/Cl2 plasma was analyzed.