High-density plasma etching characteristics of aluminum-doped zinc oxide thin films in Cl2/Ar plasma

Abstract We investigated the etching characteristics of aluminum-doped zinc oxide (AZO) thin films in an adaptively coupled plasma (ACP) system. The dry etching characteristics of AZO films were studied by changing the Cl 2 /Ar gas mixing ratio, RF power, DC bias voltage. We determined the following optimized process conditions: RF power of 500 W, DC bias voltage of −100 V, process pressure of 15 mTorr. In Cl 2 /Ar plasma (=50:50%), the maximum etching rate of AZO films is 70.45 nm min −1 . The ion composition of Cl 2 /Ar plasma was determined by optical emission spectrometry (OES). The chemical reactions on the surface of AZO films were analyzed by x-ray photoelectron spectroscopy (XPS).