Etching characteristic of ZnO thin films in an inductively coupled plasma

The etching characteristics of ZnO and etch selectivities of ZnO to SiO2 in CF4/Ar, Cl2/Ar and BCl3/Ar plasma were investigated. The etch rate in CF4/Ar plasma was lower than that in Cl containing plasma. The maximum etch rates of ZnO were 129.3 nm/min at Cl2 (80%) /Ar (20%) and 172.4 nm/min at BCl3 (80%) /Ar (20%). The etch rate of ZnO showed a non-monotonic behavior with increasing from 0% to 80% Cl2 and/or BCl3 fraction in Cl2/Ar and BCl3/Ar plasmas. The plasmas were characterized using optical emission spectroscopy (OES) analysis measurements. The chemical states of etched surfaces were investigated with X-ray photoelectron spectroscopy (XPS).