Reactive Ion Etching of ZnO Using a Cl_2/Ar Mixture

摘要

This study investigates physical properties of ZnO films after reactive ions etching (RIE) using a Cl_2/Ar mixture by varying the gas flow ratio, radio-frequency (rf) plasma power and chamber pressure. Atomic force microscopy (AFM) results and surface topographies are discussed. The etching rate at a Cl_2/Ar flow rate of 150/10 sccm, a work pressure of 60 mTorr and an rf power of 300 W is higher than under any other conditions. Additionally, the root-mean-square (rms) roughness of 24.20 nm is the highest at a Cl_2/Ar flow rate of 150/10 sccm, a work pressure of 190 mTorr and an rf power of 300 W; it is suitable for roughened transparent contact layer (TCL) in light-emitting diodes (LEDs). Bearing ratio analysis reveals that, under this condition, the nanorods covered 25.41 % of the total surface area and their maximum height was approximately 150.83 nm.