Etching Characteristics of Manganese-Doped Zinc Sulfide Film Using Cl₂/CF₄ Inductively Coupled Plasma

Abstract

The etching characteristics of manganese-doped zinc sulfide (ZnS:Mn) films were investigated using the inductively coupled plasma (ICP) of Cl 2 /CF 4 gas mixture. The chemical surface reaction of ZnS:Mn etching with Cl 2 /CF 4 ICP plasma was studied by plasma analysis using the Langmuir probe (LP) method and optical emission spectroscopy (OES), and surface analysis using X-ray photoelectron spectroscopy (XPS). The maximum ion saturation current was obtained with a gas mixture of 30% CF 4 -70% Cl 2 and the ion current of pure Cl 2 plasma was higher than that of pure CF 4 -plasma. The etch rate of ZnS gradually decreased with increasing flow rate of CF 4 gas at a fixed total flow rate. XPS indicated that Mn had accumulated on the surface after etching of the ZnS:Mn (0.39 wt.%) layer using Cl 2 plasma. The OES analysis of Cl 2 /CF 4 plasma revealed the presence of C–Cl and CF 2 radicals as well as Cl and F atoms.