Etching characteristics of manganese-doped zinc sulfide film using Cl-2/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/CF4 gas mixture. The chemical surface reaction of ZnS:Mn etching with Cl-2/CF4 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% CF4-70% Cl-2 and the ion current of pure Cl plasma was higher than that of pure CF4-plasma. The etch rate of ZnS gradually decreased with increasing flow rate of CF4 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/CF4 plasma revealed the presence of C-Cl and CF2 radicals as well as Cl and F atoms.