Film Etching Technique Using Halogen Plasma Following Diluted Hydro Fluorine Solution

Indium Gallium Zinc Oxide (IGZO) is a leading candidate for channel material of 3D semiconductor structure due to its high mobility, high stability and low temperature processes. We developed a selectivity etching of IGZO to SiO2 using halogen based chemistry in an inductively coupled plasma (ICP) system. The actual distribution analysis of etch byproducts was performed by energy dispersive X-ray (EDX) mapping. After plasma etch, diluted hydro fluorine (DHF) solution was implemented to clear the etch byproducts from the semiconductor topography.