High Density Inductively Coupled Plasma Etching of Zinc-Oxide and Indium-Zinc Oxide

摘要

The dry etching characteristics of bulk single-crystal zinc-oxide (ZnO) and RF-sputtered indium-zinc-oxide (IZO) films have been investigated using an inductively coupled high-density plasma in Ar/IBr and Ar/BI_3. In both plasma chemistries, the etch rate of ZnO is very similar to that of IZO, which indicates that zinc and indium atoms are driven by a similar plasma etching dynamics. IBr and BI_3-based plasmas show no enhancement of the etch rate over pure physical sputtering under the same experimental conditions. Also, CH4/H2 -based discharges are attractive for dry etching of single crystal ZnO because of their non-corrosive nature. The C_2H_6/H_2/Ar mixture provides a strong enhancement over pure Ar sputtering, in sharp contrast to the case of CH_4/H_2/Ar. The etched surface morphologies were smooth, independent of the chemistry and the Zn/O ratio in the near-surface region was unchanged within experimental error after etching with all chemistries.