A study on the suppression of etch residues by O-2 gas addition in dry etching of Pt film

Abstract

The properties of platinum etching were investigated using inductively coupled plasmas. However, problems such as low selectivity to oxide as an etching mask, low etch dope and the etch residues remaining on the pattern sidewall were presented. In this paper, the etching by O-2/Cl-2/Ar gas mixture was examined, And the residue-free surface and higher etch slope was observed through transmission electron microscope (TEM) and scanning electron microscopy (SEM). The selectivity to oxide as an etching mask increased without having to decrease the etch rate in 5 % additive O-2 gas. In order to investigate the residue composition, X-ray photoelectron spectroscopy (XPS) analysis was used. XPS surface analysis proved that even a little O-2 gas can remove the Pt-Cl compounds as residues on the etched surface.