Platinum Etching in an Inductively Coupled Plasma

Inductively coupled plasma as a high density plasma source and Cl
2
as main process gas are tested for etching of Pt thin films. Optical emission spectra show the possible compound formation of Pt with Cl, which is an evidence of ion-assisted chemical reaction. Addition of oxygen to Cl
2
plasma enhances the selectivity to hard SiO
2
mask to more than 2.0 while maintaining Pt etch rate higher than 200 nm/min. Patterning of half micron Pt lines is demonstrated.