Characteristics of platinum films etched with a SF6/Ar plasma

Platinum thin films were etched with a SF6/Ar gas plasma in an electron cyclotron resonance (ECR) plasma etching system and were compared with platinum films etched with a Cl-2/Ar gas plasma. For the former, the etch rate was higher and the surface roughness was lower. Analytical methods, such as x-ray photoelectron spectroscopy and secondary ion mass spectroscopy confirm that the platinum etching process produced PtFx compounds as the etch products. These products could be easily removed from the surface by a sputtering mechanism due to their high volatility. Etching with an indium-tin-oxide hard mask resulted in a steep etch profile due to suppressed residue redeposition on the patterned sidewall.