Chemical reaction during Pt etching with SF6/Ar and Cl2/Ar plasma chemistries

Recently, most studies about Pt etchihg have been focused on the mechanism of the physical sputtering with Cl-based plasma, while only the limited results are available for etch characteristics with fluorine based plasma. In this study, the etch characteristics of Pt thin films with SF6/Ar and Cl-2/Ar gas chemistries are compared using the electron cyclotron resonance plasma etching system. Moreover, the role of fluorine and sulfur in SF6 gas on Pt etching is investigated. It is confirmed that SF6/Ar plasma chemistry could result in volatile etch products through the reaction with the Pt thin film. Moreover, the improvement in etch rate, etch profile and surface toughness is obtained with SF6/Ar plasma chemistry.