Characterization of Indium Tin Oxide and Reactive Ion Etched Indium Tin Oxide Surfaces

ITO films, both before and after annealing, were characterized with various methods. The changes in film characteristics are discussed. RIE etching mechanisms for the unannealed ITO films in three reactive gases (CF₂Cl₂, CF₃Cl, and CF₄) and two diluent gases (N₂ and Ar) were delineated by analyzing and comparing the surface ESCA data with the process results. For undiluted gases, indium is the major component left on the surface, and each gas has its own etch preference for different components. The addition of a diluent into the plasma may change the surface composition as well as the etching mechanisms. To increase the whole film etch rate, each component has to be etched off effectively.