Plasma oxidation as an effective method in etching copper interconnect lines at room-temperature

Abstract

Abstract The oxygen plasma-copper reaction has been proved effective in preparing copper fine patterns at room temperature. The oxidized copper film is composed of crystalline CuO and Cu2O with a granular structure due to the volume expansion. The time-dependent oxide growth progresses in three stages with different mechanisms: penetration of native oxide, oxidation kinetics, and transportation of precursors through the porous oxide layer. The vertical copper profile is obtained from the anisotropic oxidation due to the acceleration of oxygen ions from the cathode self-bias voltage. The plasma oxidation etching method is applicable to a wide range of nano and microelectronics.