Temperature Effects and Optical Emission Spectroscopy Studies of Hydrogen-Based Plasma Etching of Copper

Optical emission spectroscopy (OES) and substrate temperature variation studies have been performed on Cu etch processes based on hydrogen (H 2 ) plasmas. Temperature was varied between −150°C and 100°C. Gas phase Cu emission was detected during the H 2 plasma etch processes. The correlation between Cu etch rate and Cu emission intensity trends as a function of temperature suggests that the Cu removal mechanism changes over the temperature range investigated. The hydrogen-Cu interaction chemistry plays a critical role in the etch process, suggesting that copper hydrides are likely etch products.