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 degrees C and 100 degrees 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. (C) 2011 The Electrochemical Society. [DOI: 10.1149/2.015202jes] All rights reserved.