Role of the Lysine as a Complexing Agent in Ge2Sb2Te5 Chemical Mechanical PolishingSlurries

Abstract

In this work,we investigate the polishing behavior, static dissolution and electrochemical performace of Ge2Sb2Te5 in the presense of lysine as a complexing agent with H2O2 employed as an oxidizer. Electrochemical techniques are used to investigate polishing behavior under static conditions as a function of lysine concentration .The polishing rate of GST increases with lysine concentraion increasing in acidic solutions at pH 5.2. The static dissolution rate shows the same trend. In the presence of lysine, the surface of GST film is smooth. To verify the complexes of the GST and lysine soluble, the Inductively Coupled Plasma is used which demonstrates that complexes with GST and lysine are soluble and the solubleness of Te element is increasing with lysine concentration increasing. In addition, electrochemical investigation indicates that an enhanced polishing rate and static dissolution is due to the Icorr increase varying lysine concentrations. Finally, X-ray photoelectron spectroscope results suggest that the chemical mechanism of lysine as a complexing agent is that lysine has the chemical reaction with GST oxide.