Study on inhibition effect of 3-amino-1, 2, 4-triazole on chemical mechanical polishing of GLSI low-techology node molybdenum barrier layer

Abstract

Considerable attention has been paid to utilizing molybdenum (Mo) as a new generation of barrier layer material in the integrated circuit industry. However, there have a small amount of papers for Mo chemical mechanical polishing (CMP). In this study, the inhibition effect of 3-amino-1, 2, 4-triazole (ATA) on corrosion and CMP of Mo in the weakly alkaline slurry was investigated. Electrochemical experiment and chemical mechanical polishing experiment demonstrated that 100 ppm ATA has an excellent inhibition performance of Mo (removal rate of Mo decreased from 509 Å/min to 322 Å/min, static etching rate of Mo decreased from 839 Å/min to 208 Å/min and Mo surface roughness decreased from 9.48 nm to 1.01 nm). Langmuir adsorption isotherm analysis found that physical and chemical adsorption exists simultaneously between ATA and Mo. X-ray photoelectron spectroscopy analysis showed that the addition of ATA changed the contents of different kinds of Mo oxides. With the decreasing of MoO3, more MoO2 was generated and protected Mo from corrosion. This paper is devoted to studying the inhibition effect of a traditional corrosion inhibitor on a new barrier layer material and analyzing its mechanism. Additionally, this paper is also helpful to prevent galvanic corrosion between Mo and other interconnection materials during CMP.