The study on corrosion inhibition effect of 3-amino-1, 2, 4-triazole and benzotriazole on molybdenum for barrier layer slurry

Molybdenum (Mo), as a barrier layer material, has great potential in integrated circuit (IC) manufacturing industries. The selection of suitable corrosion inhibitors to control the galvanic corrosion between Mo and the wiring metal is crucial in the Mo chemical mechanical polishing (CMP). In the current study, the inhibition effect of 3-amino-1, 2, 4-triazole (ATA), and benzotriazole (BTA) on Mo was investigated by experimental and theoretical methods. Static etching test found that the addition of ATA decreased the static etching rate of Mo (from 330 Å/min to 36 Å/min) more significantly than adding BTA (from 330 Å/min to 136 Å/min). Potentiodynamic polarization test indicated that ATA or low concentration (lower than 300 ppm) of BTA can improve the anti-corrosion ability of Mo. The smaller contact angle indicated that ATA (39°) was more hydrophilic than BTA (45°) in the formation of films covering the Mo surface. Scanning electron microscopy measurement observed that ATA-absorbed film was more compact and thinner, thus improving the surface morphology of Mo. The electronic properties and reactive sites of ATA were analyzed by quantum chemical calculation. Based on the simulation result, an adsorption model of ATA bonding with Mo basement was built. A large amount of ATA molecules coordinated with Mo atoms with its 4th N atom and formed a passivation film. The film is compact thus exhibits an excellent inhibition performance. Apart from this, the addition of ATA or BTA can improve the stability of solutions. The optimal dosage of ATA or BTA can keep the solution stable for 7 days. This paper combined with experimental techniques and theoretical calculations to further understand the mechanism of novel barrier layer material.