Study Of Chemical Mechanical Polishing Of The Material Of Copper Interconnection Barrier Layer

In this paper, the chemical mechanical polish(CMP) experiments were done on osmium(Os) using home-made slurries, the effect of anti-corrosives, organic acids, H2O2 concentration and surfactants on material removal rate and surface quality was investigated, and by using electrochemical methods, X-ray photoelectron spectroscopy and D5A-type multi-mode scanning probe microscope analysis of different parameters in the process of chemical mechanical polishing mechanism of osmium.Firstly, the effect of different anti-corrosives in home-made slurries was investigated in the process of chemical mechanical polish of osmium. The results revealed that corrosive inhibiter can promote the formation of the passive film on the surface of Os and better surface quality can be obtained. The effect of 1, 2, 3-Benzotriazole(BTA) may promote the formation of a thick passive film on Os surface which enhance the surface quality.Then, chemical mechanical polishing experiments were done on osmium in formic acid and lactic acid based slurries. The experimental results show that formic acid and lactic acid can enhance corrosion action of the slurry on the surface of Os, and accelerate the material removal rate(MRR). In formic acid based slurries, the chemical corrosion ability to corrode Os surface can enhance, when H2O2 concentration at 0.1-1wt. %, chemical corrosion ability no longer changes if H2O2 concentration is higher than 3 wt. %. It may be because higher H2O2 concentration leads to thickness of passive film increase, which reduces the corrosion rate and the MRR. Lactic acid can promote the formation of passive film on the surface of Os and improve the surface quality, the roughness was reduced from 6.3 nm to 2.1 nm.Finally, the CMP experiments were done on Os using home-made slurry, and the effect of surfactants in the chemical mechanical polish was studied. The results showed that addition hexadecyl trimethyl ammonium bromide can improve surface quality, and now the osmium surface roughness(Ra) is 0.57 nm, polishing rate is 14.6nm/min.