Research On Chemical Mechemical Polishing Of Barrier Layer Material Co For Cu Intercorrection

Co bilayer, as a novel diffusion barrier for copper interconnect, has good potebtial to be applied in the next generation GLSI technology. However, there is poor of study about chemical mechanical polishing(CMP) of Co based barrier. The chemical corrosion, galvanic corrosion and removal mechanism of chemical mechanical polishing of Co need to be studied. This work has significant meaning in both scientific research and potential application of novel CMP process of Co based barrier layer.Chemical mechanical polishing of Ta was firstly investigated, system research on the study of Hebei University of technology of alkaline barrier polishing liquid components, including pH value, antioxidant, chelating agent and additives, to studying the static corrosion rate, the polishing rate, correction ability and the influence of surface roughness. In high pH value, the polishing rate to a large extent depends on the rate of reaction. Experiments show that adding guanidine hydrochloride can enhance the rate of polishing.According to the study of Ta CMP, the effect of the various factors on barrier layer new material Co was studied. The effects of polishing liquid components on static corrosion rate, removal rate and electrochemical was observed. Through analysis the data of static conditions, selected polishing slurry components of CMP experiment, then observe the changes of the rate of Co, finally analysis the electrochemical experiment of cobalt. In order to improve the rate of polishing the oxidant and guanidine hydrochloride was added in the slurry. It shows that when the surfactant is 30 ml/L, chelating agent to 20 ml/L, Co has lowest static corrosion rate. when adding 30 ml/L antioxidant and 0.3 g/L guanidine hydrochloride, the polishing rate has a sharp increases. Compared with existing acidic barrier polishing slurry, the alkaline barrier polishing slurry of Co has a higher removal rate, and the static corrosion rate is lower. This study has a positive guiding significance on the barrier layer CMP.