Electrochemical And Chemical Mechanical Polishing Study Of Germani?m

With the continuous development of integrated circuit technology,in the newest process node?less than 14 nm node and below?,high mobility material as new channel materials were received the extensive concern in the semiconductor industry^[1].Germani?m has a high carrier mobility compared to the traditional channel material silicon,therefore,in the new technology nodes,germani?m as a new channel material on the pMOS transistor has become a valuable research direction.CMP is an essential process step for the realization of the integration of this high mobility material on standard Si wafers.In this paper,the corrosion and passivation characteristics of Ge in the different oxidants?H₂O₂,NaClO,C₃Cl₃N₃O₃?and pH regulators?NaOH,KOH,NH₃·H₂O?were studied through the electrochemical method.In addition,the activation and inhibition of Ge'corrisivity by NaCl and dodecylamine were studied,and we have polished Ge/SiO₂ according to the results of electrochemical test,the removal rate of Ge/SiO₂ were analyzed in the different oxidant and pH regulators?we measure the removal rate of Ge by its mass removal rate and we tested the thickness difference of SiO₂ before and after CMP to calculate its removal rate?.In addition,equal proportion NaCl and lauryl amine were added in the slurry to verify their activation and inhibition for Ge by the results of their electrochemical experiment.The surface roughness of Ge/SiO₂ before and after CMP were observed by AFM,finally confirmed 5 wt%of SiO₂ abrasive,1vol%of H₂O₂,pH 9 had a good effect to the removal rate selectivity?20.97?of Ge/SiO₂ and their surface roughness.UV lamp was added in the experiments to study its effect to the electrochemical properties of Ge,and the experimental results had confirmed that H₂O₂ was easier to decomposition and produced hydroxyl radicals which possessed stronger oxidability to promote the corrosivity of Ge.From the experiments mentioned above,we found that electrochemical method as a strong theoretical research and an relatively simple method applied in the electrochemical test of Ge which can provide reliable theoretical guidance for practical CMP research.