Role of amines and amino acids in enhancing the removal rates of undoped and P-doped polysilicon films during chemical mechanical polishing

During chemical mechanical polishing, removal rates of undoped and P-doped polysilicon films as high as 200 and 250 nm/min, respectively, have been achieved using several abrasive-free solutions, each consisting of an amine or amino acid. It was observed that only α-amine(s) solutions enhance the removal rates of both undoped and P-doped polysilicon films. Potentiodynamic, zeta potential, contact angle, thermo gravimetric and EDS measurements were performed to examine the role of these α-amines in achieving high polysilicon removal rate. Possible removal mechanism of both undoped and P-doped polysilicon film in the presence and absence of the different additives is also proposed.