| abstract |
By using a polishing liquid containing an abrasive, deionized water, a pH adjusting agent and polyethylene imine, it is possible to control the removal rate of the silicon oxide film and the silicon nitride film simultaneously exposed during CMP (Chemical Mechanical Polishing) of a conductive layer such as a polysilicon layer. Can be. In addition, the polishing liquid added with polyethylene imine and choline derivatives exhibits a synergistic effect on the removal rate of the silicon oxide film and the silicon nitride film, and by controlling the content of the choline derivative, the relative ratio between the silicon oxide film removal rate and the silicon nitride film removal rate can be controlled. have. |