CHEMICAL MECHANICAL POLISHING METHOD FOR GaAs WAFER

摘要

PROBLEM TO BE SOLVED: To increase a polishing speed and ensure the flatness and smoothness of a wafer in a chemical mechanical polishing as the primary polishing of the GaAs wafer, and to mirror-finish the wafer by a chemical polishing as a secondary polishing.;SOLUTION: A method conducts chemical mechanical polishing as a primary polishing process for the GaAs wafer by using a chemical mechanical polishing liquid containing dichlorocyanuric acid, sodium tripolyphosphate, sodium sulfate, sodium carbonate and colloidal silica as compositions except water. In the method, polishing at a first stage is conducted by loading the wafer to a chemical mechanical polishing device and supplying the polishing device with a polishing liquid having a first composition containing sodium tripolyphosphate at a mass ratio of 20 to 31% in the compositions except water. In the method, polishing at a second stage is conducted by supplying the polishing device with the polishing liquid having a second composition containing sodium tripolyphosphate at the mass ratio of 13 to 19% in the compositions excepting water.;COPYRIGHT: (C)2008,JPO&INPIT