| 摘要 |
PURPOSE:To obtain a polishing solution capable of minimizing modification of layers due to treatments and surface defects by incorporating in the solution sodium hypochloride, sodium hydroxide and sodium carbonate and adding sodium chloride as required. CONSTITUTION:A polishing solution preferably contains 0.001 to 1% by weight (concentration of effective chlorine) of sodium hypochloride, 0.01 to 5% by weight of sodium hydroxide and 0.01 to 5% by weight of sodium carbonate. If sodium chloride is to be added, it should be present in less than 1% by weight. In order to polish a GaAs wafer, the wafer is polished by a rotary polishing machine, using said polishing solution. Alternatively, the polishing solution may be blended with coloidal silica by so-called concurrent pouring process directly before supplying the mixture to the rotary polishing machine to polish the wafer. In this case, the surface roughness of the wafer can be improved in comparison with the case where no coloidal silica is used. The polishing solution, when used for polishing, preferably has a temperature of 0 to 50 deg.C, The coloidal silica preferably has a particle size of about 20 to 200nm and the coloidal silica is preferably present in the solution at a percentage of 5 to 25% by weight. |
