Polishing slurry, method of treating surface of Ga_xIn_1-xAs_yP_1-y crystal and Ga_xIn_1-xAs_yP_1-y crystal substrate

摘要

The present polishing slurry is a polishing slurry for chemically mechanically polishing a surface of a Ga_xIn_1−xAs_yP_1−y crystal (0≦x≦1, 0≦y≦1), characterized in that this polishing slurry contains abrasive grains formed of SiO₂, this abrasive grain is a secondary particle in which a primary particle is associated, and a ratio d₂/d₁ of an average particle diameter d₂ of a secondary particle to an average particle diameter d₁ of a primary particle is not less than 1.6 and not more than 10. According to such the polishing slurry, a crystal surface having a small surface roughness can be formed on a Ga_xIn_1−xAs_yP_1−y crystal at a high polishing rate and effectively.