Method of polishing compound semiconductor substrate, compound semiconductor substrate, method of manufacturing compound semiconductor epitaxial substrate, and compound semiconductor epitaxial substrate

Abstract

Compound-semiconductor-substrate polishing methods, compound semiconductor substrates, compound-semiconductor-epitaxial-substrate manufacturing methods, and compound semiconductor epitaxial substrates whereby oxygen superficially present on the substrates reduced. A compound semiconductor-substrate polishing method includes a preparation step (S), a first polishing step (S), and a second polishing step (S). In the preparation step (S), a compound semiconductor substrate is prepared. In the first polishing step (S), the compound semiconductor substrate is polished with a chloric polishing agent. In the second polishing step (S), subsequent to the first polishing step (S), a polishing operation utilizing an alkaline aqueous solution containing an inorganic builder and having pH of 8.5 to 13.0 inclusive is performed.