Surface treatment method of compound semiconductor substrate, fabrication method of compound semiconductor, compound semiconductor substrate, and semiconductor wafer

摘要

A surface treatment method of a compound semiconductor substrate, a fabrication method of a compound semiconductor, a compound semiconductor substrate, and a semiconductor wafer are provided, directed to reducing the impurity concentration at a layer formed on a substrate by reducing the impurity concentration at the surface of the substrate formed of a compound semiconductor. The compound semiconductor substrate surface treatment method includes a substrate preparation step (S10) and a first washing step (S20). The substrate preparation step (S10) includes the step of preparing a substrate formed of a compound semiconductor containing at least 5 mass % of indium. In the first washing step (S20), the substrate is washed for a washing duration of at least 3 seconds and not more than 60 seconds using washing liquid having a pH of at least - 1 and not more than 3, and an oxidation-reduction potential E (mV) satisfying the relationship of - 0.08333x + 0.750 ‰¤ E ‰¤ - 0.833x + 1.333, where x is the pH value.