Method for manufacturing III-nitride substrate and method for reducing dislocation density of III-nitride substrate

摘要

PROBLEM TO BE SOLVED: To provide a method for obtaining easily and surely a group III nitride substrate having a low dislocation density.SOLUTION: A production method of a group III nitride substrate includes: an etching step for forming a recessed part on the surface of a ground substrate so that a C-surface ratio becomes 20% or higher and 90% or lower, by applying chlorine plasma etching to the surface of the ground substrate whose surface is the flat C-surface in the state where a bias voltage is not applied to the ground substrate; and a formation step for forming a group III nitride layer on the ground substrate after the etching step.