METHOD FOR PRODUCING GaN FILM

摘要

This method for producing a GaN film includes: a step for preparing a composite substrate containing a support substrate (11) having a coefficient of thermal expansion in the main surface (11m) greater than 0.8 times and less than 1.2 times the coefficient of thermal expansion of GaN crystals in the a-axis direction, and a single-crystal film (13) positioned on the main surface (11m) side of the support film (11), said single-crystal film (13) having a three-fold symmetry with respect to the axis perpendicular to the main surface (13m) of the single-crystal film (13); and a step for forming a GaN film (20) on the main surface (13m) of the single-crystal film (13) in the composite substrate (10). A method for producing a GaN film, whereby a GaN film having large main surface area and small warp can be produced, is thus provided.