METHOD FOR MANUFACTURING FREE-STANDING SUBSTRATE, SUBSTRATE AND FREE-STANDING SUBSTRATE

摘要

PROBLEM TO BE SOLVED: To reduce dislocation density on the surface of a joint body in a method capable of obtaining a joint body of group III nitride semiconductor crystals by growing a group III nitride semiconductor crystal on a base substrate having pieces of group III nitride semiconductor crystal adjacently arranged each other to join the group III nitride semiconductor crystals grown from each piece of the crystals.SOLUTION: A method for manufacturing a free-standing substrate comprises: a mask formation step S10 of covering a boundary part between adjacent crystal pieces on a first surface of a base substrate formed by arranging two or more pieces of group III nitride semiconductor crystal to expose a portion without having the boundary part and forming a mask including an insulation layer; and a growth step S20 of growing a group III nitride semiconductor from the exposed portion of the base substrate to form a group III nitride semiconductor layer.SELECTED DRAWING: Figure 1