Manufacturing method of nitride substrate, nitride substrate, and nitride-based semiconductor device

摘要

A manufacturing method of a nitride substrate includes the steps of preparing a ground substrate; forming a mask on the ground substrate; placing the ground substrate in a reactor, and heating the ground substrate to a temperature of 850° C. to 1100° C. In the step of heating the ground substrate, HCl and NH3 are supplied into the reactor so that partial pressure PHCl satisfies (1.5+0.0005 p) kPa≦̸PHCl≦̸(4+0.0005 p) kPa and partial pressure PNH3 satisfies (15−0.0009 p) kPa≦̸PNH3≦̸(26−0.0017 p) kPa, whereby an AlxGayIn1-x-yN crystal (0≦̸x<1, 0<y≦̸1) is grown, and whereby a ridge-valley structure including a plurality of ridges and valleys parallel to one another is formed. The AlxGayIn1-x-yN crystal is grown so that the ridge-valley structure is not buried while a height of the valleys from the ground substrate is allowed to exceed 2.5 (p−s).