Patent ID: 7691732

Claim:
A manufacturing method of a nitride substrate, comprising the steps of: preparing a ground substrate having at least threefold rotational symmetry; forming, on said ground substrate, a mask having covering portions each having a width s=20 μm to 400 μm and exposing portions each having a width of 2000 μm to 10000 μm arranged in parallel to one another at regular intervals with a constant pitch p=2020 μm to 10300 μm; and placing said ground substrate having said mask formed thereon in a reactor having at least one of a Ga boat, an In boat and an Al boat, and heating said ground substrate to a temperature of 850° C. to 1100° C., wherein in said step of forming said mask, said exposing portions each interposed between said covering portions are completely exposing portions that completely expose, or partially exposing portions that partially expose and partially cover by provision of a plurality of windows, in said step of heating said ground substrate: HCl is supplied into said reactor so that partial pressure P HCl thereof satisfies (1.5+0.0005 p) kPa≦P HCl ≦(4+0.0005 p) kPa, to generate at least one of GaCl, InCl and AICl 3 ; NH 3 is supplied into said reactor so that partial pressure P NH3 thereof satisfies (15−0.0009 p) kPa≦P NH3 ≦(26−0.0017 p) kPa, to allow NH 3 to react with at least one of said GaCl, InCl and AICl 3 , whereby an Al x Ga y In 1-x-y N crystal (0≦x<1, 0<y≦1) is grown on said ground substrate having said mask formed, whereby a ridge-valley structure including facet planes and a plurality of ridges and valleys parallel to one another is formed, said ridges and valleys having tops over intermediate portions of said exposing portions and bottoms over said covering portions, respectively; and said Al x Ga y In 1-x-y N crystal is grown so that portions immediately above said covering portions become crystal defect gathering regions where dislocations are gathered and portions above said exposing portions and immediately below said facet planes become low defect single crystal regions where the dislocations are fewer than in said crystal defect gathering regions, and so that said ridge-valley structure is not buried while a height of said valleys from said ground substrate is allowed to exceed 2.5 (p−s).