| 摘要 |
The present invention relates to a method for manufacturing a high-quality gallium nitride substrate using a crystalline gradation layer. The method comprises: a first gallium nitride layer growing step of positioning a base substrate in a reaction space of a reactor and supplying gallium chloride (GaCl) gas and ammonia (NH_3) gas, which are raw gases, into the reaction space to grow a first gallium nitride layer having a first defect density on the base substrate; a second gallium nitride layer growing step of supplying gallium chloride (GaCl) gas and ammonia (NH_3) gas, which are raw gases, into the reaction space, differentiating a crystalline change section of gallium nitride from the first defect density to a second defect density, adjusting a gallium nitride growth condition to gradually lower the defect density, and growing the second gallium nitride layer to adjust a coupling speed of gallium nitride crystals; and a third gallium nitride layer growing step of a third gallium nitride layer having the second defect density. According to the present invention, a gradation layer gradually changed from a low-grade gallium nitride layer to a high-grade gallium nitride layer is grown between the low-grade gallium nitride layer and the high-grade gallium nitride layer, tensile stress according to the change of crystal quality is minimized, and it is possible to manufacture a high-quality gallium nitride substrate while suppressing the occurrence of cracks. |
