| 摘要 |
A nitride semiconductor substrate and its manufacturing method are provided to minimize warpage of the substrate and a lower dislocation density of both sides of the substrate, thereby forming a device forming layer of good quality on the both sides thereof. A sapphire single crystal substrate is loaded in a hydride HVPE(Hydride Vapor Phase Epitaxy) reactor, and then a primary nitration process is performed by flowing an ammonia gas at a temperature of 1000 to 1500 °C. After heat treatment, a secondary nitration process is performed on the substrate. While gallium is excessively loaded on a gallium boat of the reactor and is maintained at a temperature 800 to 850 °C, HCl gas is supplied into the reactor to generate GaCl gas, and then the GaCl gas is reacted with NH3 gas, thereby depositing a first GaN layer on the substrate. Then, the first GaN layer is detached from the substrate by using excimer laser. After a negative face of the first GaN layer is heat-treated, a second GaN layer is formed on the negative face through the same process as the first GaN layer. |
