| 摘要 |
<p>PROBLEM TO BE SOLVED: To prevent the breakdown of a single-crystal substrate or an epitaxial layer in its cooling operation after its growth is finished by a method wherein, after a gallium nitride-based compound semiconductor crystal is epitaxially grown on the single-crystal substrate, the substrate is cooled under a condition that a temperature lowering rate is at a specific rate or lower per minute. SOLUTION: An NdGaO3 single-crystal substrate is cleaned and then dried. The substrate is set in an apparatus. Then, while nitrogen gas is being made to flow, the temperature of the substrate is raised to 600 deg.C so as to be maintained, and the temperature of a Ga raw material is raised to 850 deg.C so as to be maintained. Then, HCl gas which is diluted with nitrogen gas is made to flow from the upstream side of the Ga raw material. At the same time, NH3 gas is made to flow to a part near a part just above the substrate so as to bypass the Ga raw material. A first Ga layer as a thin film is grow on the surface of the substrate. In succession, the temperature of the substrate is raised to 1000 deg.C so as to be maintained. A second GaN layer as a thin film is grown. After that, the substrate is cooled down to room temperature at a temperature lowering rate of 5 deg.C per minute or lower.</p> |
