| 摘要 |
PURPOSE:To enable stable preparation of GaP red light emitting element with high efficiency by holding a substrate in a low temperature portion outside of a growing furnace until just before the initiation of growth, and tightly closing a gallium solution tank in a state where the substrate is dipped in the gallium solution. CONSTITUTION:An N type GaP substrate 7 is disposed on a substrate holder of quartz 3. A predetermined amount of metallic Ga, polycrystalline GaP, Ga2O3 and Zn are put in a quartz-made solution tank 2 and thereafter heated up to 1,020 deg.C while being supplied with Ar gas. During this operation, the substrate holder 3 is held in a low-temperature zone over and outside of the furnace. After the polycrystalline GaP is fully dissolved, the substrate holder 3 is held directly over the Ga solution of 10min to be preheated, while the solution tank is tightly closed by a quartz-made cap 8. After the lapse of 10min, the substrate holder 3 is dipped in the Ga solution and held there for a given period of time to saturate the substrate 7 with oxygen. The substrate 7 is then cooled to 980 deg.C at a given cooling speed so as to cause a P type layer loaded with zinc and oxygen to grow thereon. When the temperature attains 980 deg.C, the substrate holder is removed from the solution, and the power supply is turned OFF to let the electric furnace to be cooled by itself. |
