| 摘要 |
PROBLEM TO BE SOLVED: To improve a luminous efficiency of a light-emitting element by providing an N-type GaN compound semiconductor where electron density is controlled. SOLUTION: An AlN buffer layer 2 of 500 Å is formed on a sapphire substrate 1, on which there are sequentially formed a GaN high carrier concentration N+ layer 3 of film-thickness about 2.2 μm which is silicon-doped for an electron density of 1.5×1018/cm3, a GaN low carrier concentration N layer 4 of film-thickness about 1.5 μm with an electron density of 1×1015/cm3 or less, and an I layer 5 of GaN whose film thickness is about 0.2 μm. At the I layer 5 and the high carrier concentration N+ layer 3, electrodes 7 and 8 formed of aluminum, connected to them respectively, are formed. The resistivity (=1/conductivity) of the high carrier concentration N+ layer 3 may be changed from 3×10-1 Ωcm to 8×10-3 Ωcm. |
