PURPOSE: To increase the light output and form a good ohmic electrode by forming a P-type layer with a first P-type layer and a second P-type layer and making the carrier concentration higher in the second P-type layer than in the first P-type layer.
CONSTITUTION: A GaP substrate 1, a composition changing layer 2, and composition fixed layers 3, 4 are formed. A first P-type layer 6 is formed by vapor phase growth and a second P-type layer 7 is formed by thermal diffusion which occurs after the vapor phase growth. The carrier concentration at the PN- junction face side of the first P-type layer is 0.5-5×1018cm-3, preferably 0.8-3×1018cm-3. With the first P-type layer 6 and the second P-type layer, it does not matter whether nitrogen is doped, parts of the layers are not doped, or doping is not done at all. The P-type layer which is to be used for ohmic contact is so formed that the carrier concentration may be 5×1018cm-3 or above, preferably 8×1018cm-3, which lets this device have a structure very much suitable for LED.
IMAI MEGUMI
TAKAHASHI HITOO
