| 摘要 |
PROBLEM TO BE SOLVED: To obtain a large output at high temperatures by increasing the carrier concentration of a clad layer and preventing diffusion of impurities of the cladding layer into an active layer. SOLUTION: A buffer layer 22, an n-type clad layer 23, an MQW layer 24, a p-type clad layer 25, an intermediate layer 26, and a part of a p-type contact layer 27 are grown on a substrate 21 using an MBE method. The laminated wafer is thermally treated for 120 minutes at 700 deg.C and hydrogen atoms combined with impurity atoms during crystal growth the separated therefrom. this causes the amount of impurity atoms in the p-type clad layer 25 to be increased, making the carrier concentration high. In this case, zone 32 which is not doped with impurities is provided in a side of the clad layer 25 provided with the active layer 24 and is used as a buffer region of impurity diffusion at the thermal treatment. Accordingly, impurities will not diffuse to the active layer 24, and thus the element can be used at a high output of 10 mW or more at 80 deg.C.
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