| 摘要 |
PROBLEM TO BE SOLVED: To grow an AlGaAs film wherein impurities such as oxygen and water are little without decreasing crystal growth temperature, by setting the growth temperature of compound semiconductor in a specified range, and setting the ratio of group V material gas amount to group III material gas amount to be at least a specified value. SOLUTION: A buffer layer 2, a clad layer 3, an undoped active layer 4, a P-type first clad layer 5, and an N-type block layer 6 are formed in order on a substrate 1. A P-type second clad layer 8, and a P-type contact layer 9 are formed on the block layer 6. After that, an N electrode 10 is formed on the lower surface, and a P electrode 11 is formed on the upper surface. For the P-type clad layers 5, 8, the condition at the time of crystal growth of compound semiconductor whose carrier concentration is at most 1×10<17> /cm<3> is set as follows; the growth temperature is higher than or equal to 750 deg.C and lower than or equal to 850 deg.C and, the ratio V/III of group V material gas amount to group III material gas amount is at least 150. Thereby crystals having low carrier concentrations in both an N-type and a P-type can be obtained with high quality and excellent reproducibility. |
