| 摘要 |
PURPOSE:To reduce leakage currents by forming a buried layer by diffusing an impurity to the upper section of a blocking layer previously shaped in thick size, constituting a p-n junction by a diffusion between the buried layer and the blocking layer and constituting a p-n junction between the buried layer and a clad layer. CONSTITUTION:A p type InP blocking layer 6 and an InGaAsP cap layer 8 are buried through an epitaxial method in succession. Since the blocking layer 6 is thick, an epitaxial growth layer is shaped positively extending over the whole region on a buffer layer 2, and a non-growth section such a pin holes is not generated. An impurity is diffused to a wafer to form a buried layer 7. The layer 7 is diffused into the blocking layer 6 because the impurity Te is diffused while using a mask 15 as a mask for a diffusion. A p-n junction through the diffusion in a clad layer 4 and a cap layer 5 is shaped, and the p-n junction stable in a crystallographic manner is obtained. Since the blocking layer 6, the buried layer 7 and the p-n junction also function as a p-n junction by the diffusion similarly, the p-n junction stable in the crystallographic manner is acquired. |
