| 摘要 |
PURPOSE:To prevent local concentration of electric fields on a junction bath surface and to obtain stable and highly reliable junction characteristics of a semiconductor photodetector by protecting the main junction bath surface with conductivity same as the substrate. CONSTITUTION:A P-type layer 22 is formed on the main surface of a semiconductor substrate 21 to form an SiO2 film 201. Then, an N-type layer 23 is formed, and with the film 201 as a mask it is etched. An N-type layer 23 of approx. 3mum is retained on the bath surface. Thereafter, a P<+>-type layer 24 is formed thereon, and an SiO2 film 25 is newly formed thereon, and an SiO2 film 26 is further formed again by a vapor phase growing process as a reflection preventive film. Then, a pair of main electrodes 27, 28 are formed to complete an APD. |
