PREPARATION OF PHOTODETECTOR SENSITIVE WITHIN RANGE OF SHORT WAVELENGTH LIGHT

摘要

PURPOSE: To obtain a highest doping concentration on the surface of a substrate or immediately under the surface for a segregation effect by providing a specific dielectric diffusing layer device, and executing re-diffusion so that the successive oxidation of the substrate cannot be conducted. CONSTITUTION: A plane (p-n) junction 12 is formed in a substrate 10 by ion implantation, and the substrate 10 is covered with a dielectric diffusing layer device 11, having at least one oxide layer just on the substrate 10. Then, ion is implanted through the dielectric diffusing layer device 11 into the substrate 10, and re-diffusion is conducted with a high temperature. The dielectric diffusing layer device 11, having at least one oxide layer and thickness for providing the maximum value of the implanted ions in the dielectric diffusing layer device 11, is formed on the semiconductor substrate 10 prior to the ion implantation. Then, the re-diffusion is conducted so that the successive oxidation of the substrate 11 cannot be operated. Thus, doping can be reduced continuously toward the (p-n) junction, and quantum efficiency at the extremely high place an be obtained in the range of light having short wavelengths.