METHOD OF REMOVING DEFECT IN IRRADIATION FOR NEUTRON IRRADIATION FZ SILICON SINGLE CRYSTAL

摘要

PURPOSE: To realize an irradiation treatment step with a good recovery resistance ratio, by putting an ingot of FZ silicon single crystal in heat treatment after a neutron beam is cast to the silicon single crystal in a light water reactor. ;CONSTITUTION: During a growth step for a FZ silicon single crystal, nitrogen with density of 5×10¹⁴/cm³ or below is doped in the single crystal, and neutron irradiation is carried out in a light water reactor. An ingot of silicon crystal is treated in heat at temperatures from 1050 to 1150°C for 120 to 360 minutes. Then, the nitrogen doping is carried out by mixing the nitrogen gas into an argon atmosphere in the furnace when a corn part of the crystal is formed. In the heat treatment, an atmosphere of a N₂ gas, for example, mixed with a dry O₂ gas is used. In this way, good resistivity for practical use can be obtained in a simple processing step, and an FZ silicon single crystal with an axial distribution in resistivity is made uniform in neutron irradiation in the light water reactor.;COPYRIGHT: (C)1994,JPO&Japio