摘要 |
PURPOSE:To avoid uneveness of impurity concentration and prevent a fixed pattern noise by employing a high resistance N-type Si substrate which is made by the application of a neutron beam as a semiconductor substrate for forming a solid-state image pickup device. CONSTITUTION:A neutron beam is applied to an Si wafer by a light water unclear reactor and a heavy water nuclear reactor to convert a part of Si, which is a composing element of the wafer, into P, which is an N-type impurity, by nucleus conversion and an Si substrate with a specific resistivity of 10-100OMEGA.cm is obtained. On the Si substrate obtained as described above, photodetecting parts 1, vertical shift registors 2, a horizontal shift registor 3 and so forth are formed to constitute a vertical overflow drain type solid-state image pickup device. By employing the Si substrate described above, uneveness of N-type impurity concentration can be avoided and a required high resistance N-type Si substrate can be obtained so that a fixed pattern noise can be prevented. |