Abstract: A production method includes providing field-effect transistors; irradiating the field-effect transistors; applying a current to drains of the field-effect transistors for a duration; and applying a same voltage to gates and sources of the field-effect transistors. The voltage is a grounding voltage or a reverse voltage. The field-effect transistors can be in a reverse biased state in a case of cut-off, and electron-hole pairs can be generated at an insulating oxide layer and at an interface between the insulating oxide layer and a semiconductor substrate.