| abstract |
An X-ray semiconductor detector has a pixel array structure in which a plurality of pixel elements are arrayed in a matrix. Each pixel element includes an X-ray/charge conversion film for generating charges in accordance with an incident X-ray, a storage capacitor for storing the signal charges generated in the X-ray/charge conversion film, a signal read transistor for reading the signal charges from the storage capacitor, and a protective diode arranged to remove excessive charges from the storage capacitor and prevent dielectric breakdown of the signal read transistor. The protective diode is arranged below the storage capacitor. Since the protective diode is arranged below the storage capacitor, it does not decrease the pixel density. Since the protective diode is covered with the storage capacitor, it can be shielded from an X-ray. Therefore, variations in OFF current of the protective diode by an X-ray and dielectric breakdown of the protective diode can be prevented. |