| 摘要 |
PURPOSE:To obtain a detector with improved sensitivity, by providing a light-shielding mask overlapping a bias current electrode viewed from above an element to reduce the frequency at which excess minority carriers are recombined on the sidewall of a crystal. CONSTITUTION:Bias electrodes 1 and 2 are provided across a crystal 4 for absorbing infrared rays while an anode-oxidized film 5 is provided at the central part of the crystal 4, furthermore, an opening with the area thereof smaller than the central part as light receiving section 3 is provided on the electrodes 1 and 2 and the oxidized film 5 separately and a light shielding mask 7 is provided therefore overlapping with the electrodes 1 and 2. With such an arrangement, excess minority carriers generated in the crystal 4 right under the light receiving sections 3 by infrared radiation are caused to drift and diffuse with an electric field applied between the electrodes 1 and 2 and are lost being recombined with the electrodes 1 and 2. Otherwise, the carriers also diffused in the direction vertical to the electric field and reaches the sidewall of the crystal 4, where they are lost being recombined with an interface level. Thus, the arrangement of the light-shielding mask 7 can prevent the recombination of the carriers on the sidewall thereby achieving a higher response and a higher sensitivity. |
