| 摘要 |
<p>A semiconductor photodetector is formed of interdigitated, metal-semiconductor-metal electrodes (18) disposed on a surface (30) of semi-insulating semiconductor material (12), gallium arsenide. Radiation such as infra-red or visible light is converted to an electric current flowing between the electrodes (18A, 18B) upon application of a bias voltage (22) between the electrodes. A Schottky barrier at the junction of each electrode surface and the semiconductor surface limits current flow to that produced by photons of sufficient frequency, or energy, to overcome the Schottky barrier. Tunneling of charge carriers of the current under the Schottky barrier, which tunneling results from the entrapment of charge carriers on the semiconductor surface, is inhibited by the production of a doped surface layer (14) upon the foregoing surface (30) between the electrodes (18A, 18B) to repulse the charge carriers and prevent their entrapment at the surface. The doped surface layer (14) is much thinner than an interaction region of the radiation in the semiconductor material (16) and has sufficiently high resistance to permit the photodetector to function efficiently.</p> |
