Overlapping-Gate Ccd Imagers On Gallium Arsenide

Abstract

Charge -coupled device (CCD) imagers have been fabricated on gallium arsenide (GaAs) with very closely spaced ( <100nm) Schottky-barrier metal electrodes. The short interelectrode spacing was achieved by using anodic oxidation in an ethylene glycol based electrolyte. All the active device regions of the CCD imagers were formed by silicon implantation into semi -insulating GaAs substrates followed by rapid thermal activation.The photodetectors were Schottky barrier diodes formed with thin aluminum metal anodes over silicon -implanted active regions in the semi -insulating substrate. The detectors formed a linear array along one side of the CCD channel and a three -phase transfer electrode structure was used.The imagers have been tested with front side illumination at clocking speeds up to 25 MHz.I. ABSTRACTCharge-coupled device (CCD) imagers have been fabricated on gallium arsenide (GaAs) with very closely spaced (<100nm) Schottky-barrier metal electrodes.The short interel ectrode spacing was achieved by using anodic oxidation in an ethylene glycol based electrolyte.All the active device regions of the CCD imagers were formed by silicon implantation into semi-insulating GaAs substrates followed by rapid thermal acti vati on.