Schottky barrier charge coupled device (ccd) manufacture

Abstract

The specification describes a planar gallium arsenide charge coupled device and process for making same wherein a first series of metal pattern forming steps are performed on the surface of a GaAs semiconductor body to form input, output and bias electrodes of a CCD in a first level or plane of the structure. In a subsequent, second series of metal pattern forming steps, a plurality of charge transfer electrodes are formed between the CCD input and output electrodes, and simultaneously an annular charge isolation electrode is deposited so as to completely surround the input, output, and charge transfer electrodes of the CCD. These electrodes deposited in this second series of metal pattern forming steps lie in a second level or plane of the structure being fabricated. Next, a dielectric mask is formed on the surface of the last named electrodes. Openings ('vias') are formed therein which are aligned with the input, output, charge transfer and charge isolation electrodes. Thereafter, a third series of metal pattern forming steps are utilized to form a plurality of crossover or lead-in electrodes which are deposited in the above openings in the dielectric mask to provide electrical signal and bias coupling to the electrodes formed in the above first and second series of metal pattern forming steps. Thus, by forming the charge isolation electrode simultaneously with the electrodes of the charge coupled device per se, the total number of device fabrication steps are minimized.