Self aligned ccd element including two levels of electrodes and method

Abstract

A self-aligned charge coupled device comprises a semiconductor substrate having implanted barrier regions, an insulation layer disposed over the substrate, a first layer of closely spaced electrodes, a second layer of closely spaced electrodes interlaced between electrodes of the first layer and separated by insulation, and a conductor deposited between the first and second electrodes so as to electrically connect portions of the first electrodes to portions of the second electrodes. The process for fabricating this self-aligned CCD structure comprises the steps of selectively removing portions of a first conducting layer to form the first electrodes, forming a first oxide layer over the first electrodes, implanting barrier regions in the substrate in alignment with edges of the first oxide layer, selectively removing portions of a second conducting layer to form the second electrodes between the electrodes of the first electrode layer, forming a second oxide layer over the entire structure, selectively removing portions of the first and second oxide layers, and depositing conductors over the structure to electrically connect portions of the first electrodes to portions of adjacent second electrodes. Another disclosed embodiment relates to an alternate method of fabricating a semiconductor structure having closely spaced electrodes. The disclosed method is modified to remove portions of the first insulation layer prior to forming the second conducting layer so that each of the first electrodes are formed in ohmic contact with corresponding adjacent ones of the second electrodes.