charge coupled devices impieganti concentrations not uniform of office building along the channel of information

摘要

1376640 Semi-conductor devices WESTERN ELECTRIC CO Inc 27 June 1972 [28 June 1971 (2)] 30046/72 Heading H1K A charge coupled device comprises an electrode arrangement, on an insulating layer, over a charge carrier storage medium, fixed charges being distributed beneath the electrode arrangement to form an asymmetric well during operation. The fixed charge may reside in the medium, the insulating layer or both, and may be produced by diffusion or ion implantation. In one embodiment, Figs. 1, 2 (not shown), a two-phase system has chargers fixed in the medium and distributed non-uniformly so as to form potential barriers to charge carriers in the "upstream" direction. In a second embodiment, Fig. 6, the fixed charges reside, non-uniformly, in the insulating layer, again forming potential barriers in the "upstream" direction. The use of two value clock pulses enables a single row of electrodes to be used, the first pulse to all electrodes being of a low value to form shallow potential wells beneath the electrodes enabling carriers to transfer to deeper wells beneath the interelectrode spaces, the second pulse being of a greater value to form deep wells beneath the electrodes and receive carriers, in one direction only, from the shallower inter-electrode wells. In a further embodiment, the electrodes may be mounted on insulating material of irregular thickness to assist in the formation of suitably asymmetric wells. In Fig. 12 (not shown), a single electrode extends over insulating material of irregular thickness, the material containing a non-uniform distribution of fixed charge, a two-value clock pulse enabling charge transfer by means of wells of different depths beneath different parts of the electrode. The medium may be of silicon, the insulating layer of silicon dioxide.