Bidirectional horizontal charge transfer device for image sensor

摘要

The charge transfer device has a charge transfer region (20) formed in the surface of a semiconductor substrate, overlaid by four polysilicon gate electrodes (1-4) in a repetitive sequence. The gate electrodes are separated from the charge transfer region by an insulation layer (21). Different signal levels of a first clock signal (HO1) are supplied to the first two gate electrodes (1,2) and different signal levels of a second clock signal (HO2) supplied to the remaining gate electrodes (3,4). This provides charge transfer via the resulting potential differences in the charge transfer region.