Semiconductor charge transfer device with multi-level polysilicon electrode and bus-line structure

A semiconductor charge transfer device comprising:

• a semiconductor substrate;
• a channel region in the substrate;
• an electrode structure overlying the channel region which structure comprises a plurality of layers of polycrystalline silicon and provides a row of electrode elements extending along the channel region so that storage and transfer of electric charge within the channel region can be controlled by electric potentials applied to the electrode structure, the electrode elements of each layer of polycrystalline silicon being electrically interconnected by a respective polycrystalline silicon bus-line, the bus-lines extending along a side of the row of electrode elements;
• and a metal conductor pattern in contact with the bus-lines to provide a respective high conductivity path in parallel with and extending along each bus-line, at least one said high conductivity path contacting its associated bus-line within each of a plurality of regions of its associated bus-line which do not overlap any other polysilicon layer;
• and the device including the improvement that said bus-lines are disposed in overlapping relationship, and said regions are defined by apertures in one or more of the other bus-lines which are so shaped and positioned that the number of said regions along said associated bus-line is less than the number of electrode elements connected with that bus-line and the width of each said region is greater than the width of the electrode elements.