Measurements of Transfer Inefficiency of 250-Element Undercut-Isolated Charge Coupled Devices

A 250-element charge coupled device is described in which the transfer electrodes are delineated and isolated using an undercut-etch technique. The device has metal electrodes on two thicknesses of oxide and is primarily intended to be operated in a two-phase manner. Measurements of transfer inefficiency as a function of frequency have been made on both n- and p-channel devices. Below 1 MHz, values of 4 × 10−4per transfer independent of transfer frequency have been obtained. Above 1 MHz the transfer inefficiency progressively rises as the dynamics of charge motion limit the transfer of charge.