Performance and operation of buried channel charge coupled devices

Buried-channel charge-coupled devices offer many advantages over surface channel devices at the expense of only one additional step in the fabrication process; i.e., the channel implant. Two important parameters for the implanted layer are discussed, namely, (i) the potential difference between the channel region and the dielectric interface and (ii) the depth of the channel region. Computer results showing the influence of some of the process variables on these parameters for the specific case of a two-phase, implanted barrier asymmetry, device are presented. Finally, performance results for a buried-channel device designed with an optimum choice of these parameters are compared to those of an otherwise identical surface channel device.