The design of a two-phase, buried-channel (or bulk-channel) chargecoupled device is presented. Directionality is obtained by using a steppedoxide structure. The basic operation of the device is explained, and the effect that changes in various design parameters have on its operation is examined in some detail. A set of roughly optimal parameters are found that yield an extremely fast and efficient device. We estimate a chargetransfer time of 1.8 ne and a charge capacity of 4-1 X 10 n (electrons/cm 1 ). Only existing technology is necessary for its fabrication. This paper presents some design considerations for a two-phase, buried-channel (or bulk-channel) charge-coupled device (BCCD). The concept of the BCCD has been presented previously,'·* and operation of three-phase BCCD's has been demonstrated.* -* Two-phase surface charge-coupled devices (CCD's) have advantages over three-phase surface CCD's in many applications, and several designs have been discussed.
7-11Therefore, it seems important and timely to consider the design of two-phase BCCD's.We present here a brief review of the basic η-channel BCCD struc ture. Figure 1 shows the CCD electrode configuration originally proposed for the buried-channel device.