Nonoverlapping dual-gate bucket-brigade devices

A novel bucket-brigade charge-transfer device concept is presented and experimentally verified. The dual-gate BBD exhibits operational performances comparable to surface-channel charge-coupled devices, while still enjoying fabrication simplicity and high yield. The concept is implemented using conventional p-channel aluminum-gate technology with only an additional shadowed-gap lift-off process which produces self-aligned bias-gate electrodes separated from the adjacent clock buses by submicron (typically 0.5 μm) spacings. Transfer inefficiencies below 10−4 at 100 kHz and around 5×10−4 at 1 MHz have been currently observed, despite the low carrier mobility (140 cm2/V s).