SEMICONDUCTOR CELL STRUCTURE FOR A BUCKET BRIGADE DEVICE AND PROCESS FOR MAKING SAME

摘要

The invention is the structure and process for making a bucket brigade device which comprises the merger of an MOS capacitor with an MOSFET device to form the charge transfer cell. A thin n-type region is implanted in a portion of the p-type channel region of an FET device adjacent to the drain diffusion. This structure increases the charge transfer efficiency for the cell and reduces its sensitivity of the threshold voltage to the source-drain voltage. The gate for the device has a substantial overlap over the drain and a minimal overlap over the source and the gate to drain capacitance per unit area is maximized by maintaining a uniformly thin oxide layer across the gate region.