A 1/2 inch 1.3 M Pixel Single-Layer Electrode CCD Image Sensor

Abstract

A 1/2-inch 1.3M-pixel progressive scan interline-transfer charge-coupled device (IT-CCD) image sensor has been developed for low power and high sensitivity digital cameras. A new technology of the single layer poly-Si electrode with 0.25 μm gap was used to reduce fabrication process steps and the power consumption. An original pixel layout and a self-aligned photodiode structure make it possible to achieve a progressive scan pixel with well-controlled photodiode readout characteristics. The device achieved a low driving voltage (2.1 V) on a horizontal CCD at a frequency of 24.5 MHz. An output 3-stage source follower amplifier with new multi-oxide transistors, whose gate insulator thickness is thinner than that of a CCD register, enables to attain 17% higher gain than that of the conventional amplifier. The total fabrication process steps were successfully reduced and power consumption was reduced to 70% compared with the conventional 3-layer poly-Si electrodes device.