Study of CCD Register for High-Sensitivity and Low-Dark Current Imaging Devices

提出了一种新型的CCD寄存器，该寄存器由具有垂直溢流漏极的光电二极管的倒置系列组成。利用三维数值模拟器计算了采用该寄存器的帧传输方案CCD图像传感器的性能。并对由寄存器和埋地式光电二极管组成的线间传输式CCD图像传感器的性能进行了计算。主要研究结果如下：在帧传输CCD中，在电极之间的Si-Si0_2界面处产生较大的g-r电流。在线间传输CCD中，在电极之间的耗尽Si-Si0_2界面处产生了大的g-r电流。当在界面下引入孔时，电流减小了几个数量级。由于几乎这些g-r电流被电极吸收，暗电流变得非常低。由于所提出的CCD寄存器可以在不增加暗电流的情况下由四相驱动脉冲驱动，因此CCD图像传感器具有大的充电容量和极低的暗电流。

New CCD registers that consist of series of the inverted version of photo diode with vertical overflow drain was proposed. The performance of frame transfer scheme CCD image sensor employing the registers was calculated using a three dimensional numerical simulator. And the performances of interline transfer scheme CCD image sensor that consists of the registers and buried photo diodes was also calculated. The major results are as follows.1. In the frame transfer CCD, large g-r currents are generated at the Si-Si0_2 interface between electrodes.2. In the interline transfer CCD, large g-r currents are generated at the depleted Si-Si0_2 interface between electrodes. The currents are reduced by several orders when holes are introduced under the interface.3. As almost these g-r currents are absorbed into electrodes, dark current becomes very low.4. As the proposed CCD regjster can be driven by four phase drive pulse without increasing dark current, CCD image sensors have large charge capacity and very low dark current.