ELECTRIC-FIELD CONCENTRATION AT ELECTRODE EDGE WITH DECREASING AMORPHOUS-SILICON DEFECT DENSITY

Many studies have concentrated on the decrease in a-Si defect density. However, several a-Si image sensors, such as the 2M-pixel charge coup led device (CCD) image sensor, suffer from the following problem: a de crease in defect density causes an increase in reverse biased current. Therefore, a trial was carried out to calculate the electric field ar ound the edge of the bottom electrode and, so far, have obtained the f ollowing results: (1) a decrease in defect density caused an increase in the electric field concentration at the edge of the electrode, and (2) the electric field concentration was improved by optimizing shape of the electrode edge. In addition, it was confirmed that relaxation o f the electric field concentration was observed in the prepared sample .