The current of metal-insulator-semiconductor (MIS) tunnel diodes is dependent on the Schottky barrier height and there are different mechanisms which dominate MIS tunnel currents while MIS tunnel diodes are biased at positive and negative voltages. In this work, coupled current-voltage behaviors were observed in a MIS(p) tunnel diode with a MOS structure coupled nearby (1). It was found that the MIS(p) saturation tunneling current could be controlled by the voltage bias (V G ) of the nearby MOS capacitor. While V G changes, the minority carrier distribution at the fringe of the MIS tunnel diode also changes. As a result, by wellcontrolling V G , the light to dark current ratio I light /I dark can be effectively enhanced. In this study, two intensities of illumination on MIS(p) tunnel diodes of three different oxide thicknesses were displayed. It is shown that under both intensities of illumination, the light to dark current ratio I light /I dark are all effectively enhanced by well-controlling V G . It is also found that the maxima of current ratio I light /I dark take place at different values of V G for different intensities of illumination. The coupling effect plays an important role in this phenomenon.

The current coupling effect in concentric circle MIS(p) structure was investigated. It is found that the saturation current of the central device could be affected by the distance between two electrodes (S) and the voltage bias (VG) of the nearby device. While the electrode separation and VG change, minority carrier distribution at the fringe of the MIS tunnel diode also changes causing the variation in the saturation current of the central device. In addition, it is also found that by well-controlling VG, the light to dark current ratio Ilight/Idark of the central device could be effectively enhanced. In this study, two intensities of illumination on MIS(p) tunnel diodes were displayed. It is found that the maxima of current ratio Ilight/Idark took place at different values of VG for different intensities of illumination. Coupling effect plays an important role in this phenomenon.