Sensitivity Enhancement of Metal-oxide-semiconductor Tunneling Photodiode with Trapped Electrons in Ultra-thin SiO2 Layer

The enhancement in the photo sensitivity of Si-based MOS tunneling photodiode with ultra-thin SiO2 layer is demonstrated by simple bias treatment in this work. After applying negative constant voltage stress (negative CVS) onto the device, a few electrons would be trapped in the ultra-thin SiO2 layer. The trapped electrons would result in a large decrease in the dark current at positive bias. Therefore, the photo sensitivity of the device could be enhanced. Besides, different stressing voltages of the negative CVS applied onto the device are utilized to achieve different amounts of trapped electrons. Thus, different photo sensitivities of the device could be obtained by these different treatments. The appropriate amount of trapped electrons resulting in the maximum value of the sensitivity also would be expected.