Sensitivity Enhancement of Metal-Oxide-Semiconductor Tunneling Photodiode with Trapped Electrons in Ultra-Thin SiO_2 Layer

摘要

The enhancement of the photo sensitivity of Si-based metal-oxide-semiconductor (MOS) tunneling photodiode with an ultra-thin SiO_2 layer is demonstrated by a simple bias treatment in this work. It was found that, after applying a negative constant voltage stress (NCVS) treatment onto the device, a few electrons would be trapped in the ultra-thin SiO_2 layer, subsequently the trapped electrons led to a large decrement in the inversion dark current at positive bias. As a result, the photo sensitivity of the device at positive voltage was enhanced. Different stressing voltages of the NCVS treatments applied onto the device were utilized to achieve different numbers of trapped electrons. Thus different photo sensitivities of the device were obtained by these different treatments. The device with the trapped electrons of -0.29 pC exhibits a maximum photo sensitivity enhanced factor (31.3 at 1 V) in this experiment.